Abstract

Tripura Fold belt has huge amount of natural gas reserves. The uplifted Tripura fold belt has undergone severe folding, faulting and thrusting during the different phases of post collision events. The study area has complexity in terms of overpressure, high stress and lithology. ONGC has drilled several wells in the region with encouraging result, but the main challenges faced during drilling were various well control and instability issues like: kicks, tight pull, and stuck pipe, lost in hole (LIH) etc. Past drilling experience indicated the existence of overpressure in middle and lower Bhuban formations. Drilling through these high stressed and overpressure formation led to excessive non-productive time (NPT), thereby increasing the drilling cost. Borehole instability and severe hole enlargement led to poor log data acquisition thereby affecting the reservoir characterization.