Heritage Oil Plc (TSX:HOC)(LSE:HOIL) ("Heritage" or the "Company"), an independent upstream exploration and production company, is pleased to announce the publication of an independent Competent Person's Report ("CPR") compiled by industry specialists RPS Energy Consultants Limited ("RPS"). On 29 June 2012, Heritage announced the proposed acquisition of a major interest in Oil Mining Lease 30 in Nigeria ("OML 30") and this CPR has been commissioned to provide independent reserve and resource information and a valuation of OML 30, together with an update on certain existing assets in Heritage's portfolio.

The range of reserves and resources is as at 31 March 2012 and is based on the data and information available up until that date. The CPR assumes that the acquisition of OML 30 completes on 1 September 2012. All volumes are stated net of royalties unless otherwise stated.

Highlights:

OML 30, Nigeria;
- Gross Proved plus Probable reserves(1): 1,114 million barrels, 58% higher than management estimates as set out in the announcement issued by the Company on 29 June 2012
- Proved plus Probable net entitlement reserves to Heritage: 396 million barrels of oil
- Economic valuation of Proved plus Probable reserves estimated at between US$3,089 million and US$3,789 million, depending on the income tax scenario (post-tax, net Heritage share, assuming a 10% discount rate)
Zapadno Chumpasskoye Field, Russia;
- Proved plus Probable net entitlement reserves to Heritage: 65 million barrels of oil
- Economic valuation of Proved plus Probable reserves estimated at $336 million (post-tax, net Heritage share, assuming a 10% discount rate)
Miran Field, Kurdistan Region of Iraq ("Kurdistan");
- Contingent Resources - mean estimate of Heritage working interest of 56.25%, gross of royalty: 366 million barrels of oil equivalent, comprising 53 million barrels of oil and condensate and 1,815 billion cubic feet of gas, resulting in a mean net entitlement volume to Heritage of 136 million barrels of oil equivalent
- 2C estimate of net entitlement to Heritage of Contingent Resources: 130 million barrels of oil equivalent, comprising 15 million barrels of oil and condensate and 669 billion cubic feet of gas based on Heritage interest of 56.25%
- Prospective Resources - mean(2) un-risked estimate of working interest of 56.25% to Heritage, gross of royalty: 142 million barrels of oil equivalent, comprising 96 million barrels of oil, 256 billion cubic feet of gas and condensate of 3.1 million barrels

Tony Buckingham, Chief Executive Officer, commented:

"This independent report, assessing OML 30 and certain existing assets, highlights the strength of our current portfolio and the transformational nature of the proposed acquisition of OML 30 which creates shareholder value and is cash generative upon completion. The economic valuation of between US$3.4 billion and US$4.1 billion given for the current 2P reserves at OML 30 and our assets in Russia underlines the significant opportunity we have to create substantial value for shareholders. There is considerable upside in OML 30 which has not been assessed in the CPR, notably gas in the licence, estimated by management at 2.5 TCF, as well as undeveloped reservoirs and behind pipe reserves in some of the developed reservoirs that have not currently been targeted with new wells. These additional resources could provide further significant upside which has not been quantified in the CPR. Also, significant value exists for the Contingent and Prospective resources within the Miran Field that has not been estimated in this report due to the classification as resources."

The gross reserves and the net reserves attributable to Heritage are given in Table 1 and Table 2.

⁽¹⁾	Full field (100% basis) gross of royalty.
⁽²⁾	The mean is a statistical aggregate which assumes that each of the three prospects is successful. The probability of this occurring is 3% for the oil and 12% for the non-associated gas and condensate.

Table 1: OML 30 summary of reserves as of 31 March 2012

	Gross remaining reserves		Heritage Group net working interest⁽²⁾ reserves		Heritage Group net entitlement reserves at base case price forecast
	Gross of Royalty	Net of Royalty⁽¹⁾	Gross of Royalty	Net of Royalty⁽¹⁾	Gross of Royalty	Net of Royalty⁽¹⁾
	(MMstb)	(MMstb)	(MMstb)	(MMstb)	(MMstb)	(MMstb)
Proved Reserves (1P)	538	430	225	180	240	192
Proved plus Probable Reserves (2P)	1,114	891	456	365	495	396
Proved plus Probable plus Possible Reserves (3P)	1,733	1,387	709	567	770	616

Notes:
⁽¹⁾	Values net of royalty are the most economically meaningful, as they reflect the deduction of royalty volumes to which the government is entitled. Values gross of royalty are shown at Heritage's request
⁽²⁾	Net Working Interest volumes are notional values resulting from the dynamics of changing Net Profit Interests, as detailed in the CPR. Net Entitlement volumes are more economically meaningful as they represent the actual volumes to which Heritage is entitled

Table 2: Zapadno Chumpasskoye Field summary of reserves as of 31 March 2012

	Gross remaining reserves		Heritage Group net working interest⁽²⁾ reserves		Heritage Group net entitlement reserves at base case price forecast
	Gross of Royalty	Net of Royalty⁽¹⁾	Gross of Royalty	Net of Royalty⁽¹⁾	Gross of Royalty	Net of Royalty⁽¹⁾
	(MMstb)	(MMstb)	(MMstb)	(MMstb)	(MMstb)	(MMstb)
Proved Reserves (1P)	24	24	23	23	23	23
Proved plus Probable Reserves (2P)	69	69	65	65	65	65
Proved plus Probable plus Possible Reserves (3P)	172	172	163	163	163	163

Notes:
⁽¹⁾	The Chumpasskoye fiscal regime does not include a royalty
⁽²⁾	Under the terms of the Chumpasskoye licence the Net Working Interest volumes and Net Entitlement volumes are the same

The post-tax Net Present Values of Heritage's reserves in OML 30 and Zapadno Chumpasskoye at a 10% discount rate are tabulated in Table 3, including an alternative valuation for OML 30 with a different Income Tax scenario based on Heritage's view of pending legislation (the "Alternative Income Tax Scenario"). The Alternative Income Tax Scenario uses tax rates based on a proposed Petroleum Industry Bill that differ from the current Nigerian income tax rates for petroleum production, where, following the five-year period beginning in the 2012 tax year, a variable tax rate of between 70 and 80% (based on Shoreline's interest in production) is assumed instead of a flat rate of 85%.

Table 3: Post-tax valuation (net Heritage share) of Heritage's reserves for OML 30 and Zapadno Chumpasskoye Field as of 31 March 2012 (US$ million)

	OML 30		Zapadno Chumpasskoye
	Base Income Tax Scenario⁽¹⁾	Alternative Income Tax Scenario⁽²⁾
	Post-tax NPV (10%)	Post-tax NPV (10%)	Post-tax NPV (10%)
Proved Reserves (1P)	1,699	2,014	52
Proved plus Probable Reserves (2P)	3,089	3,789	336
Proved plus Probable plus Possible Reserves (3P)	4,470	5,457	976

Notes
⁽¹⁾	Assumes the income tax applicable under current Nigeria law
⁽²⁾	Assumes the income tax under changes to Nigerian Law which Heritage thinks might occur

With regards to OML 30, under the terms of the shareholders' agreement and option agreement in respect of Shoreline Natural Resources Limited ("Shoreline"), the private limited Nigerian company established by Heritage (through a wholly-owned subsidiary) and Shoreline Power Company Limited ("Shoreline Power"), Shoreline Power has an option to acquire a 30% participating interest in Shoreline for a term of six months from the date of the OML 30 acquisition agreement, for a consideration of 30% of the OML 30 net acquisition cost and expenses (the "Option"). If the Option is exercised, the Heritage Group's Net Entitlement Reserves and Net Present Value with respect to OML 30 will be reduced by 30% from those shown in Tables 1 and 3.

A summary of the Miran Field's contingent and prospective resources are given in Table 4 and Table 5 below.

Table 4: Miran Field summary of oil, gas and condensate contingent resources as of 31 March 2012

	Gross field		Heritage net Working Interest		Heritage net entitlement volumes
	Gross of royalty	Net of Royalty⁽¹⁾	Gross of Royalty ^{(2), (3)}	Net of Royalty ^{(1), (2), (3)}	Net of Royalty⁽¹⁾
	(MMboe)	(MMboe)	(MMboe)	(MMboe)	(MMboe)
1C Resources	340	306	191	172	93
2C Resources	588	529	331	298	130
3C Resources	1,044	939	587	528	187
Mean Resources⁽⁴⁾	650	585	366	329	136

Notes:
⁽¹⁾	Values net of royalty are the most economically meaningful, as they reflect the deduction of royalty volumes to which the government is entitled. Values gross of royalty are shown at Heritage's request
⁽²⁾	Net Working Interest volumes are notional values obtained by multiplying the corresponding Gross Field values by Heritage's working interest. They are not economically meaningful, however, as they do not reflect Heritage's actual entitlement under the terms of the Miran PSC. Net Entitlement volumes are economically meaningful as they do represent the actual volumes to which Heritage is entitled. They are by definition net of royalty
⁽³⁾	Calculated assuming state back-in upon commerciality which reduces Heritage net working interest from 75% to 56.25%
⁽⁴⁾	Mean values are estimated using a probability-weighted average calculation, in which the probabilities are 30%, 40% and 30% for the 1C, 2C and 3C resources, respectively
⁽⁵⁾	A conversion of 6MMscf (gas): 1MMstb (oil) has been used to convert gas to oil equivalent volumes

Table 5: Miran Field summary of oil, gas and condensate prospective resources as of 31 March 2012

	Gross Estimate				Heritage Working Interest Share⁽¹⁾
	Low (P90)	Best (P50)	High (P10)	Mean	Low (P90)	Best (P50)	High (P10)	Mean	GPoS⁽²⁾(%)
Resources (MMstb)
Miran East Oil (MMstb)	11	44	169	74	6	25	95	42	58%
Miran West Oil (MMstb)	17	56	131	67	10	32	74	38	38%
Miran South Oil (MMstb)	4	17	64	28	2	10	36	16	14%
Total Oil (MMstb)⁽³⁾								96
Non-Associated Gas (Bscf)
Miran East Gas (Bscf)	78	212	499	256	44	119	281	144	71%
Miran West Gas (Bscf)	21	94	268	124	12	53	151	70	58%
Miran South Gas (Bscf)	15	61	155	75	8	34	87	42	28%
Total Gas (Bscf)⁽³⁾								256
Condensate (MMstb)
Miran East (MMstb)	0.6	2.0	5.3	2.6	0.3	1.1	3.0	1.5	71%
Miran West (MMstb)	0.2	1.3	4.4	1.9	0.1	0.7	2.5	1.1	58%
Miran South (MMstb)	0.1	0.6	1.7	0.8	0.1	0.3	1.0	0.5	28%
Total Condensate (MMstb)⁽³⁾								3.1

Notes	1.	Calculated assuming state back-in upon commerciality which reduces Heritage net working interest from 75% to 56.25%
	2.	The chance or probability of discovering hydrocarbon volumes within the range defined. This is not an estimation of commercial chance of success
	3.	The sum of the Mean Prospective Resources is the statistical aggregation assuming that each of the three prospects is successful and that the probability of this occurring is 3% for the oil and 12% for the non-associated gas and condensate
	4.	All volumetric data is shown on a gross of royalty basis

Notes to Editors

In estimating resources RPS has used standard petroleum engineering techniques, which combine geological and production data with information concerning fluid characteristics and reservoir pressure, where available. RPS has estimated the degree of uncertainty inherent in the measurements and interpretation of the data and has calculated a range of reserves and resources and risk factors in accordance with the 2007 SPE/WPC/AAPG/SPEE Petroleum Resource Management System.
Consistent with UKLA guidelines the value of contingent and prospective resources has not been included in the CPR.

Heritage

Heritage is listed on the Main Market of the London Stock Exchange and is a constituent of the FTSE 250 Index. The trading symbol is HOIL. Heritage has a further listing on the Toronto Stock Exchange (TSX:HOC).
Heritage is an independent upstream exploration and production company engaged in the exploration for, and the development, production and acquisition of, oil and gas in its core areas of Africa, the Middle East and Russia.
Heritage has an exploration, appraisal and development asset in the Kurdistan Region of Iraq, exploration assets in Malta, Tanzania, Mali, Pakistan, Libya and the Democratic Republic of Congo and a producing property in Russia.
All dollars are US$ unless otherwise stated.
For further information please refer to our website, [ www.heritageoilplc.com ].

These materials are not for distribution, directly or indirectly, in or into the United States (including its territories and dependencies, any State of the United States and the District of Columbia), Australia, South Africa or Japan. These materials do not constitute or form a part of any offer or solicitation to purchase or subscribe for securities in the United States.

If you would prefer to receive press releases via email please contact Jeanny So ([ jeanny@chfir.com ]) and specify "Heritage press releases" in the subject line.

CAUTIONARY NOTE REGARDING FORWARD-LOOKING INFORMATION

This news release contains forward-looking information that is subject to various risks, uncertainties and other factors. Such statements include, but are not limited to, statements with regard to intentions, beliefs or current expectations concerning, amongst other things, the outcome of the proposed acquisition of OML 30, future production and grades, the economic limit or viability of assets, estimated revenues, reserves and resources, the timing and outcome of exploration projects and drilling programmes, projected capital expenditures, transportation costs, the timing of new projects, future cash flow and debt levels, fiscal regimes, the outcome of legislative changes, the outlook for the prices of hydrocarbons, the outlook for trends in the trading environment, statements about strategies, cost synergies, revenue benefits, integration and future production levels and timing of the Company, including OML 30, and the industry and countries in which it operates. All statements other than statements and information of historical fact are forward-looking statements. The use of any words "estimate", "forecast", "expect", "project", "plan", "target", "vision", "goal", "outlook", "may", "will", "should", "believe", "intend", "anticipate", "potential", and similar expressions are intended to identify forward-looking statements. Forward-looking statements are based on the Company's experience, current beliefs, assumptions, information and perception of historical trends available to the Company, and are subject to a variety of risks and uncertainties including, but not limited to those associated with resource definition and expected reserves and contingent and prospective resources estimates, unanticipated costs and expenses, the consummation of the proposed acquisition of OML 30, regulatory approval, fluctuating oil and gas prices, expected future production levels and timing, the ability to access sufficient capital to finance future development and credit risks, changes in regulatory framework in applicable jurisdictions where the Company has oil and gas assets, including changes to regulatory approval process and land-use designations, royalty, tax, environmental, greenhouse gas, carbon and other laws or regulations and the impact thereof and the costs associated with compliance. Although the Company believes that the expectations represented by such forward-looking statements are reasonable, there can be no assurance that such expectations will prove to be correct.
A number of factors could cause actual results and developments to differ materially from those expressed or implied by the forward-looking statements. In particular, there is no assurance that the conditions precedent to completion of the proposed acquisition of OML 30 will be satisfied or waived. Readers are cautioned that the assumptions and factors discussed in this information release are not exhaustive and readers are not to place undue reliance on forward-looking statements as our actual results may differ materially from those expressed or implied. The Company disclaims any intention or obligation to update or revise any forward-looking statements as a result of new information, future events or otherwise, subsequent to the date of this news release, except as required under applicable legislation. The forward-looking statements speak only as of the date of this news release and are expressly qualified by these cautionary statements. Readers are cautioned that the foregoing lists are not exhaustive and are made as at the date hereof. For a full discussion of material risk factors, see the section entitled "Risks" in the Annual Review included in our most recently filed Annual Report for the year ending 31 December 2011, which is available on the SEDAR website at [ www.sedar.com ] or the Company's website under the tab "Reports" at [ http://www.heritageoilplc.com/annualReports.cfm ]. Statements in this news release relating to reserves and resources are deemed to be forward-looking information, as they involve the implied assessment, based on certain estimates and assumptions, that the described reserves and resources, as the case may be, exist in the quantities predicted or estimated, and can be profitably produced in the future. This news release contains estimates of the Company's contingent resources. There is no certainty that it will be commercially viable to produce any portion of the Company's contingent resources. The assumptions relating to the Company's reserves and resources are contained in the CPR.

Forward-looking statements appear in a number of places in the CPR. The CPR reproduces data derived from studies conducted on behalf of the Company relating to its interest in reserves and resources of crude oil and gas in certain of the Company's properties and the reserves and resources of crude oil and gas of OML 30, and contains projections and estimates relating to the Company's current plans regarding volume of crude oil and gas, well development, amount and type of equipment and transportation infrastructure necessary to implement the Company's exploration and production plans and associated timeline and capital and operating expenditures required to purchase or build such equipment and infrastructure. In estimating facilities and costs estimates for OML 30, including capital expenditure, drilling costs, operating costs and abandonment costs, RPS relied on recent Company studies together with in-house RPS data. The estimates and projections contained in the CPR are based certain assumptions, such as geological and engineering estimates (which have inherent uncertainties), the assumed effects of regulation by governmental agencies, the assumed fiscal regime and tax on the extraction of commercial minerals and estimates of future commodity prices, operating costs and development costs, which may prove to be incorrect.

The projections and estimates contained in the CPR may differ materially from actual results. The Company may not pursue its exploration and development plans in their current form or on the timelines proposed in the CPR, or development or operating costs may differ materially from those assumed by RPS in the preparation of the CPR. There can be no assurances that the results and events contemplated by the forward-looking statements contained in the CPR will, in fact, occur.

CAUTIONARY NOTE REGARDING REPORTING STANDARDS

Unless otherwise indicated, RPS has, in compiling the CPR, used the definitions and guidelines set out by the 2007 SPE/WPC/AAPG/SPEE Petroleum Resource Management System ("PRMS") and has not used the standards of reserves measurement applied by the US Securities and Exchange Commission ("SEC"). The SEC standards differ from PRMS. The SEC permits oil and gas companies, in their filings with the SEC, to disclose only proved reserves, probable reserves and possible reserves, each term as defined by the SEC. This announcement contains data, such as prospective and contingent resources, presented in accordance with PRMS standards, which the SEC's guidelines would prohibit the Company from including in filings with the SEC. Accordingly, information concerning descriptions of oil and gas reserves and resources contained in this document may not be comparable to information required or permitted to be made public by US or other international companies engaged in oil and gas producing activities and subject to the reporting and disclosure requirements of the SEC.

National Instrument 51-101 ("NI 51-101") of the Canadian Securities Administrators imposes oil and gas disclosure standards for public companies in Canada engaged in oil and gas activities. The Company and Heritage Oil Corporation have obtained an exemption from Canadian securities regulatory authorities to permit them to provide disclosure in accordance with the relevant legal requirements for public companies in the United Kingdom. This facilitates comparability of oil and gas disclosure with that provided by the United Kingdom and other international issuers, given that the Company is listed on the United Kingdom capital markets.

Accordingly, the reserves and resources data and other oil and gas information included in this press release is disclosed in accordance with United Kingdom disclosure requirements and practices. Such information, as well as the information that the Company and Heritage Oil Corporation disclose in the future in reliance on the exemption, may differ from the corresponding information prepared in accordance with NI 51-101 standards.

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Heritage Announces Publication of Competent Persons Report Including Analysis of OML 30, Nigeria

Heritage Announces Publication of Competent Persons Report Including Analysis of OML 30, Nigeria