走滑断裂派生裂缝发育规律影响因素探讨

Discussion on Influencing Factors of the Development Law of Strike-slip-fault Derived Fractures

为探索走滑断控裂缝体系发育的规模,主要借助数值模拟的手段,通过构建不同断裂带核部宽度、不同性质及不同组合的断裂模型,开展走滑断裂派生裂缝发育范围的定量预测,以明确不同断裂要素对裂缝发育的影响规律。结果表明:随着走滑断裂带核部宽度逐步增大,派生裂缝发育范围的最大值、均值以及最小值均无明显变化;在同等条件下,压扭断层派生裂缝带宽度明显高于纯走滑断层与逆冲断层;当平行断层组合间距小于某一距离之后,两条断裂派生裂缝发育相互叠加,受两条断裂共同控制,断裂之间派生裂缝发育强度明显变大。共轭断层交叉部位,派生裂缝发育范围明显变大。

Fractures derived from strike-slip faults in carbonate formations are an important storage space.However,due to the limitation of data and the unclear understanding of its control mechanism,the scope and scale of fracture's development are still unclear.In order to explore the scale of the fracture system controlled by the strike-slip faults,by numerical simulation we conduct a quantitative prediction of the range of the fractures derived from strike-slip faults by constructing fault models with different fracture elements such as widths,properties and combinations,to find out the regularity of how different fracture elements influence the fracture's development.The results show that when the width of strike-slip faults increases gradually,the maximum value,the average value,and the minimum value of the degree of the derived fractures do not change obviously.Under the same conditions,the width of the derived fractures of the compression-torsion fault is significantly higher than that of the pure strike-slip fault and the thrust faults;When spacing between the parallel fault is less than a certain distance,the derived fractures of the two faults would superimpose.Under the control of the two faults,the degree of the fracture development of the derived fractures between the faults become significantly larger.At the intersection of the conjugate faults,the range of the derived fractures has become significantly larger.