Asset Retirement Obligations (Tables)

9 Months Ended

Sep. 30, 2020

Asset Retirement Obligation [Abstract]

Schedule of asset retirement obligations

The changes in asset retirement obligations are as follows: 

	Nine Months Ended September 30, 2020
	(in millions)
Beginning asset retirement obligations	$	191
New wells placed on production	2
Changes in estimates (a)	(3)
Liabilities settled	(30)
Accretion of discount	7
Ending asset retirement obligations	167
Less current portion of asset retirement obligations	(32)
Asset retirement obligations - noncurrent	$	135

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(a)Changes in estimates are determined based on several factors, including updating abandonment cost estimates using recent actual costs incurred to abandon wells, credit-adjusted risk-free discount rates, economic well life estimates and forecasted timing of abandoning wells.