Sequence Stratigraphy of Miocene Deltaic Sands in the Srikail Gas Field, East-Central Bengal Basin: Insights from Mud Log and Wireline Log Data

A sequence stratigraphic analysis was conducted in the Srikail Gas Field, situated within the Tripura Uplift in the east-central Bengal Basin, near the Surma Sub-Basin. This study aimed to understand the sedimentary infill behaviour and the distribution of producing and non-producing sands by interpreting Mud Log and Wireline Log Data. Deltaic sands of the Miocene Surma Group were analysed, defining surfaces and systems tracts using Maximum Flooding Surfaces (MFS) as sequence boundaries. Four MFS and five third-order sequences (a to e) were identified. The stratigraphic relationship between this scheme and traditional Surma Group stratigraphy revealed that the Bhuban Formation corresponds to sequences a and b, while the Bokabil Formation correlates with sequences c to e. Producing sands A, B, and C were found in the transition from early to late Lowstand Systems Tract (LST), whereas non-producing sands, including the prominent D sand, were located in the Transgressive Systems Tract (TST). The sequence stratigraphic framework of the Surma Group succession offers valuable guidance for hydrocarbon exploration in the Bengal Basin, particularly in and around the Srikail field, with significant implications for both conventional and unconventional reservoirs.