Oil And Gas Properties (Tables)

6 Months Ended

Jun. 30, 2012



		Three Months Ended					Six Months Ended
		June 30,					June 30,
		2012			2011		2012			2011

Delay rental and geological and geophysical costs	$	1,146		$	1,299	$	1,757		$	1,654
Impairment of unproved properties ⁽¹⁾		—			6,640		144			6,640
Dry hole expense		(54	)		—		(55	)		(9	)
Total exploration expense	$	1,092		$	7,939	$	1,846		$	8,285

The amount recorded in the second quarter of 2011 reflects costs associated with a deepwater lease in which the term expired.

Changes In Asset Retirement Obligations


Asset retirement obligations at December 31, 2011 ..............	$	254,391
Liability incurred during the period........................................		115
Liability settled during the period.........................................		(80,166	)
Other revisions in estimated cash flows ⁽¹⁾............................		23,671
Accretion expense (included in depreciation and amortization)......		6,854
Asset retirement obligations at June 30, 2012.......................	$	204,865

The increased amount of these liabilities includes revisions to both non-producing and producing oil and gas properties. Increases to liabilities associated with non-producing properties include a corresponding cost of sales expense charge within our consolidated condensed statements of operations and comprehensive income while changes in estimates for producing properties are recorded as an increase to the related oil and gas properties property and equipment carrying costs included within our consolidated condensed balance sheet.