4D Geomechanical Research in Hydraulic Fracturing of Unconventional Resources - A Case Study From Junggar Basin, China

Abstract The application of MHFHW (multistage hydraulic fracturing horizontal well) enormously contributes to the dramatic increasing production of low permeability reservoir. Geomechanics is the key factor for fractured well by influencing SRV (stimulated reservoir volume) and post-stimulation production. Stress variation and distribution characteristics along with real-time fracturing are simulated based on 4D (four-dimension) geomechanics research, providing the effective technical support for the designing and optimization of hydraulic fracturing scheme to get larger SRV and higher post-stimulation production. 1D (one-dimension) geomechanics model is firstly built using data from drilling, mud log, well log, mini fracture and well testing, and then verified by comparing with drilling events and laboratory test of core samples. Furthermore, Project team combines 1D geomechanics model with additional data including 3D structural model, fault distribution and seismic data to achieve the regional 3D (three-dimension) geomechanics model. 3D Geomechanics model only represents the original stress field that before hydraulic fracturing, which will be changed by pumping massive fracturing fluids into reservoir. 3D geomechanics model study is integrated with the data from real-time fracturing and micro- seismic monitoring to generate 4D geomechanics model, enabling the characterization of variation of geomechanics model with real-time fracturing. 4D Geomechanical research result clearly characterizes the stress model variation and reduces the uncertainties in reservoir stimulation operation. The model helps to optimize pressure pumping rate, volume of proppant and fracturing fluids, eventually maximizes the increase of fracture flow conductivity and post-stimulation production., This case study discusses the multi-stages fracturing treatment scheme optimization of horizontal well H84001 based on the 4D Geomechanical research of this low permeability reservoir. H84001 production has improved 184.2% compared with the offset well without fracturing treatment optimization. This project established the mathematical relationships between reservoir deformation and strain, upgrading geomechanical study methods from static to dynamic. The research finding provides technical guidance to develop low permeability reservoir in an economical and efficiency stimulation scheme.