August 3, 2012. CNOOC Limited announced that Yacheng 13-4 gas field has recently commenced production successfully. Yacheng 13-4 is located about 44.5 miles southwest of Sanya, Hainan Province, in the north part of the South China Sea with an average water depth of about 279 feet. This project was designed to share the existing facilities of Yacheng 13-1 gas field and built three new subsea production equipments for overall development. Three development wells have also been arranged. Yacheng 13-4 is expected to hit its peak production of 0.35 billion cubic meters per annum in 2013. Yacheng 13-4 is an independent gas field in which the Company holds 100 percent interest and acts as the Operator.