Finite Element Analysis of Casing Wear in L-80 Steel vs P110 steel

Casing wear is a major well-integrity risk in directional drilling due to repeated sliding contact between the casing inner wall and the drill pipe tool joint (TJ). The paper analyses wear in API 5CT L-80 and P110 steel grades using Finite Element Analysis (FEA) to identify differences in their behaviour under representative operational parameters. A three-dimensional explicit contact model is developed in ANSYS Workbench LS-DYNA and implemented using Archard’s wear law, which calculates wear depth and related parameters from local contact pressure and sliding distance. Once validated against reference wear data for a baseline L-80 case (115 RPM at 1000 N), the model is used in a parametric analysis to assess side loads (1000 N to 1400 N) and rotational speeds (115 RPM to 207 RPM). The findings indicate that wear increases with both normal load and speed, with normal load having a greater influence. Under identical parameters, the materials produce different levels of wear in the worst-case scenario ( at 115 RPM and 1400 N, P110 has ~35% lower wear than L-80) and a much smaller difference (i.e., at 207 RPM and 1000 N, P110 has ~5% lower wear than L-80). Consequently, upgrading to P110 in high-load environments with severe contact will yield the greatest benefit from upgraded casing, thereby providing an economic tool for grade selection and wear-risk evaluations via calibrated FEA models.