Transocean (RIG) 10-K18 Feb 252024 FY Annual reportFinancial data

Company Profile

Document and Entity Information

Document and Entity Information - USD ($) $ in Millions	12 Months Ended
Document and Entity Information - USD ($) $ in Millions	Dec. 31, 2024	Feb. 11, 2025	Jun. 30, 2024
Document and Entity Information
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2024
Current Fiscal Year End Date	--12-31
Document Transition Report	false
Securities Act File Number	001-38373
Entity Registrant Name	TRANSOCEAN LTD
Entity Incorporation, State or Country Code	V8
Entity Tax Identification Number	98-0599916
Entity Address, Address Line One	Turmstrasse 30
Entity Address, City or Town	Steinhausen
Entity Address, Country	CH
Entity Address, Postal Zip Code	6312
City Area Code	+41 (41)
Local Phone Number	749-0500
Title of 12(b) Security	Shares
Trading Symbol	RIG
Security Exchange Name	NYSE
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	true
Document Financial Statement Error Correction [Flag]	false
Entity Shell Company	false
Entity Public Float			$ 4,680
Entity Common Stock, Shares Outstanding		878,886,948
Entity Central Index Key	0001451505
Document Fiscal Year Focus	2024
Document Fiscal Period Focus	FY
Amendment Flag	false
Auditor Name	Ernst & Young LLP
Auditor Firm ID	42
Auditor Location	Houston, Texas

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Operating revenues
Contract drilling revenues	$ 3,524	$ 2,832	$ 2,575
Revenue from Contract with Customer, Product and Service [Extensible Enumeration]	us-gaap:OilAndGasServiceMember	us-gaap:OilAndGasServiceMember	us-gaap:OilAndGasServiceMember
Costs and expenses
Operating and maintenance	$ 2,199	$ 1,986	$ 1,679
Cost, Product and Service [Extensible Enumeration]	us-gaap:OilAndGasServiceMember	us-gaap:OilAndGasServiceMember	us-gaap:OilAndGasServiceMember
Depreciation and amortization	$ 739	$ 744	$ 735
General and administrative	214	187	182
Total costs and expenses	3,152	2,917	2,596
Loss on impairment of assets	(772)	(57)
Loss on disposal of assets, net	(17)	(183)	(10)
Operating loss	(417)	(325)	(31)
Other income (expense), net
Interest income	50	52	27
Interest expense, net of amounts capitalized	(362)	(646)	(561)
Gain (loss) on retirement of debt	161	(31)	8
Other, net	45	9	(5)
Total other income (expense), net	(106)	(616)	(531)
Loss before income tax expense (benefit)	(523)	(941)	(562)
Income tax expense (benefit)	(11)	13	59
Net loss	(512)	(954)	(621)
Net loss attributable to controlling interest	$ (512)	$ (954)	$ (621)
Loss per share, basic (in dollars per share)	$ (0.6)	$ (1.24)	$ (0.89)
Loss per share, diluted (in dollars per share)	$ (0.76)	$ (1.24)	$ (0.89)
Weighted-average shares, basic (in shares)	850	768	699
Weighted-average shares, diluted (in shares)	925	768	699

CONDENSED CONSOLIDATED STATEM_2

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS)
Net loss	$ (512)	$ (954)	$ (621)
Net loss attributable to controlling interest	(512)	(954)	(621)
Components of net periodic benefit costs before reclassifications	37	6	(109)
Components of net periodic benefit costs reclassified to net loss	2		3
Other comprehensive income (loss) before income taxes	39	6	(106)
Income taxes related to other comprehensive income (loss)		2	5
Other comprehensive income (loss)	39	8	(101)
Other comprehensive income (loss) attributable to controlling interest	39	8	(101)
Total comprehensive loss	(473)	(946)	(722)
Total comprehensive loss attributable to controlling interest	$ (473)	$ (946)	$ (722)

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
Assets
Cash and cash equivalents	$ 560	$ 762
Accounts receivable, net	564	512
Materials and supplies, net	439	426
Assets held for sale	343	49
Restricted cash and cash equivalents	381	233
Other current assets	165	144
Total current assets	2,452	2,126
Property and equipment	22,417	23,875
Less accumulated depreciation	(6,586)	(6,934)
Property and equipment, net	15,831	16,941
Contract intangible assets		4
Deferred tax assets, net	45	44
Other assets	1,043	1,139
Total assets	19,371	20,254
Liabilities and equity
Accounts payable	255	323
Accrued income taxes	31	23
Debt due within one year	686	370
Other current liabilities	691	681
Total current liabilities	1,663	1,397
Long-term debt	6,195	7,043
Deferred tax liabilities, net	499	540
Other long-term liabilities	729	858
Total long-term liabilities	7,423	8,441
Commitments and contingencies
Shares, $0.10 par value, [1,057,879,029] authorized, [141,262,093] conditionally authorized, [940,828,901] issued and [875,803,595] outstanding at December 31, 2024, and CHF 0.10 par value, 1,021,294,549 authorized, 142,362,093 conditionally authorized, 843,715,858 issued and 809,030,846 outstanding at December 31, 2023	87	81
Additional paid-in capital	14,880	14,544
Accumulated deficit	(4,545)	(4,033)
Accumulated other comprehensive loss	(138)	(177)
Total controlling interest shareholders' equity	10,284	10,415
Noncontrolling interest	1	1
Total equity	10,285	10,416
Total liabilities and equity	$ 19,371	$ 20,254

CONDENSED CONSOLIDATED BALANC_2

CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) $ in Millions	Dec. 31, 2024 USD ($) $ / shares shares	Dec. 31, 2023 USD ($) $ / shares shares
CONDENSED CONSOLIDATED BALANCE SHEETS
Materials and supplies, allowance for obsolescence \| $	$ 178	$ 198
Shares, Par value \| (per share)	$ 0.1	$ 0.1
Shares, authorized	1,057,879,029	1,021,294,549
Shares, conditionally authorized	141,262,093	142,362,093
Shares, issued	940,828,901	843,715,858
Shares, outstanding	875,830,772	809,030,846

CONDENSED CONSOLIDATED STATEM_3

CONDENSED CONSOLIDATED STATEMENTS OF EQUITY - USD ($) shares in Millions, $ in Millions	Total controlling interest shareholders' equity	Shares	Additional paid-in capital	Accumulated deficit	Accumulated other comprehensive loss	Noncontrolling interest	Total
Balance, beginning at Dec. 31, 2021	$ 11,205	$ 64	$ 13,683	$ (2,458)	$ (84)	$ 1	$ 11,206
Balance, beginning (in shares) at Dec. 31, 2021		655
Increase (Decrease) in Shareholders' Equity
Total comprehensive loss attributable to controlling interest	(722)						(722)
Total comprehensive loss							(722)
Share-based compensation	29		29				29
Issuance of shares	263	$ 7	256				263
Issuance of shares (in shares)		67
Net Income (Loss)				(621)			(621)
Other comprehensive income (loss) attributable to controlling interest					(101)		(101)
Issuance of warrants	16		16				16
Balance, end at Dec. 31, 2022	10,791	$ 71	13,984	(3,079)	(185)	1	10,792
Balance, end (in shares) at Dec. 31, 2022		722
Increase (Decrease) in Shareholders' Equity
Total comprehensive loss attributable to controlling interest	(946)						(946)
Total comprehensive loss							(946)
Share-based compensation	40		40				40
Issuance of shares	530	$ 10	520				530
Issuance of shares (in shares)		87
Net Income (Loss)				(954)			(954)
Other comprehensive income (loss) attributable to controlling interest					8		8
Balance, end at Dec. 31, 2023	10,415	$ 81	14,544	(4,033)	(177)	1	10,416
Balance, end (in shares) at Dec. 31, 2023		809
Increase (Decrease) in Shareholders' Equity
Total comprehensive loss attributable to controlling interest	(473)						(473)
Total comprehensive loss							(473)
Share-based compensation	47		47				47
Issuance of shares	295	$ 6	289				295
Issuance of shares (in shares)		67
Net Income (Loss)				(512)			(512)
Other comprehensive income (loss) attributable to controlling interest					39		39
Balance, end at Dec. 31, 2024	$ 10,284	$ 87	$ 14,880	$ (4,545)	$ (138)	$ 1	$ 10,285
Balance, end (in shares) at Dec. 31, 2024		876

CONDENSED CONSOLIDATED STATEM_4

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Cash flows from operating activities
Net loss	$ (512)	$ (954)	$ (621)
Adjustments to reconcile to net cash provided by operating activities:
Amortization of contract intangible asset	4	52	117
Depreciation and amortization	739	744	735
Share-based compensation expense	47	40	29
Loss on impairment of assets	772	57
Loss on disposal of assets, net	17	183	10
Amortization of debt-related balances, net	53	51	33
(Gain) loss on adjustment to bifurcated compound exchange feature	(214)	127	157
(Gain) loss on retirement of debt	(161)	31	(8)
Loss on impairment of investment in unconsolidated affiliate	5	5
Deferred income tax expense	(42)	18	46
Other, net	(7)	43	44
Changes in deferred revenues, net	45	70	(20)
Changes in deferred costs, net	(2)	(190)	1
Changes in other operating assets and liabilities, net	(297)	(113)	(75)
Net cash provided by operating activities	447	164	448
Cash flows from investing activities
Capital expenditures	(254)	(427)	(717)
Investment in loans to unconsolidated affiliates	(3)	(3)	(5)
Investment in equity of unconsolidated affiliate		(10)	(42)
Proceeds from disposal of assets, net of costs to sell	101	10	7
Cash acquired in acquisition of unconsolidated affiliates	5	7
Net cash used in investing activities	(151)	(423)	(757)
Cash flows from financing activities
Repayments of debt	(2,103)	(1,717)	(554)
Proceeds from issuance of debt, net of issue costs	1,770	1,983	175
Proceeds from issuance of shares, net of issue costs			263
Proceeds from issuance of warrants, net of issue costs			12
Other, net	(17)	(3)	(8)
Net cash provided by (used in) financing activities	(350)	263	(112)
Net increase (decrease) in unrestricted and restricted cash and cash equivalents	(54)	4	(421)
Unrestricted and restricted cash and cash equivalents, beginning of period	995	991	1,412
Unrestricted and restricted cash and cash equivalents, end of period	$ 941	$ 995	$ 991

Business

Business	12 Months Ended
Business	Dec. 31, 2024
Business
Business	Note 1—Business Transocean Ltd. (together with its subsidiaries and predecessors, unless the context requires otherwise, “Transocean,” “we,” “us” or “our”) is a leading international provider of offshore contract drilling services for oil and gas wells. As of December 31, 2024, we owned or had partial ownership interests in and operated a fleet of 34 mobile offshore drilling units, consisting of 26 ultra-deepwater floaters and eight harsh environment floaters. We provide, as our primary business, contract drilling services in a single operating segment, which involves contracting our mobile offshore drilling rigs, related equipment and work crews to drill oil and gas wells. We specialize in technically demanding regions of the global offshore drilling business with a particular focus on ultra-deepwater and harsh environment drilling services. Our drilling fleet is one of the most versatile fleets in the world, consisting of drillships and semisubmersible floaters used in support of offshore drilling activities and offshore support services on a worldwide basis. We perform contract drilling services by deploying our high-specification fleet in a single Note 15—Supplemental Segment Information

Significant Accounting Policies

Significant Accounting Policies	12 Months Ended
Significant Accounting Policies	Dec. 31, 2024
Significant Accounting Policies
Significant Accounting Policies	Note 2—Significant Accounting Policies Accounting estimates Fair value measurements Consolidation Note 4—Unconsolidated Affiliates Note 13—Equity Functional currency Revenues and related pre-operating costs all contingencies have been resolved. We apply the optional exemption that permits us to exclude disclosure of the estimated transaction price related to the variable portion of unsatisfied performance obligations at the end of the reporting period, as our transaction price is typically based on a single performance obligation consisting of a series of distinct hourly, or more frequent, periods, the variability of which will be resolved at the time of the future services. To obtain contracts with our customers, we incur pre-operating costs to prepare a rig for contract and mobilize a rig to the drilling location. We defer such pre-operating contract preparation and mobilization costs for recognition in operating and maintenance costs over the estimated contract period on a straight-line basis, consistent with the general pace of activity. See Note 5—Revenues Income taxes We establish liabilities for estimated tax exposures, and we recognize the provisions and benefits resulting from changes to those liabilities, together with related interest and penalties, in income tax expense or benefit. Income tax exposure items include potential challenges to permanent establishment positions, intercompany pricing, disposition transactions, and withholding tax rates and their applicability. Such tax exposures may be affected by changes in applicable tax law or other factors, which could cause us to revise our prior estimates, and are generally resolved through the settlement of audits within the tax jurisdictions or by judicial means. We measure deferred tax assets and liabilities using enacted tax rates that will apply in the years in which the deferred tax assets and liabilities are expected to be recovered or paid. To evaluate our ability to realize deferred tax assets, we consider all available positive and negative evidence, including projected future taxable income and the existence of cumulative losses in recent years. We record a valuation allowance for deferred tax assets when it is more likely than not that some or all of the benefit from the deferred tax asset will not be realized. For example, we may record a valuation allowance for deferred tax assets resulting from net operating losses incurred during the year in certain jurisdictions for which the benefit of the losses will not be realized or for foreign tax credit carryforwards that may expire prior to their utilization. See Note 10—Income Taxes Cash and cash equivalents Restricted cash and cash equivalents Note 8—Debt Materials and supplies Assets held for sale Note 6—Long-Lived Assets Property and equipment We capitalize expenditures for newbuilds, renewals, replacements and improvements, including capitalized interest, if applicable, and we recognize the expense for maintenance and repair costs as incurred. For newbuild construction projects, we also capitalize the initial preparation, mobilization and commissioning costs incurred until the drilling unit is placed into service. Upon sale or other disposition of an asset, we recognize a net gain or loss on disposal of the asset, which is measured as the difference between the net carrying amount of the asset and the net proceeds received. We compute depreciation using the straight-line method after allowing for salvage values. The estimated original useful life of our drilling units is 35 years, our buildings and improvements range from three four Long lived asset impairment Note 6—LongLived Assets Equity investments and impairment Note 4—Unconsolidated Affiliates Pension and other postemployment benefit plans We measure the actuarially determined obligations and related costs for our defined benefit pension and other postemployment benefit plans, retiree life insurance and medical benefits, by applying assumptions, the most significant of which include long-term rate of return on plan assets, discount rates and mortality rates. For the long-term rate of return, we develop our assumptions regarding the expected rate of return on plan assets based on projected long-term investment returns, and we weight the assumptions based on each plan’s asset allocation. For the discount rate, we base our assumptions on a yield curve approach using Aa-rated corporate bonds and the expected timing of future benefit payments. At December 31, 2024 and 2023, the funded status of our pension and other postemployment benefit plans represented an aggregate liability of $104 million and $125 million, respectively, and an aggregate asset of $73 million and $31 million, respectively. See Note 9—Benefit Plans Share based compensation Note 14—ShareBased Compensation Contingencies

Accounting Standards Updates

Accounting Standards Updates	12 Months Ended
Accounting Standards Updates	Dec. 31, 2024
Accounting Standards Updates
Accounting Standards Update	Note 3—Accounting Standards Updates Recently adopted accounting standards Segment reporting segments. The update, which explicitly applies to entities such as us with a single reportable segment, requires disclosure of the significant expense categories and amounts that are regularly provided to the chief operating decision-maker and included in the reported measure of segment profit or loss. Additionally, the update requires disclosures about the individual or the group or committee identified as the chief operating decision-maker. We have provided new disclosures, as required, in our notes to consolidated financial statements. See Note 1—Business Note 15—Supplemental Segment Information Recently issued accounting standards updates not yet adopted Income taxes Disaggregated income statement expenses

Unconsolidated Affiliates

Unconsolidated Affiliates	12 Months Ended
Unconsolidated Affiliates	Dec. 31, 2024
Unconsolidated Affiliates
Unconsolidated Affiliates	Note 4—Unconsolidated Affiliates Equity investments Overview Contributions Ocean Rig Olympia Note 6—Long-Lived Assets Acquisition Transocean Norge Note 6—Long Lived Assets Note 8—Debt Note 13—Equity Impairments Related party transactions Investment and acquisition interest in Liquila, a previously unconsolidated Bermuda company, that was constructing the ultra-deepwater floater Deepwater Aquila Note 6—Long Lived Assets Note 13—Equity Operating and lending activities In the years ended December 31, 2024, 2023 and 2022, we received an aggregate cash payment of $11 million, $49 million and $40 million, respectively, for services and equipment provided to, and prior to our acquisition of, Orion. In the years ended December 31, 2024, 2023, and 2022, we recognized rent expense of $25 million, $26 million and $11 million, respectively, recorded in operating and maintenance costs, and made an aggregate cash payment of $25 million, $27 million and $10 million, respectively, to charter the rig and rent other equipment from, and prior to our acquisition of, Orion. Additionally, in the year ended December 31, 2023, we and Orion agreed to the non-cash net settlement of a balance of $25 million of accounts receivable and payable.

Revenues

Revenues	12 Months Ended
Revenues	Dec. 31, 2024
Revenues.
Revenues	Note 5—Revenues Overview Disaggregation Year ended December 31, 2024 Year ended December 31, 2023 Year ended December 31, 2022 Ultra- Harsh Ultra- Harsh Ultra- Harsh deepwater environment deepwater environment deepwater environment floaters floaters Total floaters floaters Total floaters floaters Total U.S. $ 1,566 $ — $ 1,566 $ 1,433 $ — $ 1,433 $ 1,135 $ — $ 1,135 Brazil 727 — 727 298 — 298 240 — 240 Norway — 654 654 — 603 603 — 835 835 Other countries (a) 225 352 577 341 157 498 333 32 365 Total contract drilling revenues $ 2,518 $ 1,006 $ 3,524 $ 2,072 $ 760 $ 2,832 $ 1,708 $ 867 $ 2,575 (a) The aggregate contract drilling revenues earned in other countries that individually represented less than 10 percent of total contract drilling revenues. Major customers Contract intangible assets Contract liabilities December 31, December 31 2024 2023 Deferred contract revenues, recorded in other current liabilities $ 231 $ 165 Deferred contract revenues, recorded in other long-term liabilities 212 233 Total contract liabilities $ 443 $ 398 Significant changes in contract liabilities were as follows (in millions): Years ended December 31, 2024 2023 Total contract liabilities, beginning of period $ 398 $ 328 Decrease due to recognition of revenues for goods and services (243) (189) Increase due to goods and services transferred over time 288 259 Total contract liabilities, end of period $ 443 $ 398 Pre-operating costs

Long- Lived Assets

Long- Lived Assets	12 Months Ended
Long- Lived Assets	Dec. 31, 2024
LONG LIVED ASSETS
Long -Lived Assets	Note 6—Long-Lived Assets Disaggregation December 31, 2024 2023 Long-lived assets U.S. $ 6,727 $ 7,472 Greece 2,531 2,652 Norway 2,017 2,103 Brazil 1,993 1,610 Other countries (a) 3,008 3,590 Total long-lived assets $ 16,276 $ 17,427 (a) The aggregate carrying amount of long-lived assets located in other countries that individually represented less than 10 percent of total long-lived assets. Because the majority of our assets are mobile, the geographic locations of such assets at the end of the periods are not necessarily indicative of the geographic distribution of the operating revenues generated by such assets during the periods presented. Our international operations are subject to certain political and other uncertainties, including risks of war and civil disturbances or other market disrupting events, expropriation of equipment, repatriation of income or capital, taxation policies, and the general hazards associated with certain areas in which we operate. Although we are organized under the laws of Switzerland, we have minimal assets located in Switzerland, and we do not conduct any operations or earn operating revenues in Switzerland. Construction work in progress Years ended December 31, 2024 2023 2022 Construction work in progress, beginning of period $ 522 $ 1,195 $ 1,017 Capital expenditures Newbuild construction program 142 331 669 Other equipment and construction projects 112 96 48 Total capital expenditures 254 427 717 Non-cash capital additions acquired in exchange for issuance of Transocean Ltd. shares — 126 — Non-cash capital additions financed under the Shipyard Loans — — 382 Changes in accrued capital additions (13) 5 3 Property and equipment placed into service Newbuild construction program (552) (1,157) (882) Other equipment and construction projects (135) (74) (42) Construction work in progress, end of period $ 76 $ 522 $ 1,195 In the years ended December 31, 2024, 2023 and 2022, we capitalized interest costs of $15 million, $39 million and $73 million, respectively, for our construction work in progress. Acquisitions Transocean Norge Deepwater Aquila Note 4—Unconsolidated Affiliates Note 8—Debt Note 13—Equity Impairments Deepwater Nautilus Development Driller III Discoverer Inspiration Paul B. Loyd, Jr. Transocean Leader Disposals Deepwater Nautilus Paul B. Loyd, Jr. Transocean Leader Ocean Rig Olympia Note 4—Unconsolidated Affiliates Assets held for sale Development Driller III Discoverer Inspiration Paul B. Loyd, Jr Transocean Leader

Leases

Leases	12 Months Ended
Leases	Dec. 31, 2024
Leases
Leases	Note 7—Leases Overview Our finance lease for the ultra-deepwater drillship Petrobras 10000 Lease costs Years ended December 31, Lease costs 2024 2023 2022 Short-term lease costs $ 10 $ 4 $ 14 Operating lease costs 16 14 12 Finance lease costs, amortization of right-of-use asset 20 20 20 Finance lease costs, interest on lease liability 24 27 30 Total lease costs $ 70 $ 65 $ 76 Lease payments Years ended December 31, 2024 2023 2022 Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from operating leases $ 20 $ 17 $ 14 Operating cash flows from finance lease 4 — 8 Financing cash flows from finance lease 7 — 3 At December 31, 2024, the aggregate future minimum lease payments were as follows (in millions): Operating Finance leases lease Years ending December 31, 2025 $ 13 $ 65 2026 12 70 2027 12 71 2028 12 70 2029 12 47 Thereafter 74 — Total future minimum rental payment 135 323 Less amount representing imputed interest (40) (52) Present value of future minimum rental payments 95 271 Current portion, recorded in other current liabilities 7 47 Long-term lease liabilities, recorded in other long-term liabilities $ 88 $ 224

Debt

Debt	12 Months Ended
Debt	Dec. 31, 2024
Debt
Debt	Note 8—Debt Overview Outstanding debt Principal amount Carrying amount December 31, December 31, December 31, December 31, 2024 2023 2024 2023 7.25% Senior Notes due November 2025 (a) $ — $ 354 $ — $ 352 4.00% Senior Guaranteed Exchangeable Bonds due December 2025 (b) 234 234 227 221 7.50% Senior Notes due January 2026 (a) — 569 — 567 11.50% Senior Guaranteed Notes due January 2027 (a) — 687 — 938 6.875% Senior Secured Notes due February 2027 (c) 330 413 328 409 8.00% Senior Notes due February 2027 (a) 655 612 653 609 7.45% Notes due April 2027 (d) 52 52 52 52 8.00% Debentures due April 2027 (d) 22 22 22 22 4.50% Shipyard Loans due September 2027 (e) 329 420 310 384 8.375% Senior Secured Notes due February 2028 (c) 525 525 518 518 7.00% Notes due June 2028 (e) 261 261 263 264 8.00% Senior Secured Notes due September 2028 (c) 295 325 292 321 8.25% Senior Notes due May 2029 (a) 900 — 887 — 4.625% Senior Guaranteed Exchangeable Bonds due September 2029 (a) 259 259 286 486 8.75% Senior Secured Notes due February 2030 (f) 999 1,116 981 1,094 7.50% Notes due April 2031 (d) 396 396 395 395 8.50% Senior Notes due May 2031 (a) 900 — 886 — 6.80% Senior Notes due March 2038 (d) 610 610 605 605 7.35% Senior Notes due December 2041 (d) 177 177 176 176 Total debt 6,944 7,032 6,881 7,413 Less debt due within one year 4.00% Senior Guaranteed Exchangeable Bonds due December 2025 (b) 234 — 227 — 11.50% Senior Guaranteed Notes due January 2027 (a) — — — 71 6.875% Senior Secured Notes due February 2027 (c) 83 83 82 81 4.50% Shipyard Loans due September 2027 (e) 120 90 108 75 8.375% Senior Secured Notes due February 2028 (c) 100 — 97 — 8.00% Senior Secured Notes due September 2028 (c) 60 30 59 30 8.75% Senior Secured Notes due February 2030 (f) 117 117 113 113 Total debt due within one year 714 320 686 370 Total long-term debt $ 6,230 $ 6,712 $ 6,195 $ 7,043 (a) Transocean International Limited, a wholly owned direct subsidiary of Transocean Ltd. formerly known as Transocean Inc., is the issuer of the unregistered notes (collectively, the “Priority Guaranteed Notes”). The guaranteed senior unsecured notes are fully and unconditionally, jointly and severally, guaranteed by Transocean Ltd. and certain wholly owned indirect subsidiaries of Transocean International Limited and rank equal in right of payment of all our existing and future unsecured unsubordinated obligations. Such notes are structurally senior to the Legacy Guaranteed Notes, as defined below, the 4.50% shipyard loans due September 2027 (each, a “Shipyard Loan”, and together, the “Shipyard Loans”) and the 7.00% notes due June 2028 and structurally subordinate to the Senior Priority Guaranteed Notes, as defined below, to the extent of the value of the assets of the subsidiaries guaranteeing the notes. (b) Transocean International Limited is the issuer of the unregistered notes (together, the “Senior Priority Guaranteed Notes”). The priority guaranteed senior unsecured notes are fully and unconditionally, jointly and severally, guaranteed by Transocean Ltd. and certain wholly owned indirect subsidiaries of Transocean International Limited and rank equal in right of payment of all of our existing and future unsecured unsubordinated obligations. Such notes are structurally senior to the Priority Guaranteed Notes to the extent of the value of the assets of the subsidiaries guaranteeing the notes. (c) Each subsidiary issuer of the respective unregistered notes is a wholly owned indirect subsidiary of Transocean International Limited. The senior secured notes are fully and unconditionally, jointly and severally, guaranteed by Transocean Ltd., Transocean International Limited and, in each case, the owner of the respective collateral rig or rigs. (d) Transocean International Limited is the issuer of the notes and debentures (the “Legacy Guaranteed Notes”). The Legacy Guaranteed Notes are fully and unconditionally, jointly and severally, guaranteed by Transocean Ltd. (e) The subsidiary borrowers under the Shipyard Loans and the subsidiary issuer of the registered notes are wholly owned indirect subsidiaries of Transocean International Limited. The loans and notes are fully and unconditionally guaranteed by Transocean International Limited. (f) Transocean International Limited is the issuer of the unregistered notes. The senior secured notes are fully and unconditionally guaranteed on an unsecured basis by Transocean Ltd. and on a limited senior secured basis by each of the wholly owned subsidiary owners of the collateral rigs. Indentures The indentures that govern the 4.00% senior guaranteed exchangeable bonds due December 2025 (the “4.00% Senior Guaranteed Exchangeable Bonds”) and the 4.625% senior guaranteed exchangeable bonds due September 2029 (the “4.625% Senior Guaranteed Exchangeable Bonds”) require such bonds to be repurchased upon the occurrence of certain fundamental changes and events, at specified prices depending on the particular fundamental change or event, which include changes and events related to certain (i) change of control events applicable to Transocean Ltd. or Transocean International Limited, (ii) the failure of our shares to be listed or quoted on a national securities exchange and (iii) specified tax matters. The indentures that govern the 6.875% senior secured notes due February 2027, the 8.375% senior secured notes due February 2028 (the “8.375% Senior Secured Notes”), the 8.00% senior secured notes due September 2028 (the “8.00% Senior Secured Notes”) and the 8.75% senior secured notes due February 2030 (the “8.75% Senior Secured Notes”) contain certain covenants, among others, related to the debt and earnings attributable to the collateral rigs and the ability of our subsidiaries that own or operate the collateral rigs to declare or pay dividends to their affiliates. We will be required to redeem the senior secured notes at a price equal to 100 percent of the aggregate principal amount without a make-whole premium, upon the occurrence of certain events related to the respective collateral rigs and related drilling contracts. The indentures that govern our senior secured notes contain certain lien requirements, including the maintenance of certain balances in a restricted cash account to satisfy debt service requirements. At December 31, 2024, we had restricted cash and cash equivalents of $351 million deposited in restricted accounts to satisfy debt service and reserve requirements for the senior secured notes. At December 31, 2024, the rigs encumbered for the senior secured notes and our Shipyard Loans include the ultra-deepwater floaters Deepwater Aquila Deepwater Atlas Deepwater Pontus Deepwater Poseidon Deepwater Proteus Deepwater Thalassa Deepwater Titan Transocean Enabler Transocean Encourage Interest rate adjustments Scheduled maturities Total Years ending December 31, 2025 $ 714 2026 541 2027 1,255 2028 664 2029 1,276 Thereafter 2,494 Total principal amount of debt 6,944 Total unamortized debt-related balances, net (199) Bifurcated compound exchange feature, at estimated fair value 136 Total carrying amount of debt $ 6,881 Credit agreements Secured Credit Facility the borrowing capacity from $600 million to $576 million through June 22, 2025 and thereafter reduce the borrowing capacity to $510 million through June 22, 2028. Throughout the term of the Secured Credit Facility, we pay a facility fee on the amount of the underlying commitment, which ranges from 0.375 percent to 1.00 percent based on the credit rating of the Secured Credit Facility. We may borrow under the Secured Credit Facility at a forward-looking term rate based on the secured overnight financing rate (“ Term SOFR Deepwater Asgard Deepwater Conqueror, Deepwater Corcovado Deepwater Invictus Deepwater Mykonos Deepwater Orion Deepwater Skyros Dhirubhai Deepwater KG2 Transocean Barents Transocean Spitsbergen The Secured Credit Facility contains covenants that, among other things, include maintenance of a minimum guarantee coverage ratio of 3.0 to 1.0, a minimum collateral coverage ratio of 2.1 to 1.0, a maximum debt to capitalization ratio of 0.60 to 1.00 and minimum liquidity of $200 million. The Secured Credit Facility also restricts the ability of Transocean Ltd. and certain of our subsidiaries to, among other things, merge, consolidate or otherwise make changes to the corporate structure, incur liens, incur additional indebtedness, enter into transactions with affiliates and permits, subject to certain conditions, the ability to pay dividends and repurchase our shares. In order to utilize the Secured Credit Facility, we must, at the time of the borrowing request, be in full compliance with the terms and conditions of the Secured Credit Facility and make certain representations and warranties, including with respect to compliance with laws and solvency, to the lenders. Repayment of borrowings under the Secured Credit Facility are subject to acceleration upon the occurrence of an event of default. Under the agreements governing certain of our debt and finance lease, we are also subject to various covenants, including restrictions on creating liens, engaging in sale/leaseback transactions and engaging in certain merger, consolidation or reorganization transactions. A default under our public debt indentures, the agreements governing our senior secured notes, our finance lease contract or any other debt owed to unaffiliated entities that exceeds $125 million could trigger a default under the Secured Credit Facility and, if not waived by the lenders or otherwise cured, could cause us to lose access to the Secured Credit Facility. At December 31, 2024, based on the credit rating of the Secured Credit Facility as of that date, the Secured Credit Facility Margin was 2.875 percent and the facility fee was 0.625 percent. At December 31, 2024, we had no borrowings outstanding, $7 million of letters of credit issued, and we had $569 million of available borrowing capacity under the Secured Credit Facility. Shipyard financing arrangement Deepwater Atlas Deepwater Titan Deepwater Atlas Deepwater Titan Deepwater Atlas Deepwater Titan Exchangeable bonds Exchange terms Implied Exchange exchange Shares rate price issuable 4.00% Senior Guaranteed Exchangeable Bonds due December 2025 190.4762 $ 5.25 45 4.625% Senior Guaranteed Exchangeable Bonds due September 2029 290.6618 $ 3.44 75 The exchange rates presented above are subject to adjustment upon the occurrence of certain events. The 4.00% Senior Guaranteed Exchangeable Bonds may be exchanged by holders at any time prior to the close of business on the second business day immediately preceding the maturity date and, at our election, such exchange may be settled by delivering cash, Transocean Ltd. shares or a combination of cash and shares. The 4.625% Senior Guaranteed Exchangeable Bonds may be exchanged by holders at any time prior to the close of business on the second business day immediately preceding the maturity date or redemption date and, at our election, such exchange may be settled by delivering cash, Transocean Ltd. shares or a combination of cash and shares. Effective interest rates and fair values Effective Fair interest rate value 4.00% Senior Guaranteed Exchangeable Bonds due December 2025 6.9% $ 247 4.625% Senior Guaranteed Exchangeable Bonds due September 2029 18.3% $ 359 We estimated the fair values of the exchangeable debt instruments, including the exchange features, by employing a binomial lattice model using significant other observable inputs, representative of Level 2 fair value measurements, including the terms and credit spreads of our debt and the expected volatility of the market price for our shares. Interest expense Years ended December 31, 2024 2023 2022 Contractual interest $ 21 $ 24 $ 16 Amortization 20 19 9 (Gain) loss on adjustment to bifurcated compound exchange feature (214) 127 157 Total $ (173) $ 170 $ 182 The indenture governing the 4.625% Senior Guaranteed Exchangeable Bonds contains a compound exchange feature that, in addition to the exchange terms presented above, requires us to pay holders a make-whole premium of future interest through March 30, 2028, for exchanges exercised during a redemption notice period. Such compound exchange feature must be bifurcated from the host debt instrument since it is not considered indexed to our stock. Accordingly, we recognize changes to the liability for the estimated fair value of the bifurcated compound exchange feature with a corresponding adjustment to interest expense. At December 31, 2024 and 2023, the carrying amount of the bifurcated compound exchange feature, recorded as a component of the carrying amount of debt, was $136 million and $350 million, respectively. Exchanges In July 2023, the holders of the remaining outstanding $25 million aggregate principal amount of 2.50% Senior Guaranteed Exchangeable Bonds exchanged such bonds under the terms of the governing indenture at the applicable exchange rate of 162.1626 Transocean Ltd. shares per $1,000 note. As part of the transaction, we delivered 4.0 million Transocean Ltd. shares. In October 2023, holders of $60 million and $41 million aggregate principal amount of 4.00% Senior Guaranteed Exchangeable Bonds and 4.625% Senior Guaranteed Exchangeable Bonds, respectively, exchanged such bonds under the terms of the governing indentures at the applicable exchange rate of 190.4762 and 290.6618 Transocean Ltd. shares, respectively, per $1,000 note. As part of the transactions, we delivered an aggregate 26.5 million Transocean Ltd. shares, including an aggregate 3.1 million additional shares. Debt issuance Senior notes percent In June 2024, as partial consideration to acquire the outstanding 67.0 percent ownership interest in Orion, we issued $130 million aggregate principal amount of 8.00% Senior Notes, with an equivalent aggregate fair value, as additional debt securities under the indenture governing such notes. See Note 4—Unconsolidated Affiliates Note 6—Long-Lived Assets Note 13—Equity Senior secured notes— Deepwater Titan In January 2023, we issued $1.175 billion aggregate principal amount of 8.75% Senior Secured Notes, and we received $1.148 billion aggregate cash proceeds, net of issue costs. The 8.75% Senior Secured Notes are secured by a lien on Deepwater Pontus Deepwater Proteus Deepwater Thalassa Transocean Enabler Transocean Encourage redeem all or a portion of the 8.75% Senior Secured Notes on or prior to February 15, 2026 at a price equal to 100 percent of the aggregate principal amount plus a make-whole premium, and subsequently, at specified redemption prices. In October 2023, we issued $325 million aggregate principal amount of 8.00% Senior Secured Notes, and we received $319 million aggregate cash proceeds, net of issue costs. The 8.00% Senior Secured Notes are secured by the assets and certain earnings associated with Deepwater Aquila Senior guaranteed exchangeable bonds Note 13—Equity Debt repayment, redemption, and retirement Early retirement Years ended December 31, 2024 2023 2022 Tendered Redeemed Total Redeemed Redeemed Exchanged Total 5.52% Senior Secured Notes due May 2022 $ — $ — $ — $ — $ 18 $ — $ 18 3.80% Senior Notes due October 2022 — — — — 27 — 27 0.50% Exchangeable Senior Bonds due January 2023 — — — — 18 73 91 5.375% Senior Secured Notes due May 2023 — — — 243 — — — 5.875% Senior Secured Notes due January 2024 — — — 311 — — — 7.75% Senior Secured Notes due October 2024 — — — 240 — — — 6.25% Senior Secured Notes due December 2024 — — — 250 — — — 6.125% Senior Secured Notes due August 2025 — — — 336 — — — 7.25% Senior Notes due November 2025 249 105 354 — 14 43 57 7.50% Senior Notes due January 2026 — 569 569 — — — — 11.50% Senior Guaranteed Notes due January 2027 596 91 687 — — — — 8.00% Senior Notes due February 2027 — 87 87 — — — — Aggregate principal amount of debt retired $ 845 $ 852 $ 1,697 $ 1,380 $ 77 $ 116 $ 193 Aggregate cash payment $ 886 $ 862 $ 1,748 $ 1,402 $ 75 $ — $ 75 Aggregate principal amount of debt issued in exchanges $ — $ — $ — $ — $ — $ 112 $ 112 Aggregate fair value of warrants issued in exchanges $ — $ — $ — $ — $ — $ 5 $ 5 Aggregate net gain (loss) $ 144 $ 17 $ 161 $ (32) $ 2 $ 6 $ 8 Additionally, in the year ended December 31, 2023, we recognized a net gain of $1 million associated with the retirement of $41 million aggregate principal amount of 4.625% Senior Guaranteed Exchangeable Bonds exchanged by holders in October 2023. Scheduled maturities and installments

Benefit Plans

Benefit Plans	12 Months Ended
Benefit Plans	Dec. 31, 2024
Benefit Plans
Benefit Plans	Note 9—Benefit Plans Defined contribution plans We sponsor defined contribution plans for our employees in most markets in which we operate worldwide, the most significant of which were as follows: (1) a qualified savings plan covering certain eligible employees working in the U.S., (2) various savings plans covering eligible employees working in Norway and (3) a non-qualified savings plan covering certain eligible expatriate employees. In the years ended December 31, 2024, 2023 and 2022, we recognized expense of $63 million, $58 million and $61 million, respectively, related to our defined contribution plans and recorded in the same financial statement line item as cash compensation paid to the respective employees. Defined benefit pension and other postemployment benefit plans Overview Net periodic benefit costs Year ended December 31, 2024 Year ended December 31, 2023 Year ended December 31, 2022 U.S. U.K. OPEB U.S. U.K. OPEB U.S. U.K. OPEB Plans Plan Plans Plans Plan Plans Plans Plan Plans Discount rate 4.88 % 4.50 % 4.80 % 5.06 % 4.80 % 4.92 % 2.92 % 1.90 % 1.83 % Expected rate of return 6.51 % 5.10 % na 6.41 % 5.00 % na 4.81 % 2.00 % na “na” means not applicable. The components of net periodic benefit costs, recognized in other income and expense, were as follows (in millions): Year ended December 31, 2024 Year ended December 31, 2023 Year ended December 31, 2022 U.S. U.K. OPEB U.S. U.K. OPEB U.S. U.K. OPEB Plans Plan Plans Total Plans Plan Plans Total Plans Plan Plans Total Net periodic benefit costs Interest cost $ 63 $ 9 $ — $ 72 $ 65 $ 9 $ — $ 74 $ 50 $ 6 $ — $ 56 Expected return on plan assets (86) (11) — (97) (84) (11) — (95) (65) (7) — (72) Special termination benefits — — 2 2 — — — — — — — — Settlements and curtailments — — (2) (2) — — — — — — — — Actuarial loss, net 1 2 — 3 — 2 — 2 5 — — 5 Prior service gain, net — — (1) (1) — — (2) (2) — — (2) (2) Net periodic benefit costs (income) $ (22) $ — $ (1) $ (23) $ (19) $ — $ (2) $ (21) $ (10) $ (1) $ (2) $ (13) Funded status December 31, 2024 December 31, 2023 U.S. U.K. OPEB U.S. U.K. OPEB Plans Plan Plans Plans Plan Plans Discount rate 5.58 % 5.60 % 5.02 % 4.88 % 4.50 % 4.80 % The changes in funded status, balance sheet classifications and accumulated benefit obligations were as follows (in millions): Year ended December 31, 2024 Year ended December 31, 2023 U.S. U.K. OPEB U.S. U.K. OPEB Plans Plan Plans Total Plans Plan Plans Total Change in projected benefit obligation Projected benefit obligation, beginning of period $ 1,328 $ 208 $ 8 $ 1,544 $ 1,307 $ 188 $ 10 $ 1,505 Actuarial (gain) loss, net (97) (27) 2 (122) 32 11 — 43 Interest cost 63 9 — 72 65 9 — 74 Currency exchange rate (gain) loss — (2) — (2) — 11 — 11 Benefits paid (77) (10) (2) (89) (76) (11) (2) (89) Special termination benefits — — 2 2 — — — — Projected benefit obligation, end of period 1,217 178 10 1,405 1,328 208 8 1,544 Change in plan assets Fair value of plan assets, beginning of period 1,211 239 — 1,450 1,143 232 — 1,375 Actual return (loss) on plan assets 30 (16) — 14 138 6 — 144 Currency exchange rate gain (loss) — (3) — (3) — 12 — 12 Employer contributions — — 2 2 6 — 2 8 Benefits paid (77) (10) (2) (89) (76) (11) (2) (89) Fair value of plan assets, end of period 1,164 210 — 1,374 1,211 239 — 1,450 Funded status asset (liability), end of period $ (53) $ 32 $ (10) $ (31) $ (117) $ 31 $ (8) $ (94) Balance sheet classification, end of period: Pension asset, non-current $ 41 $ 32 $ — $ 73 $ — $ 31 $ — $ 31 Pension liability, current (1) — (3) (4) (1) — (3) (4) Pension liability, non-current (93) — (7) (100) (116) — (5) (121) Accumulated other comprehensive loss (income), before taxes 102 88 (1) 189 144 90 (6) 228 Accumulated benefit obligation, end of period $ 1,217 $ 178 $ 10 $ 1,405 $ 1,328 $ 208 $ 8 $ 1,544 Because our defined benefit plans no longer accrue benefits for participants, the projected benefit obligation is equivalent to the accumulated benefit obligation. Certain amounts related to plans with a projected benefit obligation and accumulated benefit obligation in excess of plan assets were as follows (in millions): December 31, 2024 December 31, 2023 U.S. U.K. OPEB U.S. U.K. OPEB Plans Plan Plans Total Plans Plan Plans Total Projected benefit obligation / accumulated benefit obligation $ 100 $ — $ 10 $ 110 $ 1,328 $ — $ 8 $ 1,336 Fair value of plan assets 6 — — 6 1,211 — — 1,211 The amounts in accumulated other comprehensive loss (income) that have not been recognized were as follows (in millions): December 31, 2024 December 31, 2023 U.S. U.K. OPEB U.S. U.K. OPEB Plans Plan Plans Total Plans Plan Plans Total Actuarial (gain) loss, net $ 102 $ 87 $ 2 $ 191 $ 144 $ 88 $ (1) $ 231 Prior service cost (credit), net — 1 (3) (2) — 2 (5) (3) Accumulated other comprehensive loss (income), before taxes $ 102 $ 88 $ (1) $ 189 $ 144 $ 90 $ (6) $ 228 Plan assets December 31, 2024 December 31, 2023 Target allocation Actual allocation Target allocation Actual allocation U.S. U.K. U.S. U.K. U.S. U.K. U.S. U.K. Plans Plan Plans Plan Plans Plan Plans Plan Equity securities — % 20 % — % 26 % 38 % 20 % 37 % 21 % Fixed income securities 99 % 73 % 99 % 65 % 62 % 73 % 62 % 72 % Other investments 1 % 7 % 1 % 9 % — % 7 % 1 % 7 % Total 100 % 100 % 100 % 100 % 100 % 100 % 100 % 100 % We periodically review our investment policies, plan assets and asset allocation strategies in conjunction with asset performance relative to specified objectives. For the U.S. Plans, we establish our asset allocation strategies by reviewing the results of regression models to assess the most appropriate target allocation for each plan, given the plan’s status, demographics and duration. For the U.K. Plan, the plan trustees establish the asset allocation strategies consistent with the regulations of the United Kingdom pension regulators and in consultation with financial advisors and company representatives. Investment managers for the U.S. Plans and the U.K. Plan are given established ranges within which the investments may deviate from the target allocations. The investments for the funded defined benefit plans were categorized as follows (in millions): December 31, 2024 Significant observable inputs Significant other observable inputs Total U.S. U.K. U.S. U.K. U.S. U.K. Plans Plan Total Plans Plan Total Plans Plan Total Mutual funds Non-U.S. equity funds $ 4 $ — $ 4 $ — $ 55 $ 55 $ 4 $ 55 $ 59 Bond funds 1,149 — 1,149 2 136 138 1,151 136 1,287 Total mutual funds 1,153 — 1,153 2 191 193 1,155 191 1,346 Other investments Cash and money market funds 9 2 11 — — — 9 2 11 Synthetic leveraged credit fund — — — — 17 17 — 17 17 Total other investments 9 2 11 — 17 17 9 19 28 Total investments $ 1,162 $ 2 $ 1,164 $ 2 $ 208 $ 210 $ 1,164 $ 210 $ 1,374 December 31, 2023 Significant observable inputs Significant other observable inputs Total U.S. U.K. U.S. U.K. U.S. U.K. Plans Plan Total Plans Plan Total Plans Plan Total Mutual funds U.S. equity funds $ 316 $ — $ 316 $ — $ — $ — $ 316 $ — $ 316 Non-U.S. equity funds 139 — 139 — 51 51 139 51 190 Bond funds 746 — 746 4 171 175 750 171 921 Total mutual funds 1,201 — 1,201 4 222 226 1,205 222 1,427 Other investments Cash and money market funds 6 1 7 — — — 6 1 7 Synthetic leveraged credit fund — — — — 16 16 — 16 16 Total other investments 6 1 7 — 16 16 6 17 23 Total investments $ 1,207 $ 1 $ 1,208 $ 4 $ 238 $ 242 $ 1,211 $ 239 $ 1,450 We estimated the fair values of the plan assets by applying the market approach, as categorized above, using either (i) significant observable inputs, representative of Level 1 fair value measurements, including market prices of actively traded funds, or (ii) significant other observable inputs, representative of Level 2 fair value measurements, including market prices of the underlying securities in the trust funds. The U.S. Plans and the U.K. Plan invest in passively and actively managed funds that are referenced to or benchmarked against market indices. The plan investment managers have discretion to select securities within each asset category. Given this discretion, the plans may occasionally hold positions in our debt or equity securities. Since plan investment managers are required to maintain well diversified portfolios, the actual investment in our securities would be immaterial relative to asset categories and the overall plan assets. Funding contributions and benefit payments The projected benefits payments were as follows (in millions): U.S. U.K. OPEB Plans Plan Plans Total Years ending December 31, 2025 $ 84 $ 7 $ 3 $ 94 2026 85 7 2 94 2027 85 7 1 93 2028 85 8 1 94 2029 85 9 1 95 2030 - 2034 430 60 2 492

Income Taxes

Income Taxes	12 Months Ended
Income Taxes	Dec. 31, 2024
Income Taxes
Income Taxes	Note 10—Income Taxes Overview Tax provision and rate Years ended December 31, 2024 2023 2022 Current tax expense (benefit) $ 31 $ (5) $ 13 Deferred tax expense (benefit) (42) 18 46 Income tax expense (benefit) $ (11) $ 13 $ 59 In the years ended December 31, 2024, 2023 and 2022, our effective tax rate was 2.2 percent, (1.4) percent and (10.4) percent, respectively, based on loss before income tax expense (benefit). The relationship between our provision for or benefit from income taxes and our income or loss before income taxes can vary significantly from period to period considering, among other factors, (a) the overall level of income before income taxes, (b) changes in the blend of income that is taxed based on gross revenues rather than income before taxes, (c) rig movements between taxing jurisdictions and (d) our rig operating structures. A reconciliation of the income tax benefit computed at the Swiss holding company federal effective rate of 7.83% and our reported consolidated income tax expense (benefit) was as follows (in millions): Years ended December 31, 2024 2023 2022 Income tax benefit at Swiss federal statutory rate $ (40) $ (74) $ (44) Earnings subject to rates different than the Swiss federal statutory rate 74 129 52 Changes in valuation allowance 208 (23) 79 Tax attribute expirations 185 — — Deemed profits taxes 12 11 10 Withholding taxes 4 5 12 Changes in unrecognized tax benefits, net (4) (37) 2 Changes due to organizational restructuring (452) — (162) Swiss Federal Act on Tax Reform and AHV Financing — — 96 Audit settlement — — 12 Other, net 2 2 2 Income tax expense (benefit) $ (11) $ 13 $ 59 In the year ended December 31, 2024, as a result of operational and structural changes related to rig movements, we remeasured our deferred tax assets and liabilities related to Luxembourg, resulting in an increase of our net deferred tax asset from $8 million to $280 million, and such increase was substantially offset by an increase to our valuation allowance. In January 2020, Switzerland made effective the Federal Act on Tax Reform and AHV Financing (“TRAF”). In March 2020, we entered into discussions with the Swiss tax authorities regarding the manner by which the TRAF applies to certain Swiss subsidiaries, which allows us to access historic depreciation and costs related to financing assets not previously deducted on Swiss tax returns, which can be apportioned to offset taxable income based on the remaining useful lives of the rigs and financing assets. In the three months ended December 31, 2021, we reached an agreement with the Swiss Tax authorities regarding the TRAF treatment. At December 31, 2024 and 2023, we had a deferred tax liability of $218 million and $264 million, respectively, and a deferred tax asset of $1.05 billion and $1.21 billion, respectively, offset with a valuation allowance of $909 million, associated with TRAF. Deferred taxes December 31, 2024 2023 Deferred tax assets Net operating loss carryforwards $ 1,541 $ 1,264 Swiss historic depreciation and financing asset costs 1,053 1,210 Interest expense limitation 87 87 United Kingdom charter limitation 53 53 Accrued costs and expenses 20 47 Deferred revenues 22 — Accrued payroll costs not currently deductible 12 16 Tax credits 5 4 Loss contingencies 3 4 Other 61 54 Valuation allowance (2,089) (1,884) Total deferred tax assets, net of allowance 768 855 Deferred tax liabilities Depreciation (1,214) (1,342) Other (8) (9) Total deferred tax liabilities (1,222) (1,351) Deferred tax liabilities, net $ (454) $ (496) We include taxes related to the earnings of all of our subsidiaries since we do not consider the earnings of any of our subsidiaries to be indefinitely reinvested. At December 31, 2024 and 2023, our deferred tax assets included U.S. tax credits of $5 million and $4 million, respectively, which will expire between 2041 and 2043. Deferred tax assets related to our net operating losses were generated in various worldwide tax jurisdictions. At December 31, 2024, our net deferred tax assets related to our net operating loss carryforwards included $1,241 million, which do not expire, and $437 million, which will expire between 2025 and 2041. As of December 31, 2024, our consolidated cumulative loss incurred over the recent three-year period represented significant objective negative evidence for the evaluation of the realizability of our deferred tax assets. Because such evidence has limited our ability to consider other subjective evidence, we evaluate each jurisdiction separately. We consider objective evidence, such as contract backlog activity, in jurisdictions in which we have profitable contracts, and the ability to carryback losses or utilize losses against potential exposures. If estimated future taxable income changes during the carryforward periods or if the cumulative loss is no longer present, we may adjust the amount of deferred tax assets that we expect to realize. At December 31, 2024 and 2023, due to uncertainty of realization, we had a valuation allowance of $2.09 billion and $1.88 billion, respectively, on net operating losses and other deferred tax assets due to the uncertainty of realization. Unrecognized tax benefits Years ended December 31, 2024 2023 2022 Balance, beginning of period $ 449 $ 444 $ 402 Additions for current year tax positions 13 45 28 Additions for prior year tax positions 11 5 62 Reductions related to statute of limitation expirations and changes in law (19) (14) (13) Reductions due to settlements (30) (5) (5) Reductions for prior year tax positions (17) (26) (30) Balance, end of period $ 407 $ 449 $ 444 Our unrecognized tax benefits, including related interest and penalties that we recognize as a component of income tax expense, were as follows (in millions): December 31, 2024 2023 Unrecognized tax benefits, excluding interest and penalties $ 407 $ 449 Interest and penalties 7 9 Unrecognized tax benefits, including interest and penalties $ 414 $ 458 In the years ended December 31, 2024, 2023 and 2022, we recognized, as a component of our income tax provision, expense of $2 million, benefit of $18 million and expense of $6 million, respectively, related to interest and penalties associated with our unrecognized tax benefits. As of December 31, 2024, we have unrecognized benefits of $414 million, including interest and penalties, against which we have recorded net operating loss deferred tax assets of $372 million, resulting in net unrecognized tax benefits of $42 million, including interest and penalties, that upon reversal would favorably impact our effective tax rate. During the year ending December 31, 2025, it is reasonably possible that our existing liabilities for unrecognized tax benefits may increase or decrease, primarily due to the progression of open audits and the expiration of statutes of limitation. However, we cannot reasonably estimate a range of potential changes in our existing liabilities for unrecognized tax benefits due to various uncertainties, such as the unresolved nature of various audits. Tax positions and returns Brazil tax investigations

Loss Per Share

Loss Per Share	12 Months Ended
Loss Per Share	Dec. 31, 2024
Loss Per Share
Loss Per Share	Note 11—Loss Per Share The computation of basic and diluted loss per share was as follows (in millions, except per share data): Years ended December 31, 2024 2023 2022 Basic Diluted Basic Diluted Basic Diluted Numerator for loss per share Net loss attributable to controlling interest $ (512) $ (512) $ (954) $ (954) $ (621) $ (621) Effect of convertible debt instruments, net of tax — (189) — — — — Loss for per share calculation $ (512) $ (701) $ (954) $ (954) $ (621) $ (621) Denominator for loss per share Weighted-average shares outstanding 850 850 768 768 699 699 Effect of convertible debt instruments — 75 — — — — Weighted-average shares for per share calculation 850 925 768 768 699 699 Loss per share $ (0.60) $ (0.76) $ (1.24) $ (1.24) $ (0.89) $ (0.89) We excluded from the computations certain shares issuable as follows because the effect would have been antidilutive (in millions): Years ended December 31, 2024 2023 2022 Exchangeable bonds 45 151 128 Share-based awards 11 19 16 Warrants 6 10 -

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
Commitments and Contingencies	Dec. 31, 2024
Commitments and Contingencies.
Commitments and Contingencies	Note 12—Commitments and Contingencies Service agreement obligations We have long-term service agreements with original equipment manufacturers to provide services and parts, primarily related to our pressure control systems and drilling systems. We estimated the commitments for our service agreements based on projected operating activity, and actual operating activity could differ from such estimates. At December 31, 2024, the aggregate future payments required under our service agreement obligations were as follows (in millions): Service agreement obligations Years ending December 31, 2025 $ 137 2026 143 2027 117 2028 73 2029 49 Thereafter 91 Total $ 610 Letters of credit and surety bonds At December 31, 2024 and 2023, we had outstanding letters of credit totaling $9 million and $16 million, respectively, issued under various committed and uncommitted credit lines provided by banks to guarantee various contract bidding, performance activities and customs obligations. At December 31, 2024 and 2023, we also had outstanding surety bonds totaling $147 million and $198 million, respectively, to secure customs obligations related to the importation of our rigs and certain performance and other obligations. At December 31, 2024 and 2023, the aggregate cash collateral held by institutions to secure our letters of credit and surety bonds was $8 million and $7 million, respectively. Legal proceedings Asbestos litigation One of our subsidiaries was named as a defendant, along with numerous other companies, in lawsuits arising out of the subsidiary’s manufacture and sale of heat exchangers, and involvement in the construction and refurbishment of major industrial complexes alleging bodily injury or personal injury as a result of exposure to asbestos. As of December 31, 2024, the subsidiary was a defendant in approximately 364 lawsuits with a corresponding number of plaintiffs. For many of these lawsuits, we have not been provided sufficient information from the plaintiffs to determine whether all or some of the plaintiffs have claims against the subsidiary, the basis of any such claims, or the nature of their alleged injuries. The operating assets of the subsidiary were sold in 1989. In December 2021, the subsidiary and certain insurers agreed to a settlement of outstanding disputes that provide the subsidiary with cash. An earlier settlement, achieved in September 2018, provided the subsidiary with cash and an annuity for which installments began in December 2024. Together with a coverage-in-place agreement with certain insurers and additional coverage issued by other insurers, we believe the subsidiary has sufficient resources to respond to both the current lawsuits as well as future lawsuits of a similar nature. While we cannot predict or provide assurance as to the outcome of these matters, we do not expect the ultimate liability, if any, resulting from these claims to have a material adverse effect on our consolidated statement of financial position, results of operations or cash flows. Other matters Environmental matters We have certain potential liabilities under the Comprehensive Environmental Response, Compensation, and Liability Act (“CERCLA”) and similar state acts regulating cleanup of hazardous substances at various waste disposal sites, including those described below. CERCLA is intended to expedite the remediation of hazardous substances without regard to fault. Potentially responsible parties (“PRPs”) for each site include present and former owners and operators of, transporters to and generators of the substances at the site. It is difficult to quantify the potential cost of environmental matters and remediation obligations. Liability is strict and can be joint and several. One of our subsidiaries was named as a PRP in connection with a site located in Santa Fe Springs, California, known as the Waste Disposal, Inc. site. We and other PRPs agreed, under a participation agreement with the U.S. Environmental Protection Agency (the “EPA”) and the U.S. Department of Justice, to settle our potential liabilities by remediating the site. The remedial action for the site was completed in 2006. Our share of the ongoing operating and maintenance costs has been insignificant, and we do not expect any additional potential liabilities to be material. Resolutions of other claims by the EPA, the involved state agency or PRPs are at various stages of investigation. Nevertheless, based on available information with respect to all environmental matters, including all related pending legal proceedings, asserted legal claims and known potential legal claims that are likely to be asserted, we do not expect the ultimate liability, if any, resulting from such matters, to have a material adverse effect on our consolidated statement of financial position, results of operations or cash flows.

Equity

Equity	12 Months Ended
Equity	Dec. 31, 2024
Equity
Equity	Note 13—Equity Share capital currency change Share issuance Note 4—Unconsolidated Affiliates Note 6—Long-Lived Assets Note 8—Debt We maintain an at-the-market equity offering program (the “ATM Program”). We intend to use the net proceeds from our ongoing ATM Program for general corporate purposes, which may include, among other things, the repayment or refinancing of indebtedness and the funding of working capital, capital expenditures, investments and additional balance sheet liquidity. In June 2021, we entered into an equity distribution agreement with a sales agent for the offer and sale of our shares, with a maximum aggregate net offering price of up to $400 million, under the ATM Program. In August 2022, we entered into an equity distribution agreement with a sales agent for the offer and sale of our shares, with a maximum aggregate net offering price of up to $435 million, under the ATM Program. In the years ended December 31, 2024 and 2023, we did not issue any shares under the ATM Program. In the year ended December 31, 2022, we received aggregate cash proceeds of $263 million, net of issue costs, for the aggregate sale of 61.0 million shares under the ATM Program. Shares held by us Warrants

Share-Based Compensation

Share-Based Compensation	12 Months Ended
Share-Based Compensation	Dec. 31, 2024
Share-Based Compensation
Share-Based Compensation	Note 14—Share-Based Compensation Overview We have a long-term incentive plan (the “Long-Term Incentive Plan”) for executives, key employees and non-employee directors under which awards can be granted in the form of restricted share units, restricted shares, stock options, stock appreciation rights and cash performance awards. Awards may be granted as service awards that are earned over a defined service period or as performance awards that are earned based on the achievement of certain market factors or performance targets or a combination of market factors and performance targets. The compensation committee of our board of directors determines the terms and conditions of the awards granted under the Long-Term Incentive Plan. At December 31, 2024, we had 138.2 million shares authorized and 36.4 million shares available to be granted under the Long-Term Incentive Plan. At December 31, 2024, the total unrecognized compensation cost related to our unvested share-based awards was $35 million, which we expect to recognize over a weighted-average period of 1.7 years. Service awards typically vest either in three Service awards Restricted share units Number Weighted-average of grant-date fair value units per unit Unvested at January 1, 2024 9,560,008 $ 5.01 Granted 5,116,762 5.29 Vested (6,727,943) 4.78 Forfeited (289,799) 5.52 Unvested at December 31, 2024 7,659,028 $ 5.44 In the year ended December 31, 2024, the service-based units that vested had an aggregate grant-date fair value of $32 million. In the years ended December 31, 2023 and 2022, we granted 3,744,049 and 6,768,943 service-based units, respectively, with a per unit weighted-average grant-date fair value of $7.23 and $3.60, respectively. In the years ended December 31, 2023 and 2022, we had 6,200,155 and 5,075,374 service-based units, respectively, that vested with an aggregate grant-date fair value of $18 million. Stock options Weighted-average Number Weighted-average remaining Aggregate of shares exercise price contractual term intrinsic value under option per share (years) (in millions) Outstanding at January 1, 2024 4,083,929 $ 9.54 3.92 $ — Forfeited (14,595) 10.95 Outstanding at December 31, 2024 4,069,334 $ 9.53 2.93 $ — Vested and exercisable at December 31, 2024 4,069,334 $ 9.53 2.93 $ — At December 31, 2024 and 2023, there were no outstanding unvested stock options to purchase our shares. In the year ended December 31, 2022, the stock options that vested had an aggregate grant-date fair value of $4 million. Performance awards Restricted share units Number Weighted-average of grant-date fair value units per unit Unvested at January 1, 2024 5,432,149 $ 4.91 Granted 2,687,268 5.10 Vested (4,429,028) 4.67 Forfeited (194,464) 5.47 Unvested at December 31, 2024 3,495,925 $ 5.78 In the years ended December 31, 2024, the performance-based units that vested had an aggregate grant-date fair value of $21 million. In the years ended December 31, 2023 and 2022, we granted 1,912,292 and 3,519,857 performance-based units, respectively, with a per unit weighted-average grant-date fair value of $6.74 and $3.91, respectively. In the years ended December 31, 2023 and 2022, we had 3,025,512 and 2,363,878 performance-based units, respectively, that vested with an aggregate grant-date fair value of $11 million and $5 million, respectively.

Supplemental Segment informatio

Supplemental Segment information	12 Months Ended
Supplemental Segment information	Dec. 31, 2024
Supplemental Segment information
Supplemental Segment information	Note 15—Supplemental Segment information Our Chief Executive Officer serves as our chief operating decision maker (“CODM”) and assesses performance for and allocates resources for our single Our CODM uses our consolidated results of operations to evaluate income or loss generated from segment assets, or return on assets, to make decisions to deploy cash flows from operations for reinvestment in our contract drilling services segment or for other uses, such as for acquisitions, debt and equity investments, liability management or to pay dividends to our shareholders. Consolidated results of operations are used to monitor actual results relative to historical, budgeted and forecasted results and to assess segment performance against our peers.

Supplemental Balance Sheet Info

Supplemental Balance Sheet Information	12 Months Ended
Supplemental Balance Sheet Information	Dec. 31, 2024
Supplemental Balance Sheet Information
Supplemental Balance Sheet Information	Note 16—Supplemental Balance Sheet Information Other current liabilities were comprised of the following (in millions): December 31, 2024 2023 Other current liabilities Accrued employee benefits and payroll-related liabilities $ 136 $ 145 Accrued interest 134 146 Accrued taxes, other than income 39 47 Finance lease liability 47 43 Operating lease liabilities 7 12 Deferred revenues 231 165 Contingent liabilities 94 116 Other 3 7 Total other current liabilities $ 691 $ 681 Other long-term liabilities were comprised of the following (in millions): December 31, 2024 2023 Other long-term liabilities Postemployment benefit plan obligations $ 100 $ 121 Finance lease liability 224 276 Operating lease liabilities 88 108 Income taxes payable 65 80 Deferred revenues 212 233 Other 40 40 Total other long-term liabilities $ 729 $ 858

Supplemental Cash Flow Informat

Supplemental Cash Flow Information	12 Months Ended
Supplemental Cash Flow Information	Dec. 31, 2024
Supplemental Cash Flow Information
Supplemental Cash Flow Information	Note 17—Supplemental Cash Flow Information The reconciling adjustments of our net cash provided by operating activities that were attributable to the net change in other operating assets and liabilities were as follows (in millions): Years ended December 31, 2024 2023 2022 Changes in other operating assets and liabilities Increase in accounts receivable $ (94) $ (99) $ (15) Increase in other assets (100) (98) (12) Increase (decrease) in accounts payable and other current liabilities (91) 135 8 Decrease in other long-term liabilities (2) (7) (2) Change in income taxes receivable / payable, net (19) (36) (42) Change in receivables from / payables to affiliates, net 9 (8) (12) $ (297) $ (113) $ (75) Additional cash flow information was as follows (in millions): Years ended December 31, 2024 2023 2022 Certain cash operating activities Cash payments for interest $ 521 $ 408 $ 355 Cash payments for income taxes 60 41 66 Noncash investing and financing activities Capital additions accrued at end of period (a) $ 23 $ 36 $ 31 Capital additions acquired in exchange for debt (b) — — 382 Acquisition of outstanding ownership interests in exchange for shares and debt (c) 431 99 — Debt investment exchanged for additional equity ownership interests (d) — 37 — Finance lease installments settled with credits issued to customer (e) 40 44 41 Shares issued in exchanges of exchangeable bonds (f) — 434 — Debt and warrants issued in exchange transactions (g) — — 110 (a) Additions to property and equipment for which we had accrued a corresponding liability in accounts payable at the end of the period. See Note 6—Long-Lived Assets . (b) In the year ended December 31, 2022, we borrowed an aggregate principal amount of $439 million under the Shipyard Loans to satisfy a portion of the final milestone payments due upon delivery of Deepwater Atlas and Deepwater Titan and recorded the initial carrying amount, net of imputed interest, with a corresponding entry to construction in progress, recorded in property and equipment. See Note 6—Long-Lived Assets and Note 8—Debt . (c) In June 2024, we issued 55.5 million Transocean Ltd. shares and $130 million aggregate principal amount of 8.00% Senior Notes to acquire the outstanding ownership interest in Orion. In September 2023, we issued 11.9 million Transocean Ltd. shares to acquire the outstanding ownership interest in Liquila. See Note 4—Unconsolidated Affiliates , Note 6—Long-Lived Assets and Note 13—Equity . (d) In September 2023, we agreed to exchange borrowings due to us under a financing arrangement with Orion for additional equity ownership interests in Orion. See Note 4—Unconsolidated Affiliates . (e) In the years ended December 31, 2024, 2023 and 2022, we agreed to settle installments due to the lessor under our finance lease by issuing corresponding credits to our customer for amounts due to us under the drilling contract. See Note 7—Leases . (f) In the year ended December 31, 2023, we issued 65.1 million Transocean Ltd. shares to certain holders that elected to exchange the 2.50% Senior Guaranteed Exchangeable Bonds, the 4.00% Senior Guaranteed Exchangeable Bonds and the 4.625% Senior Guaranteed Exchangeable Bonds. See Note 8—Debt and Note 13—Equity . (g) In the year ended December 31, 2022, in connection with the 2022 Private Exchange, we issued $112 million aggregate principal amount of 4.625% Senior Guaranteed Exchangeable Bonds with an estimated fair value of $105 million and 6.7 million warrants to purchase Transocean Ltd. shares with an estimated fair value of $5 million. See Note 8—Debt and Note 13—Equity .

Financial Instruments

Financial Instruments	12 Months Ended
Financial Instruments	Dec. 31, 2024
Financial Instruments
Financial Instruments	Note 18—Financial Instruments Overview December 31, 2024 December 31, 2023 Carrying Fair Carrying Fair amount value amount value Cash and cash equivalents $ 560 $ 560 $ 762 $ 762 Restricted cash and cash equivalents 381 381 233 233 Total debt 6,881 6,888 7,413 7,308 Cash and cash equivalents Restricted cash and cash equivalents Total debt Note 8—Debt

Risk Concentration

Risk Concentration	12 Months Ended
Risk Concentration	Dec. 31, 2024
Risk Concentration
Risk Concentration	Note 19—Risk Concentration Interest rate risk Equity price risk Currency exchange rate risk Credit risk Labor agreements

Schedule II - Valuation and Qua

Schedule II - Valuation and Qualifying Accounts	12 Months Ended
Schedule II - Valuation and Qualifying Accounts	Dec. 31, 2024
Schedule II - Valuation and Qualifying Accounts
Schedule II - Valuation and Qualifying Accounts	Transocean Ltd. and Subsidiaries Schedule II—Valuation and Qualifying Accounts (in millions) Years ended December 31, 2024 2023 2022 Allowance for credit losses Balance, beginning of period $ 2 $ 2 $ 2 Additions: charged to cost and expenses — — — Additions: charged to other accounts — — — Deductions — — — Balance, end of period $ 2 $ 2 $ 2 Allowance for excess materials and supplies Balance, beginning of period $ 198 $ 199 $ 183 Additions: charged to cost and expenses 7 6 16 Additions: charged to other accounts — — — Deductions (a) (27) (7) — Balance, end of period $ 178 $ 198 $ 199 Valuation allowance on deferred tax assets Balance, beginning of period $ 1,884 $ 1,910 $ 1,820 Additions: charged to cost and expenses 208 — 79 Additions: charged to other accounts (b) — — 11 Deductions (b) (3) (26) — Balance, end of period $ 2,089 $ 1,884 $ 1,910 (a) Amount related to materials and supplies on rigs and related assets sold or classified as held for sale. (b) Amount related to adjustments to other deferred tax assets with valuation allowances .

Pay vs Performance Disclosure

Pay vs Performance Disclosure - USD ($) $ in Millions	12 Months Ended
Pay vs Performance Disclosure - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Pay vs Performance Disclosure
Net Income (Loss)	$ (512)	$ (954)	$ (621)

Insider Trading Arrangements

Insider Trading Arrangements	12 Months Ended
Insider Trading Arrangements	Dec. 31, 2024
Trading Arrangements, by Individual
Rule 10b5-1 Arrangement Adopted	false
Non-Rule 10b5-1 Arrangement Adopted	false
Rule 10b5-1 Arrangement Terminated	false
Non-Rule 10b5-1 Arrangement Terminated	false

Insider Trading Policies and Pr

Insider Trading Policies and Procedures	12 Months Ended
Insider Trading Policies and Procedures	Dec. 31, 2024
Insider Trading Policies and Procedures [Line Items]
Insider Trading Policies and Procedures Adopted	true

Cybersecurity Risk Management a

Cybersecurity Risk Management and Strategy Disclosure	12 Months Ended
Cybersecurity Risk Management and Strategy Disclosure	Dec. 31, 2024
Cybersecurity Risk Management, Strategy, and Governance [Line Items]
Cybersecurity Risk Management Processes for Assessing, Identifying, and Managing Threats [Text Block]	Our approach to managing cybersecurity risk and safeguarding information across our organization embeds data protection and cybersecurity risk management throughout our enterprise and daily operations. We maintain processes for identifying, assessing and managing material risks, including such risks from cybersecurity threats, and such processes are integrated into our overall risk management system. Our enterprise risk register inventories significant risks to our company, including significant cybersecurity risks, and we maintain a separate functional risk register, specifically focusing on potential cybersecurity risks. Within these risk registers, we record each identified risk, describe its likelihood of occurrence and assess its potential impact, including the materiality thereof. As part of this exercise, mitigating measures are planned and implemented into action as necessary. As an additional feature of our cybersecurity risk management process, we have engaged an external service provider to support our cybersecurity team by performing penetration tests and periodic external security evaluations. We undertake to align our cybersecurity program, which encompasses both enterprise security and operational security, with the standards of the National Institute of Standards and Technology Cybersecurity Framework. We maintain continuous cyber threat-detection systems and have established an incident response plan, which contains playbooks for addressing and recovering from potential material cyberattacks and breaches of data security. In addition to establishing security measures for vendors, we require onboarding orientation and periodic training for all employees and board members that focuses on cybersecurity and information management, and we conduct regular cybersecurity awareness campaigns.
Cybersecurity Risk Management Processes Integrated [Flag]	true
Cybersecurity Risk Management Processes Integrated [Text Block]	We maintain processes for identifying, assessing and managing material risks, including such risks from cybersecurity threats, and such processes are integrated into our overall risk management system
Cybersecurity Risk Management Third Party Engaged [Flag]	true
Cybersecurity Risk Third Party Oversight and Identification Processes [Flag]	true
Cybersecurity Risk Materially Affected or Reasonably Likely to Materially Affect Registrant [Flag]	false
Cybersecurity Risk Board of Directors Oversight [Text Block]	Our board of directors oversees our enterprise risk register and cybersecurity program, including related policies and procedures. As part of this oversight, the audit committee of our board of directors receives regular status reports and updates from our management team and conducts periodic executive sessions with our Vice President, Information Technology. Such status reports and executive sessions cover cybersecurity matters, such as developments to our program, key risk indicators, emerging risks, and identified incidents.
Cybersecurity Risk Board Committee or Subcommittee Responsible for Oversight [Text Block]	audit committee
Cybersecurity Risk Process for Informing Board Committee or Subcommittee Responsible for Oversight [Text Block]	As part of this oversight, the audit committee of our board of directors receives regular status reports and updates from our management team and conducts periodic executive sessions with our Vice President, Information Technology.
Cybersecurity Risk Role of Management [Text Block]	In addition, our Vice President, Information Technology, who has more than 20 years of industry experience and over 25 years of experience with the development, training and controls of effective global enterprise cybersecurity programs, oversees the implementation and compliance of our cybersecurity program and mitigation of information security related risks. Such oversight includes (i) reviewing our enterprise risk register, (ii) maintaining adequate processes to manage the identified risks under our cybersecurity program, (iii) regularly analyzing logs of cybersecurity threats and vulnerabilities and (iv) overseeing prevention, detection, mitigation and remediation efforts in general, including the development and maintenance of the above-mentioned incident response plan. Additionally, we maintain an experienced information technology team at the employee level that supports our Vice President, Information Technology in implementing our cybersecurity program and internal reporting, security and mitigation functions.
Cybersecurity Risk Management Positions or Committees Responsible [Flag]	true
Cybersecurity Risk Management Positions or Committees Responsible [Text Block]	the audit committee of our board of directors receives regular status reports and updates from our management team and conducts periodic executive sessions with our Vice President, Information Technology
Cybersecurity Risk Management Expertise of Management Responsible [Text Block]	Vice President, Information Technology, who has more than 20 years of industry experience and over 25 years of experience with the development, training and controls of effective global enterprise cybersecurity programs
Cybersecurity Risk Process for Informing Management or Committees Responsible [Text Block]	Such oversight includes (i) reviewing our enterprise risk register, (ii) maintaining adequate processes to manage the identified risks under our cybersecurity program, (iii) regularly analyzing logs of cybersecurity threats and vulnerabilities and (iv) overseeing prevention, detection, mitigation and remediation efforts in general, including the development and maintenance of the above-mentioned incident response plan.
Cybersecurity Risk Management Positions or Committees Responsible Report to Board [Flag]	true

Significant Accounting Polici_2

Significant Accounting Policies (Policies)	12 Months Ended
Significant Accounting Policies (Policies)	Dec. 31, 2024
Significant Accounting Policies
Accounting estimates	Accounting estimates
Fair value measurements	Fair value measurements
Consolidation	Consolidation Note 4—Unconsolidated Affiliates Note 13—Equity
Functional currency	Functional currency
Revenues and related pre-operating costs	Revenues and related pre-operating costs all contingencies have been resolved. We apply the optional exemption that permits us to exclude disclosure of the estimated transaction price related to the variable portion of unsatisfied performance obligations at the end of the reporting period, as our transaction price is typically based on a single performance obligation consisting of a series of distinct hourly, or more frequent, periods, the variability of which will be resolved at the time of the future services. To obtain contracts with our customers, we incur pre-operating costs to prepare a rig for contract and mobilize a rig to the drilling location. We defer such pre-operating contract preparation and mobilization costs for recognition in operating and maintenance costs over the estimated contract period on a straight-line basis, consistent with the general pace of activity. See Note 5—Revenues
Income taxes	Income taxes We establish liabilities for estimated tax exposures, and we recognize the provisions and benefits resulting from changes to those liabilities, together with related interest and penalties, in income tax expense or benefit. Income tax exposure items include potential challenges to permanent establishment positions, intercompany pricing, disposition transactions, and withholding tax rates and their applicability. Such tax exposures may be affected by changes in applicable tax law or other factors, which could cause us to revise our prior estimates, and are generally resolved through the settlement of audits within the tax jurisdictions or by judicial means. We measure deferred tax assets and liabilities using enacted tax rates that will apply in the years in which the deferred tax assets and liabilities are expected to be recovered or paid. To evaluate our ability to realize deferred tax assets, we consider all available positive and negative evidence, including projected future taxable income and the existence of cumulative losses in recent years. We record a valuation allowance for deferred tax assets when it is more likely than not that some or all of the benefit from the deferred tax asset will not be realized. For example, we may record a valuation allowance for deferred tax assets resulting from net operating losses incurred during the year in certain jurisdictions for which the benefit of the losses will not be realized or for foreign tax credit carryforwards that may expire prior to their utilization. See Note 10—Income Taxes
Cash and cash equivalents	Cash and cash equivalents
Restricted cash and cash equivalents	Restricted cash and cash equivalents Note 8—Debt
Materials and supplies	Materials and supplies
Assets held for sale	Assets held for sale Note 6—Long-Lived Assets
Property and equipment	Property and equipment We capitalize expenditures for newbuilds, renewals, replacements and improvements, including capitalized interest, if applicable, and we recognize the expense for maintenance and repair costs as incurred. For newbuild construction projects, we also capitalize the initial preparation, mobilization and commissioning costs incurred until the drilling unit is placed into service. Upon sale or other disposition of an asset, we recognize a net gain or loss on disposal of the asset, which is measured as the difference between the net carrying amount of the asset and the net proceeds received. We compute depreciation using the straight-line method after allowing for salvage values. The estimated original useful life of our drilling units is 35 years, our buildings and improvements range from three four
Long-lived asset impairment	Long lived asset impairment Note 6—LongLived Assets
Equity investments and impairment	Equity investments and impairment Note 4—Unconsolidated Affiliates
Pension and other postemployment benefit plans	Pension and other postemployment benefit plans We measure the actuarially determined obligations and related costs for our defined benefit pension and other postemployment benefit plans, retiree life insurance and medical benefits, by applying assumptions, the most significant of which include long-term rate of return on plan assets, discount rates and mortality rates. For the long-term rate of return, we develop our assumptions regarding the expected rate of return on plan assets based on projected long-term investment returns, and we weight the assumptions based on each plan’s asset allocation. For the discount rate, we base our assumptions on a yield curve approach using Aa-rated corporate bonds and the expected timing of future benefit payments. At December 31, 2024 and 2023, the funded status of our pension and other postemployment benefit plans represented an aggregate liability of $104 million and $125 million, respectively, and an aggregate asset of $73 million and $31 million, respectively. See Note 9—Benefit Plans
Share-based compensation	Share based compensation Note 14—ShareBased Compensation
Contingencies	Contingencies
Accounting standards updates	Recently adopted accounting standards Segment reporting segments. The update, which explicitly applies to entities such as us with a single reportable segment, requires disclosure of the significant expense categories and amounts that are regularly provided to the chief operating decision-maker and included in the reported measure of segment profit or loss. Additionally, the update requires disclosures about the individual or the group or committee identified as the chief operating decision-maker. We have provided new disclosures, as required, in our notes to consolidated financial statements. See Note 1—Business Note 15—Supplemental Segment Information Recently issued accounting standards updates not yet adopted Income taxes Disaggregated income statement expenses

Revenues (Tables)

Revenues (Tables)	12 Months Ended
Revenues (Tables)	Dec. 31, 2024
Revenues.
Schedule of revenue disaggregation	Year ended December 31, 2024 Year ended December 31, 2023 Year ended December 31, 2022 Ultra- Harsh Ultra- Harsh Ultra- Harsh deepwater environment deepwater environment deepwater environment floaters floaters Total floaters floaters Total floaters floaters Total U.S. $ 1,566 $ — $ 1,566 $ 1,433 $ — $ 1,433 $ 1,135 $ — $ 1,135 Brazil 727 — 727 298 — 298 240 — 240 Norway — 654 654 — 603 603 — 835 835 Other countries (a) 225 352 577 341 157 498 333 32 365 Total contract drilling revenues $ 2,518 $ 1,006 $ 3,524 $ 2,072 $ 760 $ 2,832 $ 1,708 $ 867 $ 2,575 (a) The aggregate contract drilling revenues earned in other countries that individually represented less than 10 percent of total contract drilling revenues.
Schedule of contract balances and changes	December 31, December 31 2024 2023 Deferred contract revenues, recorded in other current liabilities $ 231 $ 165 Deferred contract revenues, recorded in other long-term liabilities 212 233 Total contract liabilities $ 443 $ 398 Significant changes in contract liabilities were as follows (in millions): Years ended December 31, 2024 2023 Total contract liabilities, beginning of period $ 398 $ 328 Decrease due to recognition of revenues for goods and services (243) (189) Increase due to goods and services transferred over time 288 259 Total contract liabilities, end of period $ 443 $ 398

Long-Lived Assets (Tables)

Long-Lived Assets (Tables)	12 Months Ended
Long-Lived Assets (Tables)	Dec. 31, 2024
LONG LIVED ASSETS
Schedule of long-lived assets of the entity's continuing operations by country	December 31, 2024 2023 Long-lived assets U.S. $ 6,727 $ 7,472 Greece 2,531 2,652 Norway 2,017 2,103 Brazil 1,993 1,610 Other countries (a) 3,008 3,590 Total long-lived assets $ 16,276 $ 17,427 (a) The aggregate carrying amount of long-lived assets located in other countries that individually represented less than 10 percent of total long-lived assets.
Changes in our construction work in progress, including capital expenditures and capitalized interest	Years ended December 31, 2024 2023 2022 Construction work in progress, beginning of period $ 522 $ 1,195 $ 1,017 Capital expenditures Newbuild construction program 142 331 669 Other equipment and construction projects 112 96 48 Total capital expenditures 254 427 717 Non-cash capital additions acquired in exchange for issuance of Transocean Ltd. shares — 126 — Non-cash capital additions financed under the Shipyard Loans — — 382 Changes in accrued capital additions (13) 5 3 Property and equipment placed into service Newbuild construction program (552) (1,157) (882) Other equipment and construction projects (135) (74) (42) Construction work in progress, end of period $ 76 $ 522 $ 1,195

Leases (Tables)

Leases (Tables)	12 Months Ended
Leases (Tables)	Dec. 31, 2024
Leases
Schedule of lease costs	Years ended December 31, Lease costs 2024 2023 2022 Short-term lease costs $ 10 $ 4 $ 14 Operating lease costs 16 14 12 Finance lease costs, amortization of right-of-use asset 20 20 20 Finance lease costs, interest on lease liability 24 27 30 Total lease costs $ 70 $ 65 $ 76
Schedule of lease cash flow information	Years ended December 31, 2024 2023 2022 Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from operating leases $ 20 $ 17 $ 14 Operating cash flows from finance lease 4 — 8 Financing cash flows from finance lease 7 — 3
Schedule of future minimum payments on operating leases	Operating Finance leases lease Years ending December 31, 2025 $ 13 $ 65 2026 12 70 2027 12 71 2028 12 70 2029 12 47 Thereafter 74 — Total future minimum rental payment 135 323 Less amount representing imputed interest (40) (52) Present value of future minimum rental payments 95 271 Current portion, recorded in other current liabilities 7 47 Long-term lease liabilities, recorded in other long-term liabilities $ 88 $ 224
Schedule of future minimum payments on finance leases	Operating Finance leases lease Years ending December 31, 2025 $ 13 $ 65 2026 12 70 2027 12 71 2028 12 70 2029 12 47 Thereafter 74 — Total future minimum rental payment 135 323 Less amount representing imputed interest (40) (52) Present value of future minimum rental payments 95 271 Current portion, recorded in other current liabilities 7 47 Long-term lease liabilities, recorded in other long-term liabilities $ 88 $ 224

Debt (Tables)

Debt (Tables)	12 Months Ended
Debt (Tables)	Dec. 31, 2024
Debt
Schedule of debt	Principal amount Carrying amount December 31, December 31, December 31, December 31, 2024 2023 2024 2023 7.25% Senior Notes due November 2025 (a) $ — $ 354 $ — $ 352 4.00% Senior Guaranteed Exchangeable Bonds due December 2025 (b) 234 234 227 221 7.50% Senior Notes due January 2026 (a) — 569 — 567 11.50% Senior Guaranteed Notes due January 2027 (a) — 687 — 938 6.875% Senior Secured Notes due February 2027 (c) 330 413 328 409 8.00% Senior Notes due February 2027 (a) 655 612 653 609 7.45% Notes due April 2027 (d) 52 52 52 52 8.00% Debentures due April 2027 (d) 22 22 22 22 4.50% Shipyard Loans due September 2027 (e) 329 420 310 384 8.375% Senior Secured Notes due February 2028 (c) 525 525 518 518 7.00% Notes due June 2028 (e) 261 261 263 264 8.00% Senior Secured Notes due September 2028 (c) 295 325 292 321 8.25% Senior Notes due May 2029 (a) 900 — 887 — 4.625% Senior Guaranteed Exchangeable Bonds due September 2029 (a) 259 259 286 486 8.75% Senior Secured Notes due February 2030 (f) 999 1,116 981 1,094 7.50% Notes due April 2031 (d) 396 396 395 395 8.50% Senior Notes due May 2031 (a) 900 — 886 — 6.80% Senior Notes due March 2038 (d) 610 610 605 605 7.35% Senior Notes due December 2041 (d) 177 177 176 176 Total debt 6,944 7,032 6,881 7,413 Less debt due within one year 4.00% Senior Guaranteed Exchangeable Bonds due December 2025 (b) 234 — 227 — 11.50% Senior Guaranteed Notes due January 2027 (a) — — — 71 6.875% Senior Secured Notes due February 2027 (c) 83 83 82 81 4.50% Shipyard Loans due September 2027 (e) 120 90 108 75 8.375% Senior Secured Notes due February 2028 (c) 100 — 97 — 8.00% Senior Secured Notes due September 2028 (c) 60 30 59 30 8.75% Senior Secured Notes due February 2030 (f) 117 117 113 113 Total debt due within one year 714 320 686 370 Total long-term debt $ 6,230 $ 6,712 $ 6,195 $ 7,043 (a) Transocean International Limited, a wholly owned direct subsidiary of Transocean Ltd. formerly known as Transocean Inc., is the issuer of the unregistered notes (collectively, the “Priority Guaranteed Notes”). The guaranteed senior unsecured notes are fully and unconditionally, jointly and severally, guaranteed by Transocean Ltd. and certain wholly owned indirect subsidiaries of Transocean International Limited and rank equal in right of payment of all our existing and future unsecured unsubordinated obligations. Such notes are structurally senior to the Legacy Guaranteed Notes, as defined below, the 4.50% shipyard loans due September 2027 (each, a “Shipyard Loan”, and together, the “Shipyard Loans”) and the 7.00% notes due June 2028 and structurally subordinate to the Senior Priority Guaranteed Notes, as defined below, to the extent of the value of the assets of the subsidiaries guaranteeing the notes. (b) Transocean International Limited is the issuer of the unregistered notes (together, the “Senior Priority Guaranteed Notes”). The priority guaranteed senior unsecured notes are fully and unconditionally, jointly and severally, guaranteed by Transocean Ltd. and certain wholly owned indirect subsidiaries of Transocean International Limited and rank equal in right of payment of all of our existing and future unsecured unsubordinated obligations. Such notes are structurally senior to the Priority Guaranteed Notes to the extent of the value of the assets of the subsidiaries guaranteeing the notes. (c) Each subsidiary issuer of the respective unregistered notes is a wholly owned indirect subsidiary of Transocean International Limited. The senior secured notes are fully and unconditionally, jointly and severally, guaranteed by Transocean Ltd., Transocean International Limited and, in each case, the owner of the respective collateral rig or rigs. (d) Transocean International Limited is the issuer of the notes and debentures (the “Legacy Guaranteed Notes”). The Legacy Guaranteed Notes are fully and unconditionally, jointly and severally, guaranteed by Transocean Ltd. (e) The subsidiary borrowers under the Shipyard Loans and the subsidiary issuer of the registered notes are wholly owned indirect subsidiaries of Transocean International Limited. The loans and notes are fully and unconditionally guaranteed by Transocean International Limited. (f) Transocean International Limited is the issuer of the unregistered notes. The senior secured notes are fully and unconditionally guaranteed on an unsecured basis by Transocean Ltd. and on a limited senior secured basis by each of the wholly owned subsidiary owners of the collateral rigs.
Scheduled maturities of debt	Total Years ending December 31, 2025 $ 714 2026 541 2027 1,255 2028 664 2029 1,276 Thereafter 2,494 Total principal amount of debt 6,944 Total unamortized debt-related balances, net (199) Bifurcated compound exchange feature, at estimated fair value 136 Total carrying amount of debt $ 6,881
Schedule of interest expense	Years ended December 31, 2024 2023 2022 Contractual interest $ 21 $ 24 $ 16 Amortization 20 19 9 (Gain) loss on adjustment to bifurcated compound exchange feature (214) 127 157 Total $ (173) $ 170 $ 182
Schedule of debt retirements	Years ended December 31, 2024 2023 2022 Tendered Redeemed Total Redeemed Redeemed Exchanged Total 5.52% Senior Secured Notes due May 2022 $ — $ — $ — $ — $ 18 $ — $ 18 3.80% Senior Notes due October 2022 — — — — 27 — 27 0.50% Exchangeable Senior Bonds due January 2023 — — — — 18 73 91 5.375% Senior Secured Notes due May 2023 — — — 243 — — — 5.875% Senior Secured Notes due January 2024 — — — 311 — — — 7.75% Senior Secured Notes due October 2024 — — — 240 — — — 6.25% Senior Secured Notes due December 2024 — — — 250 — — — 6.125% Senior Secured Notes due August 2025 — — — 336 — — — 7.25% Senior Notes due November 2025 249 105 354 — 14 43 57 7.50% Senior Notes due January 2026 — 569 569 — — — — 11.50% Senior Guaranteed Notes due January 2027 596 91 687 — — — — 8.00% Senior Notes due February 2027 — 87 87 — — — — Aggregate principal amount of debt retired $ 845 $ 852 $ 1,697 $ 1,380 $ 77 $ 116 $ 193 Aggregate cash payment $ 886 $ 862 $ 1,748 $ 1,402 $ 75 $ — $ 75 Aggregate principal amount of debt issued in exchanges $ — $ — $ — $ — $ — $ 112 $ 112 Aggregate fair value of warrants issued in exchanges $ — $ — $ — $ — $ — $ 5 $ 5 Aggregate net gain (loss) $ 144 $ 17 $ 161 $ (32) $ 2 $ 6 $ 8
Exchanged
Debt
Schedule of debt	Exchange terms Implied Exchange exchange Shares rate price issuable 4.00% Senior Guaranteed Exchangeable Bonds due December 2025 190.4762 $ 5.25 45 4.625% Senior Guaranteed Exchangeable Bonds due September 2029 290.6618 $ 3.44 75 Effective interest rates and fair values Effective Fair interest rate value 4.00% Senior Guaranteed Exchangeable Bonds due December 2025 6.9% $ 247 4.625% Senior Guaranteed Exchangeable Bonds due September 2029 18.3% $ 359

Benefit Plans (Tables)

Benefit Plans (Tables)	12 Months Ended
Benefit Plans (Tables)	Dec. 31, 2024
Benefit Plans
Schedule of net periodic benefit costs before tax	Year ended December 31, 2024 Year ended December 31, 2023 Year ended December 31, 2022 U.S. U.K. OPEB U.S. U.K. OPEB U.S. U.K. OPEB Plans Plan Plans Total Plans Plan Plans Total Plans Plan Plans Total Net periodic benefit costs Interest cost $ 63 $ 9 $ — $ 72 $ 65 $ 9 $ — $ 74 $ 50 $ 6 $ — $ 56 Expected return on plan assets (86) (11) — (97) (84) (11) — (95) (65) (7) — (72) Special termination benefits — — 2 2 — — — — — — — — Settlements and curtailments — — (2) (2) — — — — — — — — Actuarial loss, net 1 2 — 3 — 2 — 2 5 — — 5 Prior service gain, net — — (1) (1) — — (2) (2) — — (2) (2) Net periodic benefit costs (income) $ (22) $ — $ (1) $ (23) $ (19) $ — $ (2) $ (21) $ (10) $ (1) $ (2) $ (13)
Schedule of weighted-average assumptions	Net periodic benefit costs Year ended December 31, 2024 Year ended December 31, 2023 Year ended December 31, 2022 U.S. U.K. OPEB U.S. U.K. OPEB U.S. U.K. OPEB Plans Plan Plans Plans Plan Plans Plans Plan Plans Discount rate 4.88 % 4.50 % 4.80 % 5.06 % 4.80 % 4.92 % 2.92 % 1.90 % 1.83 % Expected rate of return 6.51 % 5.10 % na 6.41 % 5.00 % na 4.81 % 2.00 % na “na” means not applicable. Year ended December 31, 2024 Year ended December 31, 2023 Year ended December 31, 2022 U.S. U.K. OPEB U.S. U.K. OPEB U.S. U.K. OPEB Plans Plan Plans Total Plans Plan Plans Total Plans Plan Plans Total Net periodic benefit costs Interest cost $ 63 $ 9 $ — $ 72 $ 65 $ 9 $ — $ 74 $ 50 $ 6 $ — $ 56 Expected return on plan assets (86) (11) — (97) (84) (11) — (95) (65) (7) — (72) Special termination benefits — — 2 2 — — — — — — — — Settlements and curtailments — — (2) (2) — — — — — — — — Actuarial loss, net 1 2 — 3 — 2 — 2 5 — — 5 Prior service gain, net — — (1) (1) — — (2) (2) — — (2) (2) Net periodic benefit costs (income) $ (22) $ — $ (1) $ (23) $ (19) $ — $ (2) $ (21) $ (10) $ (1) $ (2) $ (13) Funded status December 31, 2024 December 31, 2023 U.S. U.K. OPEB U.S. U.K. OPEB Plans Plan Plans Plans Plan Plans Discount rate 5.58 % 5.60 % 5.02 % 4.88 % 4.50 % 4.80 %
Schedule of changes in funded status, balance sheet classifications and accumulated benefit obligations	Year ended December 31, 2024 Year ended December 31, 2023 U.S. U.K. OPEB U.S. U.K. OPEB Plans Plan Plans Total Plans Plan Plans Total Change in projected benefit obligation Projected benefit obligation, beginning of period $ 1,328 $ 208 $ 8 $ 1,544 $ 1,307 $ 188 $ 10 $ 1,505 Actuarial (gain) loss, net (97) (27) 2 (122) 32 11 — 43 Interest cost 63 9 — 72 65 9 — 74 Currency exchange rate (gain) loss — (2) — (2) — 11 — 11 Benefits paid (77) (10) (2) (89) (76) (11) (2) (89) Special termination benefits — — 2 2 — — — — Projected benefit obligation, end of period 1,217 178 10 1,405 1,328 208 8 1,544 Change in plan assets Fair value of plan assets, beginning of period 1,211 239 — 1,450 1,143 232 — 1,375 Actual return (loss) on plan assets 30 (16) — 14 138 6 — 144 Currency exchange rate gain (loss) — (3) — (3) — 12 — 12 Employer contributions — — 2 2 6 — 2 8 Benefits paid (77) (10) (2) (89) (76) (11) (2) (89) Fair value of plan assets, end of period 1,164 210 — 1,374 1,211 239 — 1,450 Funded status asset (liability), end of period $ (53) $ 32 $ (10) $ (31) $ (117) $ 31 $ (8) $ (94) Balance sheet classification, end of period: Pension asset, non-current $ 41 $ 32 $ — $ 73 $ — $ 31 $ — $ 31 Pension liability, current (1) — (3) (4) (1) — (3) (4) Pension liability, non-current (93) — (7) (100) (116) — (5) (121) Accumulated other comprehensive loss (income), before taxes 102 88 (1) 189 144 90 (6) 228 Accumulated benefit obligation, end of period $ 1,217 $ 178 $ 10 $ 1,405 $ 1,328 $ 208 $ 8 $ 1,544
Schedule of projected benefit obligation in excess of plan assets	December 31, 2024 December 31, 2023 U.S. U.K. OPEB U.S. U.K. OPEB Plans Plan Plans Total Plans Plan Plans Total Projected benefit obligation / accumulated benefit obligation $ 100 $ — $ 10 $ 110 $ 1,328 $ — $ 8 $ 1,336 Fair value of plan assets 6 — — 6 1,211 — — 1,211
Schedule of unrecognized accumulated other comprehensive loss (income)	December 31, 2024 December 31, 2023 U.S. U.K. OPEB U.S. U.K. OPEB Plans Plan Plans Total Plans Plan Plans Total Actuarial (gain) loss, net $ 102 $ 87 $ 2 $ 191 $ 144 $ 88 $ (1) $ 231 Prior service cost (credit), net — 1 (3) (2) — 2 (5) (3) Accumulated other comprehensive loss (income), before taxes $ 102 $ 88 $ (1) $ 189 $ 144 $ 90 $ (6) $ 228
Schedule of allocations of plan assets	December 31, 2024 December 31, 2023 Target allocation Actual allocation Target allocation Actual allocation U.S. U.K. U.S. U.K. U.S. U.K. U.S. U.K. Plans Plan Plans Plan Plans Plan Plans Plan Equity securities — % 20 % — % 26 % 38 % 20 % 37 % 21 % Fixed income securities 99 % 73 % 99 % 65 % 62 % 73 % 62 % 72 % Other investments 1 % 7 % 1 % 9 % — % 7 % 1 % 7 % Total 100 % 100 % 100 % 100 % 100 % 100 % 100 % 100 %
Schedule of investments for the funded defined benefit plans	December 31, 2024 Significant observable inputs Significant other observable inputs Total U.S. U.K. U.S. U.K. U.S. U.K. Plans Plan Total Plans Plan Total Plans Plan Total Mutual funds Non-U.S. equity funds $ 4 $ — $ 4 $ — $ 55 $ 55 $ 4 $ 55 $ 59 Bond funds 1,149 — 1,149 2 136 138 1,151 136 1,287 Total mutual funds 1,153 — 1,153 2 191 193 1,155 191 1,346 Other investments Cash and money market funds 9 2 11 — — — 9 2 11 Synthetic leveraged credit fund — — — — 17 17 — 17 17 Total other investments 9 2 11 — 17 17 9 19 28 Total investments $ 1,162 $ 2 $ 1,164 $ 2 $ 208 $ 210 $ 1,164 $ 210 $ 1,374 December 31, 2023 Significant observable inputs Significant other observable inputs Total U.S. U.K. U.S. U.K. U.S. U.K. Plans Plan Total Plans Plan Total Plans Plan Total Mutual funds U.S. equity funds $ 316 $ — $ 316 $ — $ — $ — $ 316 $ — $ 316 Non-U.S. equity funds 139 — 139 — 51 51 139 51 190 Bond funds 746 — 746 4 171 175 750 171 921 Total mutual funds 1,201 — 1,201 4 222 226 1,205 222 1,427 Other investments Cash and money market funds 6 1 7 — — — 6 1 7 Synthetic leveraged credit fund — — — — 16 16 — 16 16 Total other investments 6 1 7 — 16 16 6 17 23 Total investments $ 1,207 $ 1 $ 1,208 $ 4 $ 238 $ 242 $ 1,211 $ 239 $ 1,450
Schedule of projected benefits payments	U.S. U.K. OPEB Plans Plan Plans Total Years ending December 31, 2025 $ 84 $ 7 $ 3 $ 94 2026 85 7 2 94 2027 85 7 1 93 2028 85 8 1 94 2029 85 9 1 95 2030 - 2034 430 60 2 492

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
Income Taxes (Tables)	Dec. 31, 2024
Income Taxes
Components of the provision (benefit) for income taxes	Years ended December 31, 2024 2023 2022 Current tax expense (benefit) $ 31 $ (5) $ 13 Deferred tax expense (benefit) (42) 18 46 Income tax expense (benefit) $ (11) $ 13 $ 59
Reconciliation of the differences between income tax expense computed at the Swiss holding company statutory rate and the reported provision for income taxes	Years ended December 31, 2024 2023 2022 Income tax benefit at Swiss federal statutory rate $ (40) $ (74) $ (44) Earnings subject to rates different than the Swiss federal statutory rate 74 129 52 Changes in valuation allowance 208 (23) 79 Tax attribute expirations 185 — — Deemed profits taxes 12 11 10 Withholding taxes 4 5 12 Changes in unrecognized tax benefits, net (4) (37) 2 Changes due to organizational restructuring (452) — (162) Swiss Federal Act on Tax Reform and AHV Financing — — 96 Audit settlement — — 12 Other, net 2 2 2 Income tax expense (benefit) $ (11) $ 13 $ 59
Significant components of deferred tax assets and liabilities	December 31, 2024 2023 Deferred tax assets Net operating loss carryforwards $ 1,541 $ 1,264 Swiss historic depreciation and financing asset costs 1,053 1,210 Interest expense limitation 87 87 United Kingdom charter limitation 53 53 Accrued costs and expenses 20 47 Deferred revenues 22 — Accrued payroll costs not currently deductible 12 16 Tax credits 5 4 Loss contingencies 3 4 Other 61 54 Valuation allowance (2,089) (1,884) Total deferred tax assets, net of allowance 768 855 Deferred tax liabilities Depreciation (1,214) (1,342) Other (8) (9) Total deferred tax liabilities (1,222) (1,351) Deferred tax liabilities, net $ (454) $ (496)
Reconciliation of unrecognized tax benefits, excluding interest and penalties	Years ended December 31, 2024 2023 2022 Balance, beginning of period $ 449 $ 444 $ 402 Additions for current year tax positions 13 45 28 Additions for prior year tax positions 11 5 62 Reductions related to statute of limitation expirations and changes in law (19) (14) (13) Reductions due to settlements (30) (5) (5) Reductions for prior year tax positions (17) (26) (30) Balance, end of period $ 407 $ 449 $ 444
Schedule of unrecognized tax benefits, including related interest and penalties	December 31, 2024 2023 Unrecognized tax benefits, excluding interest and penalties $ 407 $ 449 Interest and penalties 7 9 Unrecognized tax benefits, including interest and penalties $ 414 $ 458

Loss Per Share (Tables)

Loss Per Share (Tables)	12 Months Ended
Loss Per Share (Tables)	Dec. 31, 2024
Loss Per Share
Schedule of earnings (loss) per share	The computation of basic and diluted loss per share was as follows (in millions, except per share data): Years ended December 31, 2024 2023 2022 Basic Diluted Basic Diluted Basic Diluted Numerator for loss per share Net loss attributable to controlling interest $ (512) $ (512) $ (954) $ (954) $ (621) $ (621) Effect of convertible debt instruments, net of tax — (189) — — — — Loss for per share calculation $ (512) $ (701) $ (954) $ (954) $ (621) $ (621) Denominator for loss per share Weighted-average shares outstanding 850 850 768 768 699 699 Effect of convertible debt instruments — 75 — — — — Weighted-average shares for per share calculation 850 925 768 768 699 699 Loss per share $ (0.60) $ (0.76) $ (1.24) $ (1.24) $ (0.89) $ (0.89)
Schedule of antidilutive securities	Years ended December 31, 2024 2023 2022 Exchangeable bonds 45 151 128 Share-based awards 11 19 16 Warrants 6 10 -

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
Commitments and Contingencies (Tables)	Dec. 31, 2024
Commitments and Contingencies.
Schedule of aggregate future payments required under purchase obligations	Service agreement obligations Years ending December 31, 2025 $ 137 2026 143 2027 117 2028 73 2029 49 Thereafter 91 Total $ 610

Share-Based Compensation (Table

Share-Based Compensation (Tables)	12 Months Ended
Share-Based Compensation (Tables)	Dec. 31, 2024
Share Based Compensation
Summary of activity for vested and unvested stock options outstanding	Weighted-average Number Weighted-average remaining Aggregate of shares exercise price contractual term intrinsic value under option per share (years) (in millions) Outstanding at January 1, 2024 4,083,929 $ 9.54 3.92 $ — Forfeited (14,595) 10.95 Outstanding at December 31, 2024 4,069,334 $ 9.53 2.93 $ — Vested and exercisable at December 31, 2024 4,069,334 $ 9.53 2.93 $ —
Service awards
Share Based Compensation
Summary of unvested deferred units activity	Number Weighted-average of grant-date fair value units per unit Unvested at January 1, 2024 9,560,008 $ 5.01 Granted 5,116,762 5.29 Vested (6,727,943) 4.78 Forfeited (289,799) 5.52 Unvested at December 31, 2024 7,659,028 $ 5.44
Performance awards
Share Based Compensation
Summary of unvested deferred units activity	Number Weighted-average of grant-date fair value units per unit Unvested at January 1, 2024 5,432,149 $ 4.91 Granted 2,687,268 5.10 Vested (4,429,028) 4.67 Forfeited (194,464) 5.47 Unvested at December 31, 2024 3,495,925 $ 5.78

Supplemental Balance Sheet In_2

Supplemental Balance Sheet Information (Tables)	12 Months Ended
Supplemental Balance Sheet Information (Tables)	Dec. 31, 2024
Supplemental Balance Sheet Information
Schedule of other current liabilities	December 31, 2024 2023 Other current liabilities Accrued employee benefits and payroll-related liabilities $ 136 $ 145 Accrued interest 134 146 Accrued taxes, other than income 39 47 Finance lease liability 47 43 Operating lease liabilities 7 12 Deferred revenues 231 165 Contingent liabilities 94 116 Other 3 7 Total other current liabilities $ 691 $ 681
Schedule of other long term liabilities	December 31, 2024 2023 Other long-term liabilities Postemployment benefit plan obligations $ 100 $ 121 Finance lease liability 224 276 Operating lease liabilities 88 108 Income taxes payable 65 80 Deferred revenues 212 233 Other 40 40 Total other long-term liabilities $ 729 $ 858

Supplemental Cash Flow Inform_2

Supplemental Cash Flow Information (Tables)	12 Months Ended
Supplemental Cash Flow Information (Tables)	Dec. 31, 2024
Supplemental Cash Flow Information
Schedule of changes in other operating assets and liabilities	Years ended December 31, 2024 2023 2022 Changes in other operating assets and liabilities Increase in accounts receivable $ (94) $ (99) $ (15) Increase in other assets (100) (98) (12) Increase (decrease) in accounts payable and other current liabilities (91) 135 8 Decrease in other long-term liabilities (2) (7) (2) Change in income taxes receivable / payable, net (19) (36) (42) Change in receivables from / payables to affiliates, net 9 (8) (12) $ (297) $ (113) $ (75)
Additional cash flow information	Years ended December 31, 2024 2023 2022 Certain cash operating activities Cash payments for interest $ 521 $ 408 $ 355 Cash payments for income taxes 60 41 66 Noncash investing and financing activities Capital additions accrued at end of period (a) $ 23 $ 36 $ 31 Capital additions acquired in exchange for debt (b) — — 382 Acquisition of outstanding ownership interests in exchange for shares and debt (c) 431 99 — Debt investment exchanged for additional equity ownership interests (d) — 37 — Finance lease installments settled with credits issued to customer (e) 40 44 41 Shares issued in exchanges of exchangeable bonds (f) — 434 — Debt and warrants issued in exchange transactions (g) — — 110 (a) Additions to property and equipment for which we had accrued a corresponding liability in accounts payable at the end of the period. See Note 6—Long-Lived Assets . (b) In the year ended December 31, 2022, we borrowed an aggregate principal amount of $439 million under the Shipyard Loans to satisfy a portion of the final milestone payments due upon delivery of Deepwater Atlas and Deepwater Titan and recorded the initial carrying amount, net of imputed interest, with a corresponding entry to construction in progress, recorded in property and equipment. See Note 6—Long-Lived Assets and Note 8—Debt . (c) In June 2024, we issued 55.5 million Transocean Ltd. shares and $130 million aggregate principal amount of 8.00% Senior Notes to acquire the outstanding ownership interest in Orion. In September 2023, we issued 11.9 million Transocean Ltd. shares to acquire the outstanding ownership interest in Liquila. See Note 4—Unconsolidated Affiliates , Note 6—Long-Lived Assets and Note 13—Equity . (d) In September 2023, we agreed to exchange borrowings due to us under a financing arrangement with Orion for additional equity ownership interests in Orion. See Note 4—Unconsolidated Affiliates . (e) In the years ended December 31, 2024, 2023 and 2022, we agreed to settle installments due to the lessor under our finance lease by issuing corresponding credits to our customer for amounts due to us under the drilling contract. See Note 7—Leases . (f) In the year ended December 31, 2023, we issued 65.1 million Transocean Ltd. shares to certain holders that elected to exchange the 2.50% Senior Guaranteed Exchangeable Bonds, the 4.00% Senior Guaranteed Exchangeable Bonds and the 4.625% Senior Guaranteed Exchangeable Bonds. See Note 8—Debt and Note 13—Equity .

Financial Instruments (Tables)

Financial Instruments (Tables)	12 Months Ended
Financial Instruments (Tables)	Dec. 31, 2024
Financial Instruments
Carrying amounts and fair values of the financial instruments	The carrying amounts and fair values of our financial instruments were as follows (in millions): December 31, 2024 December 31, 2023 Carrying Fair Carrying Fair amount value amount value Cash and cash equivalents $ 560 $ 560 $ 762 $ 762 Restricted cash and cash equivalents 381 381 233 233 Total debt 6,881 6,888 7,413 7,308

Business (Details)

Business (Details)	12 Months Ended
Business (Details)	Dec. 31, 2024 item segment
Number of mobile offshore drilling units	34
Number of operating segments \| segment	1
Ultra-deepwater floaters
Number of mobile offshore drilling units	26
Harsh environment floaters
Number of mobile offshore drilling units	8

Significant Accounting Polici_3

Significant Accounting Policies (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Functional currency
Net foreign currency exchange gain (loss)	$ 16	$ 10	$ (8)
Materials and supplies
Materials and supplies, allowance for obsolescence	$ 178	$ 198
Property and equipment
Property and equipment as a percentage of total assets	82%
Drilling rig units
Property and equipment
Estimated original useful life	35 years
Buildings and improvements \| Minimum
Property and equipment
Estimated original useful life	3 years
Buildings and improvements \| Maximum
Property and equipment
Estimated original useful life	30 years
Machinery and equipment \| Minimum
Property and equipment
Estimated original useful life	4 years
Machinery and equipment \| Maximum
Property and equipment
Estimated original useful life	20 years

Significant Accounting Polici_4

Significant Accounting Policies (Pensions) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023
Pension and other postretirement benefits
Recognition period of investment gains or losses related to asset valuation for determining net periodic benefit cost	5 years
Conditional amortization gains or losses as percentage of greater of plan assets or liabilities, minimum	10%
Pension liability, current and noncurrent	$ 104	$ 125
Pension asset, non-current	$ 73	$ 31

Unconsolidated Affiliates (Deta

Unconsolidated Affiliates (Details) - USD ($) shares in Millions, $ in Millions	1 Months Ended				12 Months Ended
	Jun. 30, 2024	Sep. 30, 2023	Feb. 28, 2023	Nov. 30, 2022	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Investments
Equity investment income (loss)					$ 4	$ (14)	$ (24)
Loss on impairment of investment in unconsolidated affiliate					5	5
Equity method investments					$ 123	216
Payment to acquire interest						$ 10	42
Transocean Inc \| Perestroika AS
Investments
Ownership interest (as a percent)				10%
8.00% Senior Notes due February 2027
Investments
Debt instrument interest rate stated percentage					8%
Global Sea Mineral Resources
Investments
Equity ownership (as a percent)					16%
Equity method investment payment			$ 10
Equity investment non-cash contribution			$ 85
Orion/Transocean Norge
Investments
Equity ownership (as a percent)						33%
Equity method investments						$ 86
Ocean Minerals
Investments
Equity ownership (as a percent)					19%
Equity method investment payment							$ 42
Liquila/Deepwater Aquila
Investments
Payment to acquire interest				$ 15
Liquila/Deepwater Aquila \| Perestroika AS
Investments
Payment to acquire interest				$ 10
Liquila/Deepwater Aquila \| Third Party
Investments
Equity ownership (as a percent)				67%
Orion/Transocean Norge
Investments
Asset acquisition, consideration transferred	$ 431
Value shares issued in asset acquisition	$ 297
Newly issued shares in asset acquisition (in shares)	55.5
Orion/Transocean Norge \| 8.00% Senior Notes due February 2027
Investments
Debt instrument interest rate stated percentage	8%
Debt instrument face value	$ 130
Orion/Transocean Norge \| Orion/Transocean Norge
Investments
Equity ownership (as a percent)	67%
Liquila/Deepwater Aquila
Investments
Value shares issued in asset acquisition		$ 99			$ 431	$ 99
Newly issued shares in asset acquisition (in shares)		11.9
Liquila/Deepwater Aquila \| Perestroika AS
Investments
Value shares issued in asset acquisition		$ 16
Newly issued shares in asset acquisition (in shares)		2
Liquila/Deepwater Aquila \| Liquila/Deepwater Aquila
Investments
Equity ownership (as a percent)		80%

Unconsolidated Affiliates (Rela

Unconsolidated Affiliates (Related Parties) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Related party
Accounts payable	$ 255	$ 323
Orion/Transocean Norge
Related party
Non-cash net settlement of accounts receivable and payable		25
Equity Method Investee
Related party
Related party transaction	14	12	$ 7
Related party receivable, current	3	14
Long-term loans receivable from unconsolidated affiliates	10	6
Services and Equipment \| Orion/Transocean Norge
Related party
Related party transaction	11	49	40
Rent Expense \| Orion/Transocean Norge
Related party
Related party transaction	25	26	11
Charter rig and other equipment \| Orion/Transocean Norge
Related party
Related party transaction	$ 25	$ 27	$ 10

Revenues (Disaggregation) (Deta

Revenues (Disaggregation) (Details) - USD ($) $ in Millions	12 Months Ended
Revenues (Disaggregation) (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Revenue
Contract drilling revenues	$ 3,524	$ 2,832	$ 2,575
UNITED STATES
Revenue
Contract drilling revenues	1,566	1,433	1,135
BRAZIL
Revenue
Contract drilling revenues	727	298	240
NORWAY
Revenue
Contract drilling revenues	654	603	835
Other Countries
Revenue
Contract drilling revenues	577	498	365
Ultra-deepwater floaters
Revenue
Contract drilling revenues	2,518	2,072	1,708
Ultra-deepwater floaters \| UNITED STATES
Revenue
Contract drilling revenues	1,566	1,433	1,135
Ultra-deepwater floaters \| BRAZIL
Revenue
Contract drilling revenues	727	298	240
Ultra-deepwater floaters \| Other Countries
Revenue
Contract drilling revenues	225	341	333
Harsh environment floaters
Revenue
Contract drilling revenues	1,006	760	867
Harsh environment floaters \| NORWAY
Revenue
Contract drilling revenues	654	603	835
Harsh environment floaters \| Other Countries
Revenue
Contract drilling revenues	$ 352	$ 157	$ 32

Revenues (Customers) (Details)

Revenues (Customers) (Details) - Revenue - Operating revenues	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Shell
Concentration Risk
Percentage of concentration	27%	27%	33%
Petrobras
Concentration Risk
Percentage of concentration	21%	11%	11%
Equinor
Concentration Risk
Percentage of concentration	13%	16%	25%
TotalEnergies
Concentration Risk
Percentage of concentration		12%

Revenues (Contract liabilities)

Revenues (Contract liabilities) (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Contract intangible assets
Contract intangible assets gross	$ 907	$ 907
Contract intangible assets accumulated amortization	907	903
Contract balances
Deferred contract revenues, recorded in other current liabilities	231	165
Deferred contract revenues, recorded in other long-term liabilities	212	233
Total contract liabilities	$ 443	$ 398	$ 328

Revenues (Changes) (Details)

Revenues (Changes) (Details) - USD ($) $ in Millions	12 Months Ended
Revenues (Changes) (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
Changes to contract liabilities
Total contract liabilities, beginning of period	$ 398	$ 328
Decrease due to recognition of revenues for goods and services	(243)	(189)
Increase due to goods and services transferred over time	288	259
Total contract liabilities, end of period	$ 443	$ 398

Revenues (Pre-operating) (Detai

Revenues (Pre-operating) (Details) - USD ($) $ in Millions	12 Months Ended
Revenues (Pre-operating) (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Revenues.
Recognized pre-operating costs	$ 138	$ 69	$ 47
Unrecognized pre-operating costs	$ 224	$ 221

Long-Lived Assets (Disaggregati

Long-Lived Assets (Disaggregation) (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
Operating segments
Long-lived assets	$ 16,276	$ 17,427
UNITED STATES
Operating segments
Long-lived assets	6,727	7,472
GREECE
Operating segments
Long-lived assets	2,531	2,652
NORWAY
Operating segments
Long-lived assets	2,017	2,103
BRAZIL
Operating segments
Long-lived assets	1,993	1,610
Other countries
Operating segments
Long-lived assets	$ 3,008	$ 3,590

Long-Lived Assets (Construction

Long-Lived Assets (Construction WIP) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Changes in construction work in progress
Total capital expenditures	$ 254	$ 427	$ 717
Capitalized interest costs on construction work in progress	15	39	73
Construction in Progress
Changes in construction work in progress
Construction work in progress, at beginning of period	522	1,195	1,017
Total capital expenditures	254	427	717
Non-cash capital additions acquired in exchange for issuance of Transocean Ltd shares		126
Non-cash capital additions financed under the Shipyard Loan			382
Changes in accrued capital additions	(13)	5	3
Construction work in progress, at end of period	76	522	1,195
New builds
Changes in construction work in progress
Total capital expenditures	142	331	669
Property and equipment placed into service	(552)	(1,157)	(882)
Other property and equipment
Changes in construction work in progress
Total capital expenditures	112	96	48
Property and equipment placed into service	$ (135)	$ (74)	$ (42)

Long-Lived Assets (Acquisitions

Long-Lived Assets (Acquisitions) (Details) - USD ($) $ in Millions	Dec. 31, 2024	Jun. 30, 2024	Dec. 31, 2023	Sep. 30, 2023
Acquisition
Property and equipment, net	$ 15,831		$ 16,941
Cash and cash equivalents	560		762
Accounts receivable	564		512
Accounts payable	$ 255		$ 323
Orion/Transocean Norge
Acquisition
Property and equipment, net		$ 517
Cash and cash equivalents		5
Accounts receivable		$ 4
Liquila/Deepwater Aquila
Acquisition
Property and equipment, net				$ 126
Cash and cash equivalents				7
Accounts payable				$ 19

Long-Lived Assets (Disposals) (

Long-Lived Assets (Disposals) (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Disposals
Proceeds from disposal of assets, net of costs to sell	$ 101	$ 10	$ 7
Gain (loss) on the sale of assets	(17)	(183)	(10)
Assets sold, not discontinued operations \| Rig sales
Disposals
Proceeds from disposal of assets, net of costs to sell	102
Deposit received	6
Gain (loss) on the sale of assets		$ (169)
Gain (loss) on the sale of assets per diluted share		$ (0.22)
Gain (loss) on disposal of assets, tax effect		$ 0
Assets sold, not discontinued operations \| Other property and equipment
Disposals
Proceeds from disposal of assets, net of costs to sell	5	4	7
Gain (loss) on the sale of assets	$ (17)	$ (14)	$ (10)

Long-Lived Assets (Impairments)

Long-Lived Assets (Impairments) (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023
LONG LIVED ASSETS
Assets held for sale	$ 343	$ 49
Aggregate loss on impairment of assets held for sale	772	$ 57
Aggregate loss on impairment of assets held for sale, net of tax	$ 755
Loss associated with impairment, net of tax (per share)	$ 0.82	$ 0.07
Aggregate loss on impairment of assets held for sale, tax effect		$ 0

Leases (Operating leases) (Deta

Leases (Operating leases) (Details)	Dec. 31, 2024
Leases
Weighted average discount rate, operating leases (as a percent)	6.50%
Weighted-average remaining lease term, operating leases	11 years 1 month 6 days

Leases (Finance lease) (Details

Leases (Finance lease) (Details)	12 Months Ended
Leases (Finance lease) (Details)	Dec. 31, 2024 USD ($)
Leases
Implicit interest rate (as a percent)	7.80%
End of lease obligation	$ 1

Leases (Lease costs) (Details)

Leases (Lease costs) (Details) - USD ($) $ in Millions	12 Months Ended
Leases (Lease costs) (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Leases
Short-term lease costs	$ 10	$ 4	$ 14
Operating lease costs	16	14	12
Finance lease costs, amortization of right-of-use asset	20	20	20
Finance lease costs, interest on lease liability	24	27	30
Total lease costs	$ 70	$ 65	$ 76

Leases - (Cash flow) (Details)

Leases - (Cash flow) (Details) - USD ($) $ in Millions	12 Months Ended
Leases - (Cash flow) (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Leases
Operating cash flows from operating leases	$ 20	$ 17	$ 14
Operating cash flows from finance lease	4		8
Financing cash flows from finance lease	$ 7		$ 3

Leases (Maturity) (Details)

Leases (Maturity) (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
Operating lease maturity
2025	$ 13
2026	12
2027	12
2028	12
2029	12
Thereafter	74
Total future minimum rental payment	135
Less amount representing imputed interest	(40)
Present value of future minimum rental payments under operating leases	95
Current portion, recorded in other current liabilities	7	$ 12
Long-term lease liabilities, recorded in other long-term liabilities	88	108
Finance lease maturity
2024	65
2025	70
2026	71
2027	70
2028	47
Total future minimum rental payment	323
Less amount representing imputed interest	(52)
Present value of future minimum rental payments under finance leases	271
Current portion, recorded in other current liabilities	47	43
Long-term lease liabilities, recorded in other long-term liabilities	$ 224	$ 276

Debt (Details)

Debt (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Principal amount
Debt due within one year	$ 714	$ 320
Long-term debt	6,230	6,712
Carrying amount
Total debt	6,881	7,413
Debt due within one year	686	370
Long-term debt	$ 6,195	7,043
7.25% Senior Notes due November 2025
Principal amount
Total principal amount of debt		354
Carrying amount
Total debt		352
Debt instrument interest rate stated percentage	7.25%
4.00% Senior Guaranteed Exchangeable Bonds due December 2025
Principal amount
Total principal amount of debt	$ 234	234
Debt due within one year	234
Carrying amount
Total debt	227	221
Debt due within one year	$ 227
Debt instrument interest rate stated percentage	4%
7.50% Senior Notes due January 2026
Principal amount
Total principal amount of debt		569
Carrying amount
Total debt		567
Debt instrument interest rate stated percentage	7.50%
11.50% Senior Guaranteed Notes due January 2027
Principal amount
Total principal amount of debt		687
Carrying amount
Total debt		938
Debt due within one year		71
Debt instrument interest rate stated percentage	11.50%
6.875% Senior Secured Notes due February 2027
Principal amount
Total principal amount of debt	$ 330	413
Debt due within one year	83	83
Carrying amount
Total debt	328	409
Debt due within one year	$ 82	81
Debt instrument interest rate stated percentage	6.875%
8.00% Senior Notes due February 2027
Principal amount
Total principal amount of debt	$ 655	612
Carrying amount
Total debt	$ 653	609
Debt instrument interest rate stated percentage	8%
7.45% Notes due April 2027
Principal amount
Total principal amount of debt	$ 52	52
Carrying amount
Total debt	$ 52	52
Debt instrument interest rate stated percentage	7.45%
8.00% Debentures due April 2027
Principal amount
Total principal amount of debt	$ 22	22
Carrying amount
Total debt	$ 22	22
Debt instrument interest rate stated percentage	8%
4.50% Shipyard Loans due September 2027
Principal amount
Total principal amount of debt	$ 329	420
Debt due within one year	120	90
Carrying amount
Total debt	310	384
Debt due within one year	$ 108	75
Debt instrument interest rate stated percentage	4.50%
8.375% Senior Secured Notes due February 2028
Principal amount
Total principal amount of debt	$ 525	525
Debt due within one year	100
Carrying amount
Total debt	518	518
Debt due within one year	$ 97
Debt instrument interest rate stated percentage	8.375%
7.00% Notes due June 2028
Principal amount
Total principal amount of debt	$ 261	261
Carrying amount
Total debt	$ 263	264
Debt instrument interest rate stated percentage	7%
8.00% Senior Secured Notes due September 2028
Principal amount
Total principal amount of debt	$ 295	325
Debt due within one year	60	30
Carrying amount
Total debt	292	321
Debt due within one year	$ 59	30
Debt instrument interest rate stated percentage	8%
8.25% Senior Notes due May 2029
Principal amount
Total principal amount of debt	$ 900
Carrying amount
Total debt	$ 887
Debt instrument interest rate stated percentage	8.25%
4.625% Senior Guaranteed Exchangeable Bonds due September 2029
Principal amount
Total principal amount of debt	$ 259	259
Carrying amount
Total debt	$ 286	486
Debt instrument interest rate stated percentage	4.625%
8.75% Senior Secured Notes due February 2030
Principal amount
Total principal amount of debt	$ 999	1,116
Debt due within one year	117	117
Carrying amount
Total debt	981	1,094
Debt due within one year	$ 113	113
Debt instrument interest rate stated percentage	8.75%
7.50% Notes due April 2031
Principal amount
Total principal amount of debt	$ 396	396
Carrying amount
Total debt	$ 395	395
Debt instrument interest rate stated percentage	7.50%
8.50% Senior Notes due May 2031
Principal amount
Total principal amount of debt	$ 900
Carrying amount
Total debt	$ 886
Debt instrument interest rate stated percentage	8.50%
6.80% Senior Notes due March 2038
Principal amount
Total principal amount of debt	$ 610	610
Carrying amount
Total debt	$ 605	605
Debt instrument interest rate stated percentage	6.80%
7.35% Senior Notes due December 2041
Principal amount
Total principal amount of debt	$ 177	177
Carrying amount
Total debt	$ 176	176
Debt instrument interest rate stated percentage	7.35%
3.80% Senior Notes due October 2022
Carrying amount
Debt instrument interest rate stated percentage			3.80%
Principal installments
Principal amount
Total principal amount of debt	$ 6,944	$ 7,032
0.50% Exchangeable Senior Bonds due January 2023
Carrying amount
Debt instrument interest rate stated percentage			0.50%

Debt (Maturities) (Details)

Debt (Maturities) (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
Total installments
Scheduled maturities of debt
2025	$ 714
2026	541
2027	1,255
2028	664
2029	1,276
Thereafter	2,494
Total principal amount of debt	6,944
Total unamortized debt-related balances, net	(199)
Bifurcated compound exchange feature, at estimated fair value	136
Total carrying amount of debt	6,881
Principal installments
Scheduled maturities of debt
Total principal amount of debt	$ 6,944	$ 7,032

Debt (Credit Agreements) (Detai

Debt (Credit Agreements) (Details) $ in Millions	1 Months Ended			12 Months Ended
Debt (Credit Agreements) (Details) $ in Millions	Apr. 30, 2024 USD ($)	Dec. 31, 2022 USD ($)	Jun. 30, 2022 USD ($)	Dec. 31, 2024 USD ($)	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)	Mar. 31, 2024 USD ($)
Debt
Total capital expenditures				$ 254	$ 427	$ 717
Five-Year Revolving Credit Facility
Debt
Borrowing capacity, maximum							$ 600
Commitment fee (as a percent)				0.625%
Credit facility amount outstanding				$ 0
Letters of credit issued and outstanding				7
Credit facility available borrowing capacity				$ 569,000
Spread on variable rate basis (as a percent)	0.10%			2.875%
Debt Instrument, Variable Interest Rate, Type [Extensible Enumeration]	us-gaap:SecuredOvernightFinancingRateSofrMember
Early maturity trigger, principal due within 91 days	$ 325
Early maturity trigger available cash	250
Permitted commitment increase	$ 250
Minimum guarantee coverage ratio	3
Minimum collateral coverage ratio.	2.1
Debt to capitalization ratio	0.6
Minimum liquidity	$ 200
Aggregate carrying amount assets pledged				$ 4,300
Cross default trigger under credit facility	$ 125
Five-Year Revolving Credit Facility \| Minimum
Debt
Commitment fee (as a percent)	0.375%
Five-Year Revolving Credit Facility \| Maximum
Debt
Commitment fee (as a percent)	1%
Five-Year Revolving Credit Facility \| June 2025
Debt
Borrowing capacity, maximum	$ 576
Five-Year Revolving Credit Facility \| June 2028
Debt
Borrowing capacity, maximum	$ 510
4.50% Shipyard Loans due September 2027
Debt
Aggregate principal amount outstanding				329	420
Debt instrument face value		$ 439				439
Non-cash capital addition						382
4.50% Shipyard Loans due September 2027 \| Deepwater Atlas
Debt
Aggregate principal amount outstanding				259
Debt instrument face value			$ 349
Total capital expenditures			46
Non-cash capital addition			$ 300
4.50% Shipyard Loans due September 2027 \| Deepwater Atlas \| Discount rate
Debt
Debt fair value measurement input			0.094
4.50% Shipyard Loans due September 2027 \| Deepwater Titan
Debt
Aggregate principal amount outstanding				70
Debt instrument face value		90				$ 90
Total capital expenditures		325
Non-cash capital addition		$ 82
4.50% Shipyard Loans due September 2027 \| Deepwater Titan \| Discount rate
Debt
Debt fair value measurement input		0.076				0.076
7.35% Senior Notes due December 2041
Debt
Aggregate principal amount outstanding				$ 177	$ 177
Interest rate, as adjusted (as a percent)				9.35%
Senior Secured Notes
Debt
Aggregate carrying amount assets pledged				$ 6,090

Debt (Exchangeable) (Details)

Debt (Exchangeable) (Details) $ / shares in Units, shares in Millions, $ in Millions	1 Months Ended				12 Months Ended
	Oct. 31, 2023 USD ($) shares	Jul. 31, 2023 USD ($) shares	Apr. 30, 2023 USD ($) shares	Sep. 30, 2022 USD ($) $ / shares shares	Dec. 31, 2024 USD ($) $ / shares	Dec. 31, 2023 USD ($) shares	Dec. 31, 2022 USD ($) shares	Nov. 30, 2022
Debt
Shares issuable (in shares)						434
Aggregate principal amount of debt issued in exchanges							$ 112
Aggregate principal amount of debt retired					$ 1,697		$ 193
Shares issued upon conversion (in shares) \| shares	26.5					65.1
Number of warrants issued to subscribe \| shares				22.2
Shares issued in exchange (in shares) \| shares	3.1
Perestroika AS \| Transocean Inc
Debt
Ownership interest (as a percent)								10%
2022 Private Exchange
Debt
Number of warrants issued to subscribe \| shares				6.7			6.7
Gains (losses) on restructuring				$ 6
Gains (losses) on restructuring (in dollars per share) \| $ / shares				$ 0.01
Exchanged
Debt
Aggregate principal amount of debt issued in exchanges							$ 112
Aggregate principal amount of debt retired							$ 116
0.50% Exchangeable Senior Bonds due January 2023
Debt
Debt instrument interest rate stated percentage							0.50%
Aggregate principal amount of debt retired							$ 91
0.50% Exchangeable Senior Bonds due January 2023 \| 2022 Private Exchange
Debt
Original debt in exchange				$ 73
0.50% Exchangeable Senior Bonds due January 2023 \| Exchanged
Debt
Aggregate principal amount of debt retired							73
2.50% Senior Guaranteed Exchangeable Bonds due January 2027
Debt
Debt conversion ratio		0.1621626	0.1621626
Aggregate principal amount of debt retired		$ 25
Shares issued upon conversion (in shares) \| shares		4	34.6
Cash consideration to exchanging holder						$ 3
2.50% Senior Guaranteed Exchangeable Bonds due January 2027 \| Perestroika AS
Debt
Aggregate principal amount of debt issued in exchanges			$ 213
4.00% Senior Guaranteed Exchangeable Bonds due December 2025
Debt
Debt instrument interest rate stated percentage					4%
Debt conversion ratio	0.1904762				0.1904762
Debt conversion (in dollars per share) \| $ / shares					$ 5.25
Shares issuable (in shares)					45
Effective interest rate (as a percent)					6.90%
Fair value of debt					$ 247
Aggregate principal amount of debt retired	$ 60
4.625% Senior Guaranteed Exchangeable Bonds due September 2029
Debt
Debt instrument interest rate stated percentage					4.625%
Debt conversion ratio	0.2906618				0.2906618
Debt conversion (in dollars per share) \| $ / shares					$ 3.44
Shares issuable (in shares)					75
Effective interest rate (as a percent)					18.30%
Fair value of debt					$ 359
Bifurcated compound exchange feature, at estimated fair value					136	350
Aggregate principal amount of debt issued in exchanges							$ 112
Aggregate principal amount of debt retired	$ 41					$ 41
Amount to repurchase upon the occurrence of certain events (as a percent)				1.15
Trading days for calculation of average stock price				20 days
Number of warrants issued to subscribe \| shares				15.5
Original debt in exchange				$ 281
4.625% Senior Guaranteed Exchangeable Bonds due September 2029 \| 2022 Private Exchange
Debt
Aggregate principal amount of debt issued in exchanges				$ 73
Senior Secured Notes
Debt
Aggregate carrying amount assets pledged					$ 6,090

Debt (Interest Expense) (Detail

Debt (Interest Expense) (Details) - USD ($) $ in Millions	12 Months Ended
Debt (Interest Expense) (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Interest Expense
Amortization	$ 53	$ 51	$ 33
(Gain) loss on adjustment to bifurcated compound exchange feature	(214)	127	157
Total	362	646	561
Exchangeable bonds
Interest Expense
Contractual interest	21	24	16
Amortization	20	19	9
(Gain) loss on adjustment to bifurcated compound exchange feature	(214)	127	157
Total	$ (173)	$ 170	$ 182

Debt (Issuance) (Details)

Debt (Issuance) (Details) - USD ($) $ in Millions	1 Months Ended				12 Months Ended
Debt (Issuance) (Details) - USD ($) $ in Millions	Apr. 30, 2024	Oct. 31, 2023	Jan. 31, 2023	Sep. 30, 2022	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022	Jun. 30, 2024
Debt
Total capital expenditures					$ 254	$ 427	$ 717
Proceeds from issuance of debt	$ 1,770				1,770	1,983	175
Restricted cash and cash equivalents					$ 381	$ 233
Orion/Transocean Norge
Debt
Equity ownership (as a percent)						33%
Orion/Transocean Norge \| Orion/Transocean Norge
Debt
Equity ownership (as a percent)								67%
8.375% Senior Secured Notes due February 2028
Debt
Debt instrument face value			$ 525
Debt instrument interest rate stated percentage					8.375%
Proceeds from issuance of debt			516
8.75% Senior Secured Notes due February 2030
Debt
Debt instrument face value			1,175
Debt instrument interest rate stated percentage					8.75%
Proceeds from issuance of debt			$ 1,148
Redemption price of debt instrument (as a percent)			100%
8.00% Senior Secured Notes due September 2028
Debt
Debt instrument face value		$ 325
Debt instrument interest rate stated percentage		8%
Proceeds from issuance of debt		$ 319
Redemption price of debt instrument (as a percent)		100%
8.00% Senior Notes due February 2027
Debt
Debt instrument interest rate stated percentage					8%
8.00% Senior Notes due February 2027 \| Orion/Transocean Norge
Debt
Debt instrument face value								$ 130
Debt instrument interest rate stated percentage								8%
8.25% Senior Notes due May 2029
Debt
Debt instrument face value	$ 900
Debt instrument interest rate stated percentage					8.25%
Redemption price of debt instrument (as a percent)	100%
8.50% Senior Notes due May 2031
Debt
Debt instrument face value	$ 900
Debt instrument interest rate stated percentage					8.50%
Redemption price of debt instrument (as a percent)	100%
4.625% Senior Guaranteed Exchangeable Bonds due September 2029
Debt
Debt instrument face value				$ 188
Debt instrument interest rate stated percentage					4.625%
Proceeds from issuance of debt				$ 188
4.50% Shipyard Loans due September 2027
Debt
Debt instrument face value							$ 439
Debt instrument interest rate stated percentage					4.50%
Senior Secured Notes
Debt
Redemption price of debt instrument (as a percent)					100%
Restricted cash and cash equivalents					$ 351

Debt (Settled) (Details)

Debt (Settled) (Details) - USD ($) $ in Millions		1 Months Ended		12 Months Ended
Debt (Settled) (Details) - USD ($) $ in Millions	Jan. 30, 2023	Oct. 31, 2023	Sep. 30, 2022	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Debt
Aggregate principal amount of debt retired				$ 1,697		$ 193
Aggregate cash payment				1,748		75
Aggregate principal amount of debt issued in exchanges						112
Aggregate fair value of warrants issued in exchanges						5
Aggregate net gain (loss)				161	$ (31)	8
Repayments of debt				$ 2,103	$ 1,717	$ 554
5.52% Senior Secured Notes due May 2022
Debt
Debt instrument interest rate stated percentage						5.52%
Aggregate principal amount of debt retired						$ 18
3.80% Senior Notes due October 2022
Debt
Debt instrument interest rate stated percentage						3.80%
Aggregate principal amount of debt retired						$ 27
0.50% Exchangeable Senior Bonds due January 2023
Debt
Debt instrument interest rate stated percentage						0.50%
Aggregate principal amount of debt retired						$ 91
Repayments of debt	$ 49
5.375% Senior Secured Notes due May 2023
Debt
Debt instrument interest rate stated percentage					5.375%
5.875% Senior Secured Notes due January 2024
Debt
Debt instrument interest rate stated percentage					5.875%
7.75% Senior Secured Notes due October 2024
Debt
Debt instrument interest rate stated percentage					7.75%
6.25% Senior Secured Notes due December 2024
Debt
Debt instrument interest rate stated percentage					6.25%
6.125% Senior Secured Notes due August 2025
Debt
Debt instrument interest rate stated percentage					6.125%
7.25% Senior Notes due November 2025
Debt
Debt instrument interest rate stated percentage				7.25%
Aggregate principal amount of debt retired				$ 354		57
7.50% Senior Notes due January 2026
Debt
Debt instrument interest rate stated percentage				7.50%
Aggregate principal amount of debt retired				$ 569
8.00% Senior Notes due February 2027
Debt
Debt instrument interest rate stated percentage				8%
Aggregate principal amount of debt retired				$ 87
11.50% Senior Guaranteed Notes due January 2027
Debt
Debt instrument interest rate stated percentage				11.50%
Aggregate principal amount of debt retired				$ 687
4.625% Senior Guaranteed Exchangeable Bonds due September 2029
Debt
Debt instrument interest rate stated percentage				4.625%
Aggregate principal amount of debt retired		$ 41			$ 41
Aggregate principal amount of debt issued in exchanges						112
Aggregate net gain (loss)					1
Original debt in exchange			$ 281
Aggregate of unspecified debt
Debt
Repayments of debt				$ 355	262	479
2022 Private Exchange
Debt
Aggregate fair value of warrants issued in exchanges						5
2022 Private Exchange \| 0.50% Exchangeable Senior Bonds due January 2023
Debt
Original debt in exchange			73
2022 Private Exchange \| 7.25% Senior Notes due November 2025
Debt
Aggregate principal amount of debt issued in exchanges			39
Original debt in exchange			43
2022 Private Exchange \| 4.625% Senior Guaranteed Exchangeable Bonds due September 2029
Debt
Aggregate principal amount of debt issued in exchanges			$ 73
Exchanged
Debt
Aggregate principal amount of debt retired						116
Aggregate principal amount of debt issued in exchanges						112
Aggregate fair value of warrants issued in exchanges						5
Aggregate net gain (loss)						6
Exchanged \| 0.50% Exchangeable Senior Bonds due January 2023
Debt
Aggregate principal amount of debt retired						73
Exchanged \| 7.25% Senior Notes due November 2025
Debt
Aggregate principal amount of debt retired						43
Tendered
Debt
Aggregate principal amount of debt retired				845
Aggregate cash payment				886
Aggregate net gain (loss)				144
Tendered \| 7.25% Senior Notes due November 2025
Debt
Aggregate principal amount of debt retired				249
Tendered \| 11.50% Senior Guaranteed Notes due January 2027
Debt
Aggregate principal amount of debt retired				596
Redeemed
Debt
Aggregate principal amount of debt retired				852	1,380	77
Aggregate cash payment				862	1,402	75
Aggregate net gain (loss)				17	(32)	2
Redeemed \| 5.52% Senior Secured Notes due May 2022
Debt
Aggregate principal amount of debt retired						18
Redeemed \| 3.80% Senior Notes due October 2022
Debt
Aggregate principal amount of debt retired						27
Redeemed \| 0.50% Exchangeable Senior Bonds due January 2023
Debt
Aggregate principal amount of debt retired						18
Redeemed \| 5.375% Senior Secured Notes due May 2023
Debt
Aggregate principal amount of debt retired					243
Redeemed \| 5.875% Senior Secured Notes due January 2024
Debt
Aggregate principal amount of debt retired					311
Redeemed \| 7.75% Senior Secured Notes due October 2024
Debt
Aggregate principal amount of debt retired					240
Redeemed \| 6.25% Senior Secured Notes due December 2024
Debt
Aggregate principal amount of debt retired					250
Redeemed \| 6.125% Senior Secured Notes due August 2025
Debt
Aggregate principal amount of debt retired					$ 336
Redeemed \| 7.25% Senior Notes due November 2025
Debt
Aggregate principal amount of debt retired				105		$ 14
Redeemed \| 7.50% Senior Notes due January 2026
Debt
Aggregate principal amount of debt retired				569
Redeemed \| 8.00% Senior Notes due February 2027
Debt
Aggregate principal amount of debt retired				87
Redeemed \| 11.50% Senior Guaranteed Notes due January 2027
Debt
Aggregate principal amount of debt retired				$ 91

Benefit Plans (DefCont) (Detail

Benefit Plans (DefCont) (Details) - USD ($) $ in Millions	12 Months Ended
Benefit Plans (DefCont) (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Benefit Plans
Contribution expense	$ 63	$ 58	$ 61

Benefit Plans (Costs) (Details)

Benefit Plans (Costs) (Details) $ in Millions	12 Months Ended
Benefit Plans (Costs) (Details) $ in Millions	Dec. 31, 2024 USD ($) plan	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)
Net periodic benefit costs, before tax
Interest cost	$ 72	$ 74	$ 56
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Interest Cost, Statement of Income or Comprehensive Income [Extensible Enumeration]	Other Nonoperating Income (Expense)	Other Nonoperating Income (Expense)
Expected return on plan assets	$ (97)	$ (95)	(72)
Defined Benefit Plan, Net Periodic Benefit (Cost) Credit, Expected Return (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Other Nonoperating Income (Expense)	Other Nonoperating Income (Expense)
Special termination benefits	$ 2
Settlements and curtailments	$ (2)
Defined Benefit Plan, Net Periodic Benefit (Cost) Credit, Settlement and Curtailment Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Other Nonoperating Income (Expense)	Other Nonoperating Income (Expense)
Actuarial loss, net	$ 3	$ 2	5
Defined Benefit Plan, Net Periodic Benefit (Cost) Credit, Amortization of Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Other Nonoperating Income (Expense)	Other Nonoperating Income (Expense)
Prior service gain, net	$ (1)	$ (2)	(2)
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Amortization of Prior Service Cost (Credit), Statement of Income or Comprehensive Income [Extensible Enumeration]	Other Nonoperating Income (Expense)	Other Nonoperating Income (Expense)
Net periodic benefit costs (income)	$ (23)	$ (21)	$ (13)
UNITED STATES
Weighted-average assumptions
Discount rate (as a percent)	4.88%	5.06%	2.92%
Expected rate of return (as a percent)	6.51%	6.41%	4.81%
UNITED STATES \| Funded Plan
Net periodic benefit costs, before tax
Number Of Benefit Plans \| plan	3
UNITED STATES \| Unfunded Plan
Net periodic benefit costs, before tax
Number Of Benefit Plans \| plan	3
UNITED KINGDOM
Weighted-average assumptions
Discount rate (as a percent)	4.50%	4.80%	1.90%
Expected rate of return (as a percent)	5.10%	5%	2%
UNITED KINGDOM \| Funded Plan
Net periodic benefit costs, before tax
Number Of Benefit Plans \| plan	1
Transocean Plans \| UNITED STATES
Net periodic benefit costs, before tax
Interest cost	$ 63	$ 65	$ 50
Expected return on plan assets	(86)	(84)	(65)
Actuarial loss, net	1		5
Net periodic benefit costs (income)	(22)	(19)	(10)
Transocean Plans \| UNITED KINGDOM
Net periodic benefit costs, before tax
Interest cost	9	9	6
Expected return on plan assets	(11)	(11)	(7)
Actuarial loss, net	$ 2	$ 2
Net periodic benefit costs (income)			$ (1)
OPEB Plans
Weighted-average assumptions
Discount rate (as a percent)	4.80%	4.92%	1.83%
Net periodic benefit costs, before tax
Special termination benefits	$ 2
Settlements and curtailments	(2)
Prior service gain, net	(1)	$ (2)	$ (2)
Net periodic benefit costs (income)	$ (1)	$ (2)	$ (2)

Benefit Plans (Funded) (Details

Benefit Plans (Funded) (Details) - USD ($) $ in Millions	12 Months Ended
Benefit Plans (Funded) (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Change in projected benefit obligation
Projected benefit obligation, beginning of period	$ 1,544	$ 1,505
Actuarial (gains) losses, net	(122)	43
Interest cost	72	74	$ 56
Currency exchange rate (gain) loss	(2)	11
Benefits paid	(89)	(89)
Special termination benefits	2
Projected benefit obligation, end of period	1,405	1,544	1,505
Change in plan assets
Fair value of plan assets, beginning of period	1,450	1,375
Actual return (loss) on plan assets	14	144
Currency exchange rate gain (loss)	(3)	12
Employer contributions	2	8	3
Benefits paid	(89)	(89)
Fair value of plan assets, end of period	1,374	1,450	1,375
Funded status, asset (liability), end of period	(31)	(94)
Balance sheet classification, end of period:
Pension asset, non-current	73	31
Pension liability, current	(4)	(4)
Pension liability, non-current	(100)	(121)
Accumulated other comprehensive loss (income), before taxes	189	228
Accumulated benefit obligation, end of period	1,405	1,544
Projected benefit obligation in excess of plan assets
Projected benefit obligation	110	1,336
Fair value of plan assets	6	1,211
Accumulated other comprehensive loss (income) that have not been recognized
Actuarial (gain) loss, net	191	231
Prior service cost (credit), net	(2)	(3)
Accumulated other comprehensive loss (income), before taxes	189	228
Transocean Plans
Change in plan assets
Fair value of plan assets, beginning of period	1,450
Fair value of plan assets, end of period	$ 1,374	$ 1,450
Transocean Plans \| UNITED STATES
Weighted average assumptions
Discount rate (as a percent)	5.58%	4.88%
Change in projected benefit obligation
Projected benefit obligation, beginning of period	$ 1,328	$ 1,307
Actuarial (gains) losses, net	(97)	32
Interest cost	63	65	50
Benefits paid	(77)	(76)
Projected benefit obligation, end of period	1,217	1,328	1,307
Change in plan assets
Fair value of plan assets, beginning of period	1,211	1,143
Actual return (loss) on plan assets	30	138
Employer contributions		6
Benefits paid	(77)	(76)
Fair value of plan assets, end of period	1,164	1,211	1,143
Funded status, asset (liability), end of period	(53)	(117)
Balance sheet classification, end of period:
Pension asset, non-current	41
Pension liability, current	(1)	(1)
Pension liability, non-current	(93)	(116)
Accumulated other comprehensive loss (income), before taxes	102	144
Accumulated benefit obligation, end of period	1,217	1,328
Projected benefit obligation in excess of plan assets
Projected benefit obligation	100	1,328
Fair value of plan assets	6	1,211
Accumulated other comprehensive loss (income) that have not been recognized
Actuarial (gain) loss, net	102	144
Accumulated other comprehensive loss (income), before taxes	$ 102	$ 144
Transocean Plans \| UNITED KINGDOM
Weighted average assumptions
Discount rate (as a percent)	5.60%	4.50%
Change in projected benefit obligation
Projected benefit obligation, beginning of period	$ 208	$ 188
Actuarial (gains) losses, net	(27)	11
Interest cost	9	9	6
Currency exchange rate (gain) loss	(2)	11
Benefits paid	(10)	(11)
Projected benefit obligation, end of period	178	208	188
Change in plan assets
Fair value of plan assets, beginning of period	239	232
Actual return (loss) on plan assets	(16)	6
Currency exchange rate gain (loss)	(3)	12
Benefits paid	(10)	(11)
Fair value of plan assets, end of period	210	239	232
Funded status, asset (liability), end of period	32	31
Balance sheet classification, end of period:
Pension asset, non-current	32	31
Accumulated other comprehensive loss (income), before taxes	88	90
Accumulated benefit obligation, end of period	178	208
Accumulated other comprehensive loss (income) that have not been recognized
Actuarial (gain) loss, net	87	88
Prior service cost (credit), net	1	2
Accumulated other comprehensive loss (income), before taxes	$ 88	$ 90
OPEB Plans
Weighted average assumptions
Discount rate (as a percent)	5.02%	4.80%
Change in projected benefit obligation
Projected benefit obligation, beginning of period	$ 8	$ 10
Actuarial (gains) losses, net	2
Benefits paid	(2)	(2)
Special termination benefits	2
Projected benefit obligation, end of period	10	8	$ 10
Change in plan assets
Employer contributions	2	2
Benefits paid	(2)	(2)
Funded status, asset (liability), end of period	(10)	(8)
Balance sheet classification, end of period:
Pension liability, current	(3)	(3)
Pension liability, non-current	(7)	(5)
Accumulated other comprehensive loss (income), before taxes	(1)	(6)
Accumulated benefit obligation, end of period	10	8
Projected benefit obligation in excess of plan assets
Projected benefit obligation	10	8
Accumulated other comprehensive loss (income) that have not been recognized
Actuarial (gain) loss, net	2	(1)
Prior service cost (credit), net	(3)	(5)
Accumulated other comprehensive loss (income), before taxes	$ (1)	$ (6)

Benefit Plans (Assets) (Details

Benefit Plans (Assets) (Details) - USD ($) $ in Millions	12 Months Ended
Benefit Plans (Assets) (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Fair value of plan assets
Total investments	$ 1,374	$ 1,450	$ 1,375
Funding contributions
Employer contributions	2	$ 8	3
Expected defined plan contributions next year	11
Projected pension benefits payments
2025	94
2026	94
2027	93
2028	94
2029	95
2030-2034	$ 492
UNITED STATES
Weighted-average target allocations of the investments
Total target allocation percentage	100%	100%
Total actual allocation percentage	100%	100%
UNITED STATES \| Equity securities
Weighted-average target allocations of the investments
Total target allocation percentage		38%
Total actual allocation percentage		37%
UNITED STATES \| Fixed income securities
Weighted-average target allocations of the investments
Total target allocation percentage	99%	62%
Total actual allocation percentage	99%	62%
UNITED STATES \| Other investments
Weighted-average target allocations of the investments
Total target allocation percentage	1%
Total actual allocation percentage	1%	1%
UNITED KINGDOM
Weighted-average target allocations of the investments
Total target allocation percentage	100%	100%
Total actual allocation percentage	100%	100%
UNITED KINGDOM \| Equity securities
Weighted-average target allocations of the investments
Total target allocation percentage	20%	20%
Total actual allocation percentage	26%	21%
UNITED KINGDOM \| Fixed income securities
Weighted-average target allocations of the investments
Total target allocation percentage	73%	73%
Total actual allocation percentage	65%	72%
UNITED KINGDOM \| Other investments
Weighted-average target allocations of the investments
Total target allocation percentage	7%	7%
Total actual allocation percentage	9%	7%
Transocean Plans
Fair value of plan assets
Total investments	$ 1,374	$ 1,450
Funding contributions
Expected defined plan contributions next year	8
Transocean Plans \| Significant observable inputs
Fair value of plan assets
Total investments	1,164	1,208
Transocean Plans \| Significant other observable inputs
Fair value of plan assets
Total investments	210	242
Transocean Plans \| Mutual funds
Fair value of plan assets
Total investments	1,346	1,427
Transocean Plans \| Mutual funds \| Significant observable inputs
Fair value of plan assets
Total investments	1,153	1,201
Transocean Plans \| Mutual funds \| Significant other observable inputs
Fair value of plan assets
Total investments	193	226
Transocean Plans \| U.S. equity funds
Fair value of plan assets
Total investments		316
Transocean Plans \| U.S. equity funds \| Significant observable inputs
Fair value of plan assets
Total investments		316
Transocean Plans \| Non-U.S. equity funds
Fair value of plan assets
Total investments	59	190
Transocean Plans \| Non-U.S. equity funds \| Significant observable inputs
Fair value of plan assets
Total investments	4	139
Transocean Plans \| Non-U.S. equity funds \| Significant other observable inputs
Fair value of plan assets
Total investments	55	51
Transocean Plans \| Bond funds
Fair value of plan assets
Total investments	1,287	921
Transocean Plans \| Bond funds \| Significant observable inputs
Fair value of plan assets
Total investments	1,149	746
Transocean Plans \| Bond funds \| Significant other observable inputs
Fair value of plan assets
Total investments	138	175
Transocean Plans \| Other investments
Fair value of plan assets
Total investments	28	23
Transocean Plans \| Other investments \| Significant observable inputs
Fair value of plan assets
Total investments	11	7
Transocean Plans \| Other investments \| Significant other observable inputs
Fair value of plan assets
Total investments	17	16
Transocean Plans \| Cash and money market funds
Fair value of plan assets
Total investments	11	7
Transocean Plans \| Cash and money market funds \| Significant observable inputs
Fair value of plan assets
Total investments	11	7
Transocean Plans \| Synthetic leveraged credit fund
Fair value of plan assets
Total investments	17	16
Transocean Plans \| Synthetic leveraged credit fund \| Significant other observable inputs
Fair value of plan assets
Total investments	17	16
Transocean Plans \| UNITED STATES
Fair value of plan assets
Total investments	1,164	1,211	1,143
Funding contributions
Employer contributions		6
Projected pension benefits payments
2025	84
2026	85
2027	85
2028	85
2029	85
2030-2034	430
Transocean Plans \| UNITED STATES \| Significant observable inputs
Fair value of plan assets
Total investments	1,162	1,207
Transocean Plans \| UNITED STATES \| Significant other observable inputs
Fair value of plan assets
Total investments	2	4
Transocean Plans \| UNITED STATES \| Mutual funds
Fair value of plan assets
Total investments	1,155	1,205
Transocean Plans \| UNITED STATES \| Mutual funds \| Significant observable inputs
Fair value of plan assets
Total investments	1,153	1,201
Transocean Plans \| UNITED STATES \| Mutual funds \| Significant other observable inputs
Fair value of plan assets
Total investments	2	4
Transocean Plans \| UNITED STATES \| U.S. equity funds
Fair value of plan assets
Total investments		316
Transocean Plans \| UNITED STATES \| U.S. equity funds \| Significant observable inputs
Fair value of plan assets
Total investments		316
Transocean Plans \| UNITED STATES \| Non-U.S. equity funds
Fair value of plan assets
Total investments	4	139
Transocean Plans \| UNITED STATES \| Non-U.S. equity funds \| Significant observable inputs
Fair value of plan assets
Total investments	4	139
Transocean Plans \| UNITED STATES \| Bond funds
Fair value of plan assets
Total investments	1,151	750
Transocean Plans \| UNITED STATES \| Bond funds \| Significant observable inputs
Fair value of plan assets
Total investments	1,149	746
Transocean Plans \| UNITED STATES \| Bond funds \| Significant other observable inputs
Fair value of plan assets
Total investments	2	4
Transocean Plans \| UNITED STATES \| Other investments
Fair value of plan assets
Total investments	9	6
Transocean Plans \| UNITED STATES \| Other investments \| Significant observable inputs
Fair value of plan assets
Total investments	9	6
Transocean Plans \| UNITED STATES \| Cash and money market funds
Fair value of plan assets
Total investments	9	6
Transocean Plans \| UNITED STATES \| Cash and money market funds \| Significant observable inputs
Fair value of plan assets
Total investments	9	6
Transocean Plans \| UNITED KINGDOM
Fair value of plan assets
Total investments	210	239	$ 232
Projected pension benefits payments
2025	7
2026	7
2027	7
2028	8
2029	9
2030-2034	60
Transocean Plans \| UNITED KINGDOM \| Significant observable inputs
Fair value of plan assets
Total investments	2	1
Transocean Plans \| UNITED KINGDOM \| Significant other observable inputs
Fair value of plan assets
Total investments	208	238
Transocean Plans \| UNITED KINGDOM \| Mutual funds
Fair value of plan assets
Total investments	191	222
Transocean Plans \| UNITED KINGDOM \| Mutual funds \| Significant other observable inputs
Fair value of plan assets
Total investments	191	222
Transocean Plans \| UNITED KINGDOM \| Non-U.S. equity funds
Fair value of plan assets
Total investments	55	51
Transocean Plans \| UNITED KINGDOM \| Non-U.S. equity funds \| Significant other observable inputs
Fair value of plan assets
Total investments	55	51
Transocean Plans \| UNITED KINGDOM \| Bond funds
Fair value of plan assets
Total investments	136	171
Transocean Plans \| UNITED KINGDOM \| Bond funds \| Significant other observable inputs
Fair value of plan assets
Total investments	136	171
Transocean Plans \| UNITED KINGDOM \| Other investments
Fair value of plan assets
Total investments	19	17
Transocean Plans \| UNITED KINGDOM \| Other investments \| Significant observable inputs
Fair value of plan assets
Total investments	2	1
Transocean Plans \| UNITED KINGDOM \| Other investments \| Significant other observable inputs
Fair value of plan assets
Total investments	17	16
Transocean Plans \| UNITED KINGDOM \| Cash and money market funds
Fair value of plan assets
Total investments	2	1
Transocean Plans \| UNITED KINGDOM \| Cash and money market funds \| Significant observable inputs
Fair value of plan assets
Total investments	2	1
Transocean Plans \| UNITED KINGDOM \| Synthetic leveraged credit fund
Fair value of plan assets
Total investments	17	16
Transocean Plans \| UNITED KINGDOM \| Synthetic leveraged credit fund \| Significant other observable inputs
Fair value of plan assets
Total investments	17	16
OPEB Plans
Funding contributions
Employer contributions	2	$ 2
Expected defined plan contributions next year	3
Projected pension benefits payments
2025	3
2026	2
2027	1
2028	1
2029	1
2030-2034	$ 2

Income Taxes (Expense) (Details

Income Taxes (Expense) (Details) - USD ($) $ in Millions	12 Months Ended
Income Taxes (Expense) (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Income Taxes
Effective tax rate	2.20%	(1.40%)	(10.40%)
Components of provision (benefit) for income taxes
Current tax expense (benefit)	$ 31	$ (5)	$ 13
Deferred tax expense (benefit)	(42)	18	46
Income tax expense (benefit)	$ (11)	$ 13	$ 59

Income Taxes (Reconciliation) (

Income Taxes (Reconciliation) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Income tax expense reconciliation
Swiss holding company federal statutory rate (as a percent)	7.83%
Income tax benefit at Swiss federal statutory rate	$ (40)	$ (74)	$ (44)
Earnings subject to rates different than the Swiss federal statutory rate	74	129	52
Changes in valuation allowance	208	(23)	79
Tax attribute expirations	185
Deemed profits taxes	12	11	10
Withholding taxes	4	5	12
Changes in unrecognized tax benefits, net	(4)	(37)	2
Changes due to organizational restructuring	(452)		(162)
Swiss Federal Act on Tax Reform and AHV Financing			96
Audit settlement			12
Other, net	2	2	2
Income tax expense (benefit)	$ (11)	$ 13	$ 59

Income Taxes (Deferred) (Detail

Income Taxes (Deferred) (Details) - USD ($) $ in Millions	12 Months Ended
Income Taxes (Deferred) (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Deferred tax assets
Net operating loss carryforwards	$ 1,541	$ 1,264
Swiss historic depreciation and financing asset costs	1,053	1,210
Interest expense limitation	87	87
United Kingdom charter limitation	53	53
Accrued costs and expenses	20	47
Deferred revenue	22
Accrued payroll expenses not currently deductible	12	16
Tax credits	5	4
Loss contingencies	3	4
Other	61	54
Valuation allowance	(2,089)	(1,884)
Total deferred tax assets, net of allowance	768	855
Deferred tax liabilities
Depreciation	(1,214)	(1,342)
Other	(8)	(9)
Total deferred tax liabilities	(1,222)	(1,351)
Deferred tax assets (liabilities), net	(454)	(496)
U.S. foreign tax credit carryforwards	5	4
NOLs that are not subject to expiration dates	1,241
NOLs that are subject to expiration dates	437
Reconciliation of unrecognized tax benefits, excluding interest and penalties
Balance, beginning of period	449	444	$ 402
Additions for current year tax positions	13	45	28
Additions for prior year tax positions	11	5	62
Reductions related to statute of limitation expirations and changes in law	(19)	(14)	(13)
Reductions due to settlements	(30)	(5)	(5)
Reductions for prior year tax positions	(17)	(26)	(30)
Balance, end of period	407	449	444
Unrecognized tax benefits
Unrecognized tax benefits, excluding interest and penalties	407	449	444
Interest and penalties	7	9
Unrecognized tax benefits, including interest and penalties	414	458
Interest and penalties related to unrecognized tax benefits recognized as a component of income tax expense	2	(18)	$ 6
Unrecognized benefits netted against NOL deferred tax assets	372
Amount if recognized that would impact tax rate	42
LUXEMBOURG
Deferred tax liabilities
Deferred tax assets (liabilities), net	(280)	(8)
Swiss TRAF
Deferred tax assets
Valuation allowance	(909)	(909)
Total deferred tax assets, net of allowance	1,050	1,210
Deferred tax liabilities
Total deferred tax liabilities	$ (218)	$ (264)

Income Taxes (Tax Returns) (Det

Income Taxes (Tax Returns) (Details) - 12 months ended Dec. 31, 2024 - BRAZIL R$ in Millions, $ in Millions	BRL (R$)	USD ($)
Income Tax Examination
Income tax examination, exposure decrease	R$ 219	$ (35)
Corporate income tax
Income Tax Examination
Net adjustments of additional taxes, including interest and penalties	501	81
Indirect tax
Income Tax Examination
Net adjustments of additional taxes, including interest and penalties	R$ 90	$ 15

Loss Per Share (Basic and Dilut

Loss Per Share (Basic and Diluted) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Numerator for loss per share, basic
Net Income (Loss)	$ (512)	$ (954)	$ (621)
Loss for per share calculation, basic	$ (512)	$ (954)	$ (621)
Denominator for loss per share, basic
Weighted-average shares outstanding (in shares)	850	768	699
Weighted-average shares for per share calculation, basic (in shares)	850	768	699
Loss per share, basic (in dollars per share)	$ (0.6)	$ (1.24)	$ (0.89)
Numerator for loss per share, diluted
Net Income (Loss)	$ (512)	$ (954)	$ (621)
Effect of convertible debt instruments, net of tax	(189)
Loss for per share calculation, diluted	$ (701)	$ (954)	$ (621)
Denominator for loss per share, diluted
Weighted-average shares outstanding (in shares)	850	768	699
Effect of convertible debt instruments (in shares)	75
Weighted-average shares for per share calculation, diluted (in shares)	925	768	699
Loss per share, diluted (in dollars per share)	$ (0.76)	$ (1.24)	$ (0.89)
Exchangeable bonds
Anti-dilutive securities
Securities excluded from earnings per share calculation (in shares)	45	151	128
Share-based awards
Anti-dilutive securities
Securities excluded from earnings per share calculation (in shares)	11	19	16
Warrants
Anti-dilutive securities
Securities excluded from earnings per share calculation (in shares)	6	10

Commitments and Contingencies_2

Commitments and Contingencies (PurchOb) (Details) - Supply agreement $ in Millions	Dec. 31, 2024 USD ($)
Future Purchase obligations
2025	$ 137
2026	143
2027	117
2028	73
2029	49
Thereafter	91
Total	$ 610

Commitments and Contingencies_3

Commitments and Contingencies (Letters of credit and surety bonds) (Details) - Letters of credit and surety bonds - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
Letters of credit and surety bonds
Outstanding letters of credit	$ 9	$ 16
Surety bonds outstanding	147	198
Aggregate cash collateral	$ 8	$ 7

Commitments and Contingencies_4

Commitments and Contingencies (Legal proceedings) (Details)	Dec. 31, 2024 lawsuit
Asbestos litigation
Contingencies
Number of claims	364

Equity (Share Issuance) (Detail

Equity (Share Issuance) (Details) $ / shares in Units, shares in Millions, $ in Millions	1 Months Ended					12 Months Ended
	Jun. 30, 2024 USD ($) shares	Oct. 31, 2023 shares	Sep. 30, 2023 USD ($) shares	Aug. 31, 2022 USD ($)	Jun. 30, 2021 USD ($)	Dec. 31, 2024 USD ($) $ / shares	Dec. 31, 2023 USD ($) $ / shares shares	Dec. 31, 2022 USD ($) shares	Jan. 01, 2024 $ / shares	Dec. 31, 2023 SFr / shares
Equity
Par value of common stock \| (per share)						$ 0.1	$ 0.1		$ 0.1	SFr 0.1
Shares issued upon conversion (in shares) \| shares		26.5					65.1
Proceeds from issuance of shares, net of issue costs								$ 263
ATM Program
Equity
Maximum value shares to be issued				$ 435	$ 400
Proceeds from issuance of shares, net of issue costs								$ 263
Issuance of shares (in shares) \| shares								61
Orion/Transocean Norge
Equity
Equity ownership (as a percent)							33%			33%
Orion/Transocean Norge
Equity
Newly issued shares in asset acquisition (in shares) \| shares	55.5
Value shares issued in asset acquisition	$ 297
Orion/Transocean Norge \| Orion/Transocean Norge
Equity
Equity ownership (as a percent)	67%
Liquila/Deepwater Aquila
Equity
Newly issued shares in asset acquisition (in shares) \| shares			11.9
Value shares issued in asset acquisition			$ 99			$ 431	$ 99
Liquila/Deepwater Aquila \| Liquila/Deepwater Aquila
Equity
Equity ownership (as a percent)			80%

Equity (Shares held) (Details)

Equity (Shares held) (Details) - shares shares in Millions	Dec. 31, 2024	Dec. 31, 2023
Number of shares held for future use	22.5
Subsidiary
Number of shares held for future use	42.5	34.7

Equity (Warrants) (Details)

Equity (Warrants) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	1 Months Ended	12 Months Ended
	Sep. 30, 2022	Dec. 31, 2022	Dec. 31, 2024
Equity
Number of warrants issued to subscribe	22.2
Exercise price	$ 3.71
Stock price trigger	$ 10
Estimated fair value	$ 16	$ 16
Number of warrants outstanding			22.2

Share-Based Compensation (Detai

Share-Based Compensation (Details) shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2024 USD ($) shares
Share Based Compensation
Shares authorized under the plan	138.2
Shares available for grant under the plan	36.4
Total unrecognized compensation costs unvested share based awards \| $	$ 35
Weighted average period over compensation costs are expected to be recognized	1 year 8 months 12 days
Service awards
Share Based Compensation
Vesting period	3 years
General term of awards after they are vested	7 years
Performance awards
Share Based Compensation
Measurement period	3 years

Share-Based Compensation (Non o

Share-Based Compensation (Non options) (Details) - Restricted shares - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Service awards
Equity instruments other than options activity
Outstanding at the beginning of the period (in shares)	9,560,008
Granted (in shares)	5,116,762	3,744,049	6,768,943
Vested (in shares)	(6,727,943)	(6,200,155)	(5,075,374)
Forfeited (in shares)	(289,799)
Outstanding at the end of the period (in shares)	7,659,028	9,560,008
Weighted-average grant-date fair value per share
Outstanding at the beginning of the period (in dollars per share)	$ 5.01
Granted (in dollars per share)	5.29	$ 7.23	$ 3.6
Vested (in dollars per share)	4.78
Forfeited (in dollars per share)	5.52
Outstanding at the end of the period (in dollars per share)	$ 5.44	$ 5.01
Additional disclosure
Total grant date fair value	$ 32	$ 18
Performance awards
Equity instruments other than options activity
Outstanding at the beginning of the period (in shares)	5,432,149
Granted (in shares)	2,687,268	1,912,292	3,519,857
Vested (in shares)	(4,429,028)	(3,025,512,000,000)	(2,363,878,000,000)
Forfeited (in shares)	(194,464)
Outstanding at the end of the period (in shares)	3,495,925	5,432,149
Weighted-average grant-date fair value per share
Outstanding at the beginning of the period (in dollars per share)	$ 4.91
Granted (in dollars per share)	5.1	$ 6.74	$ 3.91
Vested (in dollars per share)	4.67
Forfeited (in dollars per share)	5.47
Outstanding at the end of the period (in dollars per share)	$ 5.78	$ 4.91
Additional disclosure
Total grant date fair value	$ 21	$ 11	$ 5

Share-Based Compensation (Optio

Share-Based Compensation (Options) (Details) - Service awards - Employee Stock Option - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Stock option activity
Outstanding at the beginning of the period (in shares)	4,083,929
Forfeited (in shares)	(14,595)
Outstanding at the end of the period (in shares)	4,069,334	4,083,929
Vested and exercisable at the end of the period (in shares)	4,069,334
Weighted-average exercise price per share
Outstanding at the beginning of the period (in dollars per share)	$ 9.54
Forfeited (in dollars per share)	10.95
Outstanding at the end of the period (in dollars per share)	9.53	$ 9.54
Vested and exercisable at the end of the period (in dollars per share)	$ 9.53
Additional disclosure
Weighted-average remaining contractual term, outstanding	2 years 11 months 4 days	3 years 11 months 1 day
Weighted-average remaining contractual term, vested and exercisable at the end of the period	2 years 11 months 4 days
Total grant-date fair value of awards vested			$ 4
Unvested stock options outstanding (in shares)	0	0

Supplemental Segment Informat_2

Supplemental Segment Information (Details)	12 Months Ended
Supplemental Segment Information (Details)	Dec. 31, 2024 segment
Supplemental Segment information
Number of operating segments	1

Supplemental Balance Sheet In_3

Supplemental Balance Sheet Information (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
Other current liabilities
Accrued employee benefits and payroll-related liabilities	$ 136	$ 145
Accrued interest	134	146
Accrued taxes, other than income	39	47
Finance lease liability	$ 47	$ 43
Finance Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration]	Total other current liabilities	Total other current liabilities
Operating lease liabilities	$ 7	$ 12
Operating Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration]	Total other current liabilities	Total other current liabilities
Deferred revenues	$ 231	$ 165
Contingent liabilities	94	116
Other	3	7
Total other current liabilities	691	681
Other long-term liabilities
Postemployment benefit plan obligations	100	121
Finance lease liability	$ 224	$ 276
Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration]	Total other long-term liabilities	Total other long-term liabilities
Operating lease liabilities	$ 88	$ 108
Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration]	Total other long-term liabilities	Total other long-term liabilities
Income taxes payable	$ 65	$ 80
Deferred revenues	212	233
Other	40	40
Total other long-term liabilities	$ 729	$ 858

Supplemental Cash Flow Inform_3

Supplemental Cash Flow Information (Details) - USD ($) shares in Millions, $ in Millions	1 Months Ended						12 Months Ended
	Jun. 30, 2024	Oct. 31, 2023	Sep. 30, 2023	Jul. 31, 2023	Apr. 30, 2023	Sep. 30, 2022	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Changes in other operating assets and liabilities
Increase in accounts receivable							$ (94)	$ (99)	$ (15)
Increase in other assets							(100)	(98)	(12)
Increase (decrease) in accounts payable and other current liabilities							(91)	135	8
Decrease in other long-term liabilities							(2)	(7)	(2)
Change in income taxes receivable / payable, net							(19)	(36)	(42)
Change in receivables from / payables to affiliates, net							9	(8)	(12)
Net change in operating assets and liabilities							(297)	(113)	(75)
Certain cash operating activities
Cash payments for interest							521	408	355
Cash payments for income taxes							60	41	66
Noncash investing and financing activities
Capital additions accrued at end of period							23	36	31
Finance lease installments settled with credits issued to customer							$ 40	$ 44	41
Shares issued in exchanges of exchangeable bonds								434
Warrants issued in exchange transactions									5
Shares issued upon conversion (in shares)		26.5						65.1
Debt issued in exchange transactions									112
Number of warrants issued to subscribe						22.2
Orion/Transocean Norge
Noncash investing and financing activities
Exchange								$ 37
Exchanged
Noncash investing and financing activities
Exchange									110
Warrants issued in exchange transactions									5
Debt issued in exchange transactions									112
2022 Private Exchange
Noncash investing and financing activities
Warrants issued in exchange transactions									$ 5
Number of warrants issued to subscribe						6.7			6.7
4.50% Shipyard Loans due September 2027
Noncash investing and financing activities
Capital additions acquired in exchange for debt									$ 382
Debt instrument face value									439
Debt instrument interest rate stated percentage							4.50%
4.625% Senior Guaranteed Exchangeable Bonds due September 2029
Noncash investing and financing activities
Exchange									105
Shares issued in exchanges of exchangeable bonds							75
Debt instrument face value						$ 188
Debt issued in exchange transactions									$ 112
Debt instrument interest rate stated percentage							4.625%
Number of warrants issued to subscribe						15.5
4.625% Senior Guaranteed Exchangeable Bonds due September 2029 \| 2022 Private Exchange
Noncash investing and financing activities
Debt instrument face value						$ 300
Debt issued in exchange transactions						$ 73
4.00% Senior Guaranteed Exchangeable Bonds due December 2025
Noncash investing and financing activities
Shares issued in exchanges of exchangeable bonds							45
Debt instrument interest rate stated percentage							4%
2.50% Senior Guaranteed Exchangeable Bonds due January 2027
Noncash investing and financing activities
Shares issued upon conversion (in shares)				4	34.6
8.00% Senior Notes due February 2027
Noncash investing and financing activities
Debt instrument interest rate stated percentage							8%
Liquila/Deepwater Aquila
Noncash investing and financing activities
Acquisition of outstanding ownership interests in exchange for shares			$ 99				$ 431	$ 99
Newly issued shares in asset acquisition (in shares)			11.9
Orion/Transocean Norge
Noncash investing and financing activities
Acquisition of outstanding ownership interests in exchange for shares	$ 297
Newly issued shares in asset acquisition (in shares)	55.5
Orion/Transocean Norge \| 8.00% Senior Notes due February 2027
Noncash investing and financing activities
Debt instrument face value	$ 130
Debt instrument interest rate stated percentage	8%

Financial Instruments (Details)

Financial Instruments (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
Financial instruments
Total debt	$ 6,881	$ 7,413
Carrying amount
Financial instruments
Cash and cash equivalents	560	762
Restricted cash and cash equivalents	381	233
Total debt	6,881	7,413
Fair value
Financial instruments
Cash and cash equivalents	560	762
Restricted cash and cash equivalents	381	233
Total debt	$ 6,888	$ 7,308

Risk Concentration (Details)

Risk Concentration (Details)	12 Months Ended
Risk Concentration (Details)	Dec. 31, 2024 employee
Labor Agreements
Number of employees	5,800
Number of employees engaged through contract labor providers	330
Unionized Employees \| Workforce Subject to Collective Bargaining
Labor Agreements
Percentage of concentration	43%

Schedule II - Valuation and Q_2

Schedule II - Valuation and Qualifying Accounts (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Allowance for credit losses
Reserves and allowances deducted from asset accounts
Balance, beginning of period	$ 2	$ 2	$ 2
Additions: charged to cost and expenses		0
Additions: charged to other accounts		0
Deductions		0
Balance, end of period	2	2	2
Allowance for excess materials and supplies
Reserves and allowances deducted from asset accounts
Balance, beginning of period	198	199	183
Additions: charged to cost and expenses	7	6	16
Additions: charged to other accounts		0
Deductions	(27)	(7)
Balance, end of period	178	198	199
Valuation allowance on deferred tax assets
Reserves and allowances deducted from asset accounts
Balance, beginning of period	1,884	1,910	1,820
Additions: charged to cost and expenses	208	0	79
Additions: charged to other accounts		0	11
Deductions	(3)	(26)
Balance, end of period	$ 2,089	$ 1,884	$ 1,910