Mechanical response analysis of reservoir sandstone considering fluid-solid coupling effect

A numerical method based on 3-dimensional particle flow code (PFC3D) in cylindrical coordinate system was proposed to simulate the mechanical response of the reservoir sandstone. By comparing the simulation results with the triaxial test ones, the meso-mechanical parameters were determined, and then a perforation test model was built based on the fluid-solid coupling effect. The results show that macro stress of the sandstone can reflect the effect of oil flow rate on the increase of sandstone stress, and the stress is not greater than the peak strength of reservoir sandstone, the maximum plastic zone is 12. 9 mm. The results can describe the local failure process of sandstone. When flow rate is larger than 3 m/s, obvious increase of the shearing stress will accelerate the shearing failure, the particle movement and rotation. The serious breakage of the bonds will result in the increase of dislodged particles by orders of magnitude and obvious expansion of the plastic zone. The 3-D numerical method considering fluid-solid coupling effect can reflect the mechanical characteristics of the sand production in the oil well better, and the probability of the sand production will be increased obviously when the oil flow rate controls the sandstone.