东海西湖凹陷温压系统与油气成藏

GEOTEMPERATURE-PRESSURE SYSTEMS AND RELATED RESERVOIR FORMATION IN THE XIHU SAG,EAST CHINA SEA

针对西湖凹陷存在异常温压系统的现象,利用钻井测温资料、测井声波时差压力、流体包裹体、镜质体反射率和磷灰石裂变径迹等资料对西湖凹陷的温压系统特征、类型及其对油气成藏的影响进行了系统研究。结果表明,西湖凹陷不同构造单元具有各异的温压场特征;西湖凹陷不同构造单元的温压系统类型不尽相同,其中保俶斜坡带和三潭深凹为高压型温压系统,浙东背斜带为常压型温压系统;西湖凹陷不同温压系统具有各异的流体流动样式和油气运聚规律;浙东中央背斜带内的流体能量相对最低,是研究区内有利的油气运聚区域。

Abnormal geotemperature-pressure （T-P） systems of Xihu sag in East China Sea shelf basin, based on the data of geotemperature by using well drilling and pressure by using acoustic transit time, in- clusions, vitrinite reflectivity and apatite fission track, and their characteristics, types and effects on reservoir formation are systematically analyzed during the study. The result shows that characteristics of T-P systems in different tectonic units are distinct. There are two types of T-P systems, overpressure type in the Baoshu slope belt and Santan deep sag, and normal-pressure type in the Zhedong central anticline belt. For different T-P systems, fluid flow styles and hydrocarbon migration laws are different. The fluid energy in the Zhedong central anticline belt, which is the best hydrocarbon migration region in Xihu sag, was relatively lower than any other tectonic units.