Calvalley Logs Pay with Hiswah-4 Appraisal Well

Calvalley Petroleum reports that drilling operations on the vertical wellbore at the Hiswah-4 appraisal well have now been completed. On completion of wireline logging, the well will be sidetracked and a 400m horizontal wellbore drilled and then production tested. The Hiswah-4 well was drilled approximately 3km south east of Hiswah-3 to appraise the untested S.E. extension of the Hiswah pool. The vertical well bore was drilled to a total depth of 1276 meters.

The carbonate reservoir of the Saar Formation was encountered 5m high to prognosis at 1113 meters and wire-line logs indicate 80 meters of gross hydrocarbon column. Preliminary wireline log analysis and excellent light oil and gas shows indicate net hydrocarbon pay of about 59m with an average porosity of 16% and an average water saturation of 14%. Additional wireline logs to obtain reservoir pressure data are currently being acquired. Two 9 meter cores were also obtained from the oil reservoir from 1164 to 1182 meters and will analyzed to determine reservoir properties.

The well was a long stepout from the existing Hiswah wells and has significantly extended the potential productive area of the Hiswah field. Furthermore Hiswah-4 encountered the thickest hydrocarbon column yet found in the pool. Calvalley's technical team are now incorporating the new data into the reservoir mapping to assess the impact on the estimate of recoverable oil from the Hiswah Field.

Hiswah-4 is the second of four planned appraisal wells into the Hiswah oil pool. With the success at Hiswah-3 and the initial results from Hiswah-4 the initial appraisal program has been extended to fully delineate the extent of the hydrocarbon accumulation. The Block 9 Joint Venture has now approved the acquisition of a 3D seismic survey and a further four horizontal appraisal wells (total 8 wells) in Hiswah in 2005. This program is subject to regulatory approval from the Government of Yemen.

Calvalley Petroleum is operator of Block 9 in Yemen.