Asset Retirement Obligations

6 Months Ended

Jun. 30, 2014

(9) 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 life. 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 six months ended June 30, 2014 is as follows (in thousands):

	Six Months Ended June 30, 2014
Beginning of period	$	230,077
Liabilities incurred		3,854
Acquisitions		11,927
Disposition of wells		(12,057	)
Liabilities settled		(2,142	)
Change in estimate		1,777
Accretion expense		7,370
End of period		240,806
Less current portion		(5,037	)
Long-term asset retirement obligations	$	235,769

Accretion expense is recognized as a component of depreciation, depletion and amortization expense in the accompanying statements of operations.