Mining Publication: Methane Drainage: Experience With Hydraulic Stimulation Through Slotted Casing
Original creation date: January 1978
The Bureau of Mines examined the wellbore of a vertical gas drainage well in the Mary Lee coalbed to determine the results of specific completion procedures in coal. A jet-slotting tool was used to cut four vertical slots through the casing about 1 ft below the coalbed. Even though stimulation treatment pressure was excessive, hydraulically induced channels were contained entirely within the target coal zone. Sand-filled, induced channels were horizontal, inclined, and vertical, and were propagated in directions similar to bedding planes, rock joint, and coal cleat directions measured in the mine. Variable gas flow rates, recorded during the productive life of the well, were attributed to chronic downhole pump malfunction and the slotted casing below the production zone.
Authors: SW Lambert, MA Trevits
Report of Investigations - January 1978
NIOSHTIC2 Number: 10000676
Pittsburgh, PA: U.S. Department of the Interior, Bureau of Mines, RI 8295, 1978 Jan; :1-16
See Also
- 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 Gas Content of the Mary Lee Group of Coalbeds, Jefferson, Tuscaloosa, and Walker Counties, Ala.
- A Numerical Evaluation on the Effects of Impermeable Faults on Degasification Efficiency and Methane Emissions During Underground Coal Mining
- Rotary Drilling Techniques Used in the Beckley Coalbed
- Three Coal Mine Gob Degasification Studies Using Surface Boreholes and a Bleeder System
- Two-Phase Flow in Coalbeds
- Use of Vertical Boreholes for Assisting Ventilation of Longwall Gob Areas
- Content source: National Institute for Occupational Safety and Health, Mining Program