Groups led by Brazil’s Petroleo Brasilerio SA in recent weeks have added another heavy oil discovery in ultradeep water and a light oil in shallow water in the Santos basin in the Atlantic Ocean off Brazil.
A consortium comprised of Petrobras 66%, Royal Dutch Shell PLC 20%, and Galp Energia SGPS SA 14% made the oil discovery on ultradeepwater Block BM-S-8 south of Rio de Janeiro.
And Petrobras as sole concessionaire made the light oil discovery on a group of blocks designated BM-S-40 in the far southern part of the basin.
Operator Petrobras said it proved the presence of oil in presalt reservoirs on the ultradeepwater block after drilling well 1-BRSA-532A-SPS (1-SPS-52A).
Preliminary analyses indicate an oil gravity of 25-28°, comparable to that of other presalt crudes found in the basin, the company said in a release. The wildcat is 250 km off the state of Sao Paulo in 2,139 m of water.
Drilling was completed May 18 to TD 6,773 m, and the discovery proved via oil sampling in reservoirs nearly 6,000 m deep. Press reports said a shortage of rigs and the press of block expiration deadlines has led Petrobras to forgo testing some of its subsalt discoveries in order to release the rigs to drill other blocks.
The consortium is preparing a discovery assessment plan to be sent to Brazil’s National Petroleum Agency.
Petrobras deferred tests at the discovery on BM-S-8, also known as the Bem-te-Vi block, to move the rig to the small Iara block to the northeast in the company’s Santos basin subsalt focus area. Kicking off optimism for the potential of the Santos subsalt area was the Tupi discovery, where Petrobras plans to begin extended production tests in March 2009.
Light oil discovery
Meanwhile, Petrobras said it found 36° gravity oil above the salt at the 1-BRSA-607-SPS (1-SPS-56) well.
The company estimated that the well, with a reservoir at 2,080 m in 235 m of water, is capable of a production rate of more than 12,000 b/d of oil. Petrobras said it confirmed the discovery with a “lined well formation test.”
The company plans to spud BM-S-40’s next exploration well in June 2008.