BG Group has reported an increase in total recoverable resources for the Mzia discovery and across blocks 1, 3, and 4 offshore southern Tanzania.

The drilling and testing campaign confirmed Mzia as the second giant gas discovery, after Jodari, in BG Group’s acreage offshore Tanzania, with 4.7 tcf of total gross recoverable resources. Total gross recoverable resources across BG Group’s blocks 1, 3, and 4 now are estimated to be around 15 tcf, with further exploration upside.

The Mzia-3 appraisal well, drilled 6 km (4 mi) north of the original Mzia-1 discovery in 1,780 m (5,840 ft) of water, has been cored and logged. Results confirm that the reservoir sands are extensive and of similar quality to those in Mzia-1 and Mzia-2. In addition, the gas-down-to level proven in Mzia-3 is around 100 m (328 ft) deeper than that of Mzia-2.

Further north, detailed analysis of the block 4 discoveries Chewa, Ngisi, and Pweza, which were also appraised and tested in the campaign, was positive, with total gross recoverable resources in the block now estimated around 5 tcf.

This means that an extensive exploration and appraisal campaign of 14 wells started in 2010 offshore Tanzania has had a 100% success rate with nine consecutive discoveries and five appraisal wells, three of which included drillstem tests showing high flow rates.

BG Group as operator has a 60% interest in blocks 1, 3, and 4 offshore Tanzania, with Ophir Energy holding 40%.