Segment Reporting (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Segment Reporting Information [Line Items]
Revenue from unaffiliated clients	$ 163,903	$ 148,069	$ 321,710	$ 301,716
Inter-segment revenue	0	0	0	0
Segment operating income (loss)	29,407	20,227	52,586	43,167
Total assets (at end of period)	583,758	572,106	583,758	572,106	$ 573,052
Capital expenditures	2,913	2,444	9,362	5,302
Depreciation and amortization	6,302	6,751	12,729	13,598
Operating Segments [Member] | Reservoir Description [Member]
Segment Reporting Information [Line Items]
Revenue from unaffiliated clients	104,313	108,278	209,208	215,702
Inter-segment revenue	47	304	221	1,046
Segment operating income (loss)	18,670	20,139	34,610	38,737
Total assets (at end of period)	319,433	323,623	319,433	323,623
Capital expenditures	2,098	2,274	4,675	4,356
Depreciation and amortization	4,528	4,631	9,148	9,267
Operating Segments [Member] | Production Enhancement [Member]
Segment Reporting Information [Line Items]
Revenue from unaffiliated clients	59,590	39,791	112,502	86,014
Inter-segment revenue	249	384	450	604
Segment operating income (loss)	10,765	247	18,160	4,497
Total assets (at end of period)	206,096	196,339	206,096	196,339
Capital expenditures	769	160	3,789	538
Depreciation and amortization	1,256	1,501	2,542	3,089
Corporate & Other [Member]
Segment Reporting Information [Line Items]
Revenue from unaffiliated clients	0	0	0	0
Inter-segment revenue	(296)	(688)	(671)	(1,650)
Segment operating income (loss)	(28)	(159)	(184)	(67)
Total assets (at end of period)	58,229	52,144	58,229	52,144
Capital expenditures	46	10	898	408
Depreciation and amortization	$ 518	$ 619	$ 1,039	$ 1,242