The appraisal well was drilled in the Pweza gas field, located about 70 kilometres offshore in about 1400 metres of water, by the drillship Deepsea Metro 1.
According to block partner Ophir Energy, Pweza-3 encountered 61 metres of gross pay on prognosis.
A drill stem test was then performed on the well, flowing gas at a maximum constrained rate of 57 million cubic feet per day.
Ophir said there was no observable depletion in the flow rate after five consecutive days, implying that the unconstrained flow rate is expected to be in excess of 150 MMcfd.
BG said initial results from the test confirmed the excellent properties of the Tertiary section reservoir, including flow and connectivity, and demonstrated the robustness of the company’s Tanzanian resource.
“Our acreage in Block 4 around the Pweza, Chewa and Ngisi discoveries is now fully appraised and tested, with resources in the order of 4 trillion cubic feet of natural gas,” BG chief executive Chris Finlayson said in a statement.
“The work done demonstrates the excellent quality of these fields and that they can be developed as a northern production hub to feed a potential LNG export project,” he said.
The Deepsea Metro 1 will now move south to Block 1 to drill an appraisal well on the Mzia discovery.
BG operates blocks 1 and 4 with a 60% interest while Ophir holds the remaining 40%.