Supplemental Oil & Natural Gas Data (Unaudited) (Tables)

12 Months Ended

Dec. 31, 2015

Oil and Gas Exploration and Production Industries Disclosures [Abstract]

Schedule of Cost Incurred in Oil and Gas Property Acquisition, Exploration, and Development Activities

Costs incurred in oil and natural gas property acquisition, exploration and development, whether capitalized or expensed, are presented below:

	Successor						Predecessor
	Year Ended December 31, 2015		Year Ended December 31, 2014		December 17, 2013 through December 31, 2013		January 1, 2013 through December 16, 2013
(in thousands)
Property acquisition costs:
Proved	$	—	$	478,311	$	—	$	3,457
Unproved	—		—		—		463
Exploration costs	—		148		—		868
Development costs	130,276		555,629		22,266		577,568
Asset retirement costs	2,151		6,064		—		15,998
Total costs incurred (1)	$	132,427	$	1,040,152	$	22,266	$	598,354

⁽¹⁾  The total above does not reflect approximately $2 million, $6 million, $41,000 and $6 million of capitalized interest incurred for the years ended December 31, 2015, and December 31, 2014, and for the periods from December 17, 2013 through December 31, 2013, and January 1, 2013 through December 16, 2013, respectively.

Capitalized Costs Relating to Oil and Gas Producing Activities Disclosure

Aggregate capitalized costs related to oil, natural gas and NGL production activities with applicable accumulated depletion and amortization are presented below:

	December 31,
	2015			2014
	(in thousands)
Oil and natural gas:
Proved properties	$	4,231,836		$	4,025,595
Unproved properties	779,225			846,464
	5,011,061			4,872,059
Less accumulated depletion and amortization	(1,596,165		)	(525,007		)
	$	3,414,896		$	4,347,052

Results of Operations for Oil and Gas Producing Activities Disclosure

The results of operations for oil, natural gas and NGL producing activities (excluding corporate overhead and interest costs) are presented below:

	Successor								Predecessor
	Year Ended December 31, 2015			Year Ended December 31, 2014		December 17, 2013 through December 31, 2013			January 1, 2013 through December 16, 2013
(in thousands)
Revenues and other:
Oil, natural gas and natural gas liquids sales	$	575,031		$	1,298,402	$	50,324		$	1,103,245
Gains (losses) on oil and natural gas derivatives	29,175			78,784		(5,049		)	(34,711		)
	604,206			1,377,186		45,275			1,068,534
Production costs:
Lease operating expenses	245,155			364,540		15,410			295,811
Transportation expenses	52,160			41,842		2,576			46,774
Severance taxes, ad valorem taxes and California carbon allowances	70,591			97,683		2,130			57,063
	367,906			504,065		20,116			399,648
Other costs:
Exploration costs	—			—		—			24,048
Depletion and amortization	241,019			294,107		10,612			275,927
Impairment of long-lived assets	853,810			253,362		—			—
(Gains) losses on sale of assets and other, net	372			112,303		10,208			(23		)
	1,095,201			659,772		20,820			299,952
Income tax expense (benefit)	(68		)	69		—			65,280
Results of operations	$	(858,833	)	$	213,280	$	4,339		$	303,654

Schedule of Proved Developed and Undeveloped Oil and Gas Reserve Quantities

An analysis of the change in estimated quantities of oil and natural gas reserves, all of which are located within the U.S., is shown below:

	Successor
	Year Ended December 31, 2015								Year Ended December 31, 2014
	Oil MBbls		NGL MBbls		Natural Gas MMcf		Total MBOE		Oil MBbls		NGL MBbls		Natural Gas MMcf		Total MBOE
Total proved reserves:
Beginning of year	144,410		19,992		687,037		278,908		170,903		16,459		280,117		234,048
Revisions of previous estimates	(40,348	)	(2,012	)	(270,030	)	(87,365	)	(9,256	)	(1,391	)	42,514		(3,561	)
Extensions, discoveries and other additions	793		34		4,693		1,610		20,056		379		35,552		26,360
Purchases of minerals in place	—		—		—		—		4,991		17,542		408,857		90,676
Sales of minerals in place	—		—		—		—		(28,890	)	(12,326	)	(51,065	)	(49,727	)
Production	(10,963	)	(1,061	)	(33,852	)	(17,666	)	(13,394	)	(671	)	(28,938	)	(18,888	)
End of year	93,892		16,953		387,848		175,487		144,410		19,992		687,037		278,908
Proved developed reserves	93,892		16,953		387,848		175,487		104,337		14,702		552,184		211,069
Proved undeveloped reserves	—		—		—		—		40,073		5,290		134,853		67,839
Total proved reserves	93,892		16,953		387,848		175,487		144,410		19,992		687,037		278,908

	Successor								Predecessor
	December 17, 2013 through December 31, 2013								January 1, 2013 through December 16, 2013
	Oil MBbls		NGL MBbls		Natural Gas MMcf		Total MBOE		Oil MBbls		NGL MBbls		Natural Gas MMcf		Total MBOE
Total proved reserves:
Beginning of period	171,399		16,493		280,943		234,715		184,468		19,740		425,519		275,129
Revisions of previous estimates	—		—		—		—		(10,301	)	(3,235	)	(153,330	)	(39,092	)
Extensions, discoveries and other additions	—		—		—		—		9,360		1,595		29,756		15,913
Sales of minerals in place	—		—		—		—		(1,416	)	(847	)	(3,071	)	(2,775	)
Production	(496	)	(34	)	(826	)	(667	)	(10,712	)	(760	)	(17,931	)	(14,460	)
End of period	170,903		16,459		280,117		234,048		171,399		16,493		280,943		234,715
Proved developed reserves	113,717		7,977		202,798		155,494		114,213		8,011		203,624		156,161
Proved undeveloped reserves	57,186		8,482		77,319		78,554		57,186		8,482		77,319		78,554
Total proved reserves	170,903		16,459		280,117		234,048		171,399		16,493		280,943		234,715

The tables above include changes in estimated quantities of natural gas reserves shown in BOE using the ratio of six Mcf to one barrel.

Schedule of Standardized Measure of Discounted Future Cash Flows Relating to Proved Reserves

See Note 4 for additional information about income taxes.

	December 31,
	2015			2014			2013
	(in thousands)
Future estimated revenues	$	5,483,899		$	16,844,678		$	17,863,984
Future estimated production costs	(3,458,415		)	(7,742,035		)	(6,654,536		)
Future estimated development costs	(332,311		)	(1,132,807		)	(1,854,849		)
Future net cash flows	1,693,173			7,969,836			9,354,599
10% annual discount for estimated timing of cash flows	(697,801		)	(3,639,459		)	(4,719,267		)
Standardized measure of discounted future net cash flows	$	995,372		$	4,330,377		$	4,635,332
Representative NYMEX prices: (1)
Oil (Bbl)	$	50.16		$	95.27		$	96.89
Natural gas (MMBtu)	2.59			4.35			3.67

⁽¹⁾  In accordance with SEC regulations, reserves were estimated using the average price during the 12-month period, determined as an unweighted average of the first-day-of-the-month price for each month, excluding escalations based upon future conditions. The average price used to estimate reserves is held constant over the life of the reserves.

Schedule of Changes in Standardized Measure of Discounted Future Net Cash Flows

The following table summarizes the principal sources of change in the standardized measure of discounted future net cash flows:

	Successor
	December 31, 2015			December 31, 2014
	(in thousands)
Standardized measure–beginning of year	$	4,330,377		$	4,635,332
Sales and transfers of oil, natural gas and NGL produced during the period	(207,125		)	(794,337		)
Changes in estimated future development costs	431,622			68,290
Net change in sales and transfer prices and production costs related to future production	(3,203,620		)	(1,020,605		)
Extensions, discoveries and improved recovery	20,345			674,392
Purchases of minerals in place	—			548,256
Sales of minerals in place	—			(486,903		)
Previously estimated development costs incurred during the period	67,529			269,473
Net change due to revisions in quantity estimates	(544,334		)	(66,696		)
Accretion of discount	433,038			463,533
Changes in production rates and other	(332,460		)	39,642
Net decrease	(3,335,005		)	(304,955		)
Standardized measure–end of year	$	995,372		$	4,330,377

	Successor			Predecessor
	December 17, 2013 through December 31, 2013			January 1, 2013 through December 16, 2013
(in thousands)
Standardized measure–beginning of period	$	3,558,595		$	3,833,415
Sales and transfers of oil, natural gas and NGL produced during the period	(30,208		)	(703,597		)
Changes in estimated future development costs	—			20,932
Net change in sales and transfer prices and production costs related to future production	(1,272		)	(214,489		)
Extensions, discoveries and improved recovery	—			189,625
Sales of minerals in place	—			(13,279		)
Previously estimated development costs incurred during the period	—			401,791
Net change due to revisions in quantity estimates	—			(856,118		)
Accretion of discount	19,184			496,718
Income taxes	1,109,522			237,117
Changes in production rates and other	(20,489		)	166,480
Net increase (decrease)	1,076,737			(274,820		)
Standardized measure–end of period	$	4,635,332		$	3,558,595