南海北部大陆架西段地热条件与油气资源前景

北部湾盆地下第三系由于油源母质特性原因和适于生油的空间相对局限,总体上看,天然气的潜力大于石油。生油岩与地温条件在空间上的配置适当决定了珠三盆地油气资源的良好前景。较高的地温与古地温环境是莺琼盆地成为南海北部大陆架天然气富集区的重要条件,较高的地温不仅使盆地中西部上第三系烃源岩能够广泛生气,也是本区有巨大远景的深成高压气(盆地中、西部)与浅成生化成因气的形成与富集的重要条件。

GEOTHERMAL CONDITIONS AND HYDROCARBON PROSPECTS IN WEST SECTOR SHELF OF NORTHERN SOUTH CHINA SEA

According to the study of geotemperature and palaeogeotemperature, this paper discusses generation, evolution and oil-gas prospect of three major basins in this area.Hydrocarbon source rock in Neogene of Beibuwan Basin can not generate oil in large quantity because of insufficient temperature. Owing to the features of matrix and limited space suitable for oil generation of Eogene, the potential of gas is larger than that of oil.The proper combination of kerogen and temperature condition in space results in hopeful prospects of hydrocarbon in Zhushan Basin. Prospective region for oil are the east part of north Basin and centre part of south Basin. Gas is still a major hydrocarbon resource in the basin with the largest potential in the eastern section of the southern part of the basin. Meanwhile, in the east of basin, Neogene biochemigenic gas has also good prospects.The high geotemperature and palaeogeotemperature environments are the important conditions for Yingqiong Basin to become the richest district in the gas-enriched region in shelf of nothern South China Sea. High temperature not only makes the Neogene kerogen in centre-west part of Basin generate gas widely, but also is an important condition for the formation of hypogene high-pressure gas and supergene biochemigenic gas of large prospects in this. area.