Petrophysical Characterization of Lower Cretaceous Reservoir Intervals in the Ry‐1 Well, East Pande Block, Offshore Southern Tanzania

ABSTRACT The Lower Cretaceous reservoirs off the coast of the Mandawa Basin, in the East Pande Block of southern coastal and offshore Tanzania, have been poorly studied, and their detailed petrophysical properties remain insufficiently documented. This study integrates the interpretation of velocity deviation logs and conventional well logs, including sonic, neutron, density, gamma ray, and resistivity logs, to characterize these reservoirs. The results show that they exhibit fair to good porosity and estimated average permeability values ranging between 300 and 450 mD. Their average shale volume ranges from 27% to 33%, indicating the dominance of shaly sand units within these reservoirs. Despite the relatively high estimated permeability, the results also show that permeability becomes compromised when shaliness exceeds 30%. The results further indicate that the Lower Cretaceous reservoirs in the study area are dominated by primary porosity, with limited fractured intervals. These reservoirs are devoid of hydrocarbon accumulations and are interpreted to have been deposited during episodic water level fluctuations, agreeing with regional studies. This study provides a benchmark for future research in the region, including the integration of additional well data and core analysis to further constrain the depositional environment, and fracture and permeability distribution in the entire region.