The interpretation of the logs indicates that the MBS sandstone is about 7m thick and of good quality with average porosity 26%. The uppermost sandstone of 1m thickness is gas-bearing and overlies a water bearing interval that also contains significant gas saturations and oil shows. The MBS reservoir pressure is lower than virgin pressure but clearly not in direct communication with Cambay-74 and Cambay-64 and most likely separated by a small but linearly persistent fault.
The fault is difficult to interpret from the seismic data. It may divide the structure into a western and eastern compartment, the former having been evaluated by Cambay-75. This area may be in communication with the Akhol Juni field operated by Oil and Natural Gas Corporation Limited adjacent to the western Cambay block boundary which has been producing oil from the MBS at relatively low rates over a long period of time.
The OS II sandstones in Cambay-75 are poorly developed as three separate thin units each up to 1.5m thick. High gas readings were recorded while drilling although the log analysis indicates the presence of water with gas.
The Cambay-75 well will be plugged back and suspended enabling future re-entry if warranted by further analysis.
Future Cambay Work Program
Miocene MBS – analysis of the well results will be incorporated into the geological model to determine further potential well locations for both oil and gas. Whilst oil was the primary objective at Cambay -75 the discovery of gas in this part of the block at MBS provides an additional reservoir target which in combination with gas already discovered at other geological levels and the MBS in the northern part of the block could form the basis of a future gas project at Cambay
The eastern flank of the main MBS structure is about the same area as the western flank and may be better located to receive and preserve hydrocarbon charge from the main basin to the east. The prime objective of the work program remains to develop the oil production of the MBS.
Gas Appraisal Project – gas has been proven at the level of Miocene, Oligocene and Eocene in many of the old wells and in the wells drilled last year at Cambay. The field has previously produced gas from the Oligocene and Miocene.
Substantial resources of gas remain at Cambay and were the initial focus of the drilling program in 2008. The assessment of the commercial and technical aspects of the project remains high priority to be completed before further drilling.
Participants in the Cambay production sharing contract are: Oilex (operator) 45% and Gujarat State Petroleum Corporation Limited 55%.
