Bowleven, the West Africa focused oil and gas exploration group traded on AIM, announces that the Sapele-1 exploration well drilling in the Douala Basin, offshore Cameroon has been drilled to a total depth (TD) of 4,733 metres.
Drilling was halted due to technical limitations after encountering a high pressure gas reservoir in the Cretaceous. The bottom hole section has been cemented and is now being abandoned in advance of planned appraisal drilling.
• Oil, condensate and gas confirmed as present in the Cretaceous and the well may now have encountered a significant hydrocarbon column at TD.
• Proposed forward plan includes appraisal drilling and well testing to further evaluate Tertiary discoveries.
• Additional rig secured for drilling up to four wells on the Etinde Permit; expected on contract towards end February 2011.
The Sapele-1 well location was selected to intersect multiple independent exploration targets from the proven Tertiary fairway down to the deeper Cretaceous fairway from a single location.
On 10 January 2011, Bowleven advised that further Cretaceous targets had been identified beneath the original planned target depth of the well (4,450 metres) and the plan was to deepen the well. The well was drilled to a TD of 4,733 metres before drilling was halted due to a rapid influx of very high pressure gas. Consequently, logging of the interval was not possible and the bottom hole section is being abandoned. Based on an initial analysis of the major step change in pressure encountered and the interpretation of the seismic, it is considered that the well may have encountered a significant hydrocarbon column in the Cretaceous.
Further analysis of mudlogging and wireline data, together with gas chromatograph ratio analysis, has confirmed oil shows were encountered within thin sands in the upper part of the Cretaceous Epsilon Complex.
Further interpretation and calibration of the well and seismic data is required to assess fully the implications for Cretaceous volumetrics.
The Sapele-1 well has further highlighted the significant potential of the Douala Basin, with hydrocarbons encountered in both the Tertiary and Cretaceous fairways.
The stratigraphic nature of the Sapele-1 discoveries requires that further evaluation and appraisal is required to establish their scale and commerciality. Accordingly, the next step, subject to approval by the joint venture, is appraisal drilling to delineate the Tertiary discoveries.
Due to mechanical issues as a consequence of having to abandon the lower hole section it has been decided to carry out testing in the immediate appraisal well.
An extensive drilling programme is being planned for 2011, targeting the substantial prospectivity identified across the Etinde Permit.
As a result, Bowleven has contracted an additional jack-up rig (the 15K rated Vantage Sapphire Driller) which is expected to be mobilised from Gabon towards the end of February 2011. The contract is subject to satisfactory inspection and normal approvals by the joint venture. The contract contains a programme of three firm wells plus one contingent well (subject to a break option exerciseable by the joint venture after the second well) at a day rate of $120,000.
Further update announcements on drilling activities will be made as appropriate.
Kevin Hart, Chief Executive of Bowleven plc, commented:
“In addition to the earlier Tertiary discoveries, we are delighted to announce that the ground-breaking Sapele-1 well has now confirmed the presence of oil, condensate and gas across multiple intervals in the Cretaceous, further highlighting the significance and potentially transformational nature of this play in the Douala Basin. Bowleven has contracted an additional rig that can be used to target both the Tertiary and Cretaceous substantial prospectivity identified on the acreage. This will be integral in formulating the extensive drilling programme for 2011. Sapele-1 results bode well for an exciting and successful campaign in 2011. ”
Source:Bowleven, February 7, 2011;