Kazakhstan: Tethys exploratory wells under test

May 9, 2011
Tethys Petroleum Ltd. Plans to test its AKD04 (Dero) appraisal well on the separate Dero part of the structure east of the company’s Doris oil discovery in Kazakhstan after it had indications of hydrocarbons in both zones found in the Doris well.

By OGJ editors
HOUSTON, May 9
-- Tethys Petroleum Ltd. Plans to test its AKD04 (Dero) appraisal well on the separate Dero part of the structure east of the company’s Doris oil discovery in Kazakhstan after it had indications of hydrocarbons in both zones found in the Doris well.

Tethys drilled AKD04 to 2,566 m, ran logs, and is preparing to run casing for tests. AKD04 had hydrocarbon indications in the Upper Jurassic carbonate zone and the edge of the Lower Cretaceous (Aptian) sandstone.

Meanwhile, the AKD05 Doris appraisal well is drilling ahead below 9 5/8-in. casing and should reach planned total depth of 2,500 m by end May.

Further evaluation of the recently acquired 3D seismic dataset using state of the art processing and interpretation techniques is revealing the probable presence of sand fans in the Cretaceous sandstone sequence, and these data are being integrated with the results of the well data to plan future appraisal well locations in the greater Doris area, the company said.

The AKD03 (Dione) exploratory well obtained no commercial oil flow from the overlying Upper Jurassic carbonate. The well previously tested at more than 400 b/d of dry oil from a new sandstone zone in the Upper Jurassic. The company believes that a much higher flow rate may be achieved with a horizontal or high-angle completion.

Tethys will now test the good-quality, potentially oil‐bearing Cretaceous sandstone interval that is similar to the main reservoir zone in the Doris discovery well and which shows the best reservoir properties of the zones being tested. It is evaluating the extent and potential of this Dione flank structure using the new 3D seismic dataset.

The KBD01 (Kalypso) wildcat, on a large structure 50 km northwest of Doris, is drilling at 2,498 m. Primary target is at 4,000 m with secondary objectives above. Seismic shows Kalypso to have as much as 400 m of vertical closure. Hydrocarbon shows have been observed in the drilled section, and it is expected that this well will reach total depth in July 2011.