Supplemental Oil and Natural Gas Disclosure - Unaudited | Geographic Area of Operation All the Partnership’s proved reserves are located within the continental U.S., with the majority concentrated in Texas, Louisiana, and North Dakota. However, the Partnership also owns mineral and royalty interests and non-operated working interests in various producing and non-producing oil and natural gas properties in several other areas throughout the U.S. Therefore, the following disclosures about the Partnership’s costs incurred and proved reserves are presented on a consolidated basis. Costs Incurred in Oil and Natural Gas Property Acquisitions, Exploration, and Development Activities Costs incurred in oil and natural gas property acquisition, exploration and development, whether capitalized or expensed, are presented below: Year Ended December 31, 2023 2022 2021 (in thousands) Acquisition Costs of Properties 1 : Proved $ — $ — $ 4,965 Unproved 14,605 149 15,559 Exploration Costs — — 1,049 Development Costs 1 4,601 11,293 3,964 Total $ 19,206 $ 11,442 $ 25,537 1 Unproved properties include purchases of leasehold prospects. Development costs include costs incurred on farmout wells subject to reimbursement under the Partnership's farmout agreements. See "Note 4 – Oil and Natural Gas Properties" for additional information. Property acquisition costs include costs incurred to purchase, lease, or otherwise acquire a property. Development costs include costs incurred to gain access to and prepare development well locations for drilling, to drill and equip development wells, and to provide facilities to extract, treat, and gather natural gas. Refer below for total capitalized costs and associated accumulated DD&A and impairment. Oil and Natural Gas Capitalized Costs Aggregate capitalized costs related to oil and natural gas production activities with applicable accumulated depreciation, depletion, and amortization, including impairments, are presented below: As of December 31, 2023 2022 (in thousands) Proved properties $ 2,136,056 $ 2,094,563 Unproved properties 890,338 909,344 Total 3,026,394 3,003,907 Accumulated depreciation, depletion, amortization, and impairment (1,961,899) (1,916,919) Oil and natural gas properties, net $ 1,064,495 $ 1,086,988 Oil and Natural Gas Reserve Information The following table sets forth estimated net quantities of the Partnership’s proved, proved developed, and proved undeveloped oil and natural gas reserves. Estimated reserves for the periods presented are based on the unweighted average of first-day-of-the-month commodity prices over the period January through December for the year in accordance with definitions and guidelines set forth by the SEC and the FASB. For estimates of oil reserves, the average WTI spot oil prices used were $78.21, $94.14, and $66.55 per barrel as of December 31, 2023, 2022, and 2021, respectively. These average prices are adjusted for quality, transportation fees, and market differentials. For estimates of natural gas reserves, the average Henry Hub prices used were $2.64, $6.36, and $3.60 per MMBtu as of December 31, 2023, 2022, and 2021, respectively. These average prices are adjusted for energy content, transportation fees, and market differentials. Natural gas prices are also adjusted to account for NGL revenue since there is not sufficient data to account for NGL volumes separately in the reserve estimates. These reserve estimates exclude insignificant natural gas liquid quantities owned by the Partnership. When taking these adjustments into account, the average adjusted prices weighted by production over the remaining lives of the properties were $76.90 per barrel for oil and $2.63 per Mcf for natural gas as of December 31, 2023, $92.01 per barrel for oil and $6.50 per Mcf for natural gas as of December 31, 2022, and $63.17 per barrel for oil and $3.37 per Mcf for natural gas as of December 31, 2021. Crude Oil (MBbl) Natural Gas (MMcf) Total (MBoe) Net proved reserves at December 31, 2020 15,952 240,211 55,987 Revisions of previous estimates 1 4,817 38,537 11,240 Purchases of minerals in place 2 272 216 308 Sales of minerals in place 4 (135) (6,194) (1,167) Extensions, discoveries and other additions 3 1,911 32,592 7,343 Production (3,646) (61,445) (13,886) Net proved reserves at December 31, 2021 19,171 243,917 59,824 Revisions of previous estimates 1 1,422 6,455 2,498 Extensions, discoveries and other additions 3 2,182 78,992 15,347 Production (3,591) (59,778) (13,554) Net proved reserves at December 31, 2022 19,184 269,586 64,115 Revisions of previous estimates 1 675 (20,578) (2,754) Extensions, discoveries and other additions 3 2,989 87,935 17,645 Production (3,757) (64,647) (14,532) Net proved reserves at December 31, 2023 19,091 272,296 64,474 Net Proved Developed Reserves December 31, 2021 19,111 224,222 56,481 December 31, 2022 19,184 236,529 58,606 December 31, 2023 19,091 228,061 57,101 Net Proved Undeveloped Reserves December 31, 2021 60 19,695 3,343 December 31, 2022 — 33,057 5,509 December 31, 2023 — 44,235 7,373 1 Revisions of previous estimates include technical revisions due to changes in commodity prices, historical and projected performance and other factors. The most notable revisions are related to changes in commodity pricing. 2 Includes the acquisition of mineral and royalty reserves. In 2021 these were primarily in the Permian Basin. 3 Includes extensions and additions related to drilling activities in multiple areas, primarily within the Haynesville/Bossier play trend and the Permian Basin. 4 Includes divestitures of mineral and royalty reserves. In 2021 these were primarily in the Anadarko Basin. Standardized Measure of Discounted Future Net Cash Flows Future cash inflows represent expected revenues from production of period-end quantities of proved reserves based on the 12-month unweighted average of first-day-of-the-month commodity prices for the periods presented. All prices are adjusted by field for quality, transportation fees, energy content and regional price differentials. Future cash inflows are computed by applying applicable prices relating to the Partnership’s proved reserves to the year-end quantities of those reserves. Future production, development, site restoration and abandonment costs are derived based on current costs assuming continuation of existing economic conditions. There are no future income tax expenses deducted from future production revenues in the calculation of the standardized measure because the Partnership is not subject to federal income taxes. The Partnership is subject to certain state based taxes; however, these amounts are not material. See "Note 2 – Summary of Significant Accounting Policies" for additional information. Year Ended December 31, 2023 2022 2021 (in thousands) Future cash inflows $ 2,184,038 $ 3,518,494 $ 2,033,256 Future production costs (211,826) (339,603) (206,785) Future development costs (61,723) (49,081) (43,500) Future income tax expense (6,259) (10,535) (6,322) Future net cash flows (undiscounted) 1,904,230 3,119,275 1,776,649 Annual discount 10% for estimated timing (884,720) (1,454,264) (804,527) Total $ 1,019,510 $ 1,665,011 $ 972,122 The following summarizes the principal sources of change in the standardized measure of discounted future net cash flows: Year Ended December 31, 2023 2022 2021 (in thousands) Standardized measure, beginning of year $ 1,665,011 $ 972,122 $ 493,497 Sales, net of production costs (420,228) (692,629) (428,577) Net changes in prices and production costs related to future production (649,695) 773,189 537,659 Extensions, discoveries and improved recovery, net of future production and development costs 295,413 476,342 148,732 Previously estimated development costs incurred during the period — 854 245 Revisions of estimated future development costs (4,221) (1,986) 2,254 Revisions of previous quantity estimates, net of related costs (78,139) 68,270 210,039 Accretion of discount 167,064 97,553 49,530 Purchases of reserves in place, less related costs — — 9,254 Sales of reserves in place — — (1,037) Changes in timing and other 44,305 (28,704) (49,474) Net increase (decrease) in standardized measures (645,501) 692,889 478,625 Standardized measure, end of year $ 1,019,510 $ 1,665,011 $ 972,122 The data presented should not be viewed as representing the expected cash flow from, or current value of, existing proved reserves since the computations are based on a significant amount of estimates and assumptions. The required projection of production and related expenditures over time requires further estimates with respect to pipeline availability, rates of demand and governmental control. Actual future prices and costs are likely to be substantially different from historical prices and costs utilized in the computation of reported amounts. Any analysis or evaluation of the reported amounts should give specific recognition to the computational methods utilized and the limitations inherent therein. |