Zion Oil & Gas (ZNOG) 10-Q 8 Nov 18 2018 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2018	Oct. 29, 2018
Document and Entity Information [Abstract]
Entity Registrant Name	ZION OIL & GAS INC
Entity Central Index Key	1,131,312
Trading Symbol	ZN
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Document Type	10-Q
Document Period End Date	Sep. 30, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q3
Entity Filer Category	Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Ex Transition Period	false
Entity Common Stock Shares Outstanding		64,705,258

Condensed Balance Sheets (Unaud

Condensed Balance Sheets (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Current assets
Cash and cash equivalents	$ 5,318	$ 6,892
Fixed short-term bank deposits - restricted	408	1,197
Prepaid expenses and other	256	434
Other deposits	290	540
Governmental receivables (see Note 8)	719	1,237
Other receivables	278	133
Total current assets	7,269	10,433
Unproved oil and gas properties, full cost method (see Note 4)	34,083	21,695
Property and equipment at cost Net of accumulated depreciation of $443 and $453	164	196
Other assets
Fixed long-term bank deposits - restricted	930	990
Assets held for severance benefits	273	234
Total other assets	1,203	1,224
Total assets	42,719	33,548
Current liabilities
Accounts payable	1,706	2,750
Asset retirement obligation	470	470
Estimated liability for defending legal claims (see Note 7)	500
Derivative liability (see Note 6)	984	1,866
Accrued liabilities	877	1,701
Total current liabilities	4,537	6,787
Long-term liabilities
10% Senior convertible bonds, net of unamortized deferred financing cost of $70 and $90 and unamortized debt discount of $1,047 and $1,267 at September 30, 2018 and December 31, 2017 respectively (see Note 5)	2,152	2,002
Obligation under capital lease, net of current maturities of $10	33	39
Provision for severance pay	327	280
Total long-term liabilities	2,512	2,321
Total liabilities	7,049	9,108
Commitments and contingencies (see Note 7)
Stockholders' equity
Common stock, par value $.01; Authorized: 200,000,000 shares at September 30, 2018: Issued and outstanding: 64,415,398 and 55,888,399 shares at September 30, 2018 and December 31, 2017, respectively	644	559
Additional paid-in capital	202,341	184,485
Accumulated deficit	(167,315)	(160,604)
Total stockholders' equity	35,670	24,440
Total liabilities and stockholders' equity	$ 42,719	$ 33,548

Condensed Balance Sheets (Paren

Condensed Balance Sheets (Parenthetical) (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Balance Sheets [Abstract]
Property and equipment, accumulated depreciation	$ 443	$ 453
Unamortized deferred financing cost, net	70	90
Unamortized debt discount	1,047	1,267
Obligation under capital lease of current maturities	$ 10	$ 10
Common stock, par value	$ 0.01	$ 0.01
Common stock, authorized	200,000,000	200,000,000
Common stock, issued	64,415,398	55,888,399
Common stock, outstanding	64,415,398	55,888,399

Condensed Statements of Operati

Condensed Statements of Operations (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Statements of Operations [Abstract]
General and administrative	$ 2,044	$ 930	$ 5,339	$ 5,010
Other	549	477	1,782	1,927
Loss from operations	(2,593)	(1,407)	(7,121)	(6,937)
Other income (expense), net
Gain, (loss) on derivative liability	3,448	(87)	882	(2,667)
Other income, net				10
Foreign exchange (loss), gain	(10)	(10)	(111)	100
Financial expenses, net	(64)	42	(361)	(314)
Gain (loss) before income taxes	781	(1,462)	(6,711)	(9,808)
Income taxes
Net income (loss)	$ 781	$ (1,462)	$ (6,711)	$ (9,808)
Net (loss) gain per share of common stock
Basic and diluted (in US$)	$ 0.02	$ (0.03)	$ (0.11)	$ (0.20)
Weighted-average shares outstanding
Basic and diluted (in thousands)	61,089	53,382	59,312	50,252

Condensed Statement of Changes

Condensed Statement of Changes in Stockholders' Equity (Unaudited) - 9 months ended Sep. 30, 2018 - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Additional paid-in Capital	Accumulated deficit
Beginning Balances at Dec. 31, 2017	$ 24,440	$ 559	$ 184,485	$ (160,604)
Beginning Balances (in shares) at Dec. 31, 2017		55,888
Funds received from Rights Offering	3,038	$ 7	3,031
Funds received from Rights Offering (in shares)		656
Funds received from sale of DSPP units and shares	12,608	$ 75	12,533
Funds received from sale of DSPP units and shares (in shares)		7,522
Value of bonds converted to shares	175		175
Value of bonds converted to shares (in shares)		40
Bonds interest paid in shares	331	$ 1	330
Bonds interest paid in shares (in shares)		71
Funds received from option exercises	19	$ 2	17
Funds received from option exercises (in shares)		238
Value of options granted to employees, directors and others as non-cash compensation	1,770		1,770
Net loss	(6,711)			(6,711)
Ending Balances at Sep. 30, 2018	$ 35,670	$ 644	$ 202,341	$ (167,315)
Ending Balances (in shares) at Sep. 30, 2018		64,415

Condensed Statements of Cash Fl

Condensed Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Cash flows from operating activities
Net loss	$ (6,711)	$ (9,808)
Adjustments required to reconcile net loss to net cash used in operating activities:
Depreciation	44	35
Capital gain on sale of property and equipment		(10)
Loss on Fixed Asset Disposal	3
Cost of options issued to employees, directors and others as non-cash compensation	1,431	2,418
Amortization of debt discount related to convertible bonds	325	262
Change in derivative liability	(882)	2,667
Change in assets and liabilities, net:
Other deposits	250	(530)
Prepaid expenses and other	178	141
Governmental receivables	518	(29)
Estimated liability for defending legal claims	500
Other receivables	(145)	(1,369)
Severance pay	8	5
Accounts payable	120	(155)
Accrued liabilities	187	(90)
Net cash used in operating activities	(4,174)	(6,463)
Cash flows from investing activities
Acquisition of property and equipment	(15)	(46)
Proceeds from sale of property and equipment		14
Investment in unproved oil and gas properties	(13,893)	(6,424)
Net cash used in investing activities	(13,908)	(6,456)
Cash flows from financing activities
Payments related to capital lease	(6)	(20)
Proceeds from exercise of stock options	19	550
Proceeds from Rights Offering	3,038
Proceeds from issuance of stock and exercise of warrants	12,608	15,353
Net cash provided by financing activities	15,659	15,883
Net (decrease), increase in cash, cash equivalents and restricted cash	(2,423)	2,964
Cash, cash equivalents and restricted cash - beginning of period	9,079	4,487
Cash, cash equivalents and restricted cash - end of period	6,656	7,451
Non-cash investing and financing activities:
Cost of options capitalized to oil & gas properties	339	191
Unpaid investments in oil & gas properties	1,543	3,621
Convertible Bond interest paid in shares	331	346
10% Senior Convertible Bonds converted to shares	175	146
Acquisition of property and equipment under capital lease		71
Capitalized convertible bond interest attributed to oil and gas properties	$ 244	$ 258

Condensed Statements of Cash _2

Condensed Statements of Cash Flows (Unaudited) (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Statements Of Cash Flows [Abstract]
Cash and cash equivalents	$ 5,318	$ 6,892
Restricted cash included in fixed short-term bank deposits	408	1,197
Restricted cash included in fixed long-term bank deposits	930	990
Cash, cash equivalents and restricted cash	$ 6,656	$ 9,079

Nature of Operations, Basis of

Nature of Operations, Basis of Presentation and Going Concern	9 Months Ended
	Sep. 30, 2018
Nature of Operations, Basis of Presentation and Going Concern [Abstract]
Nature of Operations, Basis of Presentation and Going Concern	Note 1 - Nature of Operations, Basis of Presentation and Going Concern A. Nature of Operations Zion Oil & Gas, Inc., a Delaware corporation (“we,” “our,” “Zion” or the “Company”) is an oil and gas exploration company with a history of 18 years of oil & gas exploration in Israel. As of September 30, 2018, the Company has no revenues from its oil and gas operations. Zion maintains its corporate headquarters in Dallas, Texas. We also have branch offices in Caesarea, Israel and Geneva, Switzerland. The purpose of the Israel branch is to support the Company’s operations in Israel, and the purpose of the Switzerland branch is to operate a foreign treasury center for the Company. Exploration Rights/Exploration Activities The Company currently holds one active petroleum exploration license onshore Israel, the Megiddo-Jezreel License, comprising approximately 99,000 acres. The Megiddo Jezreel #1 (“MJ #1”) site was completed in early March 2017, after which the drilling rig and associated equipment were mobilized to the site. Performance and endurance tests were completed, and the MJ #1 exploratory well was spud on June 5, 2017, ahead of the June 30, 2017 deadline under the then-existing license terms. The MJ #1 well has been drilled to a total depth (“TD”) of 5,060 meters (approximately 16,600 feet). Thereafter, the Company obtained three open-hole wireline log suites (including a formation image log) and the well was successfully cased and cemented. The Ministry of Energy approved the well testing protocol on April 29, 2018. Testing of the well is ongoing and the Company expects that testing will be concluded in the fourth quarter of 2018. Depending on the final outcome and results of the current MJ #1 well and having adequate cash resources, multiple wells could be drilled from this pad site as several subsurface geologic targets are reachable using directional well trajectories. Megiddo-Jezreel Petroleum License, No. 401 (“MJL”) The MJL was awarded on December 3, 2013 for a three-year primary term through December 2, 2016, with the possibility of additional one-year extensions up to a maximum of seven years. The MJL lies onshore, south and west of the Sea of Galilee, and the Company continues its exploration focus here as it appears to possess the key geologic ingredients of an active petroleum system with significant exploration potential. In late November 2016, The State of Israel’s Petroleum Commissioner officially approved Zion’s drilling date and license extension request. On October 30, 2017, the Company sought a multi-year extension to its existing license. After receiving feedback from Israel’s Petroleum Commissioner, the Company submitted a revised extension request on November 9, 2017. On November 20, 2017, Israel’s Petroleum Commissioner officially approved the Company’s multi-year extension request on its Megiddo-Jezreel License No. 401, extending its validity to December 2, 2019. Until recently, the Company remained subject to the following updated key license terms: No. Activity Description Execution by: 1 Submit final report on the results of drilling 31 May 2018 2 Submit program for continuation of work under license 30 June 2018 On June 1, 2018, Zion submitted its Megiddo-Jezreel #1 End of Well Report (EOWR) On June 14, 2018 Zion submitted its Application for Extension of Continued Work Program Due Date on the Megiddo-Jezreel License No. 401 No. Activity Description Execution by: 1 Submit program for continuation of work under license 1 November 2018 On October 23, 2018 Zion submitted its Application for Extension of Continued Work Program Due Date on the Megiddo-Jezreel License No. 401 As previously disclosed, the Company required authorization from the Israel Land Authority (the “ILA”), the formal lessor of the land to Kibbutz Sde Eliyahu, on whose property the drilling pad is currently situated, to access and utilize the drill site (“surface use agreement”). The Company received this authorization on July 4, 2016. This was preceded by the Company’s May 15, 2016 signed agreement with the kibbutz. On January 11, 2017, an agreement was signed by the Company and the ILA by which the surface usage permission agreement was extended through December 3, 2017. On December 31, 2017, an agreement was signed by the Company and the ILA by which the surface usage permission agreement was extended through December 3, 2019. Zion’s Former Jordan Valley, Joseph, and Asher-Menashe Licenses On March 29, 2015, the Energy Ministry formally approved the Company’s application to merge the southernmost portion of the Jordan Valley License into the Megiddo-Jezreel License. The Company has plugged all of its exploratory wells (in the former Joseph and Asher-Menashe Licenses) but acknowledges its obligation to complete the abandonment of these well sites in accordance with guidance from the Environmental Ministry and local officials. B. Basis of Presentation The accompanying unaudited interim condensed financial statements of Zion Oil & Gas, Inc. have been prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”) for interim financial information and with Article 8-03 of Regulation S-X. Accordingly, they do not include all of the information and notes required by GAAP for complete financial statements. In the opinion of management, all adjustments, consisting only of normal recurring accruals necessary for a fair statement of financial position, results of operations and cash flows, have been included. The information included in this Quarterly Report on Form 10-Q should be read in conjunction with the financial statements and the accompanying notes included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2017. The year-end balance sheet data presented for comparative purposes was derived from audited financial statements, but does not include all disclosures required by GAAP. The results of operations for the three and nine months ended September 30, 2018 are not necessarily indicative of the operating results for the year ending December 31, 2018 or for any other subsequent interim period. C. Going Concern The Company incurs cash outflows from operations, and all exploration activities and overhead expenses to date have been financed by way of equity or debt financing. The recoverability of the costs incurred to date is uncertain and dependent upon achieving significant commercial production. The Company’s ability to continue as a going concern is dependent upon obtaining the necessary financing to undertake further exploration and development activities and ultimately generating profitable operations from its oil and natural gas interests in the future. The Company’s current operations are dependent upon the adequacy of its current assets to meet its current expenditure requirements and the accuracy of management’s estimates of those requirements. Should those estimates be materially incorrect, the Company’s ability to continue as a going concern may be impaired. The financial statements have been prepared on a going concern basis, which contemplates realization of assets and liquidation of liabilities in the ordinary course of business. During the nine months ended September 30, 2018, the Company incurred a net loss of approximately $6.7 million and had an accumulated deficit of approximately $167 million. These factors raise substantial doubt about the Company’s ability to continue as a going concern. To carry out planned operations, the Company must raise additional funds through additional equity and/or debt issuances or through profitable operations. There can be no assurance that this capital or positive operational income will be available to the Company, and if it is not, the Company may be forced to curtail or cease exploration and development activities. The financial statements do not include any adjustments that might result from the outcome of this uncertainty.

Summary of Significant Accounti

Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2018
Summary of Significant Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Note 2 - Summary of Significant Accounting Policies A. Net Gain (Loss) per Share Data Basic and diluted net (loss) gain per share of common stock, par value $0.01 per share (“Common Stock”), is presented in conformity with ASC 260-10 “Earnings Per Share.” Diluted net loss per share is the same as basic net loss per share, as the inclusion of 9,673,173 and 9,059,091 Common Stock equivalents in the nine-month period ended September 30, 2018 and 2017 respectively, would be anti-dilutive. B. Use of Estimates The preparation of the accompanying financial statements in conformity with accounting principles generally accepted in the United States of America requires management to make estimates and assumptions about future events. These estimates and the underlying assumptions affect the amounts of assets and liabilities reported, disclosures about contingent assets and liabilities, and reported amounts of revenues and expenses. Such estimates include the valuation of unproved oil and gas properties, deferred tax assets, asset retirement obligations and legal contingencies. These estimates and assumptions are based on management’s best estimates and judgment. Management evaluates its estimates and assumptions on an ongoing basis using historical experience and other factors, including the current economic environment, which management believes to be reasonable under the circumstances. The Company adjusts such estimates and assumptions when facts and circumstances dictate. Illiquid credit markets, volatile equity, foreign currency, and energy markets have combined to increase the uncertainty inherent in such estimates and assumptions. As future events and their effects cannot be determined with precision, actual results could differ significantly from these estimates. Changes in those estimates resulting from continuing changes in the economic environment will be reflected in the financial statements in future periods. C. Oil and Gas Properties and Impairment The Company follows the full-cost method of accounting for oil and gas properties. Accordingly, all costs associated with acquisition, exploration and development of oil and gas reserves, including directly related overhead costs, are capitalized. All capitalized costs of oil and gas properties, including the estimated future costs to develop proved reserves, are amortized on the unit-of-production method using estimates of proved reserves. Investments in unproved properties and major development projects are not amortized until proved reserves associated with the projects can be determined or until impairment occurs. If the results of an assessment indicate that the properties are impaired, the amount of the impairment is included in loss from continuing operations before income taxes, and the adjusted carrying amount of the proved properties is amortized on the unit-of-production method. The Company’s oil and gas property represents an investment in unproved properties. These costs are excluded from the amortized cost pool until proved reserves are found or until it is determined that the costs are impaired. All costs excluded are reviewed at least quarterly to determine if impairment has occurred. The amount of any impairment is charged to expense since a reserve base has not yet been established. Impairment requiring a charge to expense may be indicated through evaluation of drilling results, relinquishing drilling rights or other information. During the nine months ended September 30, 2018, and 2017, the Company did not record a non-cash impairment charge of its unproved oil and gas properties (see Note 4). Currently, the Company has no economically recoverable reserves and no amortization base. The Company’s unproved oil and gas properties consist of capitalized exploration costs of $34,083,000 and $21,695,000 as of September 30, 2018, and December 31, 2017, respectively. D. Fair Value Measurements The Company follows Accounting Standards Codification (ASC) 820, “Fair Value Measurements and Disclosures,” as amended by Financial Accounting Standards Board (FASB) Financial Staff Position (FSP) No. 157 and related guidance. Those provisions relate to the Company’s financial assets and liabilities carried at fair value and the fair value disclosures related to financial assets and liabilities. ASC 820 defines fair value, expands related disclosure requirements, and specifies a hierarchy of valuation techniques based on the nature of the inputs used to develop the fair value measures. Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date, assuming the transaction occurs in the principal or most advantageous market for that asset or liability. There are three levels of inputs to fair value measurements - Level 1, meaning the use of quoted prices for identical instruments in active markets; Level 2, meaning the use of quoted prices for similar instruments in active markets or quoted prices for identical or similar instruments in markets that are not active or are directly or indirectly observable; and Level 3, meaning the use of unobservable inputs. The Company uses Level 1 inputs for its fair value measurements whenever there is an active market, with actual quotes, market prices, and observable inputs on the measurement date. The Company uses Level 2 inputs for fair value measurements whenever there are quoted prices for similar securities in an active market or quoted prices for identical securities in an inactive market. The Company uses Level 3 inputs in the Binomial Model used for the valuation of the derivative liability. E. Derivative Liabilities In accordance with ASC 815-40-25 and ASC 815-10-15 Derivatives and Hedging and ASC 480-10-25 Liabilities-Distinguishing Liabilities from Equity, the embedded derivatives associated with the Convertible Bonds are accounted for as a liability during the term of the related Convertible Bonds (see Note 6). F. Stock-Based Compensation ASC 718, “Compensation – Stock Compensation,” prescribes accounting and reporting standards for all share-based payment transactions in which employee services are acquired. Transactions include incurring liabilities, or issuing or offering to issue shares, options, and other equity instruments such as employee stock ownership plans and stock appreciation rights. Share-based payments to employees, including grants of employee stock options, are recognized as compensation expense in the financial statements based on their fair values. That expense is recognized over the period during which an employee is required to provide services in exchange for the award, known as the requisite service period (usually the vesting period). The Company accounts for stock-based compensation issued to non-employees and consultants in accordance with the provisions of ASC 505-50, “Equity – Based Payments to Non-Employees.” Measurement of share-based payment transactions with non-employees is based on the fair value of whichever is more reliably measurable: (a) the goods or services received; or (b) the equity instruments issued. The fair value of the share-based payment transaction is determined at the earlier of performance commitment date or performance completion date. G. Related parties Parties are considered to be related to the Company if the parties, directly or indirectly, through one or more intermediaries, control, are controlled by, or are under common control with the Company. Related parties also include principal owners of the Company, its management, members of the immediate families of principal owners of the Company and its management and other parties with which the Company may deal if one party controls or can significantly influence the management or operating policies of the other to an extent that one of the transacting parties might be prevented from fully pursuing its own separate interests. All transactions with related parties are recorded at fair value of the goods or services exchanged. H. Recently Adopted Accounting Pronouncements ASU 2016-02 – Leases (Topic 842) In February 2016, the Financial Accounting Standards Board (“FASB”) issued ASU 2016-02, Leases (Topic 842) (“ASU 2016-02”) in order to increase transparency and comparability among organizations by recognizing lease assets and lease liabilities on the balance sheet for those leases classified as operating leases under previous GAAP. ASU 2016-02 requires that a lessee should recognize a liability to make lease payments (the lease liability) and a right-of-use asset representing its right to use the underlying asset for the lease term on the balance sheet. ASU 2016-02 is effective for fiscal years beginning after December 15, 2018 (including interim periods within those periods) using a modified retrospective approach and early adoption is permitted. Zion will adopt ASU 2016-02 in the first quarter of 2019. Presently, Zion has operating leases for office space in Dallas, Texas and in Caesarea, Israel plus various leases for motor vehicles, among others. Those leases, and new leases entered in the future, will be accounted for under ASU 2016-02 in 2019 by establishing a right-of-use asset and a corresponding lease liability. Management is in process of evaluating its leases. Although we cannot estimate the dollar value of right-to-use assets and liabilities to be recorded next year, Zion is not subject to any loan covenants and therefore, the expected increase in assets and liabilities is not expected to have a material impact on its business. ASU 2016-15 – Statement of Cash Flows (Topic 230) In August 2016, the FASB issued AS 2016-15, “Classification of Certain Cash Receipts and Cash Payments”, which clarifies how certain cash receipts and cash payments are presented and classified in the statement of cash flows. The effective date for ASU 2016-15 is for fiscal years beginning after December 15, 2018, and interim periods within fiscal years beginning after December 15, 2019. Early adoption is permitted. We are currently evaluating the impact of adopting ASU 2016-15 on our consolidated financial statements. ASU 2016-18 – Statement of Cash Flows (Topic 230) In November 2016, the FASB issued ASU 2016-18, Statement of Cash Flows (Topic 230) (“ASU 2016-18”), which requires that restricted cash and restricted cash equivalents be included with cash and cash equivalents when reconciling the beginning-of-period and end-of-period total cash amounts shown on the statement of cash flows. The effective date for ASU 2016-18 is for fiscal years beginning after December 15, 2017, and interim periods within those fiscal years. Early adoption is permitted. We adopted ASU 2016-18 effective January 1, 2018. The adoption of ASU 2016-18 had no impact on our retained earnings, and no impact to our net income on an ongoing basis. Adoption of the new standard requires that a statement of cash flows explain the change during the period in the total of cash, cash equivalents and amounts generally described as restricted cash, or restricted cash equivalents. The amounts generally described as restricted cash and restricted cash equivalents should be included with cash and cash equivalents when reconciling the beginning-of-period and end-of-period total amounts shown on the statements of cash flows. The amendments have been applied using a retrospective transition method to each period presented, as required. The period ended September 30, 2018 has been reclassified to reflect this change. ASU 2018-01 – Leases (Topic 842) In January 2018, the FASB issued ASU 2018-01, “Land Easement Practical Expedient for Transition to “Topic 842.” The amendments in this Update provide an optional transition practical expedient to not evaluate under Topic 842 existing or expired land easements that were not previously accounted for as leases under Topic 840, Leases. An entity that elects this practical expedient should evaluate new or modified land easements under Topic 842 beginning at the date that the entity adopts Topic 842. An entity that does not elect this practical expedient should evaluate all existing or expired land easements in connection with the adoption of the new lease requirements in Topic 842 to assess whether they meet the definition of a lease. We are currently evaluating the impact of adopting ASU 2018-01 on our consolidated financial statements. ASU 2018-05 – Income Taxes (Topic 740) In March 2018, the FASB issued ASU 2018-05, “Amendments to SEC Paragraphs Pursuant to SEC Staff Accounting Bulletin No. 118”. This ASU expresses the view of the staff regarding application of Topic 740, Income Taxes, in the reporting period that includes December 22, 2017, the date on which the Tax Cuts and Jobs Act (H.R.1, An Act to Provide for Reconciliation Pursuant to Titles II and V of the Concurrent Resolution on the Budget for Fiscal Year 2018) was signed into law. We are currently evaluating the impact of adopting ASU 2018-05 on our consolidated financial statements. ASU 2016-15 In August 2016, the FASB issued ASU 2016-15, Classification of Certain Cash Receipts and Cash Payments, which clarifies how certain cash receipts and cash payments are presented and classified in the statement of cash flows. The effective date for ASU 2016-15 is for fiscal years beginning after December 15, 2018, and interim periods within fiscal years beginning after December 15, 2019. Early adoption is permitted. We are currently evaluating the impact of adopting ASU 2016-18 on our consolidated financial statements. ASU 2016-09 In March 2016, the FASB issued ASU No. 2016-09, Compensation – Stock Compensation, or ASU No. 2016-09. The areas for simplification in this Update involve several aspects of the accounting for share-based payment transactions, including the income tax consequences, classification of awards as either equity or liabilities, and classification on the statement of cash flows. For public entities, the amendments in this Update are effective for annual periods beginning after December 15, 2016, and interim periods within those annual periods. Early adoption is permitted in any interim or annual period. If an entity early adopts the amendments in an interim period, any adjustments should be reflected as of the beginning of the fiscal year that includes that interim period. An entity that elects early adoption must adopt all of the amendments in the same period. Amendments related to the timing of when excess tax benefits are recognized, minimum statutory withholding requirements, forfeitures, and intrinsic value should be applied using a modified retrospective transition method by means of a cumulative-effect adjustment to equity as of the beginning of the period in which the guidance is adopted. Amendments related to the presentation of employee taxes paid on the statement of cash flows when an employer withholds shares to meet the minimum statutory withholding requirement should be applied retrospectively. Amendments requiring recognition of excess tax benefits and tax deficiencies in the income statement and the practical expedient for estimating expected term should be applied prospectively. An entity may elect to apply the amendments related to the presentation of excess tax benefits on the statement of cash flows using either a prospective transition method or a retrospective transition method. We are currently evaluating the impact of adopting ASU No. 2016-09 on our consolidated financial statements.

Stockholders' Equity

Stockholders' Equity	9 Months Ended
	Sep. 30, 2018
Stockholders' Equity [Abstract]
Stockholders' Equity	Note 3 - Stockholders’ Equity A. 2011 Equity Incentive Stock Option Plan During the nine months ended September 30, 2018, the Company granted the following options from the 2011 Equity Incentive Plan for employees, directors and consultants, to purchase as non-cash compensation (the exercise of penny stock options is taxable at full market value on the date of exercise): i. Options to purchase 330,000 shares of Common Stock to 23 senior officers, staff members and consultants at an exercise price of $.01 per share. The options have vesting schedules of 165,000 shares on June 30, 2018 and 165,000 shares on December 31, 2018. The options are exercisable through January 1, 2028. The fair value of the options at the date of grant amounted to approximately $759,000. ii. Options to purchase 110,000 shares of Common Stock to five senior officers at an exercise price of $0.01 per share. The options vested upon grant and are exercisable through January 4, 2028. The fair value of the options at the date of grant amounted to approximately $250,000. iii. Options to purchase 55,000 shares of Common Stock to three consultants at an exercise price of $0.01 per share. The options vested upon grant and are exercisable through March 1, 2028. However, the exercisability of these options is subject to the following schedule: (a) 27,500 options are exercisable on June 30, 2018 and (b) the remaining 27,500 options are exercisable on June 30, 2019. The fair value of the options at the date of grant amounted to $222,000. iv. Options to purchase 14,000 shares of Common Stock to seven staff members at an exercise price of $0.01 per share. The options vested upon grant and are exercisable through April 5, 2028. The fair value of the options at the date of grant amounted to approximately $62,000. v. Options to purchase 10,000 shares of Common Stock to one staff member at an exercise price of $0.01 per share. The options vested upon grant and are exercisable through September 1, 2028. The fair value of the options at the date of grant amounted to approximately $18,000. B. 2011 Non-Employee Directors Stock Option Plan During the nine months ended September 30, 2018, the Company granted the following qualified (market value) options from the 2011 Non-Employee Directors Stock Option Plan for directors to purchase as non-cash compensation: i. Options to purchase 400,000 shares of Common Stock to eight board members at an exercise price of $2.31 per share. The options vested upon grant and are exercisable through January 1, 2024. The fair value of the options at the date of grant amounted to approximately $428,000. ii. Options to purchase 25,000 shares of Common Stock to one board member at an exercise price of $4.15 per share. The options vested upon grant and are exercisable through July 2, 2024. The fair value of the options at the date of grant amounted to approximately $55,000. iii. Options to purchase 25,000 shares of Common Stock to one board member at an exercise price of $1.78 per share. The options vested upon grant and are exercisable through September 4, 2024. The fair value of the options at the date of grant amounted to approximately $25,000. C. Stock Options The stock option transactions since January 1, 2018 are shown in the table below: Number of shares Weighted Average exercise price US$ Outstanding, December 31, 2017 4,339,443 1.37 Changes during 2018 to: Granted to employees, officers, directors and others * 969,000 1.11 Expired/Cancelled/Forfeited (90,000 ) 1.84 Exercised (237,500 ) 0.08 Outstanding, September 30, 2018 4,980,943 1.37 Exercisable, September 30, 2018 4,778,443 1.41 * The receipt of a stock option grant by the grantee recipient is a non-taxable event according to the Internal Revenue Service. The grantee who later chooses to exercise penny stock options must recognize the market value in income in the year of exercise. The following table summarizes information about stock options outstanding as of September 30, 2018: Shares underlying outstanding options (non-vested) Shares underlying outstanding options (fully vested) Range of exercise price Number outstanding Weighted average remaining contractual life (years) Weighted Average Exercise price Range of exercise price Number Outstanding Weighted average remaining contractual life (years) Weighted Average Exercise price US$ US$ US$ US$ — — — — 0.01 15,000 5.12 0.01 — — — — 0.01 15,000 5.50 0.01 — — — — 0.01 5,000 5.70 0.01 — — — — 0.01 10,000 7.00 0.01 — — — — 0.01 25,000 7.25 0.01 — — — — 0.01 305,000 7.67 0.01 — — — — 0.01 25,000 8.25 0.01 — — — — 0.01 500,000 8.25 0.01 — — — — 0.01 10,000 8.26 0.01 — — — — 0.01 60,000 8.54 0.01 0.01 10,000 9.00 0.01 0.01 30,000 9.00 0.01 0.01 147,500 9.25 0.01 0.01 *122,500 9.25 0.01 — — — — 0.01 **45,000 9.41 0.01 — — — — 0.01 110,000 9.26 0.01 — — — — 0.01 6,000 9.77 0.01 — — — — 0.01 10,000 9.92 0.01 — — — — 1.33 25,000 4.58 1.33 — — — — 1.38 108,000 2.26 1.38 — — — — 1.38 123,057 6.26 1.38 — — — — 1.55 400,000 3.68 1.55 — — — — 1.67 340,000 2.00 1.67 — — — — 1.67 448,886 6.01 1.67 — — — — 1.70 120,000 0.22 1.70 — — — — 1.70 283,500 4.22 1.70 — — — — 1.73 25,000 0.28 1.73 — — — — 1.75 400,000 4.77 1.70 — — — — 1.78 25,000 5.93 1.86 — — — — 1.86 25,000 0.18 1.86 — — — — 1.87 25,000 3.34 1.87 — — — — 1.95 25,000 1.50 1.95 — — — — 1.96 25,000 0.93 1.96 — — — — 2.03 25,000 2.59 2.03 — — — — 2.31 400,000 5.26 2.31 — — — — 2.61 681,500 3.18 2.61 — — — — 4.15 25,000 5.76 4.15 0.01 157,500 0.01 0.01-2.61 4,823,443 1.41 * 17,500 are exercisable on December 31, 2018. ** 27,500 are exercisable on September 30, 2019. Granted to employees The following table sets forth information about the weighted-average fair value of options granted to employees and directors during the year, using the Black Scholes option-pricing model and the weighted-average assumptions used for such grants: For the nine months ended September 30, 2018 2017 Weighted-average fair value of underlying stock at grant date $ 2.37 $ 1.42 Dividend yields — — Expected volatility 68%-87 % 45%-69 % Risk-free interest rates 2.01%-2.74 % 1.45%-1.94 % Expected lives (in years) 3.00-5.50 3.00-5.00 Weighted-average grant date fair value $ 1.61 $ 1.20 Granted to non-employees The following table sets forth information about the weighted-average fair value of options granted to non-employees during the year, using the Black Scholes option-pricing model and the weighted-average assumptions used for such grants: For the nine months ended September 30, 2018 2017 Weighted-average fair value of underlying stock at grant date $ 3.37 $ 1.36 Dividend yields — — Expected volatility 73%-76 % 68 % Risk-free interest rates 2.46%-2.81 % 2.36%-2.45 % Expected lives (in years) 10.00 10.00 Weighted-average grant date fair value $ 3.36 $ 1.36 The risk-free interest rate is based on the U.S. Treasury yield curve in effect at the time of grant for periods corresponding with the expected life of the options. The expected life represents the weighted average period of time that options granted are expected to be outstanding. The expected life of the options granted to employees and directors is calculated based on the Simplified Method as allowed under Staff Accounting Bulletin No. 110 (“SAB 110”), giving consideration to the contractual term of the options and their vesting schedules, as the Company does not have sufficient historical exercise data at this time. The expected life of the option granted to non-employees equals their contractual term. In the case of an extension of the option life, the calculation was made on the basis of the extended life. D. Compensation Cost for Warrant and Option Issuances The following table sets forth information about the compensation cost of warrant and option issuances recognized for employees and directors: For the nine months ended September 30, 2018 2017 US$ thousands US$ thousands 1,468 2,399 The following table sets forth information about the compensation cost of warrant and option issuances recognized for non-employees: For the nine months ended September 30, 2018 2017 US$ thousands US$ thousands 302 210 The following table sets forth information about the compensation cost of option issuances recognized for employees and non-employees and capitalized to Unproved Oil & Gas properties: For the nine months ended September 30, 2018 2017 US$ thousands US$ thousands 339 191 As of September 30, 2018, there was approximately $101,000 of unrecognized compensation cost, related to non-vested stock options granted under the Company’s various stock option plans. The cost is expected to be recognized during the years 2018 and 2019. E. Dividend Reinvestment and Stock Purchase Plan (“DSPP”) On March 27, 2014, the Company launched its Dividend Reinvestment and Stock Purchase Plan (the “DSPP”) pursuant to which stockholders and interested investors can purchase shares of the Company’s Common Stock as well as units of the Company’s securities directly from the Company. The terms of the DSPP are described in the Prospectus Supplement originally filed on March 31, 2014 (the “Original Prospectus Supplement”) with the Securities and Exchange Commission (“SEC”) under the Company’s effective registration Statement on Form S-3, as thereafter amended. On January 13, 2015, the Company amended the Original Prospectus Supplement (“Amendment No. 3”) to provide for a unit option (the “Unit Option”) under the DSPP comprised of one share of Common Stock and three Common Stock purchase warrants with each unit priced at $4.00. Each warrant afforded the participant the opportunity to purchase the Company’s Common Stock at a warrant exercise price of $1.00. Each of the three warrants series has different expiration dates that have been extended. The warrants became exercisable on May 2, 2016 and, in the case of ZNWAB continued to be exercisable through May 2, 2017 (1 year) and, in the case of ZNWAC continued to be exercisable through May 2, 2018 for ZNWAC (2 years) and May 2, 2019 for ZNWAD (3 years), respectively, at a per share exercise price of $1.00. As of May 2, 2017, any outstanding ZNWAB warrants expired. As of May 2, 2018, any outstanding ZNWAC warrants expired. On November 1, 2016, the Company launched a unit offering (the “Unit Program”) under the Company’s DSPP pursuant to which participants could purchase units comprised of seven shares of Common Stock and seven Common Stock purchase warrants, at a per unit purchase price of $10. The warrant is referred to as “ZNWAE.” The ZNWAE warrants became exercisable on May 1, 2017 and continue to be exercisable through May 1, 2020 at a per share exercise price of $1.00. The warrant terms provide that if the Company’s Common Stock trades above $5.00 per share at the closing price for 15 consecutive trading days at any time prior to the expiration date of the warrant, the Company may, in its sole discretion, accelerate the termination of the warrant upon providing 60 days advanced notice to the warrant holders. On February 23, 2017, the Company filed a Form S-3 with the SEC (Registration No. 333-216191) as a replacement for the Form S-3 (Registration No. 333-193336), along with the base Prospectus and Supplemental Prospectus. The Form S-3, as amended, and the new base Prospectus became effective on March 10, 2017, along with the Prospectus Supplement that was filed and became effective on March 10, 2017. The Prospectus Supplement under Registration No. 333-216191 describes the terms of the DSPP and replaces the prior Prospectus Supplement, as amended, under the prior Registration No. 333-193336. On May 22, 2017, the Company launched a new unit offering (the “New Unit Program”). The New Unit Program consisted of a new combination of common stock and warrants, a new time period in which to purchase under the program, and a new unit price, but otherwise the same unit program features, conditions and terms in the Prospectus Supplement applied. The New Unit Program terminated on July 12, 2017. This New Unit Program enabled participants to purchase Units of the Company’s securities where each Unit (priced at $250.00 each) was comprised of (i) the number of shares of Common Stock determined by dividing $250.00 (the price of one Unit) by the average of the high and low sale prices of the Company’s Common Stock as reported on the NASDAQ on the unit purchase date and (ii) Common Stock purchase warrants to purchase an additional 25 shares of Common Stock at a warrant exercise price of $1.00 per share. The warrant is referred to as "ZNWAF.” All ZNWAF warrants became exercisable on August 14, 2017 and continue to be exercisable through August 14, 2020 at a per share exercise price of $1.00. The warrant terms provide that if the Company’s Common Stock trades above $5.00 per share as the closing price for 15 consecutive trading days at any time prior to the expiration date of the warrant, the Company has the sole discretion to accelerate the termination date of the warrant upon providing 60 days advanced notice to the warrant holders. On October 16, 2017, the Company initiated another Unit Option Program which terminated on December 6, 2017. This Unit Option Program enabled participants to purchase Units of the Company’s securities where each Unit (priced at $250.00 each) was comprised of (i) a certain number of shares of Common Stock determined by dividing $250.00 (the price of one Unit) by the average of the high and low sale prices of the Company’s Common Stock as reported on the NASDAQ on the unit purchase date and (ii) Common Stock purchase warrants to purchase an additional 15 shares of Common Stock at a warrant exercise price of $1.00 per share. The warrant is referred to as “ZNWAG.” The warrants became exercisable on January 8, 2018 and continue to be exercisable through January 8, 2021 at a per share exercise price of $1.00. The warrant terms provide that if the Company’s Common Stock trades above $5.00 per share as the closing price for 15 consecutive trading days at any time prior to the expiration date of the warrant, the Company has the sole discretion to accelerate the termination date of the warrant upon providing 60 days advanced notice to the warrant holders. On February 1, 2018, the Company initiated another Unit Option Program which terminated on February 28, 2018. The Unit Option consisted of Units of our securities where each Unit (priced at $250.00 each) was comprised of (i) 50 shares of Common Stock and (ii) Common Stock purchase warrants to purchase an additional 50 shares of Common Stock. The investor’s Plan account was credited with the number of shares of the Company’s Common Stock acquired under the Units purchased. Each warrant affords the investor the opportunity to purchase one share of Company Common Stock at a warrant exercise price of $5.00. The warrant is referred to as “ZNWAH.” The warrants became exercisable on April 2, 2018 and continue to be exercisable through April 2, 2019 at a per share exercise price of $5.00. On August 21, 2018, the Company’s most recent Unit Option began and terminated on September 26, 2018. The Unit Option consisted of Units of the Company's securities where each Unit (priced at $250.00 each) was comprised of (i) a certain number of shares of Common Stock determined by dividing $250.00 (the price of one Unit) by the average of the high and low sale prices of the Company’s publicly traded common stock as reported on the NASDAQ on the Unit Purchase Date and (ii) Common Stock purchase warrants to purchase an additional twenty-five (25) shares of Common Stock. The investor’s Plan account was credited with the number of shares of the Company’s Common Stock acquired under the Units purchased. Each warrant affords the investor the opportunity to purchase one share of Company Common Stock at a warrant exercise price of $1.00. The warrant is referred to as “ZNWAJ.” The warrants became exercisable on October 29, 2018 and continue to be exercisable through October 29, 2019 at a per share exercise price of $1.00. For the nine months ended September 30, 2018, net proceeds of approximately $12,608,000 was raised under the DSPP program. The warrants represented by the ticker ZNWAA are tradable on the NASDAQ market. However, all of the other warrants characterized above, in the table below, and throughout this Form 10-Q, are not tradeable and are used internally for classification and accounting purposes only. E. Warrant Descriptions The price and the expiration dates for the series of warrants to investors are as follows * : Period of Grant US$ Expiration Date ZNWAA Warrants March 2013 – December 2014 2.00 January 31, 2020 ZNWAD Warrants January 2015 – March 2016 1.00 May 02, 2019 ZNWAE Warrants November 2016 – March 2017 1.00 May 01, 2020 ZNWAF Warrants May 2017 – July 2017 1.00 August 14, 2020 ZNWAG Warrants October 2017 – December 2017 1.00 January 08, 2021 ZNWAH Warrants February 2018 5.00 April 2, 2019 ZNWAI Warrants April 2018 – May 2018 3.00 June 29, 2019 ZNWAJ Warrants August 2018 – September 2018 1.00 October 29, 2019 * Zion’s ZNWAB Warrants expired on May 2, 2017 and its ZNWAC Warrants expired on May 2, 2018 F. Subscription Rights Offering On April 2, 2018 the Company announced an offering (“2018 Subscription Rights Offering”) through American Stock Transfer & Trust Company, LLC (the “Subscription Agent”), at no cost to the shareholders, of non-transferable Subscription Rights to purchase Rights (each “Right” and collectively, the “Rights”) of its securities to persons who owned shares of our Common Stock on April 13, 2018 (“the Record Date”). Pursuant to the 2018 Subscription Rights Offering, each holder of shares of common stock on the Record Date received non-transferable rights to subscribe for Rights, with each Right comprised of one share of the Company Common Stock, par value $0.01 per share (the “Common Stock”) and one Common Stock Purchase Warrant to purchase an additional one share of Common Stock. Each Right may be purchased at a per Right subscription price of $5.00. Each Warrant affords the investor the opportunity to purchase one share of the Company Common Stock at a warrant exercise price of $3.00. The warrants became exercisable on June 29, 2018 and will continue to be exercisable for one year thereafter. The warrant has the symbol “ZNWAI.” Each shareholder received .10 (one tenth) of a subscription right (i.e. one subscription right for each 10 shares owned) for each share of the Company’s Common Stock owned on the Record Date. The 2018 Subscription Rights Offering terminated on May 31, 2018. The Company raised net proceeds of approximately $3,038,000, from the sale of the Rights, after deducting fees and expenses of $243,000 incurred in connection with the rights offering. G. Warrant Table The warrant transactions since January 1, 2018 are shown in the table below: ZNWAA ZNWAC ZNWAD ZNWAE ZNWAF ZNWAG ZNWAH ZNWAI ZNWAJ Total Outstanding warrants, December 31, 2017 1,524,617 275,152 294,334 3,028,119 460,231 414,300 - - - 5,996,753 Exercise Price $ 2.00 $ 1.00 $ 1.00 $ 1.00 $ 1.00 $ 1.00 $ 5.00 $ 3.00 1.00 Warrant Termination Date 1/31/2020 5/2/2018 5/2/2019 5/2/2020 8/14/2020 1/8/2021 4/19/2019 6/29/2019 10/29/2019 Change during 2018 to: Issued - - - 10,493 50 30 373,400 656,274 483,050 1,523,297 Exercised (25,813 ) (196,913 ) (48,781 ) (894,002 ) (100,621 ) (173,512 ) (1,000 ) (15,439 ) - (1,456,081 ) Expired - (78,239 ) - - - - - - - (78,239 ) Outstanding and exercisable warrants, September 30, 2018 1,498,804 - 245,553 2,144,610 359,660 240,818 372,400 640,835 483,050 5,985,730

Unproved Oil and Gas Properties

Unproved Oil and Gas Properties, Full Cost Method	9 Months Ended
	Sep. 30, 2018
Unproved Oil and Gas Properties, Full Cost Method [Abstract]
Unproved Oil and Gas Properties, Full Cost Method	Note 4 - Unproved Oil and Gas Properties, Full Cost Method Unproved oil and gas properties, under the full cost method, are comprised as follows: September 30, 2018 December 31, 2017 US$ thousands US$ thousands Excluded from amortization base: Drilling costs, and other operational related costs 25,537 14,999 Capitalized salary costs 2,524 2,034 Capitalized interest costs 590 346 Legal costs, license fees and other preparation costs 5,054 4,087 Other costs 378 229 *34,083 21,695 * The unproved oil and gas properties balance at September 30, 2018 contains approximately $1,543,000 in unpaid amounts. Changes in Unproved oil and gas properties during the nine months ended September 30, 2018 and 2017 are as follows: September 30, 2018 September 30, 2017 US$ thousands US$ thousands Excluded from amortization base: Drilling costs, and other operational related costs 10,538 8,961 Capitalized salary costs 490 357 Capitalized interest costs 244 258 Legal costs, license fees and other preparation costs 967 820 Other costs 149 98 *12,388 *10,494 * Inclusive of non-cash amounts of approximately $2,126,000 and $4,070,000 during the nine months ended September 30, 2018, and 2017, respectively.

Senior Convertible Bonds

Senior Convertible Bonds	9 Months Ended
	Sep. 30, 2018
Senior Convertible Bonds [Abstract]
Senior Convertible Bonds	Note 5 - Senior Convertible Bonds Rights Offering -10% Senior Convertible Notes due May 2, 2021 On October 21, 2015, the Company filed with the SEC a prospectus supplement for a rights offering. Under the rights offering, the Company distributed at no cost, 360,000 non-transferable subscription rights to subscribe for, on a per right basis, two 10% Convertible Senior Bonds par $100 due May 2, 2021 (the “Notes”), to shareholders of the Company’s Common Stock on October 15, 2015, the record date for the offering. Each whole subscription right entitled the participant to purchase two convertible bonds at a purchase price of $100 per bond. Effective October 21, 2015, the Company executed a Supplemental Indenture, as issuer, with the American Stock Transfer & Trust Company, LLC, a New York limited liability trust company (“AST”), as trustee for the Notes (the “Indenture”). On March 31, 2016, the rights offering terminated. On May 2, 2016, the Company issued approximately $3,470,000 aggregate principal amount of Notes in connection with the rights offering. The Company received net proceeds of approximately $3,334,000, from the sale of the Notes, after deducting fees and expenses of $136,000 incurred in connection with the offering. These costs have been discounted as deferred offering costs. The Notes contain a convertible option that gives rise to a derivative liability, which is accounted for separately from the Notes (see below and Note 6). Accordingly, the Notes were initially recognized at fair value of approximately $1,844,000, which represents the principal amount of $3,470,000 from which a debt discount of approximately $1,626,000 (which is equal to the fair value of the convertible option) was deducted. During the nine months ended September 30, 2018, the Company recorded approximately $20,000 in amortization expense related to the deferred financing costs, approximately $220,000 in debt discount amortization, and approximately $85,000 related to financing costs associated with notes converted to shares. The Notes are governed by the terms of the Indenture. The Notes are senior unsecured obligations of the Company and bear interest at a rate of 10% per year, payable annually in arrears on May 2 of each year, commencing May 2, 2017. The Notes will mature on May 2, 2021, unless earlier redeemed by the Company or converted by the holder. Interest and principal may be paid, at the Company’s option, in cash or in shares of the Company’s Common Stock. The number of shares for the payment of interest in shares of Common Stock, in lieu of the cash amount, will be based on the average of the closing prices of the Company’s Common Stock as reported by Bloomberg L.P. for the 30 trading days preceding the record date for the payment of interest; such record date has been designated and will always be the 10 th On May 2, 2018, the Company paid its annual 10% interest to its bondholders of record on April 18, 2018. The interest was paid-in-kind (“PIK”) in the form of Common Stock. An average of the Company stock price of $4.68 was determined based on the 30 trading days prior to the record date of April 18, 2018. This figure was used to divide into 10% of the par value of the bonds held by the holders. The Company issued 70,780 shares to the accounts of its bondholders. At any time prior to the close of business on the business day immediately preceding April 2, 2021, holders may convert their notes into Common Stock at the conversion rate of 44 shares per $100 bond (which is equivalent to a conversion rate of approximately $2.27 per share). The conversion rate is subject to adjustment from time to time upon the occurrence of certain events, including, but not limited to, the issuance of stock dividends and payment of cash dividends. Beginning May 3, 2018, the Company was entitled to redeem for cash the outstanding Notes at an amount equal to the principal and accrued and unpaid interest, plus a 10% premium. No “sinking fund” is provided for the Notes due May 2021, which means that the Company is not required to periodically redeem or retire the Notes due May 2021. Through the nine months ended September 30, 2018 approximately 900 convertible bonds of $100 each, have been converted under this offering at a conversion rate of approximately $2.27 per share. As a result, the Company issued approximately 40,000 shares of its Common Stock and recorded approximately $85,000 in financial expenses during the same period. September 30, December 31, US$ US$ 10% Senior Convertible Bonds, on the day of issuance $ 3,470 $ 3,470 Unamortized Debt discount, net $ (1,047 ) $ (1,267 ) Bonds converted to shares $ (201 ) $ (111 ) Offering cost, net $ (70 ) $ (90 ) 10% senior Convertible bonds – Long Term Liability $ 2,152 $ 2,002 The Company recognized $244,000 in capitalized interest for the nine months ended September 30, 2018.

Derivative Liability

Derivative Liability	9 Months Ended
	Sep. 30, 2018
Derivative Liability [Abstract]
Derivative Liability	Note 6 - Derivative Liability The Notes issued by the Company and discussed in Note 5 contain a convertible option that gives rise to a derivative liability. The debt instrument the Company issued includes a make-whole provision, which provides that in the event of conversion by the investor under certain circumstances, the issuer is required to deliver to the holder additional consideration beyond the settlement of the conversion obligation. Because time value make-whole provisions are not clearly and closely related to the debt host and would meet the definition of a derivative if considered freestanding, they should be evaluated under the indexation guidance to determine whether they would be afforded the scope exception pursuant to ASC 815-10-15-74(a). This evaluation is generally performed in conjunction with the analysis of the embedded conversion feature. The Company has measured its derivative liability at fair value and recognized the derivative value as a current liability and recorded the derivative value on its balance sheet. The fair value of the shares to be issued upon conversion of the Notes was recorded as a derivative liability, with the change in the fair value recorded as a gain or loss in the accompanying statement of operations. The valuation of the Notes was done by using the Binomial Model, a well-accepted option-pricing model, and based on the Notes’ terms and other parameters the Company identified as relevant for the valuation of the Notes’ Fair Value. The Binomial Model used the forecast of the Company share price during the Note’s contractual term. As of September 30, 2018, the Company’s liabilities that are measured at fair value are as follows: September 30, 2018 December 31, 2017 Level 3 Total Level 3 Total US$ thousands US$ thousands US$ thousands US$ thousands Fair value of derivative liability 984 984 1,866 1,866 Change in value of derivative liability during 2018 are as follows: US$ thousands Derivative liability fair value at December 31, 2017 1,866 Gain on derivative liability 882 Derivative liability fair value at September 30, 2018 984 The following table presents the assumptions that were used for the model as of September 30, 2018: September 30, 2018 December 31, 2017 Convertible Option Fair Value of approximately $ 984,000 $ 1,866,000 Annual Risk-free Rate 2.85 % 2.03 % Volatility 92.71 % 68.04 % Expected Term (years) 2.59 3.34 Convertible Notes Face Value $ 3,268,900 $ 3,358,900 Expected annual yield on Regular Notes 28.77 % 28.77 % Price of the Underlying Stock $ 1.28 $ 2.16 During the nine months ended September 30, 2018, the Company recorded a gain of approximately $984,000 (net) within the Statements of Operations line item, (loss) gain on derivative liability. A slight change in an unobservable input like volatility could have a significant impact on the fair value measurement of the derivative liability.

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2018
Commitments and Contingencies [Abstract]
Commitments and Contingencies	Note 7 - Commitments and Contingencies A. Securities and Exchange Commission (“SEC”) Investigation As previously disclosed by the Company, on June 21, 2018, Zion received a subpoena to produce documents from the Fort Worth office of the SEC informing the Company of the existence of a non-public, fact-finding inquiry into the Company. Prior to the receipt of the subpoena on June 21, 2018, Zion had no previous communication with the SEC on this issue and was unaware of this investigation. The SEC stated that “the investigation and the subpoena do not mean that we have concluded that [Zion] or anyone else has violated the law.” To date, Zion has furnished all required documents to the SEC in response to the subpoena and will continue to fully cooperate with the investigation. The Company cannot predict when this matter will be resolved or what further action, if any, the SEC may take in connection with it. B. Litigation Following the commencement of the SEC investigation, on August 9, 2018, a putative class action Complaint was filed against Zion, Victor G. Carrillo, the Company’s Chief Executive Officer at such time, and Michael B. Croswell Jr., the Company’s Chief Financial Officer (collectively, the “Defendants”) in the U.S. District Court for the Northern District of Texas. The suit alleges violations of Section 10(b) of the Securities Exchange Act and Rule 10b-5 promulgated thereunder by the SEC against all defendants and alleges violations of Section 20(a) of the Exchange Act against the individual defendants in connection certain with public statements defendants made from March 12, 2018 to May 30, 2018 and claims unspecified losses to the putative class and fees and costs. On September 10, 2018, two lawsuits were filed in federal district court in Delaware derivatively and purportedly on behalf of the Company against Victor G. Carrillo, Michael B. Croswell, Jr., John M. Brown, Dustin L. Guinn, Forrest A. Garb, Kent S. Siegel, Paul Oroian, William H. Avery, the Estate of Yehezkel Druckman, Lee Russell, Justin W. Furnace, Gene Scammahorn, Ralph F. DeVore, Martin M. van Brauman (collectively, the “Derivative Defandants”), and the Company as a nominal defendant. One of the two lawsuits was voluntarily dismissed shortly thereafter. The remaining suit alleges violations of Section 14(a) of the Securities Exchange Act of 1934 based solely on negligence claims for breaches of fiduciary duty and unjust enrichment against the individual defendants in connection with certain public statements made by the Company from March 12, 2018 to May 30, 2018. On September 25, 2018, another lawsuit was filed in the 68 th . Croswell, Jr., Dustin L. Guinn, Victor G. Carrillo, Paul Oroian, William H. Avery, Justin W. Furnace, Gene Scammahorn, Martin M. van Brauman, and Lee R. Russell. This suit alleges claims for breaches of fiduciary duty and unjust enrichment against the individual defendants in connection with certain public statements made by the Company from March 12, 2018 to May 30, 2018. On November 1, 2018, another lawsuit was filed against the Derivative Defendants in federal district court in Delaware derivatively and purportedly on behalf of the Company. This suit alleges violations of Section 14(a) of the Securities Exchange Act of 1934 based solely on negligence and claims for breaches of fiduciary duty and unjust enrichment against the individual defendants in connection with certain public statements made by the Company from March 12, 2018 to June 11, 2018. These derivative suits seek unspecified damages to be awarded to the Company, orders directing the Company and individual defendants to make certain corporate governance reforms, restitution, and fees and costs. On October 29, 2018, Zion received a shareholder request to inspect books and records pursuant to Section 220 of the Delaware General Corporation Law for the purpose of investigating potential corporate mismanagement and breaches of fiduciary duty in connection with public statements made by the Company from March 12, 2018 to May 30, 2018. The Company disputes the above claims and has accrued an estimated loss of $500,000 for the cost of defending the litigation. The Company carries insurance that is applicable to these claims. Because of the uncertainties of litigation, it is not feasible to predict or determine the outcome of these matters, to guarantee that there will be no liability, or to reasonably estimate any loss in excess of the accrual. However, the Company intends to pursue a vigorous defense to the claims. From time to time, the Company may also be subject to routine litigation, claims or disputes in the ordinary course of business. The Company defends itself vigorously in all such matters. However, we cannot predict the outcome or effect of any of the litigation or any other pending litigation or claims. C. Environmental and Onshore Licensing Regulatory Matters The Company is engaged in oil and gas exploration and production and may become subject to certain liabilities as they relate to environmental cleanup of well sites or other environmental restoration procedures and other obligations as they relate to the drilling of oil and gas wells or the operation thereof. Various guidelines have been published in Israel by the State of Israel’s Petroleum Commissioner and Energy and Environmental Ministries as it pertains to oil and gas activities. Mention of these older guidelines was included in previous Zion Oil & Gas filings. On December 27, 2017, the Energy Ministry published a document entitled The Petroleum Commissioner’s Guidelines for Approving a Discovery. The Company acknowledges that these new regulations are likely to increase both the time and the expenditures associated with obtaining new exploration rights and drilling new wells. D. Bank Guarantees As of September 30, 2018, the Company provided Israeli-required bank guarantees to various governmental bodies (approximately $1,245,000) and others (approximately $83,000) with respect to its drilling operation in an aggregate amount of approximately $1,328,000. The (cash) funds backing these guarantees and additional amounts added to support currency fluctuations as required by the bank are held in restricted interest-bearing accounts and are reported on the Company’s balance sheets as fixed short-term bank deposits – restricted, and fixed long-term bank deposits – restricted. E. Risks Market risk is a broad term for the risk of economic loss due to adverse changes in the fair value of a financial instrument. These changes may be the result of various factors, including interest rates, foreign exchange rates, commodity prices and/or equity prices. In the normal course of doing business, we are exposed to the risks associated with foreign currency exchange rates and changes in interest rates. Foreign Currency Exchange Rate Risks. Interest Rate Risk. The primary objective of our investment activities is to preserve principal while at the same time maximizing yields without significantly increasing risk. To achieve this objective, we invest our excess cash in short-term bank deposits and money market funds that may invest in high quality debt instruments.

Governmental Receivables

Governmental Receivables	9 Months Ended
	Sep. 30, 2018
Governmental Receivables [Abstract]
Governmental Receivables	Note 8 - Governmental Receivables At September 30, 2018, governmental receivables included approximately $701,000 due from The State of Israel for VAT refunds and an additional $18,000 from the State of Israel for BLO refunds (excise tax on fuel).

Subsequent Events

Subsequent Events	9 Months Ended
	Sep. 30, 2018
Subsequent Events [Abstract]
Subsequent Events	Note 9 - Subsequent Events (i) Approximately $326,000 was raised through the Company’s DSPP program from October 1 through 30, 2018.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2018
Summary of Significant Accounting Policies [Abstract]
Net Gain (Loss) per Share Data	A. Net Gain (Loss) per Share Data Basic and diluted net (loss) gain per share of common stock, par value $0.01 per share (“Common Stock”), is presented in conformity with ASC 260-10 “Earnings Per Share.” Diluted net loss per share is the same as basic net loss per share, as the inclusion of 9,673,173 and 9,059,091 Common Stock equivalents in the nine-month period ended September 30, 2018 and 2017 respectively, would be anti-dilutive.
Use of Estimates	B. Use of Estimates The preparation of the accompanying financial statements in conformity with accounting principles generally accepted in the United States of America requires management to make estimates and assumptions about future events. These estimates and the underlying assumptions affect the amounts of assets and liabilities reported, disclosures about contingent assets and liabilities, and reported amounts of revenues and expenses. Such estimates include the valuation of unproved oil and gas properties, deferred tax assets, asset retirement obligations and legal contingencies. These estimates and assumptions are based on management’s best estimates and judgment. Management evaluates its estimates and assumptions on an ongoing basis using historical experience and other factors, including the current economic environment, which management believes to be reasonable under the circumstances. The Company adjusts such estimates and assumptions when facts and circumstances dictate. Illiquid credit markets, volatile equity, foreign currency, and energy markets have combined to increase the uncertainty inherent in such estimates and assumptions. As future events and their effects cannot be determined with precision, actual results could differ significantly from these estimates. Changes in those estimates resulting from continuing changes in the economic environment will be reflected in the financial statements in future periods.
Oil and Gas Properties and Impairment	C. Oil and Gas Properties and Impairment The Company follows the full-cost method of accounting for oil and gas properties. Accordingly, all costs associated with acquisition, exploration and development of oil and gas reserves, including directly related overhead costs, are capitalized. All capitalized costs of oil and gas properties, including the estimated future costs to develop proved reserves, are amortized on the unit-of-production method using estimates of proved reserves. Investments in unproved properties and major development projects are not amortized until proved reserves associated with the projects can be determined or until impairment occurs. If the results of an assessment indicate that the properties are impaired, the amount of the impairment is included in loss from continuing operations before income taxes, and the adjusted carrying amount of the proved properties is amortized on the unit-of-production method. The Company’s oil and gas property represents an investment in unproved properties. These costs are excluded from the amortized cost pool until proved reserves are found or until it is determined that the costs are impaired. All costs excluded are reviewed at least quarterly to determine if impairment has occurred. The amount of any impairment is charged to expense since a reserve base has not yet been established. Impairment requiring a charge to expense may be indicated through evaluation of drilling results, relinquishing drilling rights or other information. During the nine months ended September 30, 2018, and 2017, the Company did not record a non-cash impairment charge of its unproved oil and gas properties (see Note 4). Currently, the Company has no economically recoverable reserves and no amortization base. The Company’s unproved oil and gas properties consist of capitalized exploration costs of $34,083,000 and $21,695,000 as of September 30, 2018, and December 31, 2017, respectively.
Fair Value Measurements	D. Fair Value Measurements The Company follows Accounting Standards Codification (ASC) 820, “Fair Value Measurements and Disclosures,” as amended by Financial Accounting Standards Board (FASB) Financial Staff Position (FSP) No. 157 and related guidance. Those provisions relate to the Company’s financial assets and liabilities carried at fair value and the fair value disclosures related to financial assets and liabilities. ASC 820 defines fair value, expands related disclosure requirements, and specifies a hierarchy of valuation techniques based on the nature of the inputs used to develop the fair value measures. Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date, assuming the transaction occurs in the principal or most advantageous market for that asset or liability. There are three levels of inputs to fair value measurements - Level 1, meaning the use of quoted prices for identical instruments in active markets; Level 2, meaning the use of quoted prices for similar instruments in active markets or quoted prices for identical or similar instruments in markets that are not active or are directly or indirectly observable; and Level 3, meaning the use of unobservable inputs. The Company uses Level 1 inputs for its fair value measurements whenever there is an active market, with actual quotes, market prices, and observable inputs on the measurement date. The Company uses Level 2 inputs for fair value measurements whenever there are quoted prices for similar securities in an active market or quoted prices for identical securities in an inactive market. The Company uses Level 3 inputs in the Binomial Model used for the valuation of the derivative liability.
Derivative Liabilities	E. Derivative Liabilities In accordance with ASC 815-40-25 and ASC 815-10-15 Derivatives and Hedging and ASC 480-10-25 Liabilities-Distinguishing Liabilities from Equity, the embedded derivatives associated with the Convertible Bonds are accounted for as a liability during the term of the related Convertible Bonds (see Note 6).
Stock-Based Compensation	F. Stock-Based Compensation ASC 718, “Compensation – Stock Compensation,” prescribes accounting and reporting standards for all share-based payment transactions in which employee services are acquired. Transactions include incurring liabilities, or issuing or offering to issue shares, options, and other equity instruments such as employee stock ownership plans and stock appreciation rights. Share-based payments to employees, including grants of employee stock options, are recognized as compensation expense in the financial statements based on their fair values. That expense is recognized over the period during which an employee is required to provide services in exchange for the award, known as the requisite service period (usually the vesting period). The Company accounts for stock-based compensation issued to non-employees and consultants in accordance with the provisions of ASC 505-50, “Equity – Based Payments to Non-Employees.” Measurement of share-based payment transactions with non-employees is based on the fair value of whichever is more reliably measurable: (a) the goods or services received; or (b) the equity instruments issued. The fair value of the share-based payment transaction is determined at the earlier of performance commitment date or performance completion date.
Related parties	G. Related parties Parties are considered to be related to the Company if the parties, directly or indirectly, through one or more intermediaries, control, are controlled by, or are under common control with the Company. Related parties also include principal owners of the Company, its management, members of the immediate families of principal owners of the Company and its management and other parties with which the Company may deal if one party controls or can significantly influence the management or operating policies of the other to an extent that one of the transacting parties might be prevented from fully pursuing its own separate interests. All transactions with related parties are recorded at fair value of the goods or services exchanged.
Recently Adopted Accounting Pronouncements	H. Recently Adopted Accounting Pronouncements ASU 2016-02 – Leases (Topic 842) In February 2016, the Financial Accounting Standards Board (“FASB”) issued ASU 2016-02, Leases (Topic 842) (“ASU 2016-02”) in order to increase transparency and comparability among organizations by recognizing lease assets and lease liabilities on the balance sheet for those leases classified as operating leases under previous GAAP. ASU 2016-02 requires that a lessee should recognize a liability to make lease payments (the lease liability) and a right-of-use asset representing its right to use the underlying asset for the lease term on the balance sheet. ASU 2016-02 is effective for fiscal years beginning after December 15, 2018 (including interim periods within those periods) using a modified retrospective approach and early adoption is permitted. Zion will adopt ASU 2016-02 in the first quarter of 2019. Presently, Zion has operating leases for office space in Dallas, Texas and in Caesarea, Israel plus various leases for motor vehicles, among others. Those leases, and new leases entered in the future, will be accounted for under ASU 2016-02 in 2019 by establishing a right-of-use asset and a corresponding lease liability. Management is in process of evaluating its leases. Although we cannot estimate the dollar value of right-to-use assets and liabilities to be recorded next year, Zion is not subject to any loan covenants and therefore, the expected increase in assets and liabilities is not expected to have a material impact on its business. ASU 2016-15 – Statement of Cash Flows (Topic 230) In August 2016, the FASB issued AS 2016-15, “Classification of Certain Cash Receipts and Cash Payments”, which clarifies how certain cash receipts and cash payments are presented and classified in the statement of cash flows. The effective date for ASU 2016-15 is for fiscal years beginning after December 15, 2018, and interim periods within fiscal years beginning after December 15, 2019. Early adoption is permitted. We are currently evaluating the impact of adopting ASU 2016-15 on our consolidated financial statements. ASU 2016-18 – Statement of Cash Flows (Topic 230) In November 2016, the FASB issued ASU 2016-18, Statement of Cash Flows (Topic 230) (“ASU 2016-18”), which requires that restricted cash and restricted cash equivalents be included with cash and cash equivalents when reconciling the beginning-of-period and end-of-period total cash amounts shown on the statement of cash flows. The effective date for ASU 2016-18 is for fiscal years beginning after December 15, 2017, and interim periods within those fiscal years. Early adoption is permitted. We adopted ASU 2016-18 effective January 1, 2018. The adoption of ASU 2016-18 had no impact on our retained earnings, and no impact to our net income on an ongoing basis. Adoption of the new standard requires that a statement of cash flows explain the change during the period in the total of cash, cash equivalents and amounts generally described as restricted cash, or restricted cash equivalents. The amounts generally described as restricted cash and restricted cash equivalents should be included with cash and cash equivalents when reconciling the beginning-of-period and end-of-period total amounts shown on the statements of cash flows. The amendments have been applied using a retrospective transition method to each period presented, as required. The period ended September 30, 2018 has been reclassified to reflect this change. ASU 2018-01 – Leases (Topic 842) In January 2018, the FASB issued ASU 2018-01, “Land Easement Practical Expedient for Transition to “Topic 842.” The amendments in this Update provide an optional transition practical expedient to not evaluate under Topic 842 existing or expired land easements that were not previously accounted for as leases under Topic 840, Leases. An entity that elects this practical expedient should evaluate new or modified land easements under Topic 842 beginning at the date that the entity adopts Topic 842. An entity that does not elect this practical expedient should evaluate all existing or expired land easements in connection with the adoption of the new lease requirements in Topic 842 to assess whether they meet the definition of a lease. We are currently evaluating the impact of adopting ASU 2018-01 on our consolidated financial statements. ASU 2018-05 – Income Taxes (Topic 740) In March 2018, the FASB issued ASU 2018-05, “Amendments to SEC Paragraphs Pursuant to SEC Staff Accounting Bulletin No. 118”. This ASU expresses the view of the staff regarding application of Topic 740, Income Taxes, in the reporting period that includes December 22, 2017, the date on which the Tax Cuts and Jobs Act (H.R.1, An Act to Provide for Reconciliation Pursuant to Titles II and V of the Concurrent Resolution on the Budget for Fiscal Year 2018) was signed into law. We are currently evaluating the impact of adopting ASU 2018-05 on our consolidated financial statements. ASU 2016-15 In August 2016, the FASB issued ASU 2016-15, Classification of Certain Cash Receipts and Cash Payments, which clarifies how certain cash receipts and cash payments are presented and classified in the statement of cash flows. The effective date for ASU 2016-15 is for fiscal years beginning after December 15, 2018, and interim periods within fiscal years beginning after December 15, 2019. Early adoption is permitted. We are currently evaluating the impact of adopting ASU 2016-18 on our consolidated financial statements. ASU 2016-09 In March 2016, the FASB issued ASU No. 2016-09, Compensation – Stock Compensation, or ASU No. 2016-09. The areas for simplification in this Update involve several aspects of the accounting for share-based payment transactions, including the income tax consequences, classification of awards as either equity or liabilities, and classification on the statement of cash flows. For public entities, the amendments in this Update are effective for annual periods beginning after December 15, 2016, and interim periods within those annual periods. Early adoption is permitted in any interim or annual period. If an entity early adopts the amendments in an interim period, any adjustments should be reflected as of the beginning of the fiscal year that includes that interim period. An entity that elects early adoption must adopt all of the amendments in the same period. Amendments related to the timing of when excess tax benefits are recognized, minimum statutory withholding requirements, forfeitures, and intrinsic value should be applied using a modified retrospective transition method by means of a cumulative-effect adjustment to equity as of the beginning of the period in which the guidance is adopted. Amendments related to the presentation of employee taxes paid on the statement of cash flows when an employer withholds shares to meet the minimum statutory withholding requirement should be applied retrospectively. Amendments requiring recognition of excess tax benefits and tax deficiencies in the income statement and the practical expedient for estimating expected term should be applied prospectively. An entity may elect to apply the amendments related to the presentation of excess tax benefits on the statement of cash flows using either a prospective transition method or a retrospective transition method. We are currently evaluating the impact of adopting ASU No. 2016-09 on our consolidated financial statements.

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	9 Months Ended
	Sep. 30, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Schedule of stock option transactions	Number of shares Weighted Average exercise price US$ Outstanding, December 31, 2017 4,339,443 1.37 Changes during 2018 to: Granted to employees, officers, directors and others * 969,000 1.11 Expired/Cancelled/Forfeited (90,000 ) 1.84 Exercised (237,500 ) 0.08 Outstanding, September 30, 2018 4,980,943 1.37 Exercisable, September 30, 2018 4,778,443 1.41 * The receipt of a stock option grant by the grantee recipient is a non-taxable event according to the Internal Revenue Service. The grantee who later chooses to exercise penny stock options must recognize the market value in income in the year of exercise.
Schedule of stock options outstanding	Shares underlying outstanding options (non-vested) Shares underlying outstanding options (fully vested) Range of exercise price Number outstanding Weighted average remaining contractual life (years) Weighted Average Exercise price Range of exercise price Number Outstanding Weighted average remaining contractual life (years) Weighted Average Exercise price US$ US$ US$ US$ — — — — 0.01 15,000 5.12 0.01 — — — — 0.01 15,000 5.50 0.01 — — — — 0.01 5,000 5.70 0.01 — — — — 0.01 10,000 7.00 0.01 — — — — 0.01 25,000 7.25 0.01 — — — — 0.01 305,000 7.67 0.01 — — — — 0.01 25,000 8.25 0.01 — — — — 0.01 500,000 8.25 0.01 — — — — 0.01 10,000 8.26 0.01 — — — — 0.01 60,000 8.54 0.01 0.01 10,000 9.00 0.01 0.01 30,000 9.00 0.01 0.01 147,500 9.25 0.01 0.01 *122,500 9.25 0.01 — — — — 0.01 **45,000 9.41 0.01 — — — — 0.01 110,000 9.26 0.01 — — — — 0.01 6,000 9.77 0.01 — — — — 0.01 10,000 9.92 0.01 — — — — 1.33 25,000 4.58 1.33 — — — — 1.38 108,000 2.26 1.38 — — — — 1.38 123,057 6.26 1.38 — — — — 1.55 400,000 3.68 1.55 — — — — 1.67 340,000 2.00 1.67 — — — — 1.67 448,886 6.01 1.67 — — — — 1.70 120,000 0.22 1.70 — — — — 1.70 283,500 4.22 1.70 — — — — 1.73 25,000 0.28 1.73 — — — — 1.75 400,000 4.77 1.70 — — — — 1.78 25,000 5.93 1.86 — — — — 1.86 25,000 0.18 1.86 — — — — 1.87 25,000 3.34 1.87 — — — — 1.95 25,000 1.50 1.95 — — — — 1.96 25,000 0.93 1.96 — — — — 2.03 25,000 2.59 2.03 — — — — 2.31 400,000 5.26 2.31 — — — — 2.61 681,500 3.18 2.61 — — — — 4.15 25,000 5.76 4.15 0.01 157,500 0.01 0.01-2.61 4,823,443 1.41 * 17,500 are exercisable on December 31, 2018. ** 27,500 are exercisable on September 30, 2019.
Schedule of warrants description	Period of Grant US$ Expiration Date ZNWAA Warrants March 2013 – December 2014 2.00 January 31, 2020 ZNWAD Warrants January 2015 – March 2016 1.00 May 02, 2019 ZNWAE Warrants November 2016 – March 2017 1.00 May 01, 2020 ZNWAF Warrants May 2017 – July 2017 1.00 August 14, 2020 ZNWAG Warrants October 2017 – December 2017 1.00 January 08, 2021 ZNWAH Warrants February 2018 5.00 April 2, 2019 ZNWAI Warrants April 2018 – May 2018 3.00 June 29, 2019 ZNWAJ Warrants August 2018 – September 2018 1.00 October 29, 2019
Dividend Reinvestment and Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Schedule of warrants description	ZNWAA ZNWAC ZNWAD ZNWAE ZNWAF ZNWAG ZNWAH ZNWAI ZNWAJ Total Outstanding warrants, December 31, 2017 1,524,617 275,152 294,334 3,028,119 460,231 414,300 - - - 5,996,753 Exercise Price $ 2.00 $ 1.00 $ 1.00 $ 1.00 $ 1.00 $ 1.00 $ 5.00 $ 3.00 1.00 Warrant Termination Date 1/31/2020 5/2/2018 5/2/2019 5/2/2020 8/14/2020 1/8/2021 4/19/2019 6/29/2019 10/29/2019 Change during 2018 to: Issued - - - 10,493 50 30 373,400 656,274 483,050 1,523,297 Exercised (25,813 ) (196,913 ) (48,781 ) (894,002 ) (100,621 ) (173,512 ) (1,000 ) (15,439 ) - (1,456,081 ) Expired - (78,239 ) - - - - - - - (78,239 ) Outstanding and exercisable warrants, September 30, 2018 1,498,804 - 245,553 2,144,610 359,660 240,818 372,400 640,835 483,050 5,985,730
Non - Employees [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Schedule of assumptions used to estimate fair value of warrants granted using black-scholes option pricing model	For the nine months ended September 30, 2018 2017 Weighted-average fair value of underlying stock at grant date $ 3.37 $ 1.36 Dividend yields — — Expected volatility 73%-76 % 68 % Risk-free interest rates 2.46%-2.81 % 2.36%-2.45 % Expected lives (in years) 10.00 10.00 Weighted-average grant date fair value $ 3.36 $ 1.36
Non - Employees [Member] | Warrants and Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Schedule of compensation cost of warrant and option issuances	For the nine months ended September 30, 2018 2017 US$ thousands US$ thousands 302 210
Employees and Directors [Member] | Warrants and Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Schedule of compensation cost of warrant and option issuances	For the nine months ended September 30, 2018 2017 US$ thousands US$ thousands 1,468 2,399
Employees [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Schedule of assumptions used to estimate fair value of warrants granted using black-scholes option pricing model	For the nine months ended September 30, 2018 2017 Weighted-average fair value of underlying stock at grant date $ 2.37 $ 1.42 Dividend yields — — Expected volatility 68%-87 % 45%-69 % Risk-free interest rates 2.01%-2.74 % 1.45%-1.94 % Expected lives (in years) 3.00-5.50 3.00-5.00 Weighted-average grant date fair value $ 1.61 $ 1.20
Employees and Non Employees [Member] | Warrants and Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Schedule of compensation cost of warrant and option issuances	For the nine months ended September 30, 2018 2017 US$ thousands US$ thousands 339 191

Unproved Oil and Gas Properti_2

Unproved Oil and Gas Properties, Full Cost Method (Tables)	9 Months Ended
	Sep. 30, 2018
Unproved Oil and Gas Properties, Full Cost Method [Abstract]
Schedule of unproved oil and gas properties, full cost method	September 30, 2018 December 31, 2017 US$ thousands US$ thousands Excluded from amortization base: Drilling costs, and other operational related costs 25,537 14,999 Capitalized salary costs 2,524 2,034 Capitalized interest costs 590 346 Legal costs, license fees and other preparation costs 5,054 4,087 Other costs 378 229 *34,083 21,695 * The unproved oil and gas properties balance at September 30, 2018 contains approximately $1,543,000 in unpaid amounts.
Schedule of changes in unproved oil and gas properties	September 30, 2018 September 30, 2017 US$ thousands US$ thousands Excluded from amortization base: Drilling costs, and other operational related costs 10,538 8,961 Capitalized salary costs 490 357 Capitalized interest costs 244 258 Legal costs, license fees and other preparation costs 967 820 Other costs 149 98 *12,388 *10,494 * Inclusive of non-cash amounts of approximately $2,126,000 and $4,070,000 during the nine months ended September 30, 2018, and 2017, respectively.

Senior Convertible Bonds (Table

Senior Convertible Bonds (Tables)	9 Months Ended
	Sep. 30, 2018
Senior Convertible Bonds [Abstract]
Schedule of senior convertible bonds	September 30, December 31, US$ US$ 10% Senior Convertible Bonds, on the day of issuance $ 3,470 $ 3,470 Unamortized Debt discount, net $ (1,047 ) $ (1,267 ) Bonds converted to shares $ (201 ) $ (111 ) Offering cost, net $ (70 ) $ (90 ) 10% senior Convertible bonds – Long Term Liability $ 2,152 $ 2,002

Derivative Liability (Tables)

Derivative Liability (Tables)	9 Months Ended
	Sep. 30, 2018
Derivative Liability [Abstract]
Schedule of fair value of derivative liabilities	September 30, 2018 December 31, 2017 Level 3 Total Level 3 Total US$ thousands US$ thousands US$ thousands US$ thousands Fair value of derivative liability 984 984 1,866 1,866
Schedule of change in fair value of derivative liability	US$ thousands Derivative liability fair value at December 31, 2017 1,866 Gain on derivative liability 882 Derivative liability fair value at September 30, 2018 984
Schedule of assumption used for the model of derivatives liabilities	September 30, 2018 December 31, 2017 Convertible Option Fair Value of approximately $ 984,000 $ 1,866,000 Annual Risk-free Rate 2.85 % 2.03 % Volatility 92.71 % 68.04 % Expected Term (years) 2.59 3.34 Convertible Notes Face Value $ 3,268,900 $ 3,358,900 Expected annual yield on Regular Notes 28.77 % 28.77 % Price of the Underlying Stock $ 1.28 $ 2.16

Nature of Operations, Basis o_2

Nature of Operations, Basis of Presentation and Going Concern (Details) $ in Thousands	Dec. 03, 2013	Sep. 30, 2018USD ($)a	Sep. 30, 2017USD ($)	Sep. 30, 2018USD ($)a	Sep. 30, 2017USD ($)	Dec. 31, 2017USD ($)
Nature of Operations, Basis of Presentation and Going Concern (Textual)
Area of land depth, description				The MJ #1 well has been drilled to a total depth ("TD") of 5,060 meters (approximately 16,600 feet). Thereafter, the Company obtained three open-hole wireline log suites (including a formation image log) and the well was successfully cased and cemented. The Ministry of Energy approved the well testing protocol on April 29, 2018. Testing of the well is ongoing and the Company expects that testing will be concluded in the fourth quarter of 2018.
Net loss		$ 781	$ (1,462)	$ (6,711)	$ (9,808)
Accumulated deficit		$ (167,315)		$ (167,315)		$ (160,604)
Megiddo-Jezreel License [Member]
Nature of Operations, Basis of Presentation and Going Concern (Textual)
Area of land, approximate | a		99,000		99,000
Initial length of lease	3 years
Megiddo-Jezreel License [Member] | Maximum [Member]
Nature of Operations, Basis of Presentation and Going Concern (Textual)
Initial length of lease	7 years
Megiddo-Jezreel License [Member] | Minimum [Member]
Nature of Operations, Basis of Presentation and Going Concern (Textual)
Initial length of lease	1 year

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Details) - USD ($) $ / shares in Units, $ in Thousands	9 Months Ended			12 Months Ended
	Sep. 30, 2018		Sep. 30, 2017	Dec. 31, 2017
Summary of Significant Accounting Policies (Textual)
Common stock equivalents excluded from EPS as the inclusion would be anti-dilutive	9,673,173		9,059,091
Common stock, par value	$ 0.01			$ 0.01
Impairment of unproved oil and gas properties
Capitalized exploration costs	$ 34,083	[1]		$ 21,695
[1]	The unproved oil and gas properties balance at September 30, 2018 contains approximately $1,543,000 in unpaid amounts.

Stockholders' Equity (Stock Opt

Stockholders' Equity (Stock Options) (Details) - Options [Member]	9 Months Ended
	Sep. 30, 2018$ / sharesshares
Number of shares
Outstanding, Beginning balance | shares	4,339,443
Granted to employees, officers, directors and others | shares	969,000	[1]
Expired/Cancelled/Forfeited | shares	(90,000)
Exercised | shares	(237,500)
Outstanding, Ending balance | shares	4,980,943
Exercisable | shares	4,778,443
Weighted Average exercise price
Outstanding, Beginning balance | $ / shares	$ 1.37
Granted to employees, officers, directors and others | $ / shares	1.11	[1]
Expired/Cancelled/Forfeited | $ / shares	1.84
Exercised | $ / shares	0.08
Outstanding, Ending balance | $ / shares	1.37
Exercisable | $ / shares	$ 1.41
[1]	The receipt of a stock option grant by the grantee recipient is a non-taxable event according to the Internal Revenue Service. The grantee who later chooses to exercise penny stock options must recognize the market value in income in the year of exercise.

Stockholders' Equity (Stock O_2

Stockholders' Equity (Stock Options Outstanding) (Details)	9 Months Ended
	Sep. 30, 2018$ / sharesshares
Vested [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Shares underlying outstanding options Range of exercise price, lower range	$ 0.01
Shares underlying outstanding options Range of exercise price, upper range	$ 2.61
Shares underlying outstanding options Number Outstanding | shares	4,823,443
Shares underlying outstanding options Weighted Average Exercise price	$ 1.41
Vested [Member] | Range Exercise Price 0.01 First [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Shares underlying outstanding options Range of exercise price	$ 0.01
Shares underlying outstanding options Number Outstanding | shares	15,000
Shares underlying outstanding options Weighted average remaining contractual life (years)	5 years 1 month 13 days
Shares underlying outstanding options Weighted Average Exercise price	$ 0.01
Vested [Member] | Range Exercise Price 0.01 Second [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Shares underlying outstanding options Range of exercise price	$ 0.01
Shares underlying outstanding options Number Outstanding | shares	15,000
Shares underlying outstanding options Weighted average remaining contractual life (years)	5 years 6 months
Shares underlying outstanding options Weighted Average Exercise price	$ 0.01
Vested [Member] | Range Exercise Price 0.01 Third [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Shares underlying outstanding options Range of exercise price	$ 0.01
Shares underlying outstanding options Number Outstanding | shares	5,000
Shares underlying outstanding options Weighted average remaining contractual life (years)	5 years 8 months 12 days
Shares underlying outstanding options Weighted Average Exercise price	$ 0.01
Vested [Member] | Range Exercise Price 0.01 Four [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Shares underlying outstanding options Range of exercise price	$ 0.01
Shares underlying outstanding options Number Outstanding | shares	10,000
Shares underlying outstanding options Weighted average remaining contractual life (years)	7 years
Shares underlying outstanding options Weighted Average Exercise price	$ 0.01
Vested [Member] | Range Exercise Price 0.01 Five [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Shares underlying outstanding options Range of exercise price	$ 0.01
Shares underlying outstanding options Number Outstanding | shares	25,000
Shares underlying outstanding options Weighted average remaining contractual life (years)	7 years 2 months 30 days
Shares underlying outstanding options Weighted Average Exercise price	$ 0.01
Vested [Member] | Range Exercise Price 0.01 Six [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Shares underlying outstanding options Range of exercise price	$ 0.01
Shares underlying outstanding options Number Outstanding | shares	305,000
Shares underlying outstanding options Weighted average remaining contractual life (years)	7 years 8 months 2 days
Shares underlying outstanding options Weighted Average Exercise price	$ 0.01
Vested [Member] | Range Exercise Price 0.01 Seven [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Shares underlying outstanding options Range of exercise price	$ 0.01
Shares underlying outstanding options Number Outstanding | shares	25,000
Shares underlying outstanding options Weighted average remaining contractual life (years)	8 years 2 months 30 days
Shares underlying outstanding options Weighted Average Exercise price	$ 0.01
Vested [Member] | Range Exercise Price 0.01 Eight [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Shares underlying outstanding options Range of exercise price	$ 0.01
Shares underlying outstanding options Number Outstanding | shares	500,000
Shares underlying outstanding options Weighted average remaining contractual life (years)	8 years 2 months 30 days
Shares underlying outstanding options Weighted Average Exercise price	$ 0.01
Vested [Member] | Range Exercise Price 0.01 Nine [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Shares underlying outstanding options Range of exercise price	$ 0.01
Shares underlying outstanding options Number Outstanding | shares	10,000
Shares underlying outstanding options Weighted average remaining contractual life (years)	8 years 3 months 4 days
Shares underlying outstanding options Weighted Average Exercise price	$ 0.01
Vested [Member] | Range Exercise Price 0.01 Ten [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Shares underlying outstanding options Range of exercise price	$ 0.01
Shares underlying outstanding options Number Outstanding | shares	60,000
Shares underlying outstanding options Weighted average remaining contractual life (years)	8 years 6 months 14 days
Shares underlying outstanding options Weighted Average Exercise price	$ 0.01
Vested [Member] | Range Exercise Price 0.01 Eleven [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Shares underlying outstanding options Range of exercise price	$ 0.01
Shares underlying outstanding options Number Outstanding | shares	30,000
Shares underlying outstanding options Weighted average remaining contractual life (years)	9 years
Shares underlying outstanding options Weighted Average Exercise price	$ 0.01
Vested [Member] | Range Exercise Price 0.01 Twelve [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Shares underlying outstanding options Range of exercise price	$ 0.01
Shares underlying outstanding options Number Outstanding | shares	122,500	[1]
Shares underlying outstanding options Weighted average remaining contractual life (years)	9 years 2 months 30 days
Shares underlying outstanding options Weighted Average Exercise price	$ 0.01
Vested [Member] | Range Exercise Price 0.01 Thirteen [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Shares underlying outstanding options Range of exercise price	$ 0.01
Shares underlying outstanding options Number Outstanding | shares	45,000	[2]
Shares underlying outstanding options Weighted average remaining contractual life (years)	9 years 4 months 28 days
Shares underlying outstanding options Weighted Average Exercise price	$ 0.01
Vested [Member] | Range Exercise Price 0.01 Fourteen [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Shares underlying outstanding options Range of exercise price	$ 0.01
Shares underlying outstanding options Number Outstanding | shares	110,000
Shares underlying outstanding options Weighted average remaining contractual life (years)	9 years 3 months 4 days
Shares underlying outstanding options Weighted Average Exercise price	$ 0.01
Vested [Member] | Range Exercise Price 0.01 Fifteen [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Shares underlying outstanding options Range of exercise price	$ 0.01
Shares underlying outstanding options Number Outstanding | shares	6,000
Shares underlying outstanding options Weighted average remaining contractual life (years)	9 years 9 months 7 days
Shares underlying outstanding options Weighted Average Exercise price	$ 0.01
Vested [Member] | Range Exercise Price 0.01 Sixteen [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Shares underlying outstanding options Range of exercise price	$ 0.01
Shares underlying outstanding options Number Outstanding | shares	10,000
Shares underlying outstanding options Weighted average remaining contractual life (years)	9 years 11 months 1 day
Shares underlying outstanding options Weighted Average Exercise price	$ 0.01
Vested [Member] | Range Exercise Price 1.33 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Shares underlying outstanding options Range of exercise price	$ 1.33
Shares underlying outstanding options Number Outstanding | shares	25,000
Shares underlying outstanding options Weighted average remaining contractual life (years)	4 years 6 months 29 days
Shares underlying outstanding options Weighted Average Exercise price	$ 1.33
Vested [Member] | Range Exercise Price 1.38 First [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Shares underlying outstanding options Range of exercise price	$ 1.38
Shares underlying outstanding options Number Outstanding | shares	108,000
Shares underlying outstanding options Weighted average remaining contractual life (years)	2 years 3 months 4 days
Shares underlying outstanding options Weighted Average Exercise price	$ 1.38
Vested [Member] | Range Exercise Price 1.38 Second [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Shares underlying outstanding options Range of exercise price	$ 1.38
Shares underlying outstanding options Number Outstanding | shares	123,057
Shares underlying outstanding options Weighted average remaining contractual life (years)	6 years 3 months 4 days
Shares underlying outstanding options Weighted Average Exercise price	$ 1.38
Vested [Member] | Range Exercise Price 1.55 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Shares underlying outstanding options Range of exercise price	$ 1.55
Shares underlying outstanding options Number Outstanding | shares	400,000
Shares underlying outstanding options Weighted average remaining contractual life (years)	3 years 8 months 5 days
Shares underlying outstanding options Weighted Average Exercise price	$ 1.55
Vested [Member] | Range Exercise Price 1.67 First [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Shares underlying outstanding options Range of exercise price	$ 1.67
Shares underlying outstanding options Number Outstanding | shares	340,000
Shares underlying outstanding options Weighted average remaining contractual life (years)	2 years
Shares underlying outstanding options Weighted Average Exercise price	$ 1.67
Vested [Member] | Range Exercise Price 1.67 Second [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Shares underlying outstanding options Range of exercise price	$ 1.67
Shares underlying outstanding options Number Outstanding | shares	448,886
Shares underlying outstanding options Weighted average remaining contractual life (years)	6 years 4 days
Shares underlying outstanding options Weighted Average Exercise price	$ 1.67
Vested [Member] | Range Exercise Price 1.70 First [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Shares underlying outstanding options Range of exercise price	$ 1.70
Shares underlying outstanding options Number Outstanding | shares	120,000
Shares underlying outstanding options Weighted average remaining contractual life (years)	2 months 19 days
Shares underlying outstanding options Weighted Average Exercise price	$ 1.70
Vested [Member] | Range Exercise Price 1.70 Second [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Shares underlying outstanding options Range of exercise price	$ 1.70
Shares underlying outstanding options Number Outstanding | shares	283,500
Shares underlying outstanding options Weighted average remaining contractual life (years)	4 years 2 months 19 days
Shares underlying outstanding options Weighted Average Exercise price	$ 1.70
Vested [Member] | Range Exercise Price 1.73 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Shares underlying outstanding options Range of exercise price	$ 1.73
Shares underlying outstanding options Number Outstanding | shares	25,000
Shares underlying outstanding options Weighted average remaining contractual life (years)	3 months 11 days
Shares underlying outstanding options Weighted Average Exercise price	$ 1.73
Vested [Member] | Range Exercise Price 1.75 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Shares underlying outstanding options Range of exercise price	$ 1.75
Shares underlying outstanding options Number Outstanding | shares	400,000
Shares underlying outstanding options Weighted average remaining contractual life (years)	4 years 9 months 7 days
Shares underlying outstanding options Weighted Average Exercise price	$ 1.70
Vested [Member] | Range Exercise Price 1.78 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Shares underlying outstanding options Range of exercise price	$ 1.78
Shares underlying outstanding options Number Outstanding | shares	25,000
Shares underlying outstanding options Weighted average remaining contractual life (years)	5 years 11 months 4 days
Shares underlying outstanding options Weighted Average Exercise price	$ 1.86
Vested [Member] | Range Exercise Price 1.86 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Shares underlying outstanding options Range of exercise price	$ 1.86
Shares underlying outstanding options Number Outstanding | shares	25,000
Shares underlying outstanding options Weighted average remaining contractual life (years)	2 months 5 days
Shares underlying outstanding options Weighted Average Exercise price	$ 1.86
Vested [Member] | Range Exercise Price 1.87 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Shares underlying outstanding options Range of exercise price	$ 1.87
Shares underlying outstanding options Number Outstanding | shares	25,000
Shares underlying outstanding options Weighted average remaining contractual life (years)	3 years 4 months 2 days
Shares underlying outstanding options Weighted Average Exercise price	$ 1.87
Vested [Member] | Range Exercise Price 1.95 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Shares underlying outstanding options Range of exercise price	$ 1.95
Shares underlying outstanding options Number Outstanding | shares	25,000
Shares underlying outstanding options Weighted average remaining contractual life (years)	1 year 6 months
Shares underlying outstanding options Weighted Average Exercise price	$ 1.95
Vested [Member] | Range Exercise Price 1.96 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Shares underlying outstanding options Range of exercise price	$ 1.96
Shares underlying outstanding options Number Outstanding | shares	25,000
Shares underlying outstanding options Weighted average remaining contractual life (years)	11 months 4 days
Shares underlying outstanding options Weighted Average Exercise price	$ 1.96
Vested [Member] | Range Exercise Price 2.03 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Shares underlying outstanding options Range of exercise price	$ 2.03
Shares underlying outstanding options Number Outstanding | shares	25,000
Shares underlying outstanding options Weighted average remaining contractual life (years)	2 years 7 months 2 days
Shares underlying outstanding options Weighted Average Exercise price	$ 2.03
Vested [Member] | Range Exercise Price 2.31 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Shares underlying outstanding options Range of exercise price	$ 2.31
Shares underlying outstanding options Number Outstanding | shares	400,000
Shares underlying outstanding options Weighted average remaining contractual life (years)	5 years 3 months 4 days
Shares underlying outstanding options Weighted Average Exercise price	$ 2.31
Vested [Member] | Range Exercise Price 2.61 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Shares underlying outstanding options Range of exercise price	$ 2.61
Shares underlying outstanding options Number Outstanding | shares	681,500
Shares underlying outstanding options Weighted average remaining contractual life (years)	3 years 2 months 5 days
Shares underlying outstanding options Weighted Average Exercise price	$ 2.61
Vested [Member] | Range Exercise Price 4.15 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Shares underlying outstanding options Range of exercise price	$ 4.15
Shares underlying outstanding options Number Outstanding | shares	25,000
Shares underlying outstanding options Weighted average remaining contractual life (years)	5 years 9 months 3 days
Shares underlying outstanding options Weighted Average Exercise price	$ 4.15
Non-vested [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Shares underlying outstanding options Range of exercise price	$ 0.01
Shares underlying outstanding options Number Outstanding | shares	157,500
Shares underlying outstanding options Weighted Average Exercise price	$ 0.01
Non-vested [Member] | Range Exercise Price 0.01 Eleven [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Shares underlying outstanding options Range of exercise price	$ 0.01
Shares underlying outstanding options Number Outstanding | shares	10,000
Shares underlying outstanding options Weighted average remaining contractual life (years)	9 years
Shares underlying outstanding options Weighted Average Exercise price	$ 0.01
Non-vested [Member] | Range Exercise Price 0.01 Twelve [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Shares underlying outstanding options Range of exercise price	$ 0.01
Shares underlying outstanding options Number Outstanding | shares	147,500
Shares underlying outstanding options Weighted average remaining contractual life (years)	9 years 2 months 30 days
Shares underlying outstanding options Weighted Average Exercise price	$ 0.01
[1]	17,500 are exercisable on December 31, 2018.
[2]	27,500 are exercisable on September 30, 2019.

Stockholders' Equity (Assumptio

Stockholders' Equity (Assumptions Used to Estimate Fair Value of Warrants Granted Using Black-Scholes Option Pricing Model) (Details) - $ / shares	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Non - Employees [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted-average fair value of underlying stock at grant date	$ 3.37	$ 1.36
Dividend yields
Expected volatility		68.00%
Expected volatility, minimum	73.00%
Expected volatility, maximum	76.00%
Risk-free interest rates, minimum	2.46%	2.36%
Risk-free interest rates, maximum	2.81%	2.45%
Expected lives (in years)	10 years	10 years
Weighted-average grant date fair value	$ 3.36	$ 1.36
Employees [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted-average fair value of underlying stock at grant date	$ 2.37	$ 1.42
Dividend yields
Expected volatility, minimum	68.00%	45.00%
Expected volatility, maximum	87.00%	69.00%
Risk-free interest rates, minimum	2.01%	1.45%
Risk-free interest rates, maximum	2.74%	1.94%
Weighted-average grant date fair value	$ 1.61	$ 1.20
Employees [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected lives (in years)	5 years 6 months	5 years
Employees [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected lives (in years)	3 years	3 years

Stockholders' Equity (Compensat

Stockholders' Equity (Compensation Cost of Warrant and Option Issuances Recognized) (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Non - Employees [Member] | Warrants and Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation cost of warrant and option issuances	$ 302	$ 210
Employees and Directors [Member] | Warrants and Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation cost of warrant and option issuances	1,468	2,399
Employees and Non Employees [Member] | Unproved Oil and Gas Properties [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation cost of warrant and option issuances	$ 339	$ 191

Stockholders' Equity (Schedule

Stockholders' Equity (Schedule of Warrants Description) (Details)	9 Months Ended
	Sep. 30, 2018$ / shares
ZNWAA Warrants [Member]
Class of Warrant or Right [Line Items]
Warrant name	ZNWAA Warrants
Warrant exercise price	$ 2
Warrant expiration date	Jan. 31, 2020
ZNWAA Warrants [Member] | Beginning Date [Member]
Class of Warrant or Right [Line Items]
Warrant period of grant	Mar. 1, 2013
ZNWAA Warrants [Member] | Ending Date [Member]
Class of Warrant or Right [Line Items]
Warrant period of grant	Dec. 31, 2014
ZNWAD Warrants [Member]
Class of Warrant or Right [Line Items]
Warrant name	ZNWAD Warrants
Warrant exercise price	$ 1
Warrant expiration date	May 2, 2019
ZNWAD Warrants [Member] | Beginning Date [Member]
Class of Warrant or Right [Line Items]
Warrant period of grant	Jan. 1, 2015
ZNWAD Warrants [Member] | Ending Date [Member]
Class of Warrant or Right [Line Items]
Warrant period of grant	Mar. 31, 2016
ZNWAE Warrants [Member]
Class of Warrant or Right [Line Items]
Warrant name	ZNWAE Warrants
Warrant exercise price	$ 1
Warrant expiration date	May 1, 2020
ZNWAE Warrants [Member] | Beginning Date [Member]
Class of Warrant or Right [Line Items]
Warrant period of grant	Nov. 1, 2016
ZNWAE Warrants [Member] | Ending Date [Member]
Class of Warrant or Right [Line Items]
Warrant period of grant	Mar. 31, 2017
ZNWAF Warrants [Member]
Class of Warrant or Right [Line Items]
Warrant name	ZNWAF Warrants
Warrant exercise price	$ 1
Warrant expiration date	Aug. 14, 2020
ZNWAF Warrants [Member] | Beginning Date [Member]
Class of Warrant or Right [Line Items]
Warrant period of grant	May 1, 2017
ZNWAF Warrants [Member] | Ending Date [Member]
Class of Warrant or Right [Line Items]
Warrant period of grant	Jul. 31, 2017
ZNWAG Warrants [Member]
Class of Warrant or Right [Line Items]
Warrant name	ZNWAG Warrants
Warrant exercise price	$ 1
Warrant expiration date	Jan. 8, 2021
ZNWAG Warrants [Member] | Beginning Date [Member]
Class of Warrant or Right [Line Items]
Warrant period of grant	Oct. 1, 2017
ZNWAG Warrants [Member] | Ending Date [Member]
Class of Warrant or Right [Line Items]
Warrant period of grant	Dec. 31, 2017
ZNWAH Warrants [Member]
Class of Warrant or Right [Line Items]
Warrant name	ZNWAH Warrants
Warrant period of grant	Feb. 28, 2018
Warrant exercise price	$ 5
Warrant expiration date	Apr. 2, 2019
ZNWAI Warrants [Member]
Class of Warrant or Right [Line Items]
Warrant name	ZNWAI Warrants
Warrant exercise price	$ 3
Warrant expiration date	Jun. 29, 2019
ZNWAI Warrants [Member] | Beginning Date [Member]
Class of Warrant or Right [Line Items]
Warrant period of grant	Apr. 1, 2018
ZNWAI Warrants [Member] | Ending Date [Member]
Class of Warrant or Right [Line Items]
Warrant period of grant	May 31, 2018
ZNWAJ Warrants [Member]
Class of Warrant or Right [Line Items]
Warrant name	ZNWAJ Warrants
Warrant exercise price	$ 1
Warrant expiration date	Oct. 29, 2019
ZNWAJ Warrants [Member] | Beginning Date [Member]
Class of Warrant or Right [Line Items]
Warrant period of grant	Aug. 1, 2018
ZNWAJ Warrants [Member] | Ending Date [Member]
Class of Warrant or Right [Line Items]
Warrant period of grant	Sep. 30, 2018

Stockholders' Equity (Warrants

Stockholders' Equity (Warrants Table) (Details)	9 Months Ended
	Sep. 30, 2018$ / sharesshares
Class of Warrant or Right [Line Items]
Outstanding warrants, Beginning	5,996,753
Issued	1,523,297
Exercised	(1,456,081)
Expired	(78,239)
Outstanding and exercisable warrants, Ending	5,985,730
ZNWAA Warrants [Member]
Class of Warrant or Right [Line Items]
Outstanding warrants, Beginning	1,524,617
Exercise Price | $ / shares	$ 2
Warrant Termination Date	Jan. 31, 2020
Issued
Exercised	(25,813)
Expired
Outstanding and exercisable warrants, Ending	1,498,804
ZNWAC Warrants [Member]
Class of Warrant or Right [Line Items]
Outstanding warrants, Beginning	275,152
Exercise Price | $ / shares	$ 1
Warrant Termination Date	May 2, 2018
Issued
Exercised	(196,913)
Expired	(78,239)
Outstanding and exercisable warrants, Ending
ZNWAD Warrants [Member]
Class of Warrant or Right [Line Items]
Outstanding warrants, Beginning	294,334
Exercise Price | $ / shares	$ 1
Warrant Termination Date	May 2, 2019
Issued
Exercised	(48,781)
Expired
Outstanding and exercisable warrants, Ending	245,553
ZNWAE Warrants [Member]
Class of Warrant or Right [Line Items]
Outstanding warrants, Beginning	3,028,119
Exercise Price | $ / shares	$ 1
Warrant Termination Date	May 2, 2020
Issued	10,493
Exercised	(894,002)
Expired
Outstanding and exercisable warrants, Ending	2,144,610
ZNWAF Warrants [Member]
Class of Warrant or Right [Line Items]
Outstanding warrants, Beginning	460,231
Exercise Price | $ / shares	$ 1
Warrant Termination Date	Aug. 14, 2020
Issued	50
Exercised	(100,621)
Expired
Outstanding and exercisable warrants, Ending	359,660
ZNWAG Warrants [Member]
Class of Warrant or Right [Line Items]
Outstanding warrants, Beginning	414,300
Exercise Price | $ / shares	$ 1
Warrant Termination Date	Jan. 8, 2021
Issued	30
Exercised	(173,512)
Expired
Outstanding and exercisable warrants, Ending	240,818
ZNWAH Warrants [Member]
Class of Warrant or Right [Line Items]
Outstanding warrants, Beginning
Exercise Price | $ / shares	$ 5
Warrant Termination Date	Apr. 19, 2019
Issued	373,400
Exercised	(1,000)
Expired
Outstanding and exercisable warrants, Ending	372,400
ZNWAI Warrants [Member]
Class of Warrant or Right [Line Items]
Outstanding warrants, Beginning
Exercise Price | $ / shares	$ 3
Warrant Termination Date	Jun. 29, 2019
Issued	656,274
Exercised	(15,439)
Expired
Outstanding and exercisable warrants, Ending	640,835
ZNWAJ Warrants [Member]
Class of Warrant or Right [Line Items]
Outstanding warrants, Beginning
Exercise Price | $ / shares	$ 1
Warrant Termination Date	Oct. 29, 2019
Issued	483,050
Exercised
Expired
Outstanding and exercisable warrants, Ending	483,050

Stockholders' Equity (2011 Stoc

Stockholders' Equity (2011 Stock Option Plan) (Narrative) (Details)	9 Months Ended
	Sep. 30, 2018USD ($)$ / sharesshares
September 30, 2019 [Member]
Stockholders' Equity (Textual)
Shares purchased under option plan (in share)	27,500
2011 Plan [Member] | December 31, 2018 [Member]
Stockholders' Equity (Textual)
Shares purchased under option plan (in share)	17,500
23 Senior officers, staff members and consultants [Member] | 2011 Plan [Member]
Stockholders' Equity (Textual)
Shares purchased under option plan (in share)	330,000
Exercise price per unit | $ / shares	$ 0.01
Fair value of stock options granted | $	$ 759,000
Stock option plan, expiration date	Jan. 1, 2028
23 Senior officers, staff members and consultants [Member] | 2011 Plan [Member] | June 30, 2018 [Member]
Stockholders' Equity (Textual)
Shares purchased under option plan (in share)	165,000
23 Senior officers, staff members and consultants [Member] | 2011 Plan [Member] | December 31, 2018 [Member]
Stockholders' Equity (Textual)
Shares purchased under option plan (in share)	165,000
Five Senior officers [Member] | 2011 Plan [Member]
Stockholders' Equity (Textual)
Shares purchased under option plan (in share)	110,000
Exercise price per unit | $ / shares	$ 0.01
Fair value of stock options granted | $	$ 250,000
Stock option plan, expiration date	Jan. 4, 2028
Three Consultants [Member] | 2011 Plan [Member]
Stockholders' Equity (Textual)
Shares purchased under option plan (in share)	55,000
Exercise price per unit | $ / shares	$ 0.01
Fair value of stock options granted | $	$ 222,000
Stock option vested, description	The options vested upon grant and are exercisable through March 1, 2028. However, the exercisability of these options is subject to the following schedule: (a) 27,500 options are exercisable on June 30, 2018 and (b) the remaining 27,500 options are exercisable on June 30, 2019.
Eight board members [Member] | 2011 Non-Employee Directors Stock Option Plan [Member]
Stockholders' Equity (Textual)
Shares purchased under option plan (in share)	400,000
Exercise price per unit | $ / shares	$ 2.31
Fair value of stock options granted | $	$ 428,000
Stock option plan, expiration date	Jan. 1, 2024
Seven Staff Members [Member] | 2011 Plan [Member]
Stockholders' Equity (Textual)
Shares purchased under option plan (in share)	14,000
Exercise price per unit | $ / shares	$ 0.01
Fair value of stock options granted | $	$ 62,000
Stock option plan, expiration date	Apr. 5, 2028
One Staff [Member] | 2011 Plan [Member]
Stockholders' Equity (Textual)
Shares purchased under option plan (in share)	10,000
Exercise price per unit | $ / shares	$ 0.01
Fair value of stock options granted | $	$ 18,000
Stock option plan, expiration date	Sep. 1, 2018
One Board [Member] | 2011 Non-Employee Directors Stock Option Plan [Member] | July 2, 2024 [Member]
Stockholders' Equity (Textual)
Shares purchased under option plan (in share)	25,000
Exercise price per unit | $ / shares	$ 4.15
Fair value of stock options granted | $	$ 55,000
Stock option plan, expiration date	Jul. 2, 2024
One Board [Member] | 2011 Non-Employee Directors Stock Option Plan [Member] | September 4, 2024 [Member]
Stockholders' Equity (Textual)
Shares purchased under option plan (in share)	25,000
Exercise price per unit | $ / shares	$ 1.78
Fair value of stock options granted | $	$ 25,000
Stock option plan, expiration date	Sep. 4, 2024

Stockholders' Equity (Warrant_2

Stockholders' Equity (Warrants and Options) (Narrative) (Details) - USD ($)	9 Months Ended
	Sep. 30, 2018	Jan. 13, 2015
Stockholders' Equity (Textual)
Unrecognized compensation cost related to non vested stock	$ 101,000
Subscription rights offering, description	Each shareholder received .10 (one tenth) of a subscription right (i.e. one subscription right for each 10 shares owned) for each share of the Company's Common Stock owned on the Record Date.
ZNWAF Warrants [Member]
Stockholders' Equity (Textual)
Purchase warrants unit price	$ 1
ZNWAG Warrants [Member]
Stockholders' Equity (Textual)
Purchase warrants unit price	1
ZNWAH Warrants [Member]
Stockholders' Equity (Textual)
Purchase warrants unit price	5
ZNWAJ Warrants [Member]
Stockholders' Equity (Textual)
Purchase warrants unit price	$ 1
2018 Subscription Rights Offering [Member]
Stockholders' Equity (Textual)
Subscription rights offering, description	On April 2, 2018 the Company announced an offering ("2018 Subscription Rights Offering") through American Stock Transfer & Trust Company, LLC (the "Subscription Agent"), at no cost to the shareholders, of non-transferable Subscription Rights to purchase Rights (each "Right" and collectively, the "Rights") of its securities to persons who owned shares of our Common Stock on April 13, 2018 ("the Record Date"). Pursuant to the 2018 Subscription Rights Offering, each holder of shares of common stock on the Record Date received non-transferable rights to subscribe for Rights, with each Right comprised of one share of the Company Common Stock, par value $0.01 per share (the "Common Stock") and one Common Stock Purchase Warrant to purchase an additional one share of Common Stock. Each Right may be purchased at a per Right subscription price of $5.00. Each Warrant affords the investor the opportunity to purchase one share of the Company Common Stock at a warrant exercise price of $3.00. The warrants will become exercisable on June 29, 2018 and will continue to be exercisable for one year thereafter. The warrant has the symbol "ZNWAI."
Proceeds from the sale of the rights	$ 3,038,000
Expenses from rights offering	$ 243,000
Dividend Reinvestment and Stock Purchase Plan [Member]
Stockholders' Equity (Textual)
Unit option, description	On November 1, 2016, the Company launched a unit offering (the "Unit Program") under the Company's DSPP pursuant to which participants could purchase units comprised of seven shares of Common Stock and seven Common Stock purchase warrants, at a per unit purchase price of $10.
Warrants termination, description	The warrants became exercisable on May 2, 2016 and, in the case of ZNWAB continued to be exercisable through May 2, 2017 (1 year) and, in the case of ZNWAC continued to be exercisable through May 2, 2018 for ZNWAC (2 years) and May 2, 2019 for ZNWAD (3 years), respectively, at a per share exercise price of $1.00.
Unit Option Program [Member] | ZNWAG Warrants [Member]
Stockholders' Equity (Textual)
Warrants termination, description	The warrants became exercisable on January 8, 2018 and continue to be exercisable through January 8, 2021 at a per share exercise price of $1.00. The warrant terms provide that if the Company's Common Stock trades above $5.00 per share as the closing price for 15 consecutive trading days at any time prior to the expiration date of the warrant, the Company has the sole discretion to accelerate the termination date of the warrant upon providing 60 days advanced notice to the warrant holders.
New unit program began date	Feb. 1, 2018
New unit program termination date	Feb. 28, 2018
New unit program, description	The Unit Option consisted of Units of our securities where each Unit (priced at $250.00 each) was comprised of (i) 50 shares of Common Stock and (ii) Common Stock purchase warrants to purchase an additional 50 shares of Common Stock. The investor's Plan account was credited with the number of shares of the Company's Common Stock acquired under the Units purchased. Each warrant affords the investor the opportunity to purchase one share of Company Common Stock at a warrant exercise price of $5.00.
Unit Option Program [Member] | ZNWAH Warrants [Member]
Stockholders' Equity (Textual)
Warrants termination, description	The warrants became exercisable on April 2, 2018 and continue to be exercisable through April 2, 2019 at a per share exercise price of $5.00.
Unit Option Program [Member] | ZNWAJ Warrants [Member]
Stockholders' Equity (Textual)
Warrants termination, description	The warrants became exercisable on October 29, 2018 and continue to be exercisable through October 29, 2019 at a per share exercise price of $1.00.
New unit program began date	Aug. 21, 2018
New unit program termination date	Sep. 26, 2018
New unit program, description	The Unit Option consisted of Units of the Company's securities where each Unit (priced at $250.00 each) was comprised of (i) a certain number of shares of Common Stock determined by dividing $250.00 (the price of one Unit) by the average of the high and low sale prices of the Company's publicly traded common stock as reported on the NASDAQ on the Unit Purchase Date and (ii) Common Stock purchase warrants to purchase an additional twenty-five (25) shares of Common Stock. The investor's Plan account was credited with the number of shares of the Company's Common Stock acquired under the Units purchased. Each warrant affords the investor the opportunity to purchase one share of Company Common Stock at a warrant exercise price of $1.00.
Warrant [Member]
Stockholders' Equity (Textual)
Amount of funds raised under the DSPP program	$ 12,608,000
Warrant [Member] | ZNWAF Warrants [Member]
Stockholders' Equity (Textual)
Exercise price per unit	$ 1
Warrants termination, description	All ZNWAF warrants became exercisable on August 14, 2017 and continue to be exercisable through August 14, 2020 at a per share exercise price of $1.00. The warrant terms provide that if the Company's Common Stock trades above $5.00 per share as the closing price for 15 consecutive trading days at any time prior to the expiration date of the warrant, the Company has the sole discretion to accelerate the termination date of the warrant upon providing 60 days advanced notice to the warrant holders.
Warrant [Member] | Dividend Reinvestment and Stock Purchase Plan [Member]
Stockholders' Equity (Textual)
Warrants termination, description	The ZNWAE warrants became exercisable on May 1, 2017 and continue to be exercisable through May 1, 2020 at a per share exercise price of $1.00. The warrant terms provide that if the Company's Common Stock trades above $5.00 per share at the closing price for 15 consecutive trading days at any time prior to the expiration date of the warrant, the Company may, in its sole discretion, accelerate the termination of the warrant upon providing 60 days advanced notice to the warrant holders.
Warrant [Member] | New Unit Program [Member]
Stockholders' Equity (Textual)
Purchase warrants unit price		$ 4
Exercise price per unit		$ 1
New unit program termination date	Jul. 12, 2017
New unit program, description	This New Unit Program enabled participants to purchase Units of the Company's securities where each Unit (priced at $250.00 each) was comprised of (i) the number of shares of Common Stock determined by dividing $250.00 (the price of one Unit) by the average of the high and low sale prices of the Company's Common Stock as reported on the NASDAQ on the unit purchase date and (ii) Common Stock purchase warrants to purchase an additional 25 shares of Common Stock at a warrant exercise price of $1.00 per share.
Warrant [Member] | Unit Option Program [Member]
Stockholders' Equity (Textual)
Purchase warrants unit price	$ 1
New unit program began date	Oct. 16, 2017
New unit program termination date	Dec. 6, 2017
New unit program, description	This Unit Option Program enabled participants to purchase Units of the Company's securities where each Unit (priced at $250.00 each) was comprised of (i) a certain number of shares of Common Stock determined by dividing $250.00 (the price of one Unit) by the average of the high and low sale prices of the Company's Common Stock as reported on the NASDAQ on the unit purchase date and (ii) Common Stock purchase warrants to purchase an additional 15 shares of Common Stock at a warrant exercise price of $1.00 per share.

Unproved Oil and Gas Properti_3

Unproved Oil and Gas Properties, Full Cost Method (Details) - USD ($) $ in Thousands	9 Months Ended		12 Months Ended
	Sep. 30, 2018		Dec. 31, 2017
Excluded from amortization base:
Drilling costs, and other operational related costs	$ 25,537		$ 14,999
Capitalized salary costs	2,524		2,034
Capitalized interest costs	590		346
Legal costs, license fees and other preparation costs	5,054		4,087
Other costs	378		229
Total unproved oil and gas properties, full cost method	$ 34,083	[1]	$ 21,695
[1]	The unproved oil and gas properties balance at September 30, 2018 contains approximately $1,543,000 in unpaid amounts.

Unproved Oil and Gas Properti_4

Unproved Oil and Gas Properties, Full Cost Method (Details 1) - USD ($) $ in Thousands		9 Months Ended
		Sep. 30, 2018	Sep. 30, 2017
Excluded from amortization base:
Drilling costs, and other operational related costs		$ 10,538	$ 8,961
Capitalized salary costs		490	357
Capitalized interest costs		244	258
Legal costs, license fees and other preparation costs		967	820
Other costs		149	98
Changes in Unproved oil and gas properties	[1]	$ 12,388	$ 10,494
[1]	Inclusive of non-cash amounts of approximately $2,126,000 and $4,070,000 during the nine months ended September 30, 2018, and 2017, respectively.

Unproved Oil and Gas Properti_5

Unproved Oil and Gas Properties, Full Cost Method (Details Textual) - USD ($)	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Unproved Oil and Gas Properties, Full Cost Method (Textual)
Inclusive of non-cash amounts	$ 2,126,000	$ 4,070,000
Unproved oil and gas properties unpaid amount	$ 1,543,000

Senior Convertible Bonds (Detai

Senior Convertible Bonds (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Senior Convertible Bonds [Abstract]
10% Senior Convertible Bonds, on the day of issuance	$ 3,470	$ 3,470
Unamortized Debt discount, net	(1,047)	(1,267)
Bonds converted to shares	(201)	(111)
Offering cost, net	(70)	(90)
10% senior Convertible bonds - Long Term Liability	$ 2,152	$ 2,002

Senior Convertible Bonds (Narra

Senior Convertible Bonds (Narrative) (Details)	May 02, 2016USD ($)	Oct. 21, 2015$ / shares	May 02, 2018$ / sharesshares	Sep. 30, 2018USD ($)Bonds$ / sharesshares	Dec. 31, 2017USD ($)
Senior Convertible Bonds (Textual)
Debt discount on derivative liability				$ 1,047,000	$ 1,267,000
Convertible bonds				3,470,000	3,470,000
Principal amount				3,268,900	3,358,900
Unamortized Debt discount, net				$ (1,047,000)	$ (1,267,000)
Average Company stock price | $ / shares			$ 4.68
Stock issued to bondholders | shares			70,780
Rights offering [Member]
Senior Convertible Bonds (Textual)
Debt instrument, maturity date		May 2, 2021
Convertible bonds purchase price | $ / shares		$ 100
Senior unsecured notes interest rate		10.00%
Debt conversion, description				Under the rights offering, the Company distributed at no cost, 360,000 non-transferable subscription rights to subscribe for, on a per right basis, two 10% Convertible Senior Bonds par $100 due May 2, 2021 (the "Notes"), to shareholders of the Company's Common Stock on October 15, 2015, the record date for the offering. Each whole subscription right entitled the participant to purchase two convertible bonds at a purchase price of $100 per bond.
Principal amount	$ 3,470,000
Expenses from rights offering	136,000
Net proceeds from sale of the Notes	$ 3,334,000
10% Senior Convertible Bonds [Member]
Senior Convertible Bonds (Textual)
Debt instrument, maturity date				May 2, 2021
Debt instrument payment description				Payable annually in arrears on May 2 of each year, commencing May 2, 2017.
Senior unsecured notes interest rate			10.00%	10.00%
Debt conversion, description				At any time prior to the close of business on the business day immediately preceding April 2, 2021, holders may convert their notes into Common Stock at the conversion rate of 44 shares per $100 bond (which is equivalent to a conversion rate of approximately $2.27 per share).
Amortization expense				$ 20,000
Convertible bonds				1,844,000
Principal amount				3,470,000
Unamortized Debt discount, net				220,000
Financing costs associated notes converted to shares				$ 85,000
10% Senior Convertible Bonds [Member] | Rights offering [Member]
Senior Convertible Bonds (Textual)
Debt instrument, maturity date				May 2, 2021
Debt instrument payment description				The number of shares for the payment of interest in shares of Common Stock, in lieu of the cash amount, will be based on the average of the closing prices of the Company's Common Stock as reported by Bloomberg L.P. for the 30 trading days preceding the record date for the payment of interest; such record date has been designated and will always be the 10th business day prior to the interest payment date on May 2 of each year. The number of shares for the payment of principal, in lieu of the cash amount, shall be based upon the average of the closing price of the Company's Common Stock as reported by Bloomberg L.P. for the 30 trading days preceding the principal repayment date; such record date has been designated as the trading day immediately prior to the 30-day period preceding the maturity date of May 2, 2021.
Description of note redeemption				The Company was entitled to redeem for cash the outstanding Notes at an amount equal to the principal and accrued and unpaid interest, plus a 10% premium.
Senior unsecured notes interest rate			10.00%
10% Senior Convertible Bonds [Member] | Debt issuance [Member]
Senior Convertible Bonds (Textual)
Debt instrument payment description				The interest was paid-in-kind ("PIK") in the form of Common Stock. An average of the Company stock price of $4.68 was determined based on the 30 trading days prior to the record date of April 18, 2018. This figure was used to divide into 10% of the par value of the bonds held by the holders.
10% Senior Convertible Bonds [Member] | Debt issuance [Member] | Rights offering [Member]
Senior Convertible Bonds (Textual)
Convertible bonds purchase price | $ / shares				$ 2.27
Interest expense				$ 244,000
Number of convertible bonds | Bonds				900
Convertible bond price				$ 100
Common stock issued | shares				40,000
Financial expenses				$ 85,000

Derivative Liability (Details)

Derivative Liability (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Fair Value, Option, Qualitative Disclosures Related to Election [Line Items]
Fair value of derivative liability	$ 984	$ 1,866
Level 3 [Member]
Fair Value, Option, Qualitative Disclosures Related to Election [Line Items]
Fair value of derivative liability	$ 984	$ 1,866

Derivative Liability (Details 1

Derivative Liability (Details 1) $ in Thousands	9 Months Ended
	Sep. 30, 2018USD ($)
Derivative Liability [Abstract]
Derivative liability fair value, beginning balance	$ 1,866
Gain on derivative liability	882
Derivative liability fair value, ending balance	$ 984

Derivative Liability (Details 2

Derivative Liability (Details 2) - USD ($)	9 Months Ended	12 Months Ended
	Sep. 30, 2018	Dec. 31, 2017
Derivative Liability [Abstract]
Convertible Option Fair Value of approximately	$ 984,000	$ 1,866,000
Annual Risk-free Rate	2.85%	2.03%
Volatility	92.71%	68.04%
Expected Term (years)	2 years 7 months 2 days	3 years 4 months 2 days
Convertible Notes Face Value	$ 3,268,900	$ 3,358,900
Expected annual yield on Regular Notes	28.77%	28.77%
Price of the Underlying Stock	$ 1.28	$ 2.16

Derivative Liability (Narrative

Derivative Liability (Narrative) (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2018USD ($)
Derivative Liability (Textual)
Gain on derivative liability	$ 882

Commitments and Contingencies (

Commitments and Contingencies (Narrative) (Details) - USD ($)	9 Months Ended
	Sep. 30, 2018	Dec. 31, 2017	Sep. 30, 2017	Dec. 31, 2016
Commitments and Contingencies (Textual)
Bank guarantees to government bodies	$ 1,245,000
Bank guarantees to others	83,000
Aggregate guarantee amount	1,328,000
Accrued estimated loss amount	500,000
Restricted cash	$ 6,656,000	$ 9,079,000	$ 7,451,000	$ 4,487,000
Cash and cash equivalents weighted average interest rate	0.13%
Foreign currency exchange rate risks, description	During the period January 1, 2018 through September 30, 2018, the USD has fluctuated by approximately 4.6% against the NIS (the USD has strengthened relative to the NIS). By contrast, during the period January 1, 2017 through December 31, 2017, the USD fluctuated by approximately (9.8%) against the NIS (the USD weakened relative to the NIS).

Governmental Receivables (Narra

Governmental Receivables (Narrative) (Details) - USD ($)	Sep. 30, 2018	Dec. 31, 2017
Governmental Receivables (Textual)
Governmental receivables amount	$ 719,000	$ 1,237,000
VAT refunds [Member]
Governmental Receivables (Textual)
Governmental receivables amount	701,000
BLO Refunds [Member]
Governmental Receivables (Textual)
Governmental receivables amount	$ 18,000

Subsequent Events (Narrative) (

Subsequent Events (Narrative) (Details)	1 Months Ended
	Oct. 30, 2018USD ($)
Subsequent Event [Member]
Subsequent Events (Textual)
Amount collected from DSPP	$ 326,000