Kazakhstan: Doris offset opens new oil play

By OGJ editors
HOUSTON, Apr. 18 -- Tethys Petroleum Ltd. said its Dione exploratory well opened a new Upper Jurassic sandstone oil play in the Greater Doris area of the North Caspian basin.

The AKD03 Dione well flowed at rates of more than 400 b/d of 43° gravity oil at 2,506-20 m on a 12-mm choke with no water and no observed depletion (OGJ Online, Feb. 18, 2011). The interval opens a new play that will form an additional target in current and future exploratory and appraisal wells, including the AKD04 and AKD05 appraisal wells.

AKD04 and AKD05 are expected to reach total depth by early May and end-May 2011 as the first wells to be drilled based on a new 3D seismic dataset.

AKD03 is 10 km southwest of and on a separate prospect from the AKD01 Doris discovery well. AKD03 total depth is 3,975 m. The well is being prepared to test the Upper Jurassic carbonate interval that flowed at the AKD01 discovery well. This test will be followed by the testing of the good-quality potentially oil-bearing Cretaceous sandstone interval that is similar to the main reservoir zone in AKD01 and which shows the best reservoir properties of the zones being tested.

AKD04 Dero is east of the Doris crest to test the continuation of the structure there. AKD05 is being drilled immediately updip of AKD01 well and targets both the Lower Cretaceous (Aptian) sandstones and Jurassic carbonates that were successfully tested in AKD01, as well as a possible third, overlying, horizon in the Middle Cretaceous (Albian) sandstone horizon.

The KBD01 Kalypso exploratory well is 50 km northwest of the Doris discovery. It is drilling below 1,398 m toward a planned total depth of 4,000 m. Kalypso targets potential reservoirs at several stratigraphic levels from the Cretaceous to the Permo-Carboniferous. The KBD01 well is the company’s first deep exploratory well Kul-Bas block, which contains several other attractive prospects.

The Upper Jurassic carbonate intervals in both the AKD02 Doris NW appraisal well and the G6RE Dodone exploratory well await testing with the application of radial drilling technology which is forecast to be in June 2011 when the equipment arrives on site. Further testing of these wells will be dependent on the results of the radial drilling.

Tethys Petroleum has applied to the Kazakh government for the next well to be drilled after AKD04, which is planned to be located on the Doto prospect southwest of Doris.