Reservoir and seal rock distribution and controlling factors in hydrocarbon-bearing rift basins of China


Author : Gong Zaisheng, Zhu Weilin and Zheng BaomingPublication : Bulletin of the Geological Society of MalaysiaVolume : 37Page : 491-506Year : 1995


Description

Bulletin of the Geological Society of Malaysia, Volume 37, July 1995, pp. 491 - 506

 

Reservoir and seal rock distribution and controlling factors in hydrocarbon-bearing rift basins of China

GONG ZAISHENG, ZHU WEILIN AND ZHENG BAOMING

CNOOC, Beijing, P.R. China

 

Abstract: Hydrocarbon-bearing rift basins of China are mostly found in the Mesozoic and Cenozoic of eastern China. It can be divided into two types, namely the continental margin type represented by the Pearl River Mouth basin and East China Sea basin and the intercontinental type, examples being Songliao basin, Bohai Bay basin and South Huabei basin. Except for some rift basins of the continental margin type which show marine influence during the rift period, the majority of the basins are rift lakes. They give rise to the unique characteristics of terrestrial petroliferous basins of China.

Exploration of rift basins proved that reservoirs in them are mainly of fluvial-delta, fan delta, bar and turbidite sand bodies formed at the rift stage and post-rift stage. Seals are mainly of lacustrine mudstone of rift stage and lacustrine mudstone or shallow marine mudstone of post-rift stage. Factors which controlled the distribution of reservoir and seal rock include a) faulting activities, b) rift basin evolution, c) ancient river, d) paIaeotopography and old source region, e) palaeoclimate, and f) change of lake level, are discussed in detail.