Mechanical analysis and structural optimization of anchorage for split segment inserted tooth slips

To meet the operational requirements of slip-type packers within TP140V casing in ultra-deep wells and enhance the anchoring performance and load-bearing capacity of the packer's anchoring mechanism during setting, this paper focuses on the study of tooth-embedded slips. The Abaqus finite element software was used to analyze the stress and contact pressure distribution patterns in key components such as the embedded teeth, casing, and slip base during the anchoring process of tooth-embedded slips. An orthogonal experimental method was employed to optimize the structural parameters of segmented tooth-embedded slips. Based on the results of the orthogonal experiments, the optimal combination of slip structural parameters was obtained: the front-end distance was 12 mm, the tooth installation spacing was 24 mm, the dip angle of the groove was 76.5°, the groove depth was 6.8 mm, and the slip wedge angle was 13°. After optimization, the maximum Von Mises stress in the slip base was reduced from 1080 MPa to 512.2 MPa, the embedding depth decreased from 0.2156 mm to 0.1338 mm, and the maximum contact pressure at the tooth tips dropped from 4247 MPa to 2965 MPa. Compared to the pre-optimization values, these reductions were 52.6%, 37.9%, and 30.2%, respectively. Moreover, the optimized casing bite depth and tooth-tip contact pressure exhibited a more uniform axial distribution. Additionally, physical prototypes of the optimized slips were manufactured and subjected to laboratory tests, which demonstrated that the axial bearing capacity of the slips could reach 450 kN, capable of withstanding axial loads in a 152.5-mm inner diameter casing under a downhole pressure environment of 100 MPa. The research findings in this paper provide a theoretical reference for optimizing the structural parameters of tooth-embedded slips within TP140V steel grade casing.