The east part of Pear Rive Mouth Basin contains Huilu-Dongsha

Xijiang

Enping andBaiyun petroleum systems. Among them

Huilu-Dongsha is the richest one. The primarysource rocks of the systems are in the bottom of fracture horizon. This results in intrahorizonand allochthony types of oil migration-accumulation assemblages. The traps of the system arecomplete and contemporanous. In the system

the peak period of oil generation matched withtrap forming period

especially weak faulting period. This provides favourable conditions forthe long distance lateral migration of oil and gas. The system's oil pools are distributed inzonary type paralleling with water current direction. Accoring to the differentiae of hydrocarbon generation of the basin

and the migration and accumulation model

it is suggested thatthe deep water regions in the south part of Huilu-Dongsha system

the eastern and southernparts of Xijiang system as well as the eastern

central and south parts of Baiyun oil systemare favourible regions for oil exploration.