Technical Papers

Numerical Evaluation of Effectiveness of Drainwells in Dewatering Overburden at Surface Coal Mines

Abstract:

Typical sedimentary sequences overlying coal seams consist of interbedded sandstones, siltstones, shales, and rider coal seams. In many surface coal mine settings, these sediments are saturated; and prior dewatering of them is necessary for effective and economic mining, including the stacking of saturated spoils. Such sedimentary sections usually have a very low vertical hydraulic conductivity that does not allow them to drain in a timely manner prior to their being stripped. One potential solution is installation of drainwells. Drainwells are small diameter wells that can collect water laterally from the various more permeable layers in the overburden and then gravity drain it to a lower layer – often the coal seam being mined – where it can be removed by pumping wells or sumps located in the bottom of the pit. A ground-water flow model utilizing the 3-dimensional finite element code MINEDW has been used to evaluate the effectiveness of using drainwells in a hydrogeologic setting that is typical of the Powder River Basin. A series of numerical simulations were completed using various combinations and spacings of drainwells and pumping wells to dewater the overburden and coal seams. The numerical simulations suggest that drainwells can be a very effective method of overburden dewatering.

Citation:

Howell, R.L., L.C. Atkinson, and H. Liu. 2000. Numerical evaluation of effectiveness of drainwells in dewatering overburden at surface coal mines. Society for Mining, Metallurgy, and Exploration Annual Meeting, Salt Lake City, Utah, 28 February-1 March.

Authors:

Houmao Liu

Link to Full Text:

Dewatering a Coal Mine.pdf

Latest News
  • 2021 Tekne Award Work on machine learning to advance safety and efficiency in wind energy construction earned a...
    Read More
  • Itasca Software now Available for Linux Version 7 or greater of Itasca software (FLAC3D, 3DEC, PFC3D, and PFC2D) are now operable...
    Read More
  • Model Plot Contest Winners Itasca is pleased to announce the winners and honorary mentions of our Model Plot Contest...
    Read More

Upcoming Events
1 Feb
SPE Hydraulic Fracturing Technology Conference and Exhibition
The SPE Hydraulic Fracturing Technology Conference and Exhibition showcases existing and new hydraulic fracturing technologies, using e... Read More
7 Feb
Stanford Geothermal Workshop
The Stanford Geothermal Workshop bring together engineers, scientists and managers involved in geothermal reservoir studies and develop... Read More
14 Feb
Global Waste Management Symposium (GWMS)
Global Waste Management Symposium (GWMS) is a technical conference for research and case studies on waste management.... Read More