残留盆地及其油气保存问题

Residual Basins and the Associated Issues of Hydrocarbon Preservation

残留盆地的最本质特征是流体动力体系的改变,即由原型盆地承压流体(压实流体)转变为静压流体动力体系。残留盆地的油气保存条件是油气勘探评价的关键,虽然与多重因素有关,但主要取决于后期构造运动改造的强度,即与盆地的残留和保存程度密切相关。应用流体的压力体系及其物理化学性质的相关指标可直接对残留盆地油气保存条件作出评价。

A residual basin usually means a sedimentary basin that is tectonically altered in its original feature, architecture, structure, and hydrodynamic system. Among those changed elements, the lattermost, the hydrodynamic system converted from an initial confined fluid system into a lithostatic-pressure one, is most diagnostic of the alteration of a residual basin. Preservation conditions of hydrocarbon in a residual basin are crucial to exploration evaluation. The conditions are mainly determined by the intensity of tectonic movement occurring at the basin and are closely related to the preservation degree of the basin. Pressure system and physicochemical properties of fluid in a residual basin may give indices directly to evaluate preservation conditions of hydrocarbon in it.