The spiral seam submerged arc welded steel pipes is drilled in rotation and begins to enter the soft formation. Under the action of the tri-cone, the drill first produces elastic shear deformation of the stratum and then is removed under the pressure of the tri-cone. In the simulated environment, the soft soil is homogeneous clay, regardless of the stratum and the cracks in the soil. Horizontal directional drilling is carried out in an abrupt formation, and the formation is in random and dynamic contact with the roller cone bit. Friction occurs when the cone is in contact with the ground. The impact force causes the spiral seam submerged arc welded steel pipe to vibrate. When the tri-cone bit moves from the soft formation to the hard formation, it will inevitably produce large lateral vibration and up and down the vibration.

When the drilling speed is 0.008m/s and the bit rotation speed is 2 radians/s, the pseudo-strain energy curve during the advancing process of the roller cone bit mainly includes viscosity and elasticity. However, since the viscous term usually dominates, the transformation of most of the energy into pseudo strain energy is irreversible. The deformation energy of spiral seam submerged arc welded steel pipe is the main energy consumed to control the deformation of the hourglass. If the pseudo strain energy is too high, it means that the strain energy controlling the deformation of the hourglass is too large, and the mesh should be refined or modified. To reduce excessive pseudo strain energy. The sudden change of pseudo strain energy in this model mainly occurs when the drill bit enters the soft soil layer and the cone bit passes through the interface of the sudden change formation. The greater the hardness of the formation, the greater the pseudo strain energy of the drill bit into the formation. Simulate the drilling process of spiral welded pipe in the abrupt formation and predict the change of the drill bit’s drilling trajectory.

(1) The sudden change of pseudo-strain energy mainly occurs when the drill bit enters the soft soil layer and the cone bit crosses the interface of the sudden change formation. The higher the forming hardness, the greater the pseudo strain energy of the spiral seam submerged arc welded steel pipe when it enters the forming process.

(2) When drilling into the formation suddenly, the spiral seam submerged arc welded steel pipes moves longitudinally and the drill bit vibrates. The greater the hardness of the formation, the greater the amplitude of the drill bit.

(3) Under the condition of a certain stratum dip, the greater the drilling speed of the drill bit, the greater the longitudinal deviation of the drilling trajectory, and the greater the drill bit speed, the smaller the longitudinal deviation of the drilling trajectory. When the bit rotation speed is lower than 2.2rad/s, the influence of the rotation speed on the longitudinal deviation of the drilling trajectory is reduced.

(4) At a certain bit rotation speed, when the local formation dip angle is 0° and 90°, it has no effect on the drilling trajectory; when the local dip angle gradually increases, the longitudinal deviation of the drilling trajectory increases; when the local dip angle exceeds 45°, The influence on the trajectory of drilling longitudinal deviation is reduced. The research results in this chapter are of great significance for improving the prediction accuracy of the tri-cone drill bit in steep formations and lay a theoretical foundation for the correction of the spiral seam submerged arc welded steel pipe drilling trajectory through the horizontal pilot hole.