Anadarko Petroleum has notched up another major gas discovery in the Rovuma Basin off the east coast of Africa, with its latest wildcat in Mozambique’s deep waters hitting more than 92 m (300 ft) of natural gas pay.

The U.S. operator now estimates its total recoverable gas reserves in Offshore Area 1 now range between 30-60 trillion cu ft (Tcf), with the total upside for the permit approaching 100 Tcf.

The Atum exploration well discovered what Anadarko describes as a “significant gas accumulation” within Offshore Area 1.

The discovery well encountered the gas in two high-quality Oligocene fan systems, with preliminary data indicating this latest find is connected to the recent Golfinho discovery approximately 10 miles (16.5 km) to the northwest in the same license.

“The combined success at Atum and Golfinho and apparent connectivity of these Oligocene fan systems, indicate these discoveries represent our partnership’s second major natural gas complex offshore Mozambique,” said senior vice president of worldwide exploration, Bob Daniels. “We estimate this new complex, which is located entirely within the Offshore Area 1 block, holds 10 to 30-plus Tcf of incremental recoverable natural gas resources. We plan to immediately commence a four-well appraisal program of this complex, which has the potential to underpin a large liquefied natural gas (LNG) development.”

The Atum well was drilled to a total depth of approximately 3,860 m (12,665 ft) in a water depth of approximately 1,000 m (3,285 ft). Once operations are complete at Atum, the partnership plans to start appraisal activities that are expected to be followed by a drillstem testing program in the Golfinho and Atum complex.

“With this latest discovery at Atum and a successful upcoming appraisal program, we believe the total estimated recoverable natural gas resource in Mozambique’s Offshore Area 1 is between 30 and 60 Tcf, and the current upside for total gas in place for the discovered reservoirs on the block is approaching 100 Tcf. We still have additional exploration opportunities that could expand the resource potential further,” added Anadarko’s president and chief executive officer, Al Walker. “A recoverable resource base of this scale supports our initial two-train development plans, as well as significant future expansions. Our current activity is focused on achieving reserve certification and a final investment decision in 2013, as the partnership works toward expected first sales of LNG in 2018.”

Anadarko operates Offshore Area 1 with a 36.5% working interest. Its partners are Mitsui E&P Mozambique Area 1 Ltd. (20%), BPRL Ventures Mozambique B.V. (10%), Videocon Mozambique Rovuma 1 Ltd. (10%) and Cove Energy Mozambique Rovuma Offshore Ltd. (8.5%). Empresa Nacional de Hidrocarbonetos’ 15% interest is carried through the exploration phase.