走滑断裂带贯穿过程与发育模式的物理模拟

发布时间：2019-01-06 18:37

【摘要】：结合实际地质资料设计9组砂箱模拟实验,并利用断层CT扫描技术研究简单剪切走滑带演化规律与发育机制。结果表明,R(Riedel)剪切断裂形成早、数量多,并有一组与主走滑带低角度相交,P剪切断裂(与R剪切断裂对称分布的压剪破裂)与Y剪切断裂(与主位移带近平行的剪切破裂)形成滞后,并在Y剪切断裂发育后才从分段构造连接成贯穿的走滑带。走滑带贯穿连通过程可划分为4个阶段:萌芽阶段、R剪切断裂发育阶段、P剪切与Y剪切断裂发育阶段、走滑带贯穿阶段。实验揭示了走滑断裂由基底向盖层递进传播的发育过程,萌芽阶段剖面上断裂逐渐向上散开发育,R剪切断裂发育阶段平面上向外散开后逐渐向主位移带收敛。雁列构造具有"螺旋-拖曳"发育模式,雁列断裂的长度增长速度呈约2倍于深度增长速度线性增长,而与主位移带夹角随深度呈二次函数变小。分析表明,最大主应力方向、盖层厚度是导致雁列构造"螺旋-拖曳"结构差异的主控因素。走滑断裂的物理模拟为塔里木盆地海相碳酸盐岩断裂解析与分层、分段的勘探开发实践提供了模型基础。
[Abstract]:Combined with the actual geological data, nine groups of sand box simulation experiments were designed, and the evolution law and development mechanism of simple shear strike-slip zone were studied by fault CT scanning technique. The results show that the, R (Riedel) shear faults were formed early and in a large number, and one group intersected with the low angle of the main strike-slip zone. P shear faults (compressive shear fractures symmetrically distributed with R shear faults) and Y shear faults (shear fractures near parallel to the main displacement zone) lagged behind, and only after Y shear faults developed did they connect into strike-slip zones through the segmental structures. The process of strike-slip through and connected can be divided into four stages: budding stage, developing stage of R shear fault, developing stage of P shear and Y shear fault, and running stage of strike-slip zone. The experimental results show that the strike-slip faults propagate gradually from the basement to the caprock. The faults in the budding section gradually spread upward, and the R shear faults gradually converge to the main displacement zone after spreading outward in the plane during the development stage of the R shear faults. The echelon structure has a "helio-drag" development pattern. The length growth rate of the echelon fault is about 2 times that of the depth growth rate, and the angle between the main displacement zone and the main displacement zone becomes smaller with the depth. The analysis shows that the direction of the maximum principal stress and the thickness of the caprock are the main controlling factors leading to the difference of the helico-drag structure of the echelon structure. The physical simulation of strike-slip faults provides a model basis for the exploration and development of marine carbonate rocks in Tarim Basin.
【作者单位】：中山大学广东省海洋资源与近岸工程重点实验室;中国石油勘探开发研究院;
【基金】：国家自然科学基金(41472103)
【分类号】：P542

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