ESTIMATED PROVED OIL, NATURAL GAS AND NATURAL GAS LIQUIDS RESERVES (UNAUDITED) (Tables)

12 Months Ended

Dec. 31, 2019

Estimated Proved Oil, Natural Gas And Natural Liquids Reserves [Abstract]

Changes in Estimated Proved and Estimated Proved Developed Reserves

			Natural Gas
	Oil	Natural Gas	Liquids
	(MBbls) (1)	(Mmcf) (2)	(MBbls) (1)	Mmcfe (3)
Proved developed and undeveloped reserves:
As of December 31, 2016 (Predecessor)	12,592	575,298	33,395	851,219
Revisions of previous estimates (4)	1,141	3,558	(422)	7,867
Purchases of minerals in place	1,228	6,578	415	16,444
Extensions and discoveries (5)	105	3,035	398	6,053
Production	(1,387)	(40,979)	(2,165)	(62,293)
Sales of minerals in place (6)	(286)	(3,784)	(27)	(5,663)
As of December 31, 2017 (Predecessor)	13,393	543,706	31,594	813,627
Revisions of previous estimates (7)	4,640	7,641	4,518	62,600
Extensions and discoveries (8)	7	4,192	104	4,859
Production	(1,304)	(40,066)	(2,388)	(62,222)
Sales of minerals in place (9)	(6,823)	(38,785)	(4,544)	(106,994)
As of December 31, 2018 (Successor)	9,913	476,688	29,284	711,870
Revisions of previous estimates (10)	(568)	(35,076)	(1,305)	(46,314)
Extensions and discoveries (11)	1	8	1	20
Production	(591)	(25,470)	(1,244)	(36,479)
Sales of minerals in place (12)	(3,212)	(298,114)	(25,988)	(473,313)
As of December 31, 2019 (Successor)	5,543	118,036	748	155,784
Proved developed reserves:
December 31, 2016 (Predecessor)	11,954	523,113	28,218	764,149
December 31, 2017 (Predecessor)	13,393	543,706	31,594	813,627
December 31, 2018 (Successor)	9,881	468,510	28,442	698,445
December 31, 2019 (Successor)	5,543	118,036	748	155,784
Proved undeveloped reserves:
December 31, 2016 (Predecessor)	638	52,185	5,177	87,070
December 31, 2017 (Predecessor)	—	—	—	—
December 31, 2018 (Successor)	32	8,178	842	13,425
December 31, 2019 (Successor)	—	—	—	—

(1)Thousands of barrels.

(2)Million cubic feet.

(3)Million cubic feet equivalent; barrels are converted to Mcfe based on one barrel of oil or natural gas liquids to six Mcf of natural gas equivalent.

(4)Revisions were attributable to a combination of reserve increases (81.8 Bcfe) resulting from improvements in SEC pricing from December 31, 2016 to December 31, 2017, reductions (85.0 Bcfe) due to the removal of all PUD reserves and an aggregate increase from various other revisions (11.0 Bcfe).

(5)Extensions and discoveries were primarily associated with drilling success in the Barnett Shale (4.2 Bcfe) and Mid-Continent area (1.5 Bcfe).

(6)Sales of minerals in place were primarily associated with the sale of properties in the Appalachian Basin (4.6 Bcfe), Central Texas (0.6 Bcfe) and San Juan Basin (0.5 Bcfe).

(7)Revisions were attributable to a combination of reserve increases (66.7 Bcfe) resulting from the Company’s emergence from bankruptcy on June 4, 2018 and the availability of capital required to develop the PUDs within the SEC five-year development limitation on PUDs, reserve increases (24.3 Bcfe) resulting from improvements in SEC pricing from December 31, 2017 to December 31, 2018, reductions (20.8 Bcfe) primarily due to negative revisions in Appalachian and San Juan basins, and an aggregate decrease (7.6 Bcfe) from various other revisions.

(8)Extensions and discoveries were primarily associated with drilling success in the Barnett Shale (4.8 Bcfe).

(9)Sales of minerals in place were primarily associated with the sale of all properties in Central Texas (106.1 Bcfe) with smaller sales in the Mid-Continent area (0.8 Bcfe) and other areas.

(10)Revisions were attributable to reserve decreases (49.0 Bcfe) resulting from declines in SEC pricing from December 31, 2018 to December 31, 2019, and an aggregate increase (2.7 Bcfe) from various other revisions.

(11)Extensions and discoveries were primarily associated with drilling success in the Appalachian Basin (less than 0.1 Bcfe).

(12)Sales of minerals in place were primarily associated with the sale of all properties in the San Juan Basin (154.3 Bcfe), Mid-Continent area (27.3 Bcfe), and Monroe Field (19.4 Bcfe), and the sale of substantially all properties in the Barnett Shale (250.6 Bcfe), and Permian Basin (21.5 Bcfe).