Petronas has seen preliminary “positive indications” from its appraisal well on the deep-water Boudji pre-salt oil and gas discovery off Gabon, which was made last year.

The Malaysian state oil giant is also lining up drilling plans on nearby blocks off Gabon that it recently picked up, with drill-ready prospects already identified.

“We are still currently drilling our Boudji appraisal, but already – although this is preliminary – we do see positive indications from Boudji-2,” Emeliana Rice-Oxley, vice president exploration, said at the Africa Oil Week conference in Cape Town on Wednesday.

The Boudji-1 discovery well was drilled on Block F14 (Likuale) in 2800 metres of water, hitting 90 metres of gross high-quality hydrocarbon-bearing pre-salt sands in Gamba and Dentale horizons.

Following on from the success, Petronas in August this year was awarded two other blocks in the region – F12 (Yitu) and F13 (Meboun).

“Based on the work that we have done, we believe there are additional opportunities in the pre-salt further up-dip of Block F14, where we see further potential for oil and for reservoir,” Rice-Oxley said.

Both F12 and F13 are up-dip from Boudji.

“We are again pursuing the pre-salt play where we expect to find thicker sands in the pre-salt,” she said.

“We see ample opportunities to test numerous targets that are reachable by the (same) drilling rig.”

One prospect on the radar on F13 is called Jove Marine. Petronas is currently doing high-end seismic reprocessing on the block and is set on spudding the well in the fourth quarter next year.

“(Jove Marine) is located about 50 kilometres north-west of Boudji. It is aerially larger than Boudji – at least twice as large as Boudji in terms of area – and it is also in water depths that are 700 metres shallower,” Rice-Oxley said.

“It shares somewhat similar trap configurations – it is a simple four-way dip closure.”

On F12, Petronas is looking at a prospect called Mbama, which is eyed for drilling in the third quarter of 2021.

It is around 70 kilometres from Boudji and is also larger in area, while it is situated in just 500 metres of water. Petronas will acquire data over the area to better image the pre-salt, Rice-Oxley said.

“Before we drilled Boudji, we were concerned that the Early Cretaceous Dentale and Gamba formations, which have been proven in onshore wells and shallow-water wells, may not extend this far outboard into the basin,” she said.

“But we believe that we are dealing with two different two different sub-basins (off Gabon).”

She added that Petronas “found that the deep-water wells found better quality sands, thicker and blockier relative to the onshore and inboard wells”.