NUMERICAL SIMULATION OF A SINGLE FRACTURE WITH VARYING CONSTRAINTS

Hydraulic fracturing is a process of enhancing rock permeability through injection of highly pressurized fluids and is commonly used in the petroleum industry for the recovery of oil and natural gas. Microseismicity is commonly used to monitor the fracturing process, since shear slip events occur on the fracture surface due to increased pore pressure. These microseismic events are then used to image the affected volume of rock, and provide information about the lateral extent and orientation of the stimulated volume (Albright and Pearson 1982; Rutledge and Phillips 2002). Since the microseismic events extend beyond the fracture tips and into the formation, microseismicity alone cannot accurately predict the lateral extent of induced fractures (Evans et al. 1999). It may be possible to image the fractures using direct current resistivity (DCR) since fractures typically cause resistivity anomalies. Using the finite element method (FEM), a single fracture with varying constraints such as well geometry, electrical conductivity, and fracture orientation, will be forward modeled, them inverted. The inverted image will then be compared to the original image in order to see how well the fracture can be imaged with the specified constraints. Based on findings by Robinson et al, the addition of conductivity constraints should improve fracture detection. Additionally, well geometry should affect the inverted image since electric potential decreases with distance from the current source.