Condensed Consolidated Balance Sheets (Current Period Unaudited) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 882	$ 1,618
Accounts receivable:
Joint owners, net	19,399	14,218
Oil and gas production sales	13,323	17,789
Other	2	86
	32,724	32,093
Other current assets	703	778
Total current assets	34,309	34,489
Oil and gas properties, full cost method of accounting:
Proved	999,295	923,237
Other property and equipment	39,770	39,136
Total	1,039,065	962,373
Less accumulated depreciation, depletion, amortization and impairment	(744,109)	(724,606)
Total property and equipment - net	294,956	237,767
Deferred financing fees - net	1,277	1,285
Other assets	265	265
Total assets	330,807	273,806
Current liabilities:
Accounts payable	54,519	45,570
Joint interest oil and gas production payable	10,121	11,502
Accrued interest	179	140
Other accrued liabilities	951	539
Derivative liabilities	21,477	10,837
Current maturities of long-term debt	261	262
Total current liabilities	87,508	68,850
Long-term debt - less current maturities	115,226	87,354
Other liabilities	132	132
Derivative liabilities long-term	10,852	2,387
Future site restoration	9,075	8,775
Total liabilities	222,793	167,498
Commitments and contingencies (Note 9)
Stockholders' Equity
Preferred stock, par value $0.01 per share - authorized 1,000,000 shares; - 0- shares issued and outstanding.
Common stock, par value $0.01 per share, authorized 400,000,000 shares; 166,711,210 and 165,889,901 issued and outstanding at June 30, 2018 and December 31, 2017, respectively	1,667	1,659
Additional paid-in capital	416,944	415,471
Accumulated deficit	(310,597)	(310,822)
Total stockholders' equity	108,014	106,308
Total liabilities and stockholders' equity	$ 330,807	$ 273,806