沾化凹陷孤北洼陷沙四上亚段油气成藏组合特征

通过油源对比及储层特征、盖层特征、油气藏特征研究,将孤北地区沙四上亚段划分为自源自生自储油气成藏组合和混源旁生侧储油气成藏组合,解释了孤北地区沙四上亚段存在的3类油气成藏模式:自源侧向运聚模式、自源垂向运聚模式、混源混向运聚模式。构造圈闭、不整合面和断层发育是成藏组合油气成藏的关键因素。在异常高压的作用下,油气沿断层、不整合面和骨架砂体共同组成油气二次运移的立体网络,使陡坡、低隆起、缓坡各构造岩相带都能够成为油气运移的有利指向。

Hydrocarbon accumulation in the upper submember of the 4th member of the Shahejie Formation in the Gubei depression, Zhanhua, Shandong

The Gubei depression lies in the eastern part of the Zhanhua region,Shandong,where two oil-gas plays are recognized for the upper submember of the 4th member of the Shahejie Formation in the Gubei depression in the light of the examination of the source rocks,reservoir rocks and cap rocks and hydrocarbon accumulation.Furthermore,three models for hydrocarbon accumulation are contructed, including the endogenetic lateral accumulation and migration,endogenetic vertical accumulation and migration,and mixed types of accumulation and migration models. The key factors for hydrocarbon accumulation include the structural traps,unconformities and faults. Under the abnormally high pressures,the hydrocarbons may migrate along the faults and unconformities,and constitute the stereoscopic networks together with the skeletal sandstones,which cause the steep slopes,low uplifts and ramps to be favourable for the hydrocarbon accumulation and migration.