PROPERTY AND EQUIPMENT (Tables)

6 Months Ended

Jun. 30, 2022

PROPERTY AND EQUIPMENT.

Schedule of property and equipment

	June 30, 2022		December 31, 2021
	(in thousands)
Machinery and equipment	$	645,566	$	626,633
Buildings and leasehold improvements		131,769		108,177
Pipelines		72,829		72,829
Gathering and disposal infrastructure		64,265		63,228
Vehicles and equipment		28,501		28,502
Land		22,928		16,873
Computer equipment and software		4,956		5,395
Office furniture and equipment		773		764
Machinery and equipment - finance lease		533		544
Vehicles and equipment - finance lease		58		324
Computer equipment and software - finance lease		56		412
Construction in progress		40,996		19,834
		1,013,230		943,515
Less accumulated depreciation(1)		(574,348)		(551,727)
Total property and equipment, net	$	438,882	$	391,788

(1) Includes $0.6 million and $1.1 million of accumulated depreciation related to finance leases as of June 30, 2022 and December 31, 2021, respectively.

Schedule of amortization of intangible assets

	Three months ended June 30,				Six months ended June 30,
	2022		2021		2022		2021
	(in thousands)
Category
Depreciation expense from property and equipment	$	26,751	$	19,017	$	50,704	$	38,604
Amortization expense from finance leases		41		21		101		103
Amortization expense from intangible assets		2,720		2,616		5,445		5,233
Accretion expense from asset retirement obligations		267		(12)		596		1
Total depreciation and amortization	$	29,779	$	21,642	$	56,846	$	43,941