Capitalized Costs Relating to Oil and Gas Producing Activities
			United Kingdom		United States		Total
December 31, 2012:
	Proved	$	876,536	$	39,265	$	915,801
	Unproved		273,298		76,135		349,433
	Total capitalized costs		1,149,834		115,400		1,265,234

	Accumulated depreciation, depletion and amortization		(241,338)		(24,269)		(265,607)

	Net capitalized costs	$	908,496	$	91,131	$	999,627

December 31, 2011:
	Proved	$	429,246	$	67,421	$	496,667
	Unproved		183,110		75,224		258,334
	Total capitalized costs		612,356		142,645		755,001

	Accumulated depreciation, depletion and amortization		(192,027)		(16,735)		(208,762)

	Net capitalized costs	$	420,329	$	125,910	$	546,239

Costs Incurred in Oil and Gas Property Acquisition, Exploration and Development Activities
				United Kingdom		United States		Total
Year Ended December 31, 2012:
	Acquisition costs:
		Proved	$	143,004	$	1,176	$	144,180
		Unproved		46,878		1,156		48,034
	Exploration costs			46,730		15,397		62,127
	Development costs			302,038		8,099		310,137
Total costs incurred			$	538,650	$	25,828	$	564,478

Year Ended December 31, 2011:
	Acquisition costs:
		Proved	$	2,595	$	-	$	2,595
		Unproved		46,107		2,840		48,947
	Exploration costs			51,820		75,880		127,700
	Development costs			79,898		10,560		90,458
Total costs incurred			$	180,420	$	89,280	$	269,700

Year Ended December 31, 2010:
	Acquisition costs:
		Proved	$	-	$	2,386	$	2,386
		Unproved		1,184		40,155		41,339
	Exploration costs			50,328		32,027		82,355
	Development costs			22,047		1,884		23,931
Total costs incurred			$	73,559	$	76,452	$	150,011

Results of Operations for Oil and Gas Producing Activities
			United Kingdom		United States		Total
Year Ended December 31, 2012:
	Revenues	$	207,181	$	11,877	$	219,058
	Production expenses		51,568		6,968		58,536
	DD&A		56,813		7,574		64,387
	Impairment of oil and gas properties		-		53,072		53,072
	Income tax expense (benefit)		61,256		(19,508)		41,748
	Results of activities	$	37,544	$	(36,229)	$	1,315

Year Ended December 31, 2011:
	Revenues	$	41,754	$	18,337	$	60,091
	Production expenses		8,622		9,046		17,668
	DD&A		14,312		10,713		25,025
	Impairment of oil and gas properties		-		65,706		65,706
	Income tax expense (benefit)		11,104		(23,495)		(12,391)
	Results of activities	$	7,716	$	(43,633)	$	(35,917)

Year Ended December 31, 2010:
	Revenues	$	60,501	$	11,174	$	71,675
	Production expenses		11,086		4,261		15,347
	DD&A		22,020		5,273		27,293
	Impairment of oil and gas properties		-		7,692		7,692
	Income tax expense (benefit)		13,698		(2,118)		11,580
	Results of activities	$	13,697	$	(3,934)	$	9,763

Proved reserves are estimated quantities of oil, gas and natural gas liquids that geological and engineering data demonstrate with reasonable certainty to be recoverable in future years from known reservoirs under existing economic and operating conditions. Proved developed reserves are proved reserves that can reasonably be expected to be recovered through existing wells with existing equipment and operating methods. The reserve volumes presented are estimates only and should not be construed as being exact quantities. These reserves may or may not be recovered and may increase or decrease as a result of our future operations and changes in economic conditions. Our oil and gas reserves were audited by independent reserve engineers at December 31, 2012, 2011 and 2010.

		United Kingdom	United States	Total
Proved Oil Reserves (MBbls):
	Proved reserves at January 1, 2010	3,348	18	3,366
	Production	(545)	(6)	(551)
	Extensions and discoveries	457	34	491
	Revisions of previous estimates	404	13	417
	Proved reserves at December 31, 2010	3,664	59	3,723
	Production	(373)	(7)	(380)
	Purchases of reserves	303	-	303
	Revisions of previous estimates	466	(11)	455
	Proved reserves at December 31, 2011	4,060	41	4,101
	Production	(1,994)	(3)	(1,997)
	Purchases of reserves	11,071	-	11,071
	Sales of reserves in place	-	(19)	(19)
	Extensions and discoveries	1,992	-	1,992
	Revisions of previous estimates	(1,396)	(13)	(1,409)
	Proved reserves at December 31, 2012	13,733	6	13,739

Proved Developed Oil Reserves (MBbls):
	At December 31, 2010	1,240	14	1,254
	At December 31, 2011	1,270	41	1,311
	At December 31, 2012	5,261	6	5,267

		United Kingdom	United States	Total
Proved Gas Reserves (MMcf):
	Proved reserves at January 1, 2010	78,316	10,784	89,100
	Production	(3,071)	(2,636)	(5,707)
	Purchases of reserves	-	2,657	2,657
	Sales of reserves in place	(51,522)	-	(51,522)
	Extensions and discoveries	26,692	24,181	50,873
	Revisions of previous estimates	5,762	(3,209)	2,553
	Proved reserves at December 31, 2010	56,177	31,777	87,954
	Production	(94)	(5,076)	(5,170)
	Purchases of reserves	90	-	90
	Extensions and discoveries	-	46,100	46,100
	Revisions of previous estimates	(5,450)	(11,823)	(17,273)
	Proved reserves at December 31, 2011	50,723	60,978	111,701
	Production	(91)	(5,206)	(5,297)
	Purchases of reserves	1,409	998	2,407
	Sales of reserves in place	-	(5,213)	(5,213)
	Extensions and discoveries	473	-	473
	Revisions of previous estimates	4,387	(36,867)	(32,480)
	Proved reserves at December 31, 2012	56,901	14,690	71,591

Proved Developed Gas Reserves (MMcf):
	At December 31, 2010	555	13,281	13,836
	At December 31, 2011	795	22,704	23,499
	At December 31, 2012	3,147	14,690	17,837

		United Kingdom	United States	Total

Proved Reserves (MBOE):
	Proved reserves at January 1, 2010	16,401	1,815	18,216
	Production	(1,057)	(445)	(1,502)
	Extensions and discoveries	4,906	4,064	8,970
	Purchase of proved reserves, in place	-	443	443
	Sales of reserves	(8,587)	-	(8,587)
	Revisions of previous estimates	1,364	(522)	842
	Proved reserves at December 31, 2010	13,027	5,355	18,382
	Production	(389)	(853)	(1,242)
	Extensions and discoveries	-	7,683	7,683
	Purchase of proved reserves, in place	318	-	318
	Revisions of previous estimates	(442)	(1,981)	(2,423)
	Proved reserves at December 31, 2011	12,514	10,204	22,718
	Production	(2,009)	(871)	(2,880)
	Extensions and discoveries	2,071	-	2,071
	Purchase of proved reserves, in place	11,306	166	11,472
	Sale of reserves	-	(888)	(888)
	Revisions of previous estimates	(665)	(6,157)	(6,822)

	Proved reserves at December 31, 2012	23,217	2,454	25,671

Proved Developed Reserves (MBOE):
	At December 31, 2010	1,333	2,227	3,560
	At December 31, 2011	1,402	3,825	5,227
	At December 31, 2012	5,785	2,454	8,239

Future cash inflows and future production and development costs are determined by applying average 12-month pricing for the year. Oil, gas and condensate prices are escalated only for fixed and determinable amounts under provisions in some contracts. Estimated future income taxes are computed using current statutory income tax rates where production occurs. The resulting future net cash flows are reduced to present value amounts by applying a 10% annual discount factor.

At December 31, 2012 and 2011, the prices used to determine the estimates of future cash inflows were as follows:

Estimated future cash inflows are reduced by estimated future development, production, abandonment and dismantlement costs based on year-end cost levels, assuming continuation of existing economic conditions, and by estimated future income tax expense. Income tax expense, both U.S. and foreign, is calculated by applying the existing statutory tax rates, including any known future changes, to the pretax net cash flows giving effect to any permanent differences and reduced by the applicable tax basis. The effect of tax credits is considered in determining the income tax expense.

The standardized measure of discounted future net cash flows is not intended to present the fair market value of our oil and gas reserves. An estimate of fair value would also take into account, among other things, the recovery of reserves in excess of proved reserves, anticipated future changes in prices and costs, an allowance for return on investment and the risks inherent in reserve estimates.

Standardized Measure of Discounted Future Net Cash Flows
			United Kingdom		United States		Total
December 31, 2012:
	Future cash inflows	$	2,035,208	$	31,258	$	2,066,466
	Future production costs		(568,414)		(10,101)		(578,515)
	Future development costs		(581,277)		(896)		(582,173)
	Future income tax expense		(277,436)		-		(277,436)

	Future net cash flows (undiscounted)		608,081		20,261		628,342
	Annual discount of 10% for estimated timing		122,780		6,584		129,364

	Standardized measure of future net cash flows	$	485,301	$	13,677	$	498,978

December 31, 2011:
	Future cash inflows	$	941,208	$	218,295	$	1,159,503
	Future production costs		(144,106)		(47,344)		(191,450)
	Future development costs		(306,628)		(64,757)		(371,385)
	Future income tax expense		(238,111)		-		(238,111)

	Future net cash flows (undiscounted)		252,363		106,194		358,557
	Annual discount of 10% for estimated timing		37,250		56,435		93,685

	Standardized measure of future net cash flows	$	215,113	$	49,759	$	264,872

Principal Sources of Change in the Standardized Measure of Discounted Future Net Cash Flows
		2012		2011		2010

Standardized measure, beginning of period	$	264,872	$	111,297	$	55,698
Net changes in prices and production costs		(33,520)		147,776		86,915
Future development costs incurred		172,462		76,721		21,112
Net changes in estimated future development costs		(193,359)		(9,261)		(48,356)
Revisions of previous quantity estimates		(56,525)		(36,421)		16,375
Extensions and discoveries		102,386		68,452		110,059
Accretion of discount		42,589		18,801		2,630
Changes in income taxes, net		(74,778)		(136,157)		(35,306)
Sale of oil and gas produced, net of production costs		(165,547)		(44,556)		(56,327)
Purchased reserves		457,033		26,340		2,386
Sales of reserves in place		(6,971)		-		(48,310)
Change in production, timing and other		(9,664)		41,880		4,421

Standardized measure, end of period	$	498,978	$	264,872	$	111,297