论水平扭剪应力场对大裂缝系统的控制

On Horizontal Shear Stress Control over Large Fracture System

本文根据地质力学和岩体结构力学原理，探讨水平扭剪应力场在大裂缝系统形成、转化和分布中的重要控制作用及其物理模型．文中认为，大裂缝系统是较大的直压型裂缝网络与扭剪型裂缝网络叠加的产物，主要分布在较强的水平扭剪应力和术平直压应力复合作用的区块；水平扭剪应力场是改造和控制大裂缝网络结构异向性的最重要因素。这为研究和勘探较大的隐伏裂缝系统，提供了新的成藏模式和理论依据。

Basing on the principles of geomechanics and rock texture mechanics, this paper discusses the important role of horizontal shear stress in the formation, transformation and distribution of large fracture systems and its physical model. The paper holds that a large fracture system is the product of a larger straight press type fracture network and a shear type fracture network, and is mainly distributed over the zone on which horizontal shear stress and straight press stress jointly act. Horizontal shear stress is the most important factor of transformation and controling the incongruity of large fracture network structure So it provides new patterns of forming reservoirs and theoretical basis for researching and finding relatively large concealed fracture system.