Numerical Simulation of Abandoned Gob Methane Drainage through Surface Vertical Wells
نویسندگان
چکیده
The influence of the ventilation system on the abandoned gob weakens, so the gas seepage characteristics in the abandoned gob are significantly different from those in a normal mining gob. In connection with this, this study physically simulated the movement of overlying rock strata. A spatial distribution function for gob permeability was derived. A numerical model using FLUENT for abandoned gob methane drainage through surface wells was established, and the derived spatial distribution function for gob permeability was imported into the numerical model. The control range of surface wells, flow patterns and distribution rules for static pressure in the abandoned gob under different well locations were determined using the calculated results from the numerical model.
منابع مشابه
Numerical Analysis of the Impact of Longwall Panel Width on Methane Emissions and Performance of Gob Gas Ventholes
In coal mining, longwall mining is a preferred method to maximize production by extracting large blocks of coal that have been outlined with a set of development entries. In U.S. mines, longwall panels are typically 305 m (1,000ft) wide (with a continual trend towards even wider panels), and usually over 3,050 m (10,000ft) in length. The increasing size of longwall panels, while helping to incr...
متن کاملReservoir simulation-based modeling for characterizing longwall methane emissions and gob gas venthole production
Longwall mining alters the fluid-flow-related reservoir properties of the rocks overlying and underlying an extracted panel due to fracturing and relaxation of the strata. These mining-related disturbances create new pressure depletion zones and new flow paths for gas migration and may cause unexpected or uncontrolled migration ofgas into the underground workplace. One common technique to contr...
متن کاملDevelopment of Numerical Models to Investigate Permeability Changes and Gas Emission around Longwall Mining Panel
Underground longwall mining of coal causes large scale disturbance of the surrounding rock mass. The disturbance can increase the rock mass permeability through a reduction on the stress as well as formation of new fractures in the rock. Methane gas contained in the disturbed rock mass can migrate towards the low pressure mine workings and present an explosion hazard. This paper describes the a...
متن کاملDevelopment and application of reservoir models for the evaluation and optimization of longwall methane control systems
Comprehensive assessments of the need for additional methane control capacity beyond ventilation often require both an empirical and theoretical approach for an adequate or timely control of increased methane emission levels. Thus, the prediction of methane emissions and optimization of methane control systems prior to starting a new mining operation will be a major improvement towards eliminat...
متن کاملIdentification and characterization of high methane-emitting abandoned oil and gas wells.
Recent measurements of methane emissions from abandoned oil/gas wells show that these wells can be a substantial source of methane to the atmosphere, particularly from a small proportion of high-emitting wells. However, identifying high emitters remains a challenge. We couple 163 well measurements of methane flow rates; ethane, propane, and n-butane concentrations; isotopes of methane; and nobl...
متن کامل