Exploring the Play Potential of the Tanzania Deepwater Basin, East Africa

Following the recent gas discoveries offshore Tanzania, we have revisited the deepwater basin with regional WesternGeco Multiclient 2D seismic. The 2D lines cover 11,374 km on 12 blocks with water depth from 500 to 3500m. In 2011, these 2D lines have been re-processed through Anisotropic Prestack time and depth migration. Further analysis has helped understanding the basin evolution and associated prospectivity.

Structural highs are observed and related to inversion on fracture zones. Stratigraphic trapping is characterized by pinch-out of slope channels and depositional lobes. Combined trapping related to listric slumping is also inferred. Variance, sweetness and frequency related seismic attributes demonstrate potential reservoir sands, regional seals and possible migration routes. DHI’s amplitude anomalies are confirmed by Seismic AVO attributes i.e. fluid stacks, indicating the effectiveness of hydrocarbon generation and migration. This is also sustained by petroleum system modelling results.

This study demonstrates the potential of this frontier basin and tries to answer the most common question about Tanzania prospectivity: where is the oil?

AAPG Search and Discovery Article #90142 © 2012 AAPG Annual Convention and Exhibition, April 22-25, 2012, Long Beach, California