Kazakhstan Operations Update

May 09, 2011

BOZOI, KAZAKHSTAN, May 09, 2011 (MARKETWIRE via COMTEX) —

Tethys Petroleum Limited (“Tethys” or the “Company”) (TSX: TPL) today provided an update on the progress in its Kazakhstan oil appraisal and exploration activities.

The AKD04 (Dero) appraisal well has now reached total depth of 2,566 metres and electric logging has been carried out. This well is located on the separate Dero part of the structure to the east of the AKD01 Doris oil discovery and was designed to ascertain the potential in the Upper Jurassic carbonate zone and the edge of the Lower Cretaceous (Aptian) sandstone in this area. Interpretation of the well data shows both the Jurassic carbonate and the Aptian sand to be present in the well with both showing indications of hydrocarbons. These two horizons were the zones that tested oil in the AKD01 well. Preparations are currently being made to run casing which will be followed by an appropriate testing programme – following receipt of the usual consents from Kazakh authorities.

In the AKD05 Doris appraisal well, the 9 5/8″ casing has been set and it is drilling ahead. This well is currently on prognosis and should reach planned total depth of 2,500 metres by the end of this month.

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.

Testing of the AKD03 (Dione) exploration well continues after the successful test of a new sandstone zone in the Upper Jurassic, which flowed dry oil at over 400 barrels per day. The company believes that a significantly higher flow rate may be achieved with a horizontal or high angle completion, and will determine optimised well designs as part of the overall development plan following completion of the appraisal and exploration programme. The overlying Upper Jurassic carbonate has now been tested but no commercial oil flow was obtained. Testing will now be undertaken on the good quality potentially oil-bearing Cretaceous sandstone interval (which is similar to the main reservoir zone in the AKD01 well) and which shows the best reservoir properties of the zones being tested. The extent and potential of this Dione flank structure is currently being evaluated using the new 3D seismic dataset.

The KBD01 (Kalypso) wildcat exploration well is currently drilling at a depth of 2,498 metres. This well is being drilled on a large structure some 50 km to the north west of the Doris discovery with its primary target being at approximately 4,000 metres and with secondary targets above this. Seismic shows this prospect to have up to 400 metres of potential vertical closure. Hydrocarbon shows have been observed in the drilled section. It is expected that this well will reach total depth in July 2011.

Tethys is focused on oil and gas exploration and production activities in Central Asia with activities currently in the Republics of Tajikistan, Kazakhstan and Uzbekistan. This highly prolific oil and gas area is rapidly developing and Tethys believes that significant potential exists in both exploration and in discovered deposits.

This press release contains “forward-looking information” which may include, but is not limited to, statements with respect to our operations. Such forward-looking statements reflect our current views with respect to future events and are subject to certain risks, uncertainties and assumptions. See our Annual Information Form for the year ended December 31, 2010 for a description of risks and uncertainties relevant to our business, including our exploration and development activities. Test production rates may vary from sustained production rates when developing a well or a deposit. The commerciality of any discovery can be affected by many factors including product prices, operating costs, capital costs, government take and sustained production levels and ultimate recovery of hydrocarbons. Hydrocarbon indications from drilling or wireline log data do not necessarily mean that mobile hydrocarbons are present in the formation or can be produced.

Contacts: Tethys Petroleum Limited Sabin Rossi Vice President Investor Relations +1 416 572 2065 +1 416 572 2201 (FAX) info@tethyspetroleum.com www.tethyspetroleum.com Tethys Petroleum Limited TD Canada Trust Tower 161 Bay Street, 27th Floor Toronto M5J 2S1, Canada Mobile site: http://m.tethyspetroleum.com In Asia-Pacific: Quam IR Anita Wan Associate Director + (852) 2217-2999 + (852) 2217-2999 (FAX) anita.wan@quamgroup.com
SOURCE: Tethys Petroleum Limited

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