PTR.L Regulatory News (PTR)

PetroNeft Resources plc

("PetroNeft" or the "Company")

Discovery of Significant New Oil Field at Sibkrayevskaya

PetroNeft Resources plc (AIM: PTR), the owner and operator of Licences 61 and 67, Tomsk Oblast, Russian Federation, is pleased to announce its largest single discovery to date, a new oil field at Sibkrayevskaya in Licence 61.

Highlights:

·; Sibkrayevskaya No. 372 well makes significant oil discovery in main Upper Jurassic target

o Approximately 12.6 metres of net oil pay in J1 interval - exceeding pre-drill estimates

o Good reservoir properties indicated with oil saturation throughout

o Open hole inflow test of 170 bopd (unstimulated)

o Sixth oil field discovered in Licence 61

·; Development drilling at Lineynoye continues to push field boundary significantly further north and encounters materially thicker pay

o An additional well is now planned to be drilled 500 metres beyond the most northerly well to date

·; Exploration to commence at Licence 67 with first well scheduled later this month

·; Russian Mineral Extraction Tax reduction law passed and comes into effect on 1 January 2012

o Enhancing profit margin from qualifying fields

Sibkrayevskaya No. 372 well

The Sibkrayevskaya No. 372 well at the Sibkrayevskaya prospect located in the north east corner of Licence 61 was spudded on 9 July 2011. It was a follow up to well No. 370 which was drilled in 1972. A comprehensive re-interpretation of the vintage well logs and drilling data from the 370 well using digitalised logs and modern interpretation tools had indentified potential "missed pay" in the Upper Jurassic J1 interval. In the new well, No. 372, the Upper Jurassic J1 oil reservoir horizon was intersected as expected at -2,350.5 metres true vertical depth. Preliminary evaluation of the logs indicates that the J1 interval consists of 12.6 metres of net pay with good reservoir properties and oil saturation throughout, exceeding pre-drill estimates. An open hole test was conducted over this interval and tested at a pro-rated inflow of 170 bopd unstimulated. Based on preliminary analysis, the oil is of good quality with an API gravity of 37 degrees, which is consistent with other fields in Licence 61.

Sibkrayevskaya is a very large structure which will require additional seismic and well delineation. The 372 well was drilled in a flank position on the structure and current mapping shows an area of over 50 square kilometres up dip from the oil-down-to level defined in the well. Current indications are that the ultimate recoverable reserves in the field could be significantly larger than the 44 million barrel pre-drill target defined by Ryder Scott for the prospect. The discovery also extends the area of known oil to the northeast corner of the licence area and improves the prospectivity of other structures in this area.

This discovery well adds a sixth oil field to Licence 61 and proves the strategy of following up on re-interpreted well logs from old wells that show potential by-passed oil pay zones. It is hoped to further appraise the Sibkrayevskaya oil field with a seismic programme and the drilling of at least one appraisal well in 2012.

Licence 61 Development programme

Two further development wells have been drilled from Pad 2 at the Lineynoye oil field. Well 208 encountered 8.8 metres of net oil pay. Well 207, which was the northernmost well drilled to date encountered 17.8 metres of net oil pay. This well was drilled at a location that had originally been interpreted to be outside the boundaries of the oil field and the result further proves that the Lineynoye field extends much further north than previously estimated. An additional well will now be added to this year's programme at Pad 2 to drill the reservoir approximately 500 metres further north of the 207 location.

The results of well 207 and other recent Pad 2 wells have shown that the northern part of the Lineynoye field has materially thicker pay and extends significantly further north than originally anticipated. This has positive implications for reserves and productivity in this region of the field and for the likelihood of several new structures north of Lineynoye/West Lineynoye to be oil bearing.

Licence 67 Exploration programme

Exploration on Licence 67 is due to commence shortly. The mobilisation of the drilling rig to the Cheremshanskaya site has been completed and rig-up operations are underway. It is expected that the well will be spudded later this month. The well is targeting objectives at the Upper, Middle and Lower Jurassic horizons following up on previously drilled wells. The well will take up to two months to complete drilling and testing.

Mineral Extraction Tax (MET) reduction law for small fields

The MET reduction law for small fields was signed into law by President Medvedev on 21 July 2011. The law will become effective from 1 January 2012. The law is applicable to undeveloped fields with Russian C1+C2 recoverable reserves below 5 million tonnes (approximately 37.5 mmbbls). The law applies a sliding scale of discounts depending on the initial size of the field. The Arbuzovskoye field which is the focus of our development activities for next year has Russian registered C1+C2 recoverable reserves of 1.3 million tonnes and consequently it will qualify for a 46% MET discount. This will significantly enhance the profitability and cashflows of the Arbuzovskoye and other qualifying oil fields and accelerate the development of such fields in the Licence area.

Dennis Francis, Chief Executive Officer of PetroNeft Resources plc commented:

"We are delighted with the discovery at Sibkrayevskaya, a significant new oil field which is our largest single discovery to date in terms of reserves. This is an especially important discovery, because it proves our strategy of following up on previously drilled structures by re-interpreting old well data using modern software and techniques to identify by-passed pay. The two well exploration programme now commencing at Licence 67 is also based on re-interpreted data from old wells. We look forward to updating shareholders on the results of these wells later in the year. "

For further information, contact:

The information contained in this announcement has been reviewed and verified by Mr. Dennis Francis, Director and Chief Executive Officer of PetroNeft, for the purposes of the Guidance Note for Mining, Oil and Gas Companies issued by the London Stock Exchange in March 2006. Mr. Francis holds a B.S. Degree in Geophysical Engineering and a M.S. Degree in Geology from the Colorado School of Mines. He has also graduated from the Harvard University Program for Management Development. He is a member of the American Association of Petroleum Geologists and the Society of Exploration Geophysicists. He has over 35 years experience in oil and gas exploration and development.

Forward Looking Statements

This announcement contains forward-looking statements. These statements relate to the Company's future prospects, developments and business strategies. Forward-looking statements are identified by their use of terms and phrases such as 'believe', 'could', 'envisage', 'potential', 'estimate', 'expect', 'may', 'will' or the negative of those, variations or comparable expressions, including references to assumptions.

The forward-looking statements in this announcement are based on current expectations and are subject to risks and uncertainties that could cause actual results to differ materially from those expressed or implied by those statements. These forward-looking statements speak only as at the date of this announcement. No statement in this announcement is intended to constitute a profit forecast or profit estimate for any period.

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