In this paper the Discrete Element Model (DEM) ‘ESyS_Particle’, previously used to model fracture of brittle rocks and earthquake processes, is further developed to be able to be applied to the hydraulic fracturing process in Engineered Geothermal Systems (EGS). The advantage of DEM is that large deformations and dynamic process can be modelled easily. ESyS_Particle has been used to successfull...

A series of experiments were performed to determine rock mechanical parameters related to was studied. Experimental results show that the coal seam in the study areas has a relatively low elastic modulus, high Poisson’s ratio, high fragility and is easily broken and compressed. The coal seam is considered as a transversely isotropic medium, since the physical properties in the direction of bedd...

This chapter reviews the recent progress toward computer simulation of the growth of vast systems of branched hydraulic cracks needed for the efficient extraction of gas or oil from shale strata. It is emphasized that, to achieve significant gas extraction, the spacing of parallel hydraulic cracks must be on the order of 0.1m, which means that the fracturing of the entire fracking stage would r...

According to the basic parameters of Yangquan mining area, based on determined meso physical and mechanical geological parameters, several groups numerical calculation models considering different fracturing (water injection flow water time) are established. Then, simulation test is carried out by using particle discrete element program, influence effect related coal seam hydraulic analyzed num...

Hydraulic fracturing is used to increase the permeability of shale gas formations and involves pumping large volumes of fluids into these formations. A portion of the frac fluid remains in the formation after the fracturing process is complete, which could potentially contribute to deleterious microbially induced processes in natural gas wells. Here, we report on the geochemical and microbiolog...

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...

Background The goal of this work was to investigate the potential for subsurface migration of fluids from the stimulated oil and gas reservoir to an overlying drinking water aquifer. Researchers conducted two types of numerical simulation experiments: (1) exploration of hypothetical scenarios that could result in emergence of fluid pathways; and (2) evaluation of the range of conditions that ma...

Exploration of oil and natural gas from shale deposits can bring to the surface radioactivity. Naturally occurring Uranium-238 and Thorium-232 as part of their decay chains can produce radium isotopes, which are themselves precursors of radon gas. Due to the solubility of radium and its contaminated impact on the environments and health concerns, regulations on the levels of Ra226 and Ra228 in ...

I model the interaction between dynamic decision making and social learning about new technologies in driving industry takeoff and productivity growth. Learning about the use of new technologies is an important factor in economic growth, but I demonstrate that anticipated social learning can lead to a free-riding dynamic in scenarios with high uncertainty. I consider the empirical setting of hy...

Twenty-eight states require disclosure of hydraulic fracturing chemicals. Twenty-three states direct reporting to FracFocus; additionally, companies in other states use this registry. FracFocus contains the most comprehensive dataset on fracturing chemicals but faces data quality and transparency criticisms. In response, FracFocus announced upgrades, and since May 2015, publishes aggregated dat...