An appraisal well drilled by Statoil in block 218 off Nigeria has confirmed that the gas reservoir in the Nnwa structure extends into the neighbouring block 219 operated by Shell.
A successful production test was carried out in this Nnwa-2 well, which was plugged last November.
The field was discovered with the Nnwa-1 wildcat in 1999, while Shell has earlier made a find with its Doro-1 well in block 219.
Transocean Sedco Energy spudded Nnwa-2 last July in 1,191 metres of water. Drilled to a planned depth of 4,984 metres, the well encountered hydrocarbons in several reservoir levels.
Nnwa-2 lies 180 kilometres south-west of Port Harcourt, 6.5 kilometres north-west of the Nnwa discovery well and 10.4 kilometres north-west of Doro-1.
The partners in the two blocks have earlier signed a memorandum of understanding with the state-owned Nigerian National Petroleum Company (NNPC) and the national authorities.
This agreement covers a feasibility study for a possible joint development of Nnwa and Doro. Being led by Statoil, this investigation is due to be completed by the end of 2003.
The size of the structure makes it necessary to conduct further appraisal work in order to characterise Nnwa/Doro fully.
Statoil has a 53.85 per cent interest in block 218, with ChevronTexaco as its partner.