Wellbore stability of highly deviated well intervals for large-diameter boreholes

ABSTRACT: In this paper, the analytical study, and the Discrete Element Method (DEM) simulation were conducted to evaluate the wellbore stability of steeply dipping mining utilizing various wellbore failure criteria. Mining site data of surface and subsurface in-situ stress, and rock mechanics properties were collected to support the study. The dimensions of the studied wellbore were 100m maximum depth, 1.3m maximum diameter, and 45 degrees inclination. The wellbore rock failure was analyzed, and the critical wellbore pressure after drilling in four essential azimuths (i.e. 0o, 90o, 180o, and 270o) using pure water was calculated. The results of the individual and the analytical-DEM coupled study demonstrated the wellbore stability.