幕式成藏的机理和规律探讨

MECHANISM AND REGULARITY OF EPISODIC RESERVOIRING

根据国内外油气成藏特点及盆地流体动力学综合分析,认为幕式成藏也是含油气盆地一种普遍存在的成藏方式,特别是对于多构造运动、断裂发育的盆地以及异常压力比较发育的盆地,幕式成藏往往占有重要地位。幕式成藏的机理主要有构造幕和构造泵作用、断层阀效应或地震泵作用以及超压积聚效应等3种作用。但与渐进式成藏不同,幕式成藏在时间上并不完全受生烃窗控制,而主要受控于区域构造运动、断裂活动或异常压力的演化,因此盆地的构造演化史、断裂活动史和异常压力发育史往往决定了幕式成藏史。

Based on a comprehensive analysis of reservoiring characteristics and basinal flow dynamics both at home and abroad, it is believed that episodic reservoiring also is a common type of reservoiring in petroliferous basins and usually plays an important role especially in those basins that have experienced multiple stage tectonic movements and have well-developed fractures and that have relatively high abnormal pressures. The mechanisms of episodic reservoiring mainly include tectonic episodes (or tectonic pumping), valve effect of fault (or seismic pumping) and overpressure buildup effect. Unlike progressive reservoiring, the timing of episodic reservoiring is not completely controlled by hydrocarbon generation window, but mainly controlled by regional tectonic movement, faulting or evolution of abnormal pressure. Therefore, episodic reservoiring history is usually controlled by tectonic evolution history, faulting history and abnormal pressure development history of a basin.