四川盆地晚三叠世动力学特征及与油气运聚的关系

晚三叠世是四川盆地形成演化的起点，其地层是油气勘探的一个重要目标层。通过对四川盆地晚三叠世动力学特征的分析，建立其动力学模型（构造应力（叠加）场模型），采用有限单元法进行模拟，其结果显示，四川盆地晚三叠世构造应力条件以ＮＷ—ＳＥ方向的挤压占主导。构造动力是油气运聚的驱动力，驱使油气运移的动力来自构造应力场，通过模拟认为，四川盆地晚三叠世构造应力场形成的圈闭为模拟计算的最大应力值２．０～４．０ＭＰａ之间的区域。

GEODYNAMIC FEATURES OF SICHUAN BASIN IN THE LATE TRIASSIC AND THEIR RELATION WITH OIL GAS MIGRATION AND ACCUMULATION

Sichuan Basin was formed in the late Triassic,the stratigraph in horizon formed in this period is one of important target strata in oil gas exploration. In this paper, a geodynamics model is constructed with the analysis of dynamic features in the late Triassic of Sichuan basin, and simulated with the elastic plastic finite element method. Computer simulation result indicates that the tectonic stress conditions at sichuan basin in the late Triassic was chiefly of NW SE compression. The oil gas migration and accumulation is promoted by tectonic stress field. The traps formed by tectonic stress field in Sichuan Basin in the late Triassic loinsido with the regions in which the maxium values of stresses by simulating calculation is 2.0 MPa to 4.0 MPa.