Optimization design of tie-back casing centralizer in ultra-deep well

As a simple and effective method, centralizer can directly improve the buckling behavior of casing in deep and ultra-deep wells. In this paper, an ultra-deep well in Shunbei block is taken as an example. Based on elastic-plastic contact theory and Abaqus finite element software, the finite element model of the wellbore and reconnection casing is established. The buckling behavior of the reconnection casing string under dead weight is analyzed, and corresponding schemes are designed according to its buckling behavior. The results show that, under the action of self-weight, the return casing produces a serious spiral buckling behavior in the wellbore, and the spiral buckling phenomenon of the casing string is significantly improved by applying a centralizer at the peak and trough of the wave caused by the buckling in the direction of U1 and U2. It is shown that the casing buckling can be avoided by adopting the centralizer placement design scheme, which provides some reference for the actual field study of the buckling behavior of the casing string and the optimization design of the centralizer.