Asset Retirement Obligations

9 Months Ended

Sep. 30, 2011

Asset Retirement Obligation [Abstract]

ASSET RETIREMENT OBLIGATIONS

(10) ASSET RETIREMENT OBLIGATIONS

     Our asset retirement obligations primarily represent the estimated present value of the amount 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. A reconciliation of our liability for plugging, abandonment and remediation costs for the nine months ended September 30, 2011 is as follows (in thousands):

	Nine Months
	Ended
	September 30,
	2011
Beginning of period — continuing operations	$	60,693
Liabilities incurred		2,299
Liabilities settled		(3,109	)
Accretion expense — continuing operations		3,980
Change in estimate		11,270
End of period — continuing operations	$	75,133

     Accretion expense is recognized as a component of depreciation, depletion and amortization expense on our consolidated statements of operations.