东海盆地西湖凹陷中央反转构造带异常高压与油气成藏的耦合关系  

Coupling relationship between abnormal overpressure and hydrocarbon accumulation in a central overturned structural belt,Xihu Sag,East China Sea Basin

作　　者：陈智远[1] 徐志星 徐国盛[1] 徐昉昊[1] 刘金水 

机构地区：[1]成都理工大学油气藏地质及开发工程国家重点实验室,四川成都610059 [2]中海石油(中国)有限公司上海分公司,上海200030

出　　处：《石油与天然气地质》2017年第3期570-581,共12页Oil & Gas Geology

基　　金："十三五"国家科技重大专项(2016ZX05027002-006);中海油上海分公司重点项目(CCL2014SHPS0014RSI)

摘　　要：东海陆架盆地西湖凹陷中央反转构造带花港组、平湖组普遍发育异常高压,高压地层中油气显示活跃。在声波时差测井、地球化学及分析测试等资料的基础之上,运用Eaton法计算单井地层压力,建立单井压力剖面,并在实测压力的约束下,明确研究区地层压力的纵、横向分布特征。分析认为,异常压力在纵向上主要起始于花港组下段,并且异常高压段呈"阶梯式"增大;横向上从中央反转构造带南部向中部,异常高压顶界面有变深趋势。接着,利用Petro Mod软件模拟地层剩余压力演化,认为距今13~9 Ma和4~0 Ma是地层压力大幅度增大的关键时期。最后,结合油气充注历史的研究,确定出油气大规模充注和地层压力的大幅度增加在时间上具有很好的吻合性,并最终建立起研究区异常高压演化与油气成藏的耦合关系。Abnormal overpressure is generally developed in the Huagang and Pinghu Formations of the central overturned structural belt in Xihu Sag,East China Sea Shelf Basin. Oil gas shows have been reported frequently in these overpressured formations. Formation pressure and pressure profiles of single wells in the formations were calculated and established through Eaton method and based on acoustic well logging,geochemical and testing data,and pressure distribution（both lateral and horizontal） of the area was also defined under the constraint of measured pressure data of the formations. Vertically,the abnormal pressure mainly initiates in the lower member of the Huagang Formation,and increases in stepwise way upwards; and laterally,its top boundary deepens from south to central of the belt. The Petro Mod software was employed to simulate the evolution of the formation residual pressure. The results suggest that periods of 13-9 Ma and 4-0 Ma be the key pressure incremental stages. A combination of the above mentioned research with the history of hydrocarbon charging in the area indicates a well match between the times of large scale hydrocarbon charging and pressure increase. A coupling relationship between the abnormal high pressure evolution and hydrocarbon accumulations is finally defined.

关 键 词：异常高压 油气成藏 耦合关系 中央反转构造带 西湖凹陷 东海盆地 

分 类 号：TE122.3[石油与天然气工程—油气勘探]