Asset Retirement Obligations

9 Months Ended

Sep. 30, 2018

Asset Retirement Obligation Disclosure [Abstract]

(10) ASSET RETIREMENT OBLIGATIONS

Our asset retirement obligations primarily represent the estimated present value of the amounts we will incur to plug, abandon and remediate our producing properties at the end of their productive lives. Significant inputs used in determining such obligations include estimates of plugging and abandonment costs, estimated future inflation rates and well lives. The inputs are calculated based on historical data as well as current estimated costs. A reconciliation of our liability for plugging and abandonment costs for the nine months ended September 30, 2018 is as follows (in thousands):

	Nine Months Ended September 30, 2018
Beginning of period	$	276,855
Liabilities incurred		2,668
Disposition of wells		(8,665	)
Acquisitions		13,438
Liabilities settled		(3,803	)
Accretion expense		12,132
Change in estimate		4,347
End of period		296,972
Less current portion		(6,327	)
Long-term asset retirement obligations	$	290,645

Accretion expense is recognized as a component of depreciation, depletion and amortization expense in the accompanying consolidated statements of operations. Acquisitions include an increase in our interest in certain properties in Northwest Pennsylvania.