The spiral seam submerged arc welded steel pipe is rotated and drilled and begins to enter the soft formation. Under the action of the three-cone wheel, the drill bit first produces elastic shear deformation of the formation and then is removed under the pressure of the three-cone wheel. In the simulation environment, the soft soil is homogeneous clay, and the cracks in the formation and soil are not considered. Horizontal directional drilling is carried out in the sudden change formation, and the formation is in random dynamic contact with the roller drill bit. Friction is generated when the cone contacts the formation. The impact force causes the spiral seam submerged arc welded steel pipe to vibrate. When the three-cone drill bit moves from the soft formation to the hard formation, it will inevitably produce large lateral vibration and up and down vibration.
When the drilling speed is 0.008m/s and the drill bit speed is 2 radians/s, the pseudo-strain energy curve during the advancement of the roller drill bit mainly includes viscosity and elasticity. However, since the viscosity term usually occupies a dominant position, most of the energy is irreversible when converted into pseudo-strain energy. The deformation energy of the spiral seam submerged arc welded steel pipe is the main energy consumed to control the hourglass deformation. If the pseudo strain energy is too high, it means that the strain energy controlling the hourglass deformation is too large, and the mesh is refined or modified. To reduce excessive pseudo strain energy. The pseudo strain energy mutation in this model mainly occurs when the drill bit enters the soft soil layer and the roller drill bit passes through the interface of the sudden formation. The greater the formation hardness, the greater the pseudo-strain energy of the drill bit entering the formation. Simulate the drilling process of the spiral welded pipe in the sudden formation and predict the change of the drill bit drilling trajectory.
(1) The pseudo strain energy mutation mainly occurs when the drill bit enters the soft soil layer and the roller drill bit passes through the interface of the sudden formation. The higher the forming hardness, the greater the pseudo strain energy of the spiral seam submerged arc welded steel pipe when entering the forming.
(2) When drilling in the sudden formation, the spiral seam submerged arc welded steel pipe moves longitudinally and the drill bit vibrates. The greater the formation hardness, the greater the amplitude of the drill bit.
(3) Under certain formation inclination conditions, 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 drill bit speed is lower than 2.2rad/s, the influence of the speed on the longitudinal deviation of the drilling trajectory is reduced.
(4) At a certain drill bit speed, when the local formation inclination is 0° and 90°, there is no influence on the drilling trajectory; when the local inclination gradually increases, the longitudinal deviation of the drilling trajectory increases; when the local inclination exceeds 45°, the influence on the longitudinal deviation of the drilling trajectory decreases. The research results of this chapter are of great significance to improving the prediction accuracy of the drilling trajectory of the three-cone drill bit in steep formations and lay a theoretical foundation for correcting the drilling trajectory of spiral seam submerged arc welded steel pipes through horizontal guide holes.
Post time: Aug-29-2024