Research on the Influence of Changes in Slip Structure on the Residual Strength of Casing.

In order to study the influence of slip structure on the mechanical behavior and residual strength of casing, parameters such as support force and friction force between slips and casing were derived based on the interaction relationship between slips and casing. Tensile tests were conducted on casing materials in this paper, and the working process of anchoring casing with single and double slips was simulated. The influence of indentation depth on the residual strength of casing was analyzed. The results show that the deformation of the casing is relatively severe when the single slip sealing force reaches 120 kN. According to the law of residual strength curve, there is a turning point where the stress concentration factor tends to be gentle, and the corresponding indentation depth value at this point increases with the increase in casing diameter. Single slips were unable to effectively bite into P110 and P125 casings, and the bite did not achieve the effect of setting the casing. However, when double slips were used to anchor the casing, the inner wall of the casing had deeper indentation, and the double slips could firmly seat the casing. These results indicate that replacing single slips with double slips can effectively achieve the setting effect. [ABSTRACT FROM AUTHOR]