| Title | Numerical Investigation of PDC Bit Wear under Thermo-Mechanical Coupling in Hot Dry Rock Drilling |
|---|---|
| Authors | E. Jahangir, A. Vetsak |
| Year | 2026 |
| Conference | World Geothermal Congress |
| Keywords | |
| Abstract | The longevity and efficiency of polycrystalline diamond compact (PDC) bits are key to the economic viability of deep drilling in high-temperature geothermal environments. In hot dry rock (HDR) formations, cutter wear is governed by complex thermo-mechanical interactions involving abrasive mechanisms, thermal softening of the matrix, and cyclic loading effects. This study presents a coupled numerical model to simulate the progressive wear of PDC cutters under realistic downhole conditions, including temperatures up to 400 °C and confining pressures of 150 MPa. The simulation framework, developed in Abaqus and enhanced by a user-defined material subroutine (UMAT), integrates temperature-dependent rock behavior, thermal expansion, and heat generation at the bit–rock interface. Results highlight the influence of local thermal gradients and rock hardness transitions on stress concentration and wear localization. A parametric study explores the impact of bit design variables, rotational speed, and rate of penetration on cutter degradation and mechanical specific energy (MSE). The model enables the generation of predictive wear maps and supports the design of thermally resilient drilling tools for future geothermal operations. |