Experimental and numerical investigation on influence of pore-pressure distribution on multi-fractures propagation in tight sandstone

• DOI: 10.1016/j.engfracmech.2020.106993
• Publication Date: 2020-03-11T07:05:10Z
• Authors: Heng Zheng; Chunsheng Pu; Yong Wang; Chao Sun
• Keywords: 01 natural sciences; 0105 earth and related environmental sciences

Abstract During the process of reservoir stimulation, how to create more fractures has become a key issue for the tight sandstone reservoir development. From the experimental investigation and numerical simulation, the effect of pore pressure distribution on fracture propagation was analyzed. The experiment consisted of 300 × 300 × 600 mm3 sandstone specimens was divided into two laboratory tests to investigate the fracture propagation of simultaneous fracturing and sequence fracturing subjected to true tri-axial confinement stresses. The experimental results showed that the fracture distribution was asymmetric due to the influence of pore pressure and stress field. Meanwhile, the numerical simulation results discovered that the increase of pore pressure can not only cause the deflection of fracture, but also increase the breakdown pressure and extension pressure of rock. When the pore pressure increment was over 4 MPa, the fracture deflected obviously in the process of extension, and the breakdown pressure and extension pressure can increase by 22.8% and 23.05%.