Property, Plant and Equipment (Tables)

12 Months Ended

Dec. 31, 2011

Property, Plant and Equipment [Abstract]

Schedule of Property, Plant and Equipment

	As at December 31, 2011
(Thousands of U.S. Dollars)	Cost		Accumulated DD&A				Net Book Value
Oil and natural gas properties
Proved	$	1,181,503		$	(562,521	)		$	618,982
Unproved		417,868			-				417,868
		1,599,371			(562,521	)			1,036,850
Furniture and fixtures and leasehold improvements		6,973			(4,002	)			2,971
Computer equipment		8,443			(4,174	)			4,269
Automobiles		1,295			(543	)			752
Total Property, Plant and Equipment	$	1,616,082		$	(571,240	)		$	1,044,842

	As at December 31, 2010
(Thousands of U.S. Dollars)	Cost		Accumulated DD&A				Net Book Value
Oil and natural gas properties
Proved	$	777,262		$	(334,858	)		$	442,404
Unproved		278,753			-				278,753
		1,056,015			(334,858	)			721,157
Furniture and fixtures and leasehold improvements		5,233			(2,831	)			2,402
Computer equipment		5,521			(2,358	)			3,163
Automobiles		779			(477	)			302
Total Property, Plant and Equipment	$	1,067,548		$	(340,524	)		$	727,024

Summary of Oil and Natural Gas Properties

The following is a summary of Gran Tierra's oil and natural gas properties not subject to depletion as at December 31, 2011:

	Costs Incurred in
(Thousands of U.S. Dollars)	2011		2010		2009		Prior to 2009		Total
Acquisition costs - Colombia	$	76,346		-		-		159,045	$	235,391
Acquisition costs - Argentina		45,015		-		-		-		45,015
Acquisition costs - PeruT		23,423		2,000		-		-		25,423
Acquisition costs - Brazil		22,891		12,395		-		-		35,286
Exploration costs - Colombia		19,233		12,427		3,311		487		35,458
Exploration costs - Argentina		181		683		163		229		1,256
Exploration costs - Peru		7,389		301		372		189		8,251
Exploration costs - Brazil		17,155		-		-		-		17,155
Development costs - Colombia		3,929		-		-		-		3,929
Development costs - Argentina		5,683		5,021		-				10,704
Total oil and natural gas properties not subject to depletion	$	221,245		32,827	$	3,846	$	159,950	$	417,868

Schedule of capitalized general and administrative expenses

The amounts capitalized in each of the Company's cost centers during the years ended December 31, 2011 and 2010 were as follows:

	Year ended December 31, 2011
(Thousands of U.S. Dollars)	Colombia		Argentina		Peru		Brazil		Total
Capitalized G&A, including stock-based compensation	$	7,996	$	3,189	$	1,183	$	1,985	$	14,353
Capitalized stock-based compensation	$	456	$	266	$	-	$	234	$	956

	Year ended December 31, 2010
(Thousands of U.S. Dollars)	Colombia		Argentina		Peru		Brazil		Total
Capitalized G&A, including stock-based compensation	$	4,127	$	1,171	$	287	$	-	$	5,585
Capitalized stock-based compensation	$	308	$	150	$	-	$	-	$	458

	Year ended December 31, 2009
(Thousands of U.S. Dollars)	Colombia		Argentina		Peru		Brazil		Total
Capitalized G&A, including stock-based compensation	$	1,600	$	600	$	30	$	-	$	2,230
Capitalized stock-based compensation	$	198	$	117	$	-	$	-	$	315