Stress behavior in the near fracture region between adjacent horizontal wells during multistage fracturing using a coupled stress-displacement to hydraulic diffusivity model

Abstract

This work presents results for the application of finite element simulation to determine changes in stress orientation and magnitude during a multistage fracturing job in horizontal wellbores. A technique that couples stress-displacement with hydraulic diffusivity was used to account for effective in-situ stress and to estimate pore pressure distribution in the near fracture region. The results captured in this study aid understanding of propagation of induced fractures in a multistage fracturing job and in a multiple horizontal wellbore scenario. This study is a valid and reliable estimation of effective stresses in the near fracture area because effective stresses control strain in a saturated poroelastic material. Additionally, reorientation of in-situ stress in the same near region to the fracture was confirmed. The local reorientation of in-situ stresses will consequently cause the reorientation of subsequent fractures which will stop growing transverse to the horizontal wellbore. As a result, induced fractures do not propagate as expected, creating a non-efficient drainage pattern in the reservoir.