Supplemental Information On Oil And Gas Exploration And Production Activities (Unaudited) (Tables)

12 Months Ended

Dec. 31, 2018

Extractive Industries [Abstract]

Costs Incurred in Oil and Gas Producing Activities

The Company’s oil and natural gas activities for 2018 and 2017 were entirely within the United States of America. Costs incurred in oil and natural gas producing activities were as follows (in thousands):

	Years Ended December 31,
	2018		2017
Acquisition cost (1):
Proved	$	41,569	$	315,376
Unproved	31,268		245,589
Exploration costs:
Exploratory drilling	—		—
Geological and geophysical	630		1
Development costs	153,161		77,876
Total additions	$	226,628	$	638,842

(1) Acquisition costs incurred during 2018 consisted primarily of an acreage trade in the Midland Basin and during 2017 consisted primarily of the assets acquired in the Bold Transaction, both described in Note 3. Acquisitions and Divestitures of the Notes to Consolidated Financial Statements.  

Summary of Capitalized Costs, Impairment, and Depreciation, Depletion and Amortization

Capitalized costs, impairment, and depreciation, depletion and amortization relating to the Company’s oil and natural gas properties producing activities, all of which are conducted within the continental United States as of December 31, 2018 and 2017, are summarized below (in thousands):

	December 31,
	2018			2017
Oil and gas properties, successful efforts method:
Proved properties	$	830,843		$	708,646
Accumulated impairment to proved properties	(75,400		)	(103,608		)
Proved properties, net of accumulated impairments	755,443			605,038
Unproved properties	311,828			319,569
Accumulated impairment to Unproved properties	(45,688		)	(44,543		)
Unproved properties, net of accumulated impairments	266,140			275,026
Land	5,382			5,534
Total oil and gas properties, net of accumulated impairments	1,026,965			885,598
Accumulated depreciation, depletion and amortization	(127,256		)	(118,028		)
Net oil and gas properties	$	899,709		$	767,570

Summary of Changes in Quantities of Proved Oil and Natural Gas Reserves

A summary of the Company’s changes in quantities of proved oil, natural gas and NGLs reserves for the years ended December 31, 2018 and 2017 are as follows:      

	Oil (MBbl)		Natural Gas (MMcf)		NGLs (MBbl)		Total (MBOE)
Balance - December 31, 2016	7,111		20,401		1,540		12,051
Extensions and discoveries	19,558		29,644		6,264		30,763
Sales of minerals in place	(1,833	)	(6,853	)	(1	)	(2,976	)
Purchases of minerals in place	28,176		46,709		9,950		45,911
Production	(1,828	)	(3,260	)	(500	)	(2,872	)
Revision to previous estimates	(3,857	)	4,447		215		(2,901	)
Balance - December 31, 2017	47,327		91,088		17,468		79,976
Extensions and discoveries	10,148		17,673		3,116		16,209
Sales of minerals in place	(2,651	)	(14,300	)	(1,562	)	(6,596	)
Purchases of minerals in place	3,532		9,890		1,629		6,810
Production	(2,370	)	(3,610	)	(655	)	(3,627	)
Revision to previous estimates	3,048		12,476		947		6,075
Balance - December 31, 2018	59,034		113,217		20,943		98,847
Proved developed reserves:
December 31, 2016	6,052		13,545		1,051		9,361
December 31, 2017	11,949		23,336		4,123		19,961
December 31, 2018	14,325		26,110		4,969		23,646
Proved undeveloped reserves:
December 31, 2016	1,059		6,856		489		2,690
December 31, 2017	35,378		67,752		13,345		60,015
December 31, 2018	44,709		87,107		15,974		75,201

The table below presents the quantities of proved oil, natural gas and NGLs reserves attributable to noncontrolling interests as of December 31, 2018 and 2017:

As of December 31, 2018	Oil (MBbl)	Natural Gas (MMcf)	NGLs (MBbl)	Total (MBOE)
Proved developed	7,917	14,430	2,746	13,068
Proved undeveloped	24,709	48,140	8,828	41,560
Total proved	32,626	62,570	11,574	54,628
As of December 31, 2017	Oil (MBbl)	Natural Gas (MMcf)	NGLs (MBbl)	Total (MBOE)
Proved developed	6,775	13,232	2,338	11,318
Proved undeveloped	20,059	38,415	7,566	34,028
Total proved	26,834	51,647	9,904	45,346

Changes in PUD Reserves

Changes in PUD reserves for the years ended December 31, 2018 and 2017 were as follows (in MBOE):

Proved undeveloped reserves at December 31, 2016	2,690
Conversions to developed	(2,756	)
Extensions and discoveries	27,977
Sales of minerals in place	(391	)
Purchases of minerals in place	37,327
Revision to previous estimates	(4,832	)
Proved undeveloped reserves at December 31, 2017 (1)	60,015
Conversions to developed	(4,419	)
Extensions and discoveries	13,734
Sales of minerals in place	(4,702	)
Purchases of minerals in place	4,735
Revision to previous estimates	5,838
Proved undeveloped reserves at December 31, 2018 (2)	75,201

(1) Includes 34,029 MBOE attributable to noncontrolling interests.

(2) Includes 41,560 MBOE attributable to noncontrolling interests.

Schedule Of Standardized Measure

The Standardized Measure is as follows (in thousands):

	December 31,
	2018			2017
Future cash inflows	$	4,479,757		$	2,948,989
Future production costs	(1,013,131		)	(757,716		)
Future development costs	(963,536		)	(677,093		)
Future income tax expense	(90,570		)	(33,644		)
Future net cash flows	2,412,520			1,480,536
10% annual discount for estimated timing of cash flows	(1,453,068		)	(887,836		)
Standardized measure of discounted future net cash flows (1)	$	959,452		$	592,700

(1) At December 31, 2018 and 2017, the portion of the standardized measure of discounted future net cash flows attributable to noncontrolling interests was $530.2 million and $336.1 million, respectively.

Schedule Of Changes In Standardized Measure Of Discontinued Future Net Cash Flows Relating To Proved Oil And Natural Gas Reserves

The following is a summary of the changes in the Standardized Measure for the Company’s proved oil and natural gas reserves during each of the years in the three-year period ended December 31, 2018 (in thousands):

	December 31,
	2018			2017
Beginning of year	$	592,700		$	85,883
Sales of oil and gas produced, net of production costs	(136,143		)	(81,926		)
Sales of minerals in place	(41,320		)	(15,553		)
Net changes in prices and production costs	319,486			155,629
Extensions, discoveries, and improved recoveries	185,540			201,801
Changes in income taxes, net	(43,108		)	(5,941		)
Previously estimated development costs incurred during the period	153,161			76,447
Net changes in future development costs	(316,765		)	(168,940		)
Purchases of minerals in place	57,013			244,785
Revisions of previous quantity estimates	144,356			68,705
Accretion of discount	51,222			28,985
Changes in timing of estimated cash flows and other	(6,690		)	2,825
End of year (1)	$	959,452		$	592,700

(1) At December 31, 2018 and 2017, the portion of the standardized measure of discounted future net cash flows attributable to noncontrolling interests was $530.2 million and $336.1 million, respectively.