By using ANSYS software,this paper makes the mechanical analysis on the structure of oil well casing,builds the mechanical model in accordance with the actual projects and conducts nonlinear contact analysis solution for it,which is more practical than simply for the casing and whose conclusion is more reasonable.

The deformation of oil well casing by creep of surrounding rocks is analysed with finite element methods.

Combined with practical engineering of oil fields,the influences of one opening and multi-openings with different shapes on a oil well casing are studied in this paper.

Although cathodic protection has been widely applied to oil well casings, it is a challenging job to determine the cathodic protection level of well casings at any depth without interruption of production.

It is indicated that for oilfields with regular well patterns this method may provide a cheap and efficient tool for the searching of residual oils.