鄂尔多斯盆地基底断裂多期演化及其主控因素分析——基于构造物理模拟实验

An Analysis of Polyphasic Evolution and the Main Controlling Factors of Basement Faults in the Ordos Basin Based on Structural Physical Simulation Experiments

针对鄂尔多斯盆地基底断裂多期活化对上覆层系的影响,开展了基于伸展环境的基底断裂多期发育的构造物理模拟实验。实验结果表明:鄂尔多斯盆地基底断裂控制上覆盖层及滑脱层的断裂体系展布和活动。前寒武系同沉积时期,基底断裂具有生长正断裂的特征;寒武系以来非同沉积时期,基底断裂具有多期活动特征。基底断裂多期活动产生一系列切穿上覆岩层和滑脱层的正断层组合,导致盆地内部应力条件的差异,从而影响了油气分布。

A structural physical modeling experiment was conducted in the polyphasic basement faults of the Ordos basin to identify the influences of polyphasic activation based on the environment of the basement faults on the overburden strata.The experimental results indicate that the basement faults in the basin controlled the spreading and activity of the fault systems in the overburden cover and detachment layer.Syn-rift modeling was conducted to observe the activity during the sedimentation period of pre-Cambrian sedimentary action,which exhibits that the basement faults of this period display the characteristics of positive growth fault.Furthermore,extensional faulting sedimentation modeling was conducted to investigate the sedimentation of the Cambrian and later period,which shows that the basement faults exhibit inheritance signatures.The modeling exhibits that the basement faults resulted in differences in the internal stress conditions of the basin,thereby influencing the oil and gas distribution.