Abstract: As the first exploration well in the deep water area of eastern South China Sea, Well LW3-1-1 is located in eastern Baiyun sag, Pearl River Mouth basin. The four industrial gas flow zones (Gas1-Gas4) are discovered in Zhujiang and Zhuhai Formations in this well. The fluorescence color, homogeneous temperature, hydrocarbon inclusion abundance and diagenesis order of fluid inclusions in the four gas zones are conducted. In combination with bury history and thermal evaluation history, the results show that the two periods of oil and one period of gas charging occurred in Zhujiang and Zhuhai Formations in this well. The hydrocarbons mainly derived from Enping and Zhuhai source rocks. The hydrocarbon charging time of Gas1-Gas3 zones and Gas4 zone is respectively about 8-0Ma and 5-0Ma, with relatively intensive oil charging in Gas1 and Gas2 zones.

Key words: Pearl RiverMouth Basin, Baiyun sag, deep water area, fluid inclusion, fluorescence color, homogeneous temperature, hydrocarbon charging history