SUPPLEMENTAL INFORMATION - NATURAL GAS AND CRUDE OIL PROPERTIES Supplemental Information on Natural Gas and Crude Oil Exploration, Development and Production Activities (Tables)

12 Months Ended

Dec. 31, 2016

Supplemental Information on Natural Gas and Oil Exploration, Development and Production Activities [Abstract]

Index price for reserves, by commodity [Table Text Block]

The indicated index prices for our reserves, by commodity, are presented below.

	Average Benchmark Prices
As of December 31,	Crude Oil (per Bbl)		Natural Gas (per Mcf)		NGLs (per Bbl)
2016	$	42.75	$	2.48	$	42.75
2015	50.28		2.59		50.28
2014	94.99		4.35		94.99

Schedule of Prices Used to Estimate Natural Gas and Crude Oil Reserves [Table Text Block]

The netted back price used to estimate our reserves, by commodity, are presented below.

	Price Used to Estimate Reserves*
As of December 31,	Crude Oil (per Bbl)		Natural Gas (per Mcf)		NGLs (per Bbl)
2016	$	38.67	$	1.85	$	11.97
2015	42.10		2.05		12.23
2014	84.65		3.92		32.27

Schedule of Proved Developed and Undeveloped Oil and Gas Reserve Quantities [Table Text Block]

The following tables present the changes in our estimated quantities of proved reserves:

	Crude Oil, Condensate (MBbls)		Natural Gas (MMcf)		NGLs (MBbls)		Total (MBoe)
Proved Reserves:
Proved reserves, January 1, 2014 (1)	93,830		739,640		48,671		265,774
Revisions of previous estimates	(29,777	)	(149,064	)	(10,204	)	(64,825	)
Extensions, discoveries and other additions, including infill reserves in an existing proved field	40,792		202,957		23,411		98,029
Acquisition of reserves	5		43		5		17
Dispositions	(13	)	(237,306	)	(8	)	(39,572	)
Production	(4,322	)	(19,298	)	(1,756	)	(9,294	)
Proved reserves, December 31, 2014	100,515		536,972		60,119		250,129
Revisions of previous estimates	(43,268	)	(154,775	)	(24,407	)	(93,471	)
Extensions, discoveries and other additions, including infill reserves in an existing proved field	48,707		311,709		30,835		131,494
Acquisition of reserves	17		215		23		76
Dispositions	(12	)	(82	)	(8	)	(34	)
Production	(6,984	)	(33,302	)	(2,835	)	(15,369	)
Proved reserves, December 31, 2015	98,975		660,737		63,727		272,825
Revisions of previous estimates	(22,097	)	(80,426	)	(7,130	)	(42,631	)
Extensions, discoveries and other additions	494		4,094		355		1,531
Acquisition of reserves	50,126		305,224		32,586		133,583
Dispositions	(601	)	(4,202	)	(424	)	(1,725	)
Production	(8,728	)	(51,730	)	(4,826	)	(22,176	)
Proved reserves, December 31, 2016	118,169		833,697		84,288		341,407

Proved Developed Reserves, as of:
December 31, 2014	26,798	186,633	17,002	74,905
December 31, 2015	26,257	175,367	15,011	70,496
December 31, 2016	30,013	264,452	24,196	98,284
Proved Undeveloped Reserves, as of:
December 31, 2014	73,717	350,339	43,117	175,224
December 31, 2015	72,718	485,370	48,716	202,329
December 31, 2016	88,156	569,245	60,092	243,122

Results of Operations for Oil and Gas Producing Activities Disclosure [Table Text Block]

The results of operations for crude oil and natural gas producing activities are presented below. The results include activities related to both continuing and discontinued operations and exclude activities related to gas marketing and other income.

	Year Ended December 31,
	2016			2015			2014
	(in thousands)
Revenue:
Crude oil, natural gas and NGLs sales	$	497,353		$	378,713		$	495,562
Commodity price risk management gain (loss), net	(125,681		)	203,183			309,219
	371,672			581,896			804,781
Expenses:
Lease operating expenses	59,950			56,992			43,682
Production taxes	31,410			18,443			27,194
Transportation, gathering and processing expenses	18,415			10,151			8,128
Exploration expense	4,669			1,102			948
Impairment of properties and equipment	9,973			161,620			167,280
Depreciation, depletion, and amortization	413,105			298,760			201,656
Accretion of asset retirement obligations	7,080			6,293			3,455
Loss on sale of properties and equipment	(43		)	(385		)	(75,972		)
	544,559			552,976			376,371
Results of operations for crude oil and natural gas producing activities before provision for income taxes	(172,887		)	28,920			428,410
Provision for income taxes	64,733			(10,394		)	(166,930		)
Results of operations for crude oil and natural gas producing activities, excluding corporate overhead and interest costs	$	(108,154	)	$	18,526		$	261,480

Cost Incurred in Oil and Gas Property Acquisition, Exploration, and Development Activities Disclosure [Table Text Block]

Costs incurred in crude oil and natural gas property acquisition, exploration, and development are presented below.

	Year Ended December 31,
	2016		2015		2014
	(in thousands)
Acquisition of properties: (1)
Proved properties (2)	$	268,567	$	3,561	$	11,973
Unproved properties	1,843,985		15		45,999
Development costs (3)	383,336		552,104		608,176
Exploration costs: (4)
Exploratory drilling	—		—		—
Geological and geophysical	4,669		—		1
Total costs incurred	$	2,500,557	$	555,680	$	666,149

__________

(1) Property acquisition costs represent costs incurred to purchase, lease or otherwise acquire a property.

(2) Includes approximately $40.9 million of infrastructure and pipeline costs in 2016.

(3) Development costs represent costs incurred to gain access to and prepare development well locations for drilling, drill and equip development wells, recomplete wells, and provide facilities to extract, treat, gather, and store crude oil, natural gas, and NGLs. Of these costs incurred for the years ended December 31, 2016, 2015, and 2014, $204.6 million, $207.8 million, and $125.2 million, respectively, were incurred to convert proved undeveloped reserves to proved developed reserves from the prior year end.

(4) Exploration costs - represents costs incurred in identifying areas that may warrant examination and in examining specific areas that are considered to have prospects of containing crude oil, natural gas, and NGLs

Capitalized Costs Relating to Oil and Gas Producing Activities Disclosure [Table Text Block]

Aggregate capitalized costs related to crude oil and natural gas exploration and production activities with applicable accumulated DD&A are presented below:

	As of December 31,
	2016			2015
	(in thousands)
Proved crude oil and natural gas properties	$	3,499,718		$	2,881,189
Unproved crude oil and natural gas properties	1,874,671			60,498
Uncompleted wells, equipment and facilities	150,424			109,385
Capitalized costs	5,524,813			3,051,072
Less accumulated DD&A	(1,534,678		)	(1,131,705		)
Capitalized costs, net	$	3,990,135		$	1,919,367

Standardized Measure of Discounted Future Cash Flows Relating to Proved Reserves Disclosure [Table Text Block]

The following table presents information with respect to the standardized measure of discounted future net cash flows relating to proved reserves. Changes in the demand for crude oil, natural gas, and NGLs, inflation and other factors make such estimates inherently imprecise and subject to substantial revision. This table should not be construed to be an estimate of the current market value of our proved reserves.

	As of December 31,
	2016			2015			2014
	(in thousands)
Future estimated cash flows	$	7,122,525		$	6,297,298		$	12,550,515
Future estimated production costs*	(1,624,167		)	(1,493,040		)	(2,746,811		)
Future estimated development costs	(2,219,914		)	(2,036,685		)	(2,528,755		)
Future estimated income tax expense	(597,476		)	(508,332		)	(2,336,510		)
Future net cash flows	2,680,968			2,259,241			4,938,439
10% annual discount for estimated timing of cash flows	(1,260,339		)	(1,162,377		)	(2,631,974		)
Standardized measure of discounted future estimated net cash flows	$	1,420,629		$	1,096,864		$	2,306,465

___________

* Represents future estimated lease operating expenses, production taxes, transportation, gathering and processing expenses.

Schedule of Changes in Standardized Measure of Discounted Future Net Cash Flows [Table Text Block]

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

	Year Ended December 31,
	2016			2015			2014
	(in thousands)
Beginning of period	$	1,096,864		$	2,306,465		$	1,782,163
Sales of crude oil, natural gas and NGLs production, net of production costs	(387,576		)	(293,127		)	(387,789		)
Net changes in prices and production costs (1)	(205,760		)	(1,752,921		)	129,213
Extensions, discoveries, and improved recovery, less related costs	15,128			489,178			1,444,581
Sales of reserves	(3,745		)	(463		)	(402,595		)
Purchases of reserves	487,636			374			238
Development costs incurred during the period	268,672			368,840			161,404
Revisions of previous quantity estimates	(320,286		)	(1,286,462		)	(654,318		)
Changes in estimated income taxes	(13,630		)	902,994			(221,874		)
Net changes in future development costs	391,145			112,958			46,499
Accretion of discount	133,747			345,007			270,389
Timing and other	(41,566		)	(95,979		)	138,554
End of period	$	1,420,629		$	1,096,864		$	2,306,465

__________

(1) Our weighted-average price, net of production costs per Boe, in our 2016 reserve report decreased to $15.73 as compared to $17.30 for 2015 and $37.78 for 2014.