Mechanism of Mud Overflow in Inclined Boreholes During Horizontal Directional Drilling and a Critical Mud Pressure Model

Abstract

There are numerous considerations during Horizontal Directional Drilling (HDD) operations. Research provides new knowledge to address such considerations. This paper offers a critical advancement in the field of HDD by addressing one of its longstanding challenges, mud overflow in inclined hole sections. By integrating theoretical analysis, laboratory modeling, and numerical simulations, the study refines the calculation models for allowable mud pressure, considering the complex elliptical boundary conditions of shallow strata. A key contribution of this paper is the development of a model that accounts for the interplay between hole inclination angles and burial depths, shedding light on their impact on maximum permissible mud pressure. The identification of fracture mechanisms and mud overflow pathways further enhances its practical relevance. This work has significant implications for the HDD industry, particularly in minimizing drilling-induced risks and optimizing project safety. These findings could be incorporated into HDD design software for real-time pressure monitoring and predictive analysis.