(EnergyAsia, July 18) — Nigeria will soon begin supplying China 30,000 barrels/day of crude oil following the signing of an agreement between PetroChina International and the Nigerian National Petroleum Corporation (NNPC).   Si Bingjun, managing director of PetroChina, and Edmund Daukoru, special adviser to Nigerian President Olusegun Obasanjo on Energy and Oil Matters, signed the…