Analyses of fracturing and thermal performance of fractured reservoirs in engineered geothermal system (EGS) are extended from a depth of 5 km to 10 km, and models for flow and heat transfer in EGS are improved. Effects of the geofluid flow direction choice, distance between fractures, fracture width, permeability, radius, and number of fractures, on reservoir heat drawdown time are computed. T...

Fully mechanized top-coal caving mining with high height, hard roofs and strong pressure are popular in the Shendong area, China. The occurrence of dynamic disasters, such as rock burst, coal gas outburst, mine earthquakes goaf hurricanes during exploitation process under roof conditions, pose a threat to safe production mines. In this study, characteristics overburden fracture fully height stu...

In this paper, numerical simulations of circular boreholes under internal hydraulic pressure are carried out to investigate the energy transferred to the surrounding rock and the breakdown pressure. The simulations are conducted by using a micromechanical continuum damage model proposed by Golshani et al. (2006). The simulation results suggest that the borehole breakdown pressure and the energy...

An overview of key experimental data and theoretical representations on fracture processes in nanoceramics is presented. The focuses are placed on crack growth in nanoceramics and their toughening micromechanics. Conventional toughening micromechanisms are discussed which effectively operate in both microcrystalline-matrix ceramics containing nanoinclusions and nanocrystalline-matrix ceramics. ...

hydraulic fracturing (hf), as a stimulation technique in petroleum engineering, has made possible the oil production from reservoirs with very low permeability. the combination of horizontal drilling and multiple hf with various perforation angles has been widely used to stimulate oil reservoirs for economical productions. despite the wide use of hf, there are still ambiguous aspects that requi...

Hydraulic fracturing in shale gas reservoirs has usually resulted in complex fracture network. The results of micro-seismic monitoring showed that the nature and degree of fracture complexity must be clearly understood to optimize stimulation design and completion strategy. This is often called stimulated reservoir volume (SRV). In the oil & gas industry, stimulated reservoir volume has made th...

The petroleum industry’s use of horizontal drilling and hydraulic fracturing technologies has changed organic-rich mudstones, like the Devonian Marcellus Formation, from conventional hydrocarbon sources and seals to unconventional ‘shale gas’ reservoirs. Organic-richness and formation brittleness are two principal components of reservoir quality assessment, as the former is indicative of the am...