摘要
含油气盆地不同类型凹陷地层压力场具有明显差异,压力场与油气富集关系密切。以渤海湾盆地含油气凹陷实测地层压力资料为基础,探讨了含油气凹陷压力场类型及分布特征,以及超压与生烃作用、压力场与油气富集等关系。研究表明,渤海湾盆地含油气凹陷新生界纵向压力场大致可归为3类,即常压型、单超压型、双超压型;不同类型压力场凹陷的分布具有分区性:常压型多分布于盆地外围凹陷,单超压型在盆地广泛分布,双超压型主要分布于环渤海地区。生烃作用对凹陷超压的形成具有重要影响,超压层系与主力生烃层系相对应,凹陷充填演化历史及主力生烃层系的差异可能是形成3类凹陷压力场的主要原因。凹陷生烃层系超压与油气富集关系密切:平面上油气围绕超压中心分布,超压程度影响油气二次运移距离;纵向上油气富集层系受凹陷压力场类型控制,常压型凹陷油气主要富集于生烃层系及紧邻层系,单超压型凹陷油气富集于生烃层系及上下多套层系,而在双超压型凹陷,新近系油气富集程度较高;生烃层系超压程度影响凹陷油气富集程度,富油凹陷均为超压幅度较大的凹陷。
There are significant differences among pressure fields of different depressions in a petroliferous basin, and intimate relationship existed between pressure field and hydrocarbon enrichment. Based on the measured pressure data of different depressions in Bohai Bay Basin, distribution of different types of pressure field and the relationships between overpressure and hydrocarbon generation, pressure field and hydrocarbon enrichment were discussed. Research shows that the Paleogene pressure fields of different depressions in the Bohai Bay Basin can be divided into three types:normal pressure type, single overpressure type and double overpressure type. These three types of pressure fields have zoned features in their distributions. Normal pressure filed is mostly distributed in peripheral depressions of the basin, while single overpressure field is widespread in the basin, and double overpressure field is concentrated in the areas around the Bohai Sea. Hydrocarbon generation plays a significant role in overpressure formation, thus overpressure layers generally correspond to the major source rock layers, and the difference of the filling evolution history and the main hydrocarbon generating strata of different depressions may be important factors for the formation of the three types of pressure fields. Overpressure in source rocks is closely relat- ed to hydrocarbon enrichment. Horizontally, hydrocarbons are mainly distributed around the overpressure center, and the secondary migration distance of hydrocarbons was affected by the degree of overpressure. Vertically, hydrocarbon distribution was controlled by the type of pressure fields. Hydrocarbon accumulation in the normal pressure type depressions is mainly concentrated in the major hy- drocarbon-generating layers and their adjacent layers, and hydrocarbons are enriched in the hydrocarbon-generating layers and upper and lower layers in the single overpressure type depressions, while hydrocarbons mainly accumulate in shallower layers of non-hydrocarbon generation in the double overpressure type depressions. The degree of overpressure in hydrocarbon-generating layers influences hydro- carbon enrichment, and those enormously oil-rich depressions all have stronger overpressure.
出处
《石油学报》
EI
CAS
CSCD
北大核心
2016年第11期1361-1369,共9页
Acta Petrolei Sinica
基金
国家重大科技专项(2011ZX05006-003)
国家自然科学基金项目(No.41372132)资助
关键词
压力场
超压成因
生烃作用
油气分布
富油凹陷
渤海湾盆地
pressure field
overpressure mechanisms
hydrocarbon generation
hydrocarbon distribution
oil-rich depression
Bohai Bay Basin