Cairn Energy has discovered oil at its FAN South-1 well, offshore Senegal, although there seem to be questions over whether it will be commercially viable – similar to the earlier FAN-1 discovery.
The UK-listed company, which serves as operator, said in a statement that the oil appeared to be 31 degrees API. Work is going on to integrate the data from this well with its wider basin plan.
The FAN South-1 was drilled 90 km offshore, in 2,175 metres of water, reaching a total depth of 5,343 metres. The well site is in the Sangomar Deep Offshore block, 30 km southwest of the FAN-1 exploration well.
The well was targeting two areas, in an Upper Cretaceous stacked multi-layer turbidite fan prospect, with a Lower Cretaceous slope turbidite fan. The oil discovery was made in the Lower Cretaceous reservoir alone. The Upper Cretaceous was reported to have good reservoir qualities – but be dry.
Next up for the Stena DrillMAX rig is the SNE North well. This lies 15 km north of SNE-1 and will be the most northerly location tested. The well will be in around 900 metres of water, with a total projected depth of 2,800 metres.
This next well is targeting a prospective volume of more than 80 million barrels, Cairn said. The company’s partner, Australia’s FAR, citing an assessment from RISC Operations, said the prospective recoverable best estimate number for the well was 294 million barrels, with a 60% chance of success.
“The basinal fan play offshore Senegal is clearly a very large, but technically complex system which will require further evaluation to understand the commerciality of this deep-water basin area,” FAR’s managing director, Cath Norman, said.
GMP First Energy described the find as “uninspiring”. Net pay was less than expected and with mixed reservoir quality, the analysts said, similar to the FAN-1 find in 2014. “The commerciality of FAN-1 was already uncertain and it is not clear if FAN South-1 is improving the picture as the encountered volumes are much less than expected,” GMP said.
Cairn has previously suggested FAN and FAN South-1 might be tied back to the broader SNE development.