There is considerable interest in using remote elastostatic deformations to identify the evolving geometry of underground fractures that are forced to propagate by the injection of a high pressure viscous fluid. These so-called hydraulic fractures are used to increase the permeability in oil and gas reservoirs as well as to pre-fracture ore-bodies in preparation for a mining process known as bl...

We introduce a discrete element simulation for the hydraulic fracture process in a petroleum well which takes into account the elastic behavior of the rock and the Mohr-Coulomb fracture criterium. The rock is modeled as an array of Voronoi polygons joined by elastic beams, which are submitted to tectonical stresses and the hydrostatic pressure of the fracturing fluid. The fluid pressure is trea...

A concept of "Fractal Fracture Mechanics" for HDR .(Hot Dry Rock) geothermal reservoir design has been developed as an extension of conventional rock fracture mechanics. It is suggested that this concept is successfully applicable to characterize and model subsurface fracture network in HDR geothermal reservoir. Furthermore, this modeling procedure makes it possible to evaluate the thermal ener...

OBJECTIVE The mixed levator and frontalis muscles lack the interior muscle spindles normally required to induce involuntary contraction of their slow-twitch fibers. To involuntarily move the eyelid and eyebrow, voluntary contraction of the levator nonskeletal fast-twitch muscle fibers stretches the mechanoreceptors in Müller's muscle to evoke trigeminal proprioception, which then induces reflex...

Shale gas is one of the primary types of unconventional reservoirs to be exploited in search for long-lasting resources. Production from shale gas reservoirs requires horizontal drilling with hydraulic fracturing to achieve the most economic production. However, plenty of parameters (e.g., fracture conductivity, fracture spacing, half-length, matrix permeability, and porosity, etc) have high un...

Numerical methods such as boundary element and finite element methods are widely used for the stress analysis in solid mechanics. This study presents boundary element method based on the displacement discontinuity formulation to solve general problems of interaction between hydraulic fracturing and discontinuities. The crack tip element and a higher order boundary displacement collocation techn...

The purpose of this paper is to report the first stage of the implementation within FLAC of a hydromechanical model using an iterative procedure between two independent hydraulic and mechanical sub-models. The fracture network of the rock mass is considered using the multilaminated medium concept. The implemented model is illustrated through its application to the hydraulic circuit of the Venda...

A continuum damage mechanics (CDM) based constitutive model has been developed to describe elastic, plastic and damage behavior of porous rocks. The pressure sensitive inelastic deformation of porous rocks together with their damage mechanisms are studied for drained and undrained conditions. Fracture mechanics of microcrack andmicro-void nucleation and their coalescence are incorporated into t...

Hydraulic stimulation in Enhanced Geothermal Systems is performed by injecting water at high pressure into low permeability, typically crystalline, rock. In most cases, the elevated pore pressure induces slip on preexisting fractures, resulting in an increase in permeability. This process involves interacting hydraulic, thermal, mechanical, and thermoelastic processes. It is complicated by the ...