摘要
威荣深层页岩气区作为中石化页岩气开发的重点突破区块，开发以来一直面临着严重的套管变形问题，而水力压裂诱发的断层滑移正是导致套管变形的主要因素之一。因此，明确断层滑移与套管剪切变形的关系，对套管变形的防控具有重要的意义。文中考虑了2种断层触发机理，采用Mohr￣Coulomb准则，建立了三维断层滑移计算模型；在此基础上，建立套管剪切变形有限元模型，以断层滑移量为边界条件，研究了不同断层参数对套管变形程度的影响；最后，提出了断层滑移精细化防控理念。研究结果表明：摩擦因数越大，套管变形量越小；随着断层长度增大，套管变形量也逐渐增大；随着水平地应力趋于均匀，套管变形量逐渐减小；断层夹角为0°，15°，30°时，套管变形量较大，而后迅速减小。
Abstract
Weirong deep shale gas area, as a key breakthrough block for Sinopec shale gas development, has been faced with serious casing deformation since its development, and hydraulic fracturing?鄄induced fault slip is one of the main factors leading to casing deformation. Therefore, it is of great significance to clarify the relationship between fault slip and casing shear deformation for casing deformation prevention and control. In this paper, a 3D fault slip calculation model is established by using Moore?鄄Coulomb criterion considering two fault trigger mechanisms. On this basis, a finite element model of casing shear deformation was established, and the influence of different fault parameters on casing deformation was studied by taking fault slip amount as boundary condition. Finally, the concept of fine prevention and control of fault slip is proposed. The research results show that the larger the friction factor is, the smaller the casing deformation is. With the increase of fault length, the casing deformation increases gradually. With the horizontal in?鄄situ stress becoming uniform, the casing deformation decreases gradually. When the fault angle is 0°, 15° and 30°, the casing deformation is large, and then decreases rapidly.
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