Abstract

The Zafarani and Tangawizi giant discoveries are two of the most significant natural gas accumulations offshore Tanzania. Discovered by Statoil (now Equinor) with partner ExxonMobil in 2012 and 2013, Zafarani contains approximately 5.2 and Tangawizi 4.8 trillion ft³ (TCF; 147 and 136 billion m³, respectively) of gas in place and are located in Block 2, approximately 100 km (62 mi) from shore.

The partnership drilled 15 wells and made 9 discoveries. In total, more than 20 TCF of gas in place have been discovered in Block 2 from eight reservoirs dating from Early Cretaceous–Albian to Miocene in age. The Zafarani and Tangawizi discoveries are important play openers in the region, representing clastic reservoirs charged by the same nondrilled source rock but with very different trap styles and depositional settings. Although the Zafarani reservoir is interpreted as deep marine slope channels and channelized lobes trapped in a four-way closure along the Seagap fault system, the Tangawizi reservoir is a shallow buried Miocene stratigraphic trap interpreted to be remobilized deep marine sand-rich deposits associated with a major mass transport complex (MTC).