Background
The Ebok Field (Ebok) was awarded to Oriental in May 2007 by the ExxonMobil / Nigerian National Petroleum Corporation (NNPC) Joint Venture. The farm-out was structured such that the field benefits from the Nigerian Marginal Field Fiscal and Tax Regime.
 
Ebok is an undeveloped oil field located in OML 67, 50 km offshore in 135 ft of water in Nigeria's prolific south eastern producing area. The field was discovered by the ExxonMobil / NNPC 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); none of the zones were production tested although 24°API oil was recovered from the Ebok- 1 well.

The Ebok area is covered with good quality (1992) 3D seismic data and an extensive data set is available for all well drilled to date. Ebok is also located close to several producing ExxonMobil / NNPC JV fields and 55 km south-east of ExxonMobil’s onshore QIT Terminal. The initially estimated mean STOIIP at Ebok (pre 2008/2009 appraisal drilling) was 118 mmbbls of which 25 mmbbls was estimated as recoverable by the Company.
 
Commercial terms
In March 2008, Afren signed a Farm-In Agreement with Oriental to participate in the development of Ebok. Under the terms of the agreement, Afren is responsible for funding all capital and operating costs for the development of the field, and will recover the costs (with interest) from 100% of field revenues. Following cost recovery, the ExxonMobil JV will receive a Net Profit Interest, with Afren and Oriental sharing net revenues equally.

Further to the Ebok farm in, Afren has entered into a collaboration agreement with Oriental to pursue other potential development assets in the region and has subsequently farmed in to the nearby Okwok field and surrounding OML 115 acreage.

Delivering new production
IIn 2011, Afren and its local partner Oriental successfully commenced production at the Ebok field. By year end the partners had commissioned all 14 production wells associated with the initial phases of the field development. The project is Afren’s second major greenfield development offshore south-east Nigeria, following the Okoro field development, and first oil was achieved in a record time of little over two years following the first appraisal well drilled by the partners.

By the end of 2011 the Ebok field had produced approximately 3.0 million barrels of oil.

Fast track development solution
The selected development solution for the field incorporated two un-manned wellhead platforms, one positioned in the Central Area and one at the West Fault Block, tied back to a Mobile Offshore Production Unit (MOPU) where crude oil is processed, from where it is then piped to a Floating Storage Offloading vessel (FSO) spread-moored nearby, where it is stored prior to sale directly into the international market.

The MOPU is a former jack-up drilling rig that has been converted to a production facility by removing the drilling package and replacing it with a processing unit. The facility has the initial capacity to handle oil production of 50,000 bopd, and has been designed to allow for onsite expansion and upgrade to accommodate production from future additional development phases. The advantages of utilising a converted jack-up were many; the installation of the unit did not require a derrick barge, and it could be installed whilst drilling operations were in progress, allowing for simultaneous installation and drilling with minimal interruptions to work.

The FSO provides a storage volume in excess of 1.2 mmbbls, which allows for the sale of million-barrel cargoes that in turn provide us with maximum flexibility to optimise shipping and crude marketing economics. Similarly, the vessel was converted from a pre-existing tanker, greatly reducing lead times to delivery compared to if a new build vessel was commissioned. Furthermore, opting for the MOPU and FSO development configuration has provided an estimated total cost saving of US$51 million in upfront costs and day rate charges compared to alternative FPSO development solutions that were considered.

Progressive de-risking of upside potential
The Group completed an Ocean Bottom Cable 3D seismic survey over the whole Ebok/ Okwok/OML 115 area in November 2011, acquiring in total 348 km2 of new, high quality data. Processing of the new data is under way and expected to be completed by the second quarter of 2012. One of the primary purposes of the new data is to assist
in development planning for the Okwok field, alongside determining the optimal placement of one further appraisal well.

Creating a new production hub offshore south east Nigeria
Our development strategy is to systematically bring each proven area onstream, and through ongoing drilling continue to increase the reserves base and production from the field. We plan for the MOPU and FSO to become a central facility for not just the immediately surrounding Ebok structure but also for the broader Ebok/Okwok/OML 115 area, allowing for the economical and rapid tie-back of production from potential future developments on the acreage.    

Outlook
Afren and Oriental plan to drill a further four horizontal production wells from the West Fault Block location in 2012.
These will target proved oil bearing zones that were not captured by the initial phases of field development work. The field partners also plan to drill an exploration well on the Ebok North Fault Block during the first half of the year.
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