Research on Finite-Element Simulation of Influential Factors of Wall-Thickness after Expansion on Solid Expandable Tubular

Wall-thickness after expansion is one of the key parameters of expandable tubular system, and friction factor between expansion cone and casing inner wall, expansion ratio and angle of expansion cone have direct effect on it. Because the expansion process of expandable tubular is highly non-linear elastic-plastic contact problem, it is very difficulty to solve it by means of analytical method. In this paper, using finite-element method, the mechanical model of plane non-linear contact model during the expansion process of expandable tubular is established. The relational curves of friction factor, expansion ratio and angle of expansion vs wall-tickness after expansion are obtained and the matching formulas of quantitative relation are arrived. Finally, using multi-parameters linear regression in Statistics, the matching formula of wall-tickness after expansion including the three factors is obtained. The results provide theoretical grounds for the structure and strength design of the Solid Expandable Tubular.