Based on techniques of close upper protective coal-rock layer mining, relieved gas extraction, and underground gangue washing-discharging-backfilling, this paper initiates the concept of mixed fully-mechanized coal mining, which combines a solid backfilling method and a caving method (hereinafter referred to as “backfill and caving mixed mining”). After the principle and key techniques are intr...

2.1 Background .................................................................................................... 26 2.2 Syngas Classification Based on its Heating Value ........................................ 28 2.2.1 Low-Btu Gas ...................................................................................... 29 2.2.2 Medium-Btu Gas........................................................

The mechanism and critical conditions of rock failure in underground coal mining processes have attracted great attention. Based on the origin and properties of radon gas, we propose that radon release from underground strata to the surface occurs in two stages, i.e., the formation of free radon and the migration of radon gas. Due to its optimal combination of efficiency and low background meas...

In this work, studies of underground gas storage (UGS) were performed on a partially depleted, naturally fractured gas reservoir through compositional simulation. Reservoir dynamic model was calibrated by history matching of about 20 years of researvoir production. Effects of fracture parameters, i.e. fracture shape factor, fracture permeability and porosity were studied. Results show...

We have proposed a static model, a dynamical model and a modified dynamical model of a geyser induced by inflow of gas based on observation and model experiments of it and have also proposed a combined model combining above two models. And numerical simulations of the modified dynamical model or the combined model reappear spouting dynamics of a geyser induced by inflow of gas and it becomes po...

Carbon Dioxide Storage in Natural Gas Reservoir — The general idea of CO2 disposal in gas reservoirs is that the underground volume of the ultimately recoverable hydrocarbons (gas and condensate) is replaced by CO2. This paper investigates the feasibility of carbon dioxide disposal in depleted gas reservoirs. Gas reservoirs are a practical storage site for the carbon dioxide, because the presen...

For underground particle physics experiments, noble gas radon from U-chain decay series could be a source of serious background events. We have developed a high sensitivity detector for radon using electrostatic collection and PIN photodiode. Recently, we have developed a new type of radon detector. We report basic performance of the new 80L radon detector.

Effective gas management in coal mines, as well as proper ventilation design, is very important for maintaining the safety of underground coal miners. Advances in numerical modeling techniques have enabled evaluations of the coal mining environment using advanced grid designs and computed gas distributions through detailed mathematical models. These models help engineers to “see” the “unseen” a...

nowadays one of the most important energy sources is natural gas. by depletion of oil reservoirs in the world, natural gasâ will emerge as the future energy source for human life. one of the major concerns of gas suppliers is being able to supply this source of energy the entire year. this concern intensifies during more consuming seasons of the year when the demand for natural gas increases, r...