断陷盆地层序格架中岩性地层油气藏分布特征

运用层序地层学原理,对渤海湾盆地东营、沾化、南堡和西部凹陷的岩性及地层油气藏在层序地层格架中的分布特征进行了分析.结果表明,层序界面控制了地层油气藏的发育,主裂陷幕三级层序湖扩展域优质烃源岩控制岩性油气藏发育的层段,盆缘沟谷和构造坡折带控制的层序低位域和高位域砂体是岩性油藏的主要储集体,该砂体发育带与湖扩展域优质烃源岩的有效配置部位就是岩性油气藏的富集带.高异常流体压力封存箱保留了原生孔隙,有机酸产生了次生孔隙,流体压裂、幕式排烃以及高异常流体压力有利于克服储层毛细管阻力,这些特性使得有高异常流体压力封存箱发育的受坡折带控制的岩性油气藏富集、高产.

Distribution of stratigraphic and lithologic reservoirs in sequence framework of rift-subsidence basin

The characteristics of stratigraphic and lithologic reservoirs distributed in sequence frameworks of Dongying, Zhanhua, Nanpu and West Depressions of Bohai Bay Basin were analyzed by using sequence stratigraphy. The sequence boundaries controlled distribution of stratigraphic reservoir. Good source rocks of lake expanding systems tract in the third-level sequences of the main rifting episode controlled horizons of lithologic reservoirs. The lowstand systems tract and highstand systems tract sand-body controlled by basin edge valleys and the structural slope-break zones are the main lithologic reservoirs. Good arranged regions of sand-body horizons and good source rocks of lake expanding systems tract are the main distribution zone of lithologic reservoirs. The original and secondary pores, fluid fracturing, episodic hydrocarbon fluid flow and high fluid overpressure are favorable for overcoming capillary force in the abnormal overpressure compartment and make sand bodies under the control of structural slope-break zone in high-pressure compartment have high oil saturation and productivity.