Note 3 - Revenue from Contracts with Customers (Tables)

6 Months Ended

Jun. 30, 2021

Notes Tables

Revenue from External Customers by Geographic Areas [Table Text Block]

	Three Months Ended June 30,				Six Months Ended June 30,
	2021		2020		2021		2020
Europe	$	6,599	$	4,684	$	10,965	$	12,156
Africa		6,479		4,117		8,251		16,358
Asia Pacific		3,437		2,631		5,638		10,393
Latin America		1,072		7,992		4,575		28,053
North America		934		2,204		2,141		6,092
Middle East		704		942		1,432		1,896
Other		489		161		748		4,197
Total	$	19,714	$	22,731	$	33,750	$	79,145

Contract with Customer, Contract Asset, Contract Liability, and Receivable [Table Text Block]

	June 30,		December 31,
	2021		2020
New Venture	$	5,396	$	9,158
Imaging and Reservoir Services		1,604		680
Devices		127		1,424
Total	$	7,127	$	11,262

Unbilled receivables at December 31, 2020	$	11,262
Recognition of unbilled receivables (a)		30,111
Revenues billed to customers (a)		(34,246	)
Unbilled receivables at June 30, 2021	$	7,127

	June 30,		December 31,
	2021		2020
New Venture	$	500	$	2,169
Imaging and Reservoir Services		316		665
Optimization Software & Services		946		766
Devices		78		48
Total	$	1,840	$	3,648

Deferred revenue at December 31, 2020	$	3,648
Cash collected in excess of revenue recognized		1,831
Recognition of deferred revenue		(3,639	)
Deferred revenue at June 30, 2021	$	1,840