基于统一强度理论的牙齿侵入井底岩石问题研究

onsidering the condition of the bottom hole pressure, basing on unified strength theory to analyze the mechanical process of teeth invade rock, build bottomhole rock intrusive equation with unified strength parameters and give intrusive coefficient without the impact of axial load, invasion depth and bit angle. The equation considers the impacts of intermediate stress on intrusive coefficient. The results of the equation and Mohr-Coulomb strength theory are identical when b equals to 0. Analyze the impact of angle of internal friction, fluid column pressure, pore pressure and bit angle on intrusive coefficient. The results show that with b, angle of internal friction and bit angle, fluid column pressure and pore pressure increasing, the intrusive coefficient increases, increases exponentially, increases linearly and decreases linearly respectively.