Determination of fluid-propagated fracture under biaxial loading conditions at varied rheological properties of the fracturing fluids in elastic medium*

The hydraulic fracturing technique has been studied in conventional and unconventional reservoirs to enhance oil and gas recovery for the past few years. However, this technique is still challenging in unconventional reservoirs such as shale rocks. On the laboratory scale, very few studies have reported the deformation of layered rocks or fluid-induced fractures under biaxial loading. The present study uses lab-scale experiments and a numerical model to examine crack propagation due to fluid injection in isotropic (homogenous) and anisotropic (layered elastic medium/heterogeneous) material when loaded in different directions. In this current work, the biaxial loading system is particularly designed for the fracture propagation studies in analogue mediums. Gelatin of various compositions is used as an analogue medium owing to its transparency. We use water as a fracturing fluid in homogeneous and heterogeneous mediums, maintaining a 1 ml/min flow rate at a temperature of 15°C inside the matrix through a syringe pump.  In the present investigation, the parameters investigated for fracture propagation are the rheology of fracturing fluids, variable loads, and different solid matrices. Also, the mechanical properties of isotropic and anisotropic materials are determined. This lab scale analysis can be compared with the field-scale geological reservoirs using scaling laws in future investigations. The FEM-based numerical phase-field damage model is built to simulate the propagation of fluid fractures. Premilinary results are comparison with the experimentally observed fluid crack propagation to the simulation results.