Research on Drilling Tool Wear and Anti-Wear Technology for Hot Dry Rock Drilling

In order to clarify the wear mechanism of drilling tools during hot dry rock drilling and propose an appropriate anti-wear technical scheme to alleviate the wear of drilling tools, the motion state of drilling string in the wellbore was first analyzed and the contact relationship between the drilling string and the sidewall was described. Furthermore, the finite element method was used to establish a model for analyzing the drilling string dynamics. Later, by taking the drilling of a typical hot dry rock well as an example, the contact state between the drilling tool and the sidewall was analyzed by solving the dynamic model of the drilling string. Finally, with the goal of reducing the contact force between drilling tool and sidewall, the influence law of BHA (bottom hole assembly) and drilling parameters on the dynamic characteristics of drilling tools were analyzed. In addition, the recommended anti-wear technical scheme of BHA and drilling parameters was proposed through the optimization of BHA and drilling parameters. The technical scheme was then tested and applied in on-site hot dry rock drilling. After drilling 116.00 m, the stabilizer was worn by only 3.0 mm, indicating that a good anti-wear effect was obtained. This technical scheme can provide a new solution to alleviate drilling tool wear in hot dry rock drilling.