A Tight – Low Resistivity Coastal Deposit Reservoir as Potential Prospect in Sungai Gelam Area, Jambi

Abstract

Sungai Gelam Structure is one of the backbone structure in Jambi Field. Air Benakat Formation (ABF) have been known as the main productive sand beside Talang Akar Formation, which oil and gas bearing, supporting most of South Sumatra Basin’s hydrocarbon production. The ABF is Miocene sediment deposited in coastal depositional environment. Typical clean and porous sand showed from lithology and porosity log are representation of main reservoirs. Since the main reservoirs found lower than estimated at S-X1 well, another potential reservoir was needed, on the other hand, the potential sand is typically shaly sand, tight, and low resistivity value. Integration method of sequence stratigraphy, pressure test/fluid analysis, ratio gas analysis, and petrophysical analysis has conducted to capture the other potential reservoirs. New uncovered A1 and A2 reservoirs are the potential sands which proven containing oil, despite resistivity value of 4 ohm.m, with oil rate ranging from 30-60 bopd. In conclusion, the integration evaluation method is successfully in identifying potential bypassed zone reservoirs within coastal deposit sediments.