Asset Retirement Obligation

12 Months Ended

Dec. 31, 2011

Asset Retirement Obligation [Abstract]

Asset Retirement Obligation

8.Asset Retirement Obligation

As at December 31, 2011, the Company's asset retirement obligation was comprised of a Colombian obligation in the amount of $5.5 million (December 31, 2010 - $3.7 million), an Argentine obligation in the amount of $6.7 million (December 31, 2010 - $1.1 million) and a Brazilian obligation in the amount of $0.5 million (December 31, 2010 - nil). As at December 31, 2011, the undiscounted asset retirement obligation was $29.9 million. Revisions to estimated liabilities during the period relate primarily to changes in estimates of asset retirement costs and include, but are not limited to, revisions of estimated inflation rates, changes in property lives and the expected timing of settling asset retirement obligations. Changes in the carrying amounts of the asset retirement obligations associated with the Company's oil and natural gas properties were as follows:

	As at December 31,
(Thousands of U.S. Dollars)	2011			2010
Balance, beginning of year	$	4,807		$	4,708
Settlements		(345	)		(286	)
Disposal		(172	)		(720	)
Liability incurred		867			719
Liability assumed in a business combination (Note 3)		4,901			-
Foreign exchange		17			58
Accretion		673			328
Revisions in estimated liability		1,921			-
Balance, end of year	$	12,669		$	4,807
Asset retirement obligation - current	$	326		$	338
Asset retirement obligation - long term		12,343			4,469
Balance, end of year	$	12,669		$	4,807