Fluid penetration has been observed to have significant impacts on the distributions of pore pressure and effective stress in hydraulic fracturing experiments. This fluid penetration is usually simulated by the invariable boundary method which neglects the impacts of fluid front motion and introduces significant errors in the simulation of hydraulic fracturing. This study proposed a moving boundary method to describe the fluid front motion and established an anisotropic fluid-solid-motion coupling model for fluid penetration into anisotropic porous media. The performances of invariable and moving boundary methods were numerically evaluated for the impacts of fluid front motion on the field variables (including pore pressure, principal stresses and permeability) and breakdown pressure. Simulation results showed that the penetration depth and pore pressure distribution obtained from the moving boundary method fit experimental observations better than those obtained from the invariable boundary method. Anisotropic fluid front motion forms a changing elliptical seepage zone. The pore pressure, principal stresses, hoop and radial permeability have significant changes within seepage zone. The fluid front is the dividing line between seepage zone and initial state zone. The moving boundary method can accurately simulate the hydraulic fracturing.

Item Type:	Refereed Article
Keywords:	fluid penetration, invariable boundary method, moving boundary method, anisotropic porous media, breakdown pressure
Research Division:	Engineering
Research Group:	Civil engineering
Research Field:	Civil geotechnical engineering
Objective Division:	Energy
Objective Group:	Energy exploration
Objective Field:	Geothermal exploration
UTAS Author:	Zhang, X (Mr Xiangxiang Zhang)
UTAS Author:	Wang, X (Professor Xiaolin Wang)
ID Code:	136972
Year Published:	2020
Deposited By:	Engineering
Deposited On:	2020-01-23
Last Modified:	2020-12-07
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