Note 8 - Supplemental Information Relating to Oil and Gas Producing Activities (Unaudited) (Tables)

12 Months Ended

Dec. 31, 2018

Notes Tables

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

	Years ended December 31,
	2018		2017
Proved oil and gas properties	$	175,062,777	$	179,141,990
Pipeline and support equipment		762,440		682,135
Gross capitalized costs		175,825,217		179,824,125
Accumulated depreciation, depletion, amortization and write down		167,611,775		171,337,190
Net capitalized costs	$	8,213,442	$	8,486,935

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

	Years ended December 31,
	2018		2017
Property acquisition costs	$	49,855	$	11,045
Development costs		277,899		192,284

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

	Years ended December 31,
	2018			2017
Crude oil and natural gas sales	$	9,547,117		$	7,086,476
Production costs		(3,256,946	)		(2,160,029	)
Depreciation, depletion and amortization		(637,642	)		(940,143	)
Accretion expense		(313,641	)		(355,127	)
Results of operations before income tax benefit		5,338,888			3,631,177
Income tax benefit		(60,000	)		(30,000	)
Results of operations for oil and gas producing activities (excluding corporate overhead and financing costs)	$	5,398,888		$	3,661,177

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

	Oil			Gas
	(BBLS)			(MCF)
Balance, January 1, 2017		244,000			5,280,000
Extensions, discoveries and other additions		8,000			17,000
Production		(40,000	)		(1,904,000	)
Revision of previous estimates		78,000			7,851,000
Balance, December 31, 2017		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

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

	December 31,
	2018			2017
	(Thousands of Dollars)
Future cash inflows from sales of oil and gas	$	67,050		$	37,232
Future production and development costs		(36,575	)		(22,716	)
Future asset retirement obligations, net of salvage		(15,871	)		(16,360	)
Future income tax expense		(321	)		(132	)
Future net cash flows		14,283			(1,976	)
Effect of discounting future net cash flows at 10% per annum		(9,839	)		(3,078	)
Standardized measure of discounted future net cash flows	$	4,444		$	(5,054	)

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

	Years Ended December 31,
	2018			2017
	(Thousands of Dollars)
Balance, beginning of year	$	(5,054	)	$	(9,924	)
Extensions, discoveries and other additions		-			197
Revision of quantity estimates		8,543			4,031
Sales of crude oil and natural gas, net of production costs		(6,290	)		(4,926	)
Net change in income taxes		(112	)		(20	)
Net changes in prices and production costs		4,096			2,478
Accretion of discount		(505	)		(992	)
Other		3,766			4,102
Balance, end of year	$	4,444		$	(5,054	)