Supplemental Information on Natural Gas and Oil Exploration, Development and Production Activities (Unaudited) (Tables)

12 Months Ended

Dec. 31, 2019

Capitalized Costs and Accumulated Depreciation, Depletion and Amortization

Capitalized Costs and Accumulated Depreciation, Depletion and Amortization ^(a)

	December 31,
	2019			2018			2017
	(in thousands)
Natural gas and oil properties:
Properties subject to depletion	$	9,345,557		$	10,974,929		$	10,572,453
Unproved properties		868,180			2,110,277			2,644,000
Total		10,213,737			13,085,206			13,216,453
Accumulated depreciation, depletion and amortization		(4,172,702	)		(4,062,021	)		(3,649,716	)
Net capitalized costs	$	6,041,035		$	9,023,185		$	9,566,737

^(a)	^{Includes capitalized asset retirement costs and the associated accumulated amortization.}

Costs Incurred for Property Acquisition, Exploration and Development

Costs Incurred for Property Acquisition, Exploration and Development ^(a)

	December 31,
	2019		2018		2017
	(in thousands)
Acquisitions
Acreage purchases	$	57,324	$	62,390	$	62,075
Oil and gas properties		—		1,683		18,269
Development		666,984		834,552		1,177,526
Exploration:
Drilling		—		1,380		2,030
Expense		35,117		32,196		50,920
Stock-based compensation expense		1,566		1,921		2,742
Gas gathering facilities:
Development		3,583		10,218		15,097
Subtotal		764,574		944,340		1,328,659
Asset retirement obligations		11,193		28,826		20,245
Total costs incurred	$	775,767	$	973,166	$	1,348,904

^(a)

^{Includes cost incurred whether capitalized or expensed.}

Proved Developed and Undeveloped Reserves


	Natural Gas			NGLs			Crude Oil and Condensate			Natural Gas Equivalents
	(Mmcf)			(Mbbls)			(Mbbls)			(Mmcfe) ^(a)
Proved developed and undeveloped reserves:
Balance, December 31, 2016		7,870,416			630,066			70,252			12,072,322
Revisions		70,222			83,338			(10,555	)		506,919
Extensions, discoveries and additions		2,866,103			87,572			15,997			3,487,519
Purchases		7,738			330			66			10,116
Property sales		(60,278	)		(2,356	)		(1,121	)		(81,133	)
Production		(490,552	)		(35,686	)		(4,785	)		(733,382	)
Balance, December 31, 2017		10,263,649			763,264			69,854			15,262,361
Revisions		178,595			84,993			7,197			731,735
Extensions, discoveries and additions		2,269,427			128,436			17,309			3,143,898
Purchases		—			—			—			—
Property sales		(135,884	)		(16,774	)		(4,276	)		(262,180	)
Production		(548,085	)		(38,325	)		(4,228	)		(803,408	)
Balance, December 31, 2018		12,027,702			921,594			85,856			18,072,406
Revisions		33,122			57,311			(12,320	)		303,068
Extensions, discoveries and additions		959,901			26,505			7,057			1,161,274
Property sales		(327,634	)		(28,324	)		(2,371	)		(511,811	)
Production		(578,114	)		(38,850	)		(3,690	)		(833,354	)
Balance, December 31, 2019		12,114,977			938,236			74,532			18,191,583
Proved developed reserves:
December 31, 2017		5,437,674			448,258			36,808			8,348,074
December 31, 2018		6,451,012			512,318			38,658			9,756,870
December 31, 2019		6,486,211			535,007			34,369			9,902,468
Proved undeveloped reserves:
December 31, 2017		4,825,975			315,006			33,046			6,914,287
December 31, 2018		5,576,690			409,276			47,198			8,315,536
December 31, 2019		5,628,766			403,229			40,163			8,289,115

^(a)	Oil and NGLs volumes are converted to mcfe at the rate of one barrel equals six mcf based upon the approximate relative energy content of oil to natural gas, which is not indicative of the relationship between oil and natural gas prices.

Changes in Proved Undeveloped Reserves

The following details the changes in proved undeveloped reserves for 2019 (Mmcfe):

Beginning proved undeveloped reserves at December 31, 2018	8,315,536
Undeveloped reserves transferred to developed	(1,215,684	)
Revisions^(a)	265,947
Sales	(214,637	)
Extension and discoveries	1,137,953
Ending proved undeveloped reserves at December 31, 2019	8,289,115

^(a) Includes 601 Bcfe of proved undeveloped reserves removed and deferred due to the five-year rule which can be included in our future proved reserves as these locations are added back to our five-year development plan.

Standardized Measure of Discounted Future Net Cash Flows

The standardized measure of discounted future net cash flows relating to proved natural gas, NGLs, crude oil and condensate reserves is as follows and excludes cash flows associated with derivatives outstanding at each of the respective reporting dates. Future cash inflows are net of third-party transportation, gathering and compression expense.

	As of December 31,
	2019			2018
	(in thousands)
Future cash inflows	$	48,718,733		$	64,287,737
Future costs:
Production		(23,320,477	)		(25,626,373	)
Development^(a)		(3,219,349	)		(3,824,936	)
Future net cash flows before income taxes		22,178,907			34,836,428
Future income tax expense		(4,179,297	)		(7,285,274	)
Total future net cash flows before 10% discount		17,999,610			27,551,154
10% annual discount		(11,371,037	)		(16,435,560	)
Standardized measure of discounted future net cash flows	$	6,628,573		$	11,115,594

^(a) 2019 includes $339.1 million of undiscounted future asset retirement costs estimated as of December 31, 2019, using current estimates of future abandonment costs.

Changes in Discounted Future Net Cash Flows

The following table summarizes changes in the standardized measure of discounted future net cash flows.

	December 31,
	2019			2018			2017
	(in thousands)
Revisions of previous estimates:
Changes in prices and production costs	$	(6,560,107	)	$	2,959,488		$	2,615,825
Revisions in quantities		(12,741	)		667,763			445,667
Changes in future development and abandonment costs		104,585			(686,632	)		(814,215	)
Net change in income taxes		1,125,639			(1,075,867	)		(706,531	)
Accretion of discount		1,317,349			814,725			372,743
Purchases of reserves in place		—			—			6,173
Additions to proved reserves from extensions, discoveries and improved recovery		552,710			2,543,296			2,128,135
Natural gas, NGLs and oil sales, net of production costs		(881,883	)		(1,547,580	)		(1,237,970	)
Actual development costs incurred during the period		676,520			851,188			1,202,618
Sales of reserves in place		(688,937	)		(226,953	)		(32,946	)
Timing and other		(120,156	)		(349,048	)		(266,214	)
Net change for the year		(4,487,021	)		3,950,380			3,713,285
Beginning of year		11,115,594			7,165,214			3,451,929
End of year	$	6,628,573		$	11,115,594		$	7,165,214

- Definition

Tabular disclosure of the net quantities of an enterprise's interests in proved developed and undeveloped reserves of (a) crude oil (including condensate and natural gas liquids), (b) natural gas (including coal bed methane), (c) synthetic oil, (d) synthetic gas, and (e) other nonrenewable natural resources that are intended to be upgraded during the period as of the beginning of the period, changes in quantities during the period, and as of the end of the period.

+ References + Details

- Definition

Tabular disclosure of the future net cash flows relating to proved oil and gas reserves and oil and gas subject to purchase under long-term agreements in which the enterprise participates in the operation of the properties on which the oil and gas is located or otherwise serves as the producer. This information is presented in aggregate and for each geographic area for which reserve quantities are disclosed.

+ References + Details