Further to the announcement on 3rd February, 2009 relating to the completion of appraisal drilling on the Ebok Field, offshore Nigeria. Afren plc and its partner Oriental Energy Resources (“Oriental”) are pleased to announce the independent analysis of the appraisal programme data.
An independent assessment of the in place oil and recoverable oil reserves from the Ebok field by Netherland, Sewell & Associates, Inc. (“NSAI”), post drilling of the Ebok-4 appraisal well has preliminarily confirmed a P50 STOIIP of 148 mmbbls oil for the FB1 and FB-2 areas of the field. Recoverable reserves have been calculated at 41.2 mmbbls. NSAI has further assigned 14 mmbbls oil of resources to the FB-1 and FB-2 field area.
An additional 21 mmbbls oil of contingent reserves and 33 mmbbls prospective resources have been assigned to other areas of the field including the Ebok West and Ebok North Fault Blocks.
Afren’s Management Case comprises a STOIIP of 178 mmbbls with recoverable reserves of 52 mmbbls for the FB-1 and FB-2 on Ebok, recognising amplitude conformance indicating oil in the D2 reservoir extending further south as a most likely scenario.
Successful appraisal of the Ebok West fault block and Northern area closures plus down flank potential in the FB1/FB-2 areas, during the initial development phase of the field is expected to lead to increased field production and a potential reserves upgrade in line with the resource assessment outlined by NSAI.
This represents a significant success for the Ebok field partners with the results considerably exceeding pre-drill expectations.
Ebok-4, drilled by the Transocean Trident IV jack up drilling unit, was spudded on 24th November 2008. The well reached a Total Depth of 3,838ft-measured depth (“md”) on 17th December 2008.
The well encountered a total gross oil column of 284ft in high quality reservoir sands ranging in depth from 2,560ft to 3,718ft. Of these gross pay intervals, 274ft is calculated as net oil pay. After an extensive logging and sampling programme, drill stem testing delivered a rate of 1,450 bopd of 20° to 25° API crude oil. Well test analysis indicates Page 2 of 4 that high skin conditions, which restricts oil flow into the well bore were prevailing over the test interval and as such constrained the surface flow rates. Well test analysis and dynamic reservoir simulation modelling confirms that flow-rates of circa 3,500 bopd per well in a production scenario will be achieved which is also consistent with offset production data from analogous fields in the area.
Based on these substantially better than expected results and the upgrade to the resource base established with the Ebok-4 well, it was decided that the Ebok-5 well (designated to test the Ebok West Fault Block) would be deferred and drilled as part of the phased development.
Afren and its partner Oriental are currently defining the field development scenario which includes the potential to install an Early Production System (“EPS”) at the field (subject to all necessary approvals in country) that could deliver production of 15,000 – 25,000 bopd from the field in early 2010 from 5 or more horizontal production wells and 1 water injection well drilled in the FB-1 and FB-2 areas of the field and tied back to a Floating Production Storage Offloading (“FPSO”) vessel moored at the field. A second development phase on the FB1 and FB-2 area of the field would entail the drilling of a further 8 or more development wells and increase full field production from between 35,000 to 50,000 bopd by end 2010.
Osman Shahenshah, Chief Executive of Afren, commented:
“The exceptional results from the Ebok appraisal drilling, well ahead of pre-drill expectations, confirm a material 52 million barrels recoverable oil development with upside potential of up to 106 million barrels. The Field Development Plan which will be submitted shortly by the partners for approval, encompasses a fast track Early Production System that will deliver up to 25,000 bopd in early 2010, with a full field development achieving up to 50,000 bopd by end 2010. This represents an outstanding success for the Ebok field partners and a transformational outcome for Afren. With a visible exit production rate of circa 65,000 bopd by end 2010, this ranks Afren firmly towards the top end of the London quoted established independent producers.”
Alhaji Mohammed Indimi, Chairman of Oriental, commented:
“We are delighted with the exceptional results of the Ebok appraisal drilling. From the quick turn around in the necessary preparation, and seamless operations during the appraisal drilling, is a testament to Afren’s strong technical skills, understanding of Nigerian oil and gas operations and strong partnership with Oriental. I am very proud of this achievement and look forward to working closely with Afren in finalising the Field Development Plan, the requisite approvals and preparations for development drilling on what will be one of the largest independent oil developments to date in Nigeria.”
Field technical description
Ebok is an undeveloped oil field, 50 km offshore in 135 ft of water in Nigeria's prolific south eastern producing area. The field is located close to several producing NNPC / Mobil JV fields and 55 km south-east of Mobil’s onshore QIT Terminal. The field was discovered by the NNPC / Mobil JV in 1968 (M-QQ1 (Ebok-1)), and two subsequent appraisal wells were drilled in 1970 (Ebok-2 and Ebok-3). A total of 271 ft. (83m) of net oil pay was encountered in Ebok-1 in four sands between 2,600 ft (800m) and 3,600 ft (1,100m). The Ebok-4 appraisal well was drilled by the Afren – Oriental partners in November 2008 and encountered a total gross oil column of 284ft in high quality reservoir sands ranging in depth from 2,560ft to 3,718ft. Drill stem testing delivered a consolidated rate of 1,544 bopd of 20° to 25° API crude oil. Afren has a 40% working interest in the Ebok field.