SUPPLEMENTAL INFORMATION ON OIL AND NATURAL GAS PRODUCING ACTIVITIES (UNAUDITED)

This supplemental information is presented in accordance with certain provisions of ASC Topic 932 – Extractive Activities- Oil and Natural Gas. The geographic areas reported are the United States (North America), which includes our producing properties in the state of Texas, and International, which includes our producing properties offshore Gabon (Africa).

Costs Incurred for Acquisition, Exploration and Development Activities



	Year Ended December 31,
Costs incurred during the year:	2015		2014		2013
International:	(in thousands)
Exploration - capitalized	$	-	$	-	$	2,942
Exploration - expensed		28,052		15,358		12,431
Acquisition		-		-		-
Development		60,397		79,722		54,420
Total	$	88,449	$	95,080	$	69,793
United States:
Exploration - capitalized	$	-	$	-	$	-
Exploration - expensed		-		-		11,497
Acquisition		-		-		-
Development		-		8		113
Total	$	-	$	8	$	11,610

Capitalized Costs Relating to Oil and Natural Gas Producing Activities

Capitalized costs pertain to our producing activities in Gabon and the U.S and to undeveloped leasehold in Gabon, Angola, Equatorial Guinea and the U.S.

Capitalized costs pertain our producing activities in Gabon and the U.S and to undeveloped leasehold in Gabon, Angola, Equatorial Guinea, and the U.S.

	December 31,
	2015		2014
Capitalized costs:	(in thousands)
Properties not being amortized	$	10,000	$	47,290
Properties being amortized (1)		423,541		347,186
Total capitalized costs	$	433,541	$	394,476
Less accumulated depreciation, depletion, and amortization		(400,168)		(289,272)
Net capitalized costs	$	33,373	$	105,204

(1) Includes $8.7 million and $5.2 million asset retirement cost in 2015 and 2014.

Results of Operations for Oil and Natural Gas Producing Activities



	International						United States
	Year Ended December 31,							Year Ended December 31,
	2015		2014		2013		2015		2014		2013
	(in thousands)
Crude oil and natural gas sales	$	79,947	$	126,322	$	167,386	$	498	$	1,369	$	1,891
Production and other expense (1)		(51,959)		(34,503)		(38,783)		(171)		(467)		(735)
Depreciation, depletion and amortization		(32,137)		(19,079)		(15,302)		(633)		(901)		(1,528)
Exploration expenses		(45,203)		(15,358)		(12,431)		(1,250)		-		(11,497)
Impairment of proved properties		(78,080)		(98,341)		-		(3,242)		-		-
Bad debt expense		(2,700)		(2,400)		(1,562)		-		-		-
Income tax		(13,238)		(22,486)		(34,115)		(1,349)		-		-
Results from oil and natural gas producing activities	$	(143,370)	$	(65,845)	$	65,193	$	(6,147)	$	1	$	(11,869)

(1)Excludes corporate costs, general and administrative expenses and allocated corporate overhead.

Estimated Quantities of Proved Reserves

The estimation of net recoverable quantities of crude oil and natural gas is a highly technical process which is based upon several underlying assumptions that are subject to change. See “Item 1A. Risk Factors” and “Item 7. Management’s Discussion and Analysis of Financial Condition, Cash Flows and Liquidity – Critical Accounting Estimates – Estimated Quantities of Net Reserves”. For a discussion of our reserve estimation process, including internal controls, see “Item 1. Business – Reserves”.



	Oil	Natural
Proved reserves:	(MBbls)	Gas (MMCF)*
Balance at January 1, 2013	7,488	1,544
Production	(1,549)	(325)
Revisions of previous estimates	771	114
Extensions and discoveries	522	-
Balance at December 31, 2013	7,232	1,333
Production	(1,351)	(227)
Revisions of previous estimates	2,312	300
Extensions and discoveries	67	-
Balance at December 31, 2014	8,260	1,406
Production	(1,659)	(181)
Revisions of previous estimates	(3,746)	(172)
Balance at December 31, 2015	2,855	1,053

*The natural gas reserves shown as of December 31, 2015 include natural gas liquids (“NGL”) expressed as gas volumes using a ratio of 4.9 MMcf to 1 MBbl of NGL.



	Oil	Natural
Proved developed reserves:	(MBbls)	Gas (MMCF)
Balance at January 1, 2013	3,750	1,544
Balance at December 31, 2013	3,305	1,333
Balance at December 31, 2014	3,224	1,406
Balance at December 31, 2015	2,855	1,053

Our proved developed reserves are located offshore Gabon, in Texas and in waters of the Gulf of Mexico. The net negative revisions of previous estimates in 2015 were primarily a result of the loss of 3.5 years of production due to lower oil prices (2,705 MBOE) and the removal of sour reserves (1,440 MBbl), partially offset by positive revisions due to the performance of wells drilled in the 2014-2015 drilling campaign exceeding expectations (370 MBbl). The net positive revisions in 2014 were primarily due to better reservoir performance at the Avouma/South Tchibala field (1,500 MBbls) and a combination of better reservoir performance from existing wells at Etame, and revisions to proved undeveloped reserves at Etame (1,100 MBbls). Ebouri proved undeveloped reserves were revised downward (300 MBbls) due to higher costs of developing the reserves rendering them uneconomic. The net positive revisions in 2013 were primarily due to better reservoir performance at the Etame field (800 MBbls). In 2014, the extensions and discoveries were associated with the booking of the Southeast Etame/North Tchibala reserves. Extensions and discovery reserve additions in 2013 were due to the drilling of the Avouma 3H well which extended the reservoir boundary further to the north at the Avouma field.

We maintain a policy of not booking proved reserves on discoveries until such time as a development plan has been prepared for the discovery. Additionally, the development plan is required to have the approval of our partners in the discovery. Furthermore, if a government agreement that the reserves are commercial is required to develop the field, this approval must have been received prior to booking any reserves.

Standardized Measure of Discounted Future Net Cash Flows Relating to Proved Oil Reserves

The information that follows has been developed pursuant to procedures prescribed U.S. GAAP and uses reserve and production data estimated by independent petroleum consultants. The information may be useful for certain comparison purposes, but should not be solely relied upon in evaluating us or our performance.

In accordance with the guidelines of the SEC, our estimates of future net cash flow from our properties and the present value thereof are made using oil and natural gas contract prices using a twelve month average of beginning of month prices and are held constant throughout the life of the properties except where such guidelines permit alternate treatment, including the use of fixed and determinable contractual price escalations. The future cash flows are also based on costs in existence at the dates of the projections, excluding Gabon royalties, and the interests of other consortium members. Future production costs do not include overhead charges allowed under joint operating agreements or headquarters general and administrative overhead expenses. All future development costs related to future abandonment when the wells become uneconomic to produce.



	International						United States						Total
	December 31,						December 31,						December 31,
(In thousands)	2015		2014		2013		2015		2014		2013		2015		2014		2013
Future cash inflows	$	140,190	$	814,059	$	725,485	$	3,086	$	9,598	$	8,276	$	143,276	$	823,657	$	733,761
Future production costs		(81,973)		(307,331)		(223,643)		(1,644)		(1,475)		(3,038)		(83,617)		(308,806)		(226,681)
Future development costs (1)		(10,900)		(136,137)		(164,142)		(259)		-		-		(11,159)		(136,137)		(164,142)
Future income tax expense		(21,598)		(177,924)		(154,519)		-		(359)		(825)		(21,598)		(178,283)		(155,344)
Future net cash flows		25,719		192,667		183,181		1,183		7,764		4,413		26,902		200,431		187,594
Discount to present value at 10% annual rate		491		(47,528)		(48,859)		(252)		(3,516)		(1,299)		239		(51,044)		(50,158)
Standardized measure of discounted future net cash flows	$	26,210	$	145,139	$	134,322	$	931	$	4,248	$	3,114	$	27,141	$	149,387	$	137,436

(1)Includes costs expected to be incurred to abandon the properties.

International income taxes represent amounts payable to the Government of Gabon on profit oil as final payment of corporate income taxes, and domestic income taxes (including other expenses treated as taxes), and domestic income taxes represent amounts payable for severance and ad-valorem taxes in Texas.

Changes in Standardized Measure of Discounted Future Net Cash Flows

The following table sets forth the changes in standardized measure of discounted future net cash flows as follows:



	December 31,
	2015		2014		2013
	(in thousands)
Balance at beginning of period	$	149,387	$	137,436	$	152,902
Sales of oil and natural gas, net of production costs		(40,349)		(95,973)		(132,662)
Net changes in prices and production costs		(146,536)		(28,098)		(52,056)
Revisions of previous quantity estimates		(104,158)		74,497		43,815
Additions		-		2,188		29,620
Changes in estimated future development costs		(15,604)		31,686		(5,345)
Development costs incurred during the period		60,004		-		44,389
Accretion of discount		27,312		24,163		15,290
Net change of income taxes		104,303		(15,609)		26,120
Change in production rates (timing) and other		(7,218)		19,097		15,363
Balance at end of period	$	27,141	$	149,387	$	137,436

There are numerous uncertainties inherent in estimating quantities of proved reserves and in projecting future rates of production and timing of development expenditures, including many factors beyond our control. Reserve engineering is a subjective process of estimating underground accumulations of oil and natural gas that cannot be measured in an exact manner, and the accuracy of any reserve estimate is a function of the quality of available data and of engineering and geological interpretation and judgment. The quantities of oil and natural gas that are ultimately recovered, production and operating costs, the amount and timing of future development expenditures and future oil and natural gas sales prices may all differ from those assumed in these estimates. The standardized measure of discounted future net cash flow should not be construed as the current market value of the estimated oil and natural gas reserves attributable to our properties. The information set forth in the foregoing tables includes revisions for certain reserve estimates attributable to proved properties included in the preceding year’s estimates. Such revisions are the result of additional information from subsequent completions and production history from the properties involved or the result of a decrease (or increase) in the projected economic life of such properties resulting from changes in product prices. Moreover, crude oil amounts shown for Gabon are recoverable under a service contract and the reserves in place at the end of the contract period remain the property of the Gabon government.

In accordance with the current guidelines of the SEC, estimates of future net cash flow from our properties and the present value thereof are made using an unweighted, arithmetic average of the first-day-of-the-month price for each of the 12 months the year. Such prices are held constant throughout the life of the properties except where such guidelines permit alternate treatment, including the use of fixed and determinable contractual price escalations. For 2015, such average prices used for our reserve estimates reflected consistently low prices during the year and were $49.36 per Bbl for crude oil from Gabon, $40.43 per Bbl of U.S. crude oil and condensate and $2.35 per Mcf for U.S. natural gas. Further declines in prices could result in the estimated quantities and present values of our reserves being reduced.

Under the PSC in Gabon, the Gabonese government is the owner of all oil and natural gas mineral rights. The right to produce the oil and natural gas is stewarded by the Directorate Generale de Hydrocarbures and the Production Sharing Contract was awarded by a decree from the State. Pursuant to the contract, the Gabon government receives a fixed royalty rate of 13%. Originally, under the PSC, Gabonese government was not anticipated to take physical delivery of its allocated production. Instead, we were authorized to sell the Gabonese government’s share of production and remit the proceeds to the Gabonese government. Beginning in 2016, the Gabonese government has elected to take physical delivery of its allocated production and royalty volumes.

The consortium maintains a Cost Account, which entitles it to receive 70% of the production remaining after deducting the 13% royalty so long as there are amounts remaining in the Cost Account (“Cost Recovery”). At December 31, 2015, there was $87.9 million in the cost account net to our interest. As payment of corporate income taxes, the consortium pays the government an allocation of the remaining “profit oil” production from the contract area ranging from 50% to 60% of the oil remaining after deducting the royalty and Cost Recovery. The percentage of “profit oil” paid to the government as tax is a function of production rates. However, when the Cost Account becomes substantially recovered, we only recover ongoing operating expenses and new project capital expenditures, resulting in a higher tax rate. Also because of the nature of the Cost Account, decreases in oil prices result in a higher number of barrels required to recover costs, therefore at higher oil prices, our net reserves after taxes would decrease, but at lower prices our Cost Recovery barrels increase.

The Etame PSC allows for the carve-out of development areas which include all producing fields in the Etame Marin block. The Etame development area has a term of 20 years and will expire in 2021. The Avouma/South Tchibala field development area has a term of 20 years and will expire in 2025. The Ebouri field development area has a term of 20 years and will expire in 2026. The balance of the Etame Marin block comprises the exploration area, which expired in July 2014. This compares to the economic end date of reserves under the current reserve report prepared by our independent reserve engineering firm of May 2018.

The Mutamba Iroru PSC entitles us to receive 70% of any future production remaining after deducting the royalty so long as there are amounts remaining in the Cost Account. The Mutamba Iroru PSC provides for all commercial discoveries to be reclassified into a development area with a term of twenty years. At December 31, 2015, we have no proved reserves related to the Mutamba Iroru block.

The PSC for Block 5in Angola entitles us to receive 50% of the any future production so long as there are amounts remaining in the Cost Account. There are no royalty payments under the contract. The Block 5 PSC provides for a discovery to be reclassified into a development area with a term of 20 years. At December 31, 2015, we have no proved reserves related to Block 5 in Angola.

The PSC for Block P in Equatorial Guinea entitles us to receive up to 70% of any future production after royalty deduction so long as there are amounts remaining in the Cost Account. Royalty rates are 10-16% depending on production rates. The consortium pays the government an allocation of the remaining “profit oil” production from the contract area ranging from 10% to 60% of the oil remaining after deducting the royalty and Cost Recovery. The percentage of “profit oil” paid to the government as tax is a function of cumulative production. In addition, Equatorial Guinea imposes a 25% income tax on net profits. The Block P PSC provides for a discovery to be reclassified into a development area with a term of 25 years. At December 31, 2015, we have no proved reserves related to Block P in Equatorial Guinea.