London-listed Ophir Energy has spudded an ultra-deepwater wildcat well with the potential to host about 10 Tcf of gas offshore Tanzania.

Drilling operations are under way on the Mlinzi Mbali-1 well in Block 7, in which Ophir has an 80% net interest. The well is located around 210 km east of Dar es Salaam, and is being drilled by the Deepsea Metro I drillship.

Mlinzi Mbali-1 is the first well in the block, targeting a structural crest within a Lower Cretaceous channel complex, with secondary targets in the Upper Cretaceous and the Jurassic. Pre-drill estimates show that the two primary channel reservoirs in the Lower Cretaceous have the potential to contain mean prospective resources of around 10 Tcf. Success would significantly derisk the total resource potential within the overall Mlinzi Channel complex, which is estimated at up to 20 Tcf, as well as in other structures within the block.

The well is being drilled in a water depth of approximately 2,600 m (8,531 ft) and has a planned total depth of 5,650 m (18,538 ft) True Vertical Depth subsea. Operations are expected to take approximately 50 days.

Nick Cooper, CEO, said: “Mlinzi Mbali-1 is a playfinder well designed as the first test of the Cretaceous and Jurassic plays in the Northern Tanzanian Coastal Basin, and is the first of several high-impact wells that Ophir will be drilling over the next 12 months. The Mlinzi Mbali prospect is one of the largest prospects (on pre-drill estimates) to be drilled to date offshore East Africa. It is a high-risk frontier well, but in the success case this could unlock a significant new gas resource to support a second LNG project for Tanzania, following on from the deepwater discoveries already made in Blocks 1-4 to the south.”

Offshore