Numerical Modelling for Microfracture Treatment in Unconventional Reservoir based on Fluid Injection

Unconventional energy sources are the future hope for the fulfillment of increasing energy demand. Global energy demand has continued to grow, averaging around 1% annually between 2019 and 2023. The authors of the present paper aim to establish unconventional reservoirs as a bridge solution to fill the gap. The study focuses on the integrity of the fracture network for the successful transportation of CO2 in unconventional reservoirs. A well-developed microfracture network leads to smooth, fluid transportation in the formation. Microfracture analysis is a common challenge in the petroleum industry due to the variation in reservoir conditions. Therefore, it is crucial to investigate the microfracture network for smooth fluid flow in the reservoir. The present paper deals with improving the fracture propagation of reservoir rock with the help of a phase field model (PFM). The fracture propagation was examined using COMSOL Multiphysics software based on the classical Biot poroelasticity theory. Results thus obtained indicated that the fracture generation on either side of the initial fractures was due to the induced tensile stress. A critical pressure was estimated for the fracture initiation and its propagation. Higher fluid injection pressure was observed for the fracture's coalescence and the development of the fracture network in the unconventional reservoir.