Application of numerical simulation in the solid expandable tubular repair for casing damaged wells

In order to analyze the stress, strain, and residual stress of the solid expandable tubular (SET) applied in repairing casing damaged wells and to analyze the internal tube changes, the SET finite element model is established by ANSYS; the boundary condition of the model is optimized, and numerical simulation is carried out. The numerical simulation results directly reflect the stress–strain in the expansion process. With the laboratory and field tests, it is concluded that effective measures could be taken to reduce the residual stress in pipe manufacturing, casing expanding, and postprocessing stages. The secondary deformation of the SET occurs under high-pressure liquid, and compared with the expansion cone, the radius size unilaterally increases 0.9–1.3 mm. This is used to amend the empirical size formula of the expansion cone, SET, and original casing. After the application of the SET repair technology in Well Jing 708 in Huabei Oilfield, oil production increased and water cut decreased, showing that the finite element analysis of the SET meets the oil field needs.