Computation Model for Collapse Strength of the Casing Wear

With the combination of theoretical analysis, numerical simulation and actual test, the factors and rules impacting the collapse strength are studied. The collapse strength of the casing wear presents changes of exponent, power function, and linear trend with the residual casing wall thickness, wear radius and axial load respectively. Based on this, the computation model of collapsing strength for the whole casing wear has been established and the model is tested for verification by computing collapse strength of non-casing wear. The study results provide a guide for design of the casing sting strength and down-hole safety.