Further to the announcement on February 3, 2009 relating to the completion of appraisal drilling on the Ebok Field, offshore Nigeria, Afren and its partner Oriental Energy Resources have announced the independent analysis of the appraisal program 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 MMbo for the FB1 and FB-2 areas of the field. Recoverable reserves have been calculated at 41.2 MMb. NSAI has further assigned 14 MMbo of resources to the FB-1 and FB-2 field area.
An additional 21 Mmbo of contingent reserves and 33 MMb 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 MMb with recoverable reserves of 52 MMb 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 jackup, was spudded on November 24, 2008. The well reached a Total Depth of 3,838 feet measured depth on December 17, 2008.
The well encountered a total gross oil column of 284 feet in high quality reservoir sands ranging in depth from 2,560 feet to 3,718 feet. Of these gross pay intervals, 274 feet 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 degrees to 25 degrees API crude oil. Well test analysis indicates 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.
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 finalizing 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 kilometers offshore in 135 feet of water in Nigeria's prolific south eastern producing area. The field is located close to several producing NNPC / Mobil JV fields and 55 kilometers southeast 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 feet (83m) of net oil pay was encountered in Ebok-1 in four sands between 2,600 feet (800m) and 3,600 feet (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 284 feet in high quality reservoir sands ranging in depth from 2,560 feet to 3,718 feet. Drill stem testing delivered a consolidated rate of 1,544 bopd of 20 degrees to 25 degrees API crude oil. Afren has a 40% working interest in the Ebok field.
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