The propagation of Stoneley waves in a fluid-filled borehole with a vertical fracture is investigated both theoretically and experimentally. The borehole propagation excites fluid motion in the fracture and the resulting fluid flow at the fracture opening perturbs the fluid-solid interface boundary condition at the borehole wall. By developing a boundary condition perturbation technique for the...

An experiment was conducted to demonstrate the utility of quantitative fracture flow visualization techniques in the study of entrapped fluid phase (air) dissolution into a flowing phase (water) within a horizontal, transparent, analog rough-walled fracture. The fracture aperture field and phase occupancy were measured using light transmission techniques and then combined to calculate bulk wate...

*Correspondence: Shigekazu Kusumoto, Graduate School of Science and Engineering for Research, University of Toyama, 3190 Gofuku, Toyama-shi, Toyama 930-8555, Japan e-mail: [email protected] Many rock fractures are entirely driven open by fluids such as ground water, geothermal water, gas, oil, and magma. These are a subset of extension fractures (mode I cracks; e.g., dikes, mineral veins ...

[1] We present a theory for dynamic longitudinal dispersion coefficient (D) for transport by Poiseuille flow, the foundation for models of many natural systems, such as in fractures or rivers. Our theory describes the mixing and spreading process from molecular diffusion, through anomalous transport, and until Taylor dispersion. D is a sixth order function of fracture aperture (b) or river widt...

Some fundamental mechanisms associated with cooling/heating of the rock in the context of drilling and reservoir stimulation in enhanced geothermal systems are described. The role of temperature and pore pressure in wellbore failure and fracture width is considered using analytical and boundary element models. Results indicate that cooling induces a pore pressure drop inside the formation that ...

Shear fracture network is important to the hydraulic fracturing treatment of a shale gas reservoir. In this paper, the formation of shear fracture network is investigated by a Displacement Discontinuity Method (DDM) based model. The results show that the sliding of fracture surface is irreversible but may change significantly after fluid pressure dissipates. The final sliding distance is differ...