Vinson & Elkins and SNR Denton have taken lead roles on French energy giant Total’s $2.5 billion sale of a 20 percent stake in an offshore Nigerian oil field to the China Petroleum & Chemical Corp., better known as Sinopec.

SNR Denton is advising on the Total side of the deal, working with an in-house legal team led by Total group general counsel Peter Herbel; Marc-Olivier Nicolas, who is with a related holding company; and Marie-Joelle Lanista, who is with Total’s exploration and production division.