To study the casing deformation (CD) in shale gas well fracturing caused by natural fracture slip, a fracture face stress model is built based on stress analysis, and a CD prediction model is established based on complex function to analyze factors affecting wellbore shear stress and CD. (1) The fracture and wellbore approach angles have significant impacts on the wellbore shear stress. In Weiyuan shale gas field, Sichuan Basin, under the common wellbore approach angle of nearly 90°, the wellbore is subjected to large shear stress and high risk of CD at the fracture approach angle range of 20° to 55° or its supplementary angle range. (2) When the fracture is partially opened, the wellbore shear stress is positively correlated with the fluid pressure, and negatively correlated with the fracture friction coefficient; when the fracture is fully opened, the wellbore shear stress is positively correlated with the natural fracture area. (3) The lower the elastic modulus and the longer the fracture length, the more serious the CD will be, and the Poisson's ratio has a weak influence on the CD. The deformation first increases and then decreases with the increase of fracture approach angle, and reaches the maximum when the fracture approach angle is 45°. (4) At a given fracture approach angle, appropriately adjusting the wellbore approach angle can avoid high shear stress acting on wellbore, and reasonable control of the fluid pressure in the fracture can reduce the CD risk. The shear stress acting on casing is usually much greater than the shear strength of casing, so increasing casing strength or cementing quality have limited effect on reducing the risk of CD. Caliper logging data has verified that the CD prediction model is reliable, so the model can be used to establish risk analysis chart and calculate deformation value, to provide a reference for quick CD risk prediction in fracturing design.

为了研究自然裂缝滑动引起的页岩气井压裂过程中的套管变形（CD），建立了基于应力分析的裂缝面应力模型，并建立了基于复函数的CD预测模型，以分析影响井眼剪切应力和压力的因素。光盘。（1）裂缝和井筒进近角对井筒切应力有重大影响。在四川盆地威远页岩气田中，在普通井眼接近角为90°的情况下，在20°至55°的裂隙接近角范围或其补充角度范围内，井眼承受较大的剪切应力和较高的CD风险。 。（2）当裂缝部分打开时，井眼切应力与流体压力成正相关，与裂缝摩擦系数成负相关；当裂缝完全打开时，井眼切应力与自然裂缝面积成正相关。（3）弹性模量越低，断裂长度越长，CD越严重，泊松比对CD的影响较弱。变形首先随着裂缝接近角的增加而增加，然后减小，并在裂缝接近角为45°时达到最大值。（4）在给定的裂缝进近角下，适当调节井眼进近角可以避免作用在井眼上的高剪切应力，合理控制裂缝中的流体压力可以降低CD风险。作用在套管上的剪切应力通常比套管的剪切强度大得多，因此增加套管强度或固井质量对降低CD风险的作用有限。