22 December 2011, Sweetcrude, Lagos – Shell Nigeria Exploration and Production Company, SNEPCo, said on Thursday that up to 50% of the oil spilled at its deepwater Bonga field has now dissipated, and that the company is using dispersants to break up the oil sheen at sea.
SNEPCo had said on Wednesday that it shut the 200,000 b/d Bonga field after a leak from an export line linking the field’s FPSO to a waiting oil tanker.
Shell said early indications showed that less than 40,000 barrels of oil leaked into the sea in total, but it closed the FPSO as a precaution.
“We now assess that up to 50% of the leaked oil has already dissipated due to natural dispersion and evaporation,” Shell said in an update.
“As satellite pictures have shown, the overall area covered by the sheen is large. However, the sheen itself is very thin — less than a hundredth of a millimeter — in most areas,” it said.
Shell’s country chair in Nigeria , Mutiu Sunmonu, said the company was deploying vessels with dispersants to break up the oil sheen.
“We are mobilizing airplanes that will support the vessels in this operation. We are deploying infra-red equipment to be able to trace the few areas where the sheen may be thicker. That allows for a targeted use of the dispersant,” he said.
Sunmonu added that Shell was working with the Nigerian government to inform local communities and fishermen about the situation.
On Wednesday, a Shell spokesman said the spill was unlikely to reach shore. Shell said it continued to believe the leak occurred during a routine operation to transfer crude oil from Bonga’s FPSO to a waiting oil tanker.