四川盆地东北缘含气藏构造分析

STRUCTURE ANALYSIS ON THE GAS BEARING TRAPS IN THE NORTHEASTERN BORDER OF SICHUAN BASIN

四川盆地周边冲断褶皱变形带内有很大的含天然气前景。然而，气藏的分布是非均一的。通过对川东北构造变形带的平衡地质剖面研究，结合对构造演化过程中有机质成熟历史和油气产出特征的分析，认为川东北气藏的形成主要受构造变形过程中天然气的二次运移造成在有利的构造圈闭中富集；特别是在生储盖条件类同的前提下，气藏的分布主要受发育在弱能干层中台阶状逆断层所控制的具有一定高宽比的相关褶皱中。据此，对川东北区天然气藏的靶区进行了分析和预测。

In the fold and thrust deformation belt bordered the Sichuan Basin,there are great prospects of natural gas potentiality.The distribution of gas bearing traps are different in various deformation units.In the light of researches on the balanced cross section of the thrust deformation belt and the mature history of organic materials in different tectonic evolution stages in northeastern border of Sichuan Basin,the author suggests that for the formation of gas pool,there is mainly controlled by the second horizontal migration of hydrocarbon within the reservoir strata in the process of structural deformation.Thus the gas accumulation is formed in ideal structural traps.Furtherly,under the same condition of source rock,reservoir and cover characteristics,the distribution of natural gas generally located within the fault related folds with a suitable ratio of height to width.Under the comprehensive analysis,the targets of gas pool are predicted in the researched area.