Condensed Consolidated Balance Sheets (Current Period Unaudited) - USD ($)	Mar. 31, 2021	Dec. 31, 2020
Current Assets:
Cash and cash equivalents	$ 9,638,000	$ 19,552,000
Accounts receivable	16,915,000	7,722,000
Subscription receivable	0	3,596,000
Prepaid expenses	816,000	2,254,000
Inventory	109,000	121,000
Deposits	50,000	50,000
Total current assets	27,528,000	33,295,000
Oil and natural gas properties, using the successful efforts method of accounting:
Proved properties	433,693,000	367,372,000
Unproved properties	131,709,000	152,741,000
Accumulated depletion, depreciation and amortization	(30,392,000)	(17,477,000)
Total oil and natural gas properties, net	535,010,000	502,636,000
Other property and equipment, net	1,044,000	1,092,000
Other noncurrent assets	745,000	907,000
Total assets	564,327,000	537,930,000
Current liabilities:
Accounts payable - trade	12,760,000	7,581,000
Accrued liabilities	20,525,000	12,374,000
Other current liabilities	1,520,000	2,480,000
Total current liabilities	34,805,000	22,435,000
Noncurrent liabilities:
Deferred income taxes	40,013,000	38,898,000
Asset retirement obligations	2,481,000	2,293,000
Other	52,000	78,000
Commitments and contingencies (Note 9)
Stockholders' equity:
Preferred stock, $0.0001 par value, 10,000,000 shares authorized, none issued and outstanding at March 31, 2021 and December 31, 2020
Common stock, $0.0001 par value, 600,000,000 shares authorized, 92,675,898 and 91,967,565 shares issued and outstanding at March 31, 2021 and December 31, 2020, respectively	9,000	9,000
Additional paid-in capital	589,432,000	581,426,000
Accumulated deficit	102,465,000	107,209,000
Total stockholders' equity	486,976,000	474,226,000
Total liabilities and stockholders' equity	$ 564,327,000	$ 537,930,000