Note 13 - Segment Reporting - Reportable Segments (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2018	Dec. 31, 2017
Revenues		$ 46,919	$ 37,068
Cost of Revenue		37,450	29,625
Segment Profit		9,469	7,443
Depreciation and amortization		5,989	5,833
Capital Expenditures		1,781	1,677
Identifiable assets(1)	[1]	44,949	41,148
Identifiable assets(1)	[1]	44,949	41,148
Well Enhancement Services Segment [Member]
Revenues		42,759	34,686
Cost of Revenue		32,852	25,902
Segment Profit		9,907	8,784
Depreciation and amortization		4,848	4,817
Capital Expenditures		988	1,184
Identifiable assets(1)	[1]	41,442	37,651
Identifiable assets(1)	[1]	41,442	37,651
Water Transfer Services Segment [Member]
Revenues		4,160	2,128
Cost of Revenue		3,972	2,666
Segment Profit		188	(538)
Depreciation and amortization		1,118	985
Capital Expenditures		724	487
Identifiable assets(1)	[1]	3,080	2,986
Identifiable assets(1)	[1]	3,080	2,986
Unallocated and Other Segments [Member]
Revenues			254
Cost of Revenue		626	1,057
Segment Profit		(626)	(803)
Depreciation and amortization		23	31
Capital Expenditures		69	6
Identifiable assets(1)	[1]	427	511
Identifiable assets(1)	[1]	$ 427	$ 511

[1] Identifiable assets is calculated by summing the balances of accounts receivable, net; inventories; property and equipment, net; and other assets.