Note 7 - Supplemental Information Relating to Oil and Gas Producing Activities (Unaudited) (Tables)

12 Months Ended

Dec. 31, 2019

Notes Tables

Capitalized Costs Relating to Oil and Gas Producing Activities Disclosure [Table Text Block]

	Years ended December 31,
	2019		2018
Proved oil and gas properties	$	174,633,910	$	175,062,777
Pipeline and support equipment		791,756		762,440
Gross capitalized costs		175,425,666		175,825,217
Accumulated depreciation, depletion, amortization and write down		167,541,207		167,611,775
Net capitalized costs	$	7,884,459	$	8,213,442

Cost Incurred in Oil and Gas Property Acquisition, Exploration, and Development Activities Disclosure [Table Text Block]

	Years ended December 31,
	2019		2018
Property acquisition costs	$	23,018	$	49,855
Development costs		125,071		277,899

Results of Operations for Oil and Gas Producing Activities Disclosure [Table Text Block]

	Years ended December 31,
	2019			2018
Crude oil and natural gas sales	$	7,298,279		$	9,547,117
Production costs		(2,612,507	)		(3,256,946	)
Depreciation, depletion and amortization		(600,180	)		(637,642	)
Accretion expense		(273,023	)		(313,641	)
Results of operations before income tax expense (benefit)		3,812,569			5,338,888
Income tax expense (benefit)		30,000			(60,000	)
Results of operations for oil and gas producing activities (excluding corporate overhead and financing costs)	$	3,782,569		$	5,398,888

Schedule of Proved Developed and Undeveloped Oil and Gas Reserve Quantities [Table Text Block]

	Oil			Gas
	(BBLS)			(MCF)
Balance, January 1, 2018		290,000			11,244,000
Production		(55,000	)		(2,301,000	)
Revision of previous estimates		151,000			7,415,000
Balance, December 31, 2018		386,000			16,358,000
Extensions, discoveries and other additions		20,000			95,000
Production		(42,000	)		(1,840,000	)
Revision of previous estimates		(35,000	)		(1,578,000	)
Balance, December 31, 2019		329,000			13,035,000

Standardized Measure of Discounted Future Cash Flows Relating to Proved Reserves Disclosure [Table Text Block]

	December 31,
	2019			2018
	(Thousands of Dollars)
Future cash inflows from sales of oil and gas	$	45,488		$	67,050
Future production and development costs		(26,931	)		(36,575	)
Future asset retirement obligations, net of salvage		(15,828	)		(15,871	)
Future income tax expense		(170	)		(321	)
Future net cash flows		2,559			14,283
Effect of discounting future net cash flows at 10% per annum		(5,061	)		(9,839	)
Standardized measure of discounted future net cash flows	$	(2,502	)	$	4,444

Schedule of Changes in Standardized Measure of Discounted Future Net Cash Flows [Table Text Block]

	Years Ended December 31,
	2019			2018
	(Thousands of Dollars)
Balance, beginning of year	$	4,444		$	(5,054	)
Extensions, discoveries and other additions		551			-
Revision of quantity estimates		(1,650	)		8,543
Sales of crude oil and natural gas, net of production costs		(4,686	)		(6,290	)
Net change in income taxes		88			(112	)
Net changes in prices and production costs		(5,161	)		4,096
Accretion of discount		444			(505	)
Other		3,468			3,766
Balance, end of year	$	(2,502	)	$	4,444