New Control Method of Casing Deformation in Shale Gas Slip Fault Based on Solid Expandable Tubular

How to slow down the casing deformation of shale gas wells is one of the problems to be solved urgently. Fault slip is inevitable, so how to prevent casing deformation has become an important research hotspot. In this paper, a new casing deformation control method based on solid expandable tubular (SET) technology is proposed to reduce casing deformation. This paper establishes a three-dimensional dynamic model of casing deformation considering formation pressure, frictional contact, and nonlinear loads, analyzes the advantages of using SET technology in cementing, and researches the influence of SET and annular cement parameters on casing deformation. The research results show that: on the basis of the existing cementing cement, the use of SET technology is more effective. The inner diameter of the casing after deformation will increase by more than 10 mm on the current basis, which is more conducive to subsequent construction. The expansion ratio of SET has different slowing effects on the casing deformation. In addition, the study also found that the effect of using “flexible cement + SET” is better. If only flexible cement is used, the elastic modulus of ring cement is 0.01 GPa. In order to achieve the same effect, in the case of the “flexible cement + SET” process, only annular cement with an elastic modulus of 0.1 GPa is required, which is equivalent to reducing the difficulty of cement construction. The research results of this paper provide new ideas and methods for casing deformation.