Simulating three dimensional hydraulic fracture propagation using displacement correlation method

Abstract

The TOUGH-FEMM simulator is used to investigate the interaction of multiple simultaneous hydraulic fractures. In TOUGH-FEMM simulator, rock deformation is modeled using the hybrid Finite Element-Meshfree Method (FEMM) and fluid flow is simulated through the Transport Of Unsaturated Groundwater and Heat (TOUGH2) simulator. The stress intensity factors are calculated by using the Displacement Correlation Method (DCM). The equivalent mode I stress intensity factor is used for determining fracture propagation criterion and direction. Successfully creating multiple hydraulic fractures in horizontal wells is critical for unconventional gas production economically. These previous works focussed on the propagation of fractures which are parallel initially. However, because of inevitable error in practical engineering and natural flaws in rock, the initial fractures might be inclined. The overall objective of the current work is to study the influence of initial fracture orientation on the simultaneous hydraulic fracturing of a horizontal well. The results of the present work show that initial fracture orientation has significant effect on the fracture propagation direction and final fracture contour. Different fracture contours will result in distinct fracture network, which will greatly affect the reservoir permeability.