Mining Publication: A Numerical Evaluation on the Effects of Impermeable Faults on Degasification Efficiency and Methane Emissions During Underground Coal Mining
Original creation date: September 2008
Impermeable geologic faults in the coal seam can cause intermittent production problems or can cause unexpected amounts of water or gas to issue from degasification boreholes. These faults also can impact methane emissions into the mine workings, especially if they hinder proper and effective degasification of the coal bed. They may also act as barriers for methane flow in the coal seam. Although this might seem beneficial for advancing mine workings, faulting may also cause gas pressure buildups and result in compartmentalization of the gassy regions from which large quantities of water and methane may rush into mine workings. This study uses reservoir simulations to illustrate the effects of impermeable faults, with and without throws, on the production performance of vertical and horizontal degasification boreholes. These boreholes were drilled from the surface to intercept the coal layer and fault and were assumed to produce methane two years prior to mining of the coal seam. Longwall advances and face-position-related emissions and reservoir properties were characterized using sector definitions along the path of the panel grids. This work numerically evaluates water and gas productions of each borehole and presents the effects and the impacts of impermeable faults on methane emissions due to an advancing coal face. The results can be used to understand the effects of impermeable faults on borehole productions and face emissions due to these coal seam anomalies.
Authors: CĂ Karacan, JP Ulery, GV Goodman
Peer Reviewed Journal Article - September 2008
NIOSHTIC2 Number: 20034357
Int J Coal Geol 2008 Sep; 75(4):195-203
See Also
- Coal Bed Discontinuity Effects on the Production of Degasification Boreholes and on Emissions During Longwall Mining
- Coal Mine Methane: A Review of Capture and Utilization Practices with Benefits to Mining Safety and to Greenhouse Gas Reduction
- Degasification System Selection for U.S. Longwall Mines Using an Expert Classification System
- Drainage of Methane From the Overlying Pocahontas No. 4 Coalbed From Workings in the Pocahontas No. 3 Coalbed
- Hydraulic Stimulation of a Surface Borehole for Gob Degasification
- Methane Drainage and Migration
- Methane Drainage: Experience With Hydraulic Stimulation Through Slotted Casing
- Rotary Drilling Techniques Used in the Beckley Coalbed
- Stochastic Modeling of Gob Gas Venthole Production Performances in Active and Completed Longwall Panels of Coal Mines
- Three Coal Mine Gob Degasification Studies Using Surface Boreholes and a Bleeder System
- Two-Phase Flow in Coalbeds
- Content source: National Institute for Occupational Safety and Health, Mining Program