Abstract

Deccan Trap section in Cambay Basin occasionally is hydrocarbon bearing which makes it an unconventional reservoir. Evaluation of Deccan Trap section using resistivity based equation is usually taken with suspicion because interpretation results often do not confirm to test data and hence much confidence is not attached to its predictive value. Doubts are usually raised among geoscientists about the validity of modified Archie’s equation in such unconventional reservoirs.

To address this kind of alleged incompetency and to increase the level of interpretation confidence, rock physics based analysis was introduced as an additional resource and complementary support to resistivity based evaluation. Rock physics based analysis effectively displayed likely hydrocarbon bearing layers giving credence to usual resistivity based evaluation. A broad convergence of interpretation conclusions emanating from two independent sources, in three wells of Cambay Basin, was found encouraging.