ABSTRACT: Gas exploration potential in deep water area of South China Sea

Dai, Yiding , China National Offshore Oil Corporation, Beijing, China

The Pearl River Mouth Basin (PRMB) is located in the northern continental margin, South China Sea. During Late Cretaceous to Early Oligocene, the syn-rifting fluvio-lacustrine deposition, Wenchang and Enping formations were developed in the separated or half-separated rifts, which form the main source rocks of the basin. Since Oligocene the basin started subsidence and lasting transgression to present day, and sequentially post-rift marine mega-sequence was formed, which is the major reservoir interval of the present oil field in the northern part of the basin.

Mainly by reason of deep water, the southern part--Zhu II Depression is a frontier of petroleum exploration. In Zhu II Depression, there is thick syn-rift Eocene fluvio-lacustrin deposition like the scenario in northern sub-basins of the basin. The richness of organic matter from Eocene lacustrine shale is fair to good with 0.5~1.5% of TOC and type III kerogen. Considering a high maturity (R0 above 2% in the center) and the gas shows observed in the wells and seismic section, it is belived that there is great gas potential in Zhu II Depression.

Both large scale structural traps and stratigraphic closures are already found in the depression, so that Zhu II Depression is thought to be a great promising area in petroleum exploration.

AAPG Search and Discovery Article #90913©2000 AAPG International Conference and Exhibition, Bali, Indonesia