Supplementary Information on Oil and Gas Operations—Unaudited (Tables)

12 Months Ended

Dec. 31, 2015

Oil and Gas Exploration and Production Industries Disclosures [Abstract]

Costs incurred in oil and gas property acquisition

The following tables disclose certain financial data relative to the Company’s oil and gas producing activities, which are located onshore and offshore in the continental United States:

Costs Incurred in Oil and Gas Property Acquisition, Exploration and Development Activities

(amounts in thousands)

	For the Year-Ended December 31,
	2015		2014		2013
Acquisition costs:
Proved (1)	$	2,287	$	3,064	$	177,880
Unproved (1)	2,550		39,164		35,008
Exploration costs:
Proved	29,322		67,297		34,344
Unproved	7,677		13,515		20,112
Development costs	9,888		55,722		41,328
Capitalized general and administrative and interest costs	12,881		22,121		19,911
Total costs incurred	$	64,605	$	200,883	$	328,583

Rollforward of accumulated depreciation, depletion and amortization of oil and gas producing activities

	For the Year-Ended December 31,
	2015			2014			2013
Accumulated depreciation, depletion and amortization (DD&A)
Balance, beginning of year	$	(1,648,060	)	$	(1,553,044	)	$	(1,472,244	)
Provision for DD&A	(62,138		)	(86,406		)	(69,357		)
Ceiling test writedown	(266,562		)	—			—
Sale of proved properties and other (2) (3)	819,305			(8,610		)	(11,443		)
Balance, end of year	$	(1,157,455	)	$	(1,648,060	)	$	(1,553,044	)
DD&A per Mcfe	$	1.82		$	1.99		$	1.82

(1) During 2014, the Company entered into a joint venture in Louisiana for an aggregate purchase price of $24 million for an approximate 30,000 acre leasehold position. During 2013, the Company closed on the Gulf of Mexico Acquisition for an aggregate cash purchase price of $188.8 million (see Note 2). Additionally, the Company acquired 13,500 net unevaluated acres in Oklahoma targeting the Woodford Shale in 2013.

(2) During 2015, the Company sold its Woodford and Mississippian Lime assets for an aggregate cash purchase price of $274.1 million (see Note 2).

(3) During 2015, the Company sold its Fort Trinidad assets for net proceeds of approximately $0.5 million and its East Haynesville assets for net proceeds of approximately $0.1 million. During 2014, the Company sold its Eagle Ford assets for net proceeds of approximately $9.8 million. During 2013, the Company sold 50% of its saltwater disposal systems and related surface assets in the Woodford for net proceeds of approximately $10.4 million and its non-operated Wyoming assets for a cash purchase price of $1.0 million.

Schedule of proved developed reserve quantities

The following table sets forth an analysis of the Company’s estimated quantities of net proved and proved developed oil (including condensate), gas and natural gas liquid reserves, all located onshore and offshore in the continental United States:

	Oil in MBbls		NGL in MMcfe		Natural Gas in MMcf		Total Reserves in MMcfe
Proved reserves as of December 31, 2012	1,635		24,366		188,264		222,441
Revisions of previous estimates	(156	)	804		38,383		38,247
Extensions, discoveries and other additions	434		6,099		30,429		39,132
Purchase of producing properties	1,833		1,915		22,274		35,187
Sale of reserves in place	(34	)	—		(15	)	(218	)
Production	(681	)	(4,754	)	(29,226	)	(38,066	)
Proved reserves as of December 31, 2013	3,031		28,430		250,109		296,723
Revisions of previous estimates	(37	)	2,894		9,976		12,650
Extensions, discoveries and other additions	475		49,990		82,364		135,205
Sale of reserves in place	(229	)	(334	)	(2,396	)	(4,105	)
Production	(803	)	(7,482	)	(31,028	)	(43,325	)
Proved reserves as of December 31, 2014	2,437		73,498		309,025		397,148
Revisions of previous estimates	(211	)	(3,571	)	(9,852	)	(14,698	)
Extensions, discoveries and other additions	163		16,078		45,645		62,702
Sale of reserves in place	(54	)	(45,692	)	(186,972	)	(232,988	)
Production	(529	)	(5,487	)	(25,502	)	(34,160	)
Proved reserves as of December 31, 2015	1,806		34,826		132,344		178,004
Proved developed reserves
As of December 31, 2013	2,709		23,173		163,728		203,152
As of December 31, 2014	2,089		42,584		182,567		237,688
As of December 31, 2015	1,549		15,792		78,533		103,615
Proved undeveloped reserves
As of December 31, 2013	322		5,257		86,381		93,571
As of December 31, 2014	348		30,914		126,458		159,460
As of December 31, 2015	257		19,034		53,811		74,389

Standardized measure of discounted future cash flows

Standardized Measure

	December 31,
	2015			2014			2013
Future cash flows	$	487,834		$	1,711,404		$	1,243,627
Future production costs	(171,678		)	(372,690		)	(295,666		)
Future development costs	(116,591		)	(244,784		)	(185,188		)
Future income taxes	—			(121,192		)	(37,404		)
Future net cash flows	199,565			972,738			725,369
10% annual discount	(71,880		)	(424,176		)	(274,189		)
Standardized measure of discounted future net cash flows	$	127,685		$	548,562		$	451,180

Schedule of changes in standardized measure of discounted future net cash flows

Changes in Standardized Measure

	Year Ended December 31,
	2015			2014			2013
Standardized measure at beginning of year	$	548,562		$	451,180		$	230,823
Sales and transfers of oil and gas produced, net of production costs	(55,849		)	(173,540		)	(134,184		)
Changes in price, net of future production costs	(267,710		)	37,204			55,601
Extensions and discoveries, net of future production and development costs	70,928			237,290			70,181
Changes in estimated future development costs, net of development costs incurred during this period	31,007			11,094			(25,389		)
Revisions of quantity estimates	(14,427		)	25,591			58,508
Accretion of discount	60,071			47,130			23,776
Net change in income taxes	52,149			(32,034		)	(13,182		)
Purchase of reserves in place	—			—			191,964
Sale of reserves in place	(194,454		)	(7,240		)	(411		)
Changes in production rates (timing) and other	(102,592		)	(48,113		)	(6,507		)
Net increase (decrease) in standardized measure	(420,877		)	97,382			220,357
Standardized measure at end of year	$	127,685		$	548,562		$	451,180

Average sales price and average production costs

The historical twelve-month average prices of oil, gas and natural gas liquids used in determining standardized measure were:

	2015	2014	2013
Oil, $/Bbl	$50.29	$96.45	$106.19
Ngls, $/Mcfe	2.24	4.11	5.10
Natural Gas, $/Mcf	2.41	3.80	3.11