BG Group has made a gas discovery in the Ngisi-1 well in Block 4 offshore Tanzania.
The Ngisi-1 well, drilled by the Deepsea Metro 1 drillship, was also used to appraise the Chewa gas field, resulting in an upgrade in estimated recoverable resources in the block.
Ophir Energy, 40% owner in Block 4, with BG holding the other 60%, said recoverable resource across the Chewa-Pweza-Ngisi hub was now 4.5TCF, up from 3.7TCF.
The Deepsea Metro I has now moved to drill the Mkizi-1 exploration well, in Block 1, also operated by BG.
Ophir said Mkizi is a 0.6 TCF prospect of Tertiary age, close to the Jodari discovery. After Mkizi, appraisal of the Block 4 Pweza discovery is planned.
Nick Cooper, CEO of Ophir, said: "The successful Ngisi drilling results provide critical mass for the aggregation and development of the gas discoveries in Block 4. These will be piped ashore and combined with the Block 1 resources for Tanzania's LNG development."