Afren Plc (Afren) has announced significant upgrade to Ebok volumetrics following full analysis of the Ebok-5 appraisal well results offshore Nigeria. The Ebok-5 appraisal well, which was drilled by the Transocean Adriatic IX jack up drilling unit, was drilled to a total depth of 3,743 feet on the Ebok Fault Block West (FBW), with drilling operations completed on November 17, 2009.
The well encountered a total gross oil column of 377 feet (comprising 323 feet in the D1 and LD-1E reservoir sands, in addition to a further 54 feet of gross oil pay in the D2 and LD-1F reservoirs).
The greater than expected oil column (particularly in the LD-1E reservoir) has led to an upgrade in volumetrics for FBW to 158 mmbbls STOIIP of which 40 mmbbls is estimated as recoverable (versus pre-drill estimates of 92 mmbbls STOIIP, 25 mmbbls recoverable), representing a 72% increase in volumes. This increases total 2P Ebok recoverable reserve estimates to 93 mmbbls.
The Ebok-5 well results will be fully integrated into Afren’s subsurface model and will further assist in de-risking the remaining 74 mmbbls appraisal potential at the Ebok field (with total resource potential of 167 mmbbls).
Post completion of the Ebok-5 appraisal well, the drilling rig re-located to the central area of the field and spudded the Ebok-6 appraisal well on November 20, 2009. The well is targeting an estimated 33 mmbbls STOIIP and 8mmbbls recoverable in the D2 Southern Lobe. Following completion of the Ebok-6 well, Development Phase 1a drilling will commence.
The Phase 1a development plan comprises five horizontal oil production wells in the D2 reservoir, one horizontal oil production well targeting the D1 reservoir and one water injection well in the central Fault Block 1 and Fault Block 2 areas of the field. All wells will be drilled from a single field location via a Well-head Support Structure (WSS) and mobile offshore production unit (MOPU). Fabrication of the WSS is complete and is in transit for delivery to the project.
The company is in the process of finalizing contract discussions on the production facilities. Associated gas produced will be utilized as fuel for the facilities’ power generation and as gas lift to assist well productivity.
Osman Shahenshah, chief executive of Afren, said: “The better than expected Ebok-5 well results further upgrade the reserve estimates for the project and provide a greater understanding of the broader Ebok – Okwok complex. With the benefit of an additional oil bearing data point, we will continue to deploy our core technical strengths and enhanced understanding in further unlocking the remaining upside potential at both the Ebok and Okwok fields.”
Alhaji Mohammed Indimi, chairman of Oriental, said: “We are very pleased with the Afren-Oriental partnership. The Ebok-5 appraisal well, supplements Ebok-4 drilling success, both of which have exceeded our pre-drill expectations and materially increased the Ebok resource base.”