Page 348 - Advanced Mine Ventilation

Economics of Coal Mine 20

Degasification

Chapter Outline

20.1 Safety in Mines 325
20.2 Reduced Cost of Mining by Improved Productivity 326
20.3 Revenues From Drained Methane 326
3
20.3.1 Estimated Cost for Mildly Gassy Coal Seams (Gas Content Less Than 100 ft /ton) 327
3
20.3.2 Estimated Cost for Moderately Gassy Coal Seams (Gas Content 100e300 ft /ton) 327
3
20.3.3 Estimated Cost for Highly Gassy Coal Seams (Gas Content Over 300 ft /ton) 327
20.4 Gas Production From Coal SeamsdA Stand-Alone Business 328
20.4.1 Reserve Estimate 328
20.4.2 Production Techniques and Gas Production Forecast 329
20.4.2.1 Vertical Well Production Forecast 329
20.4.2.2 Horizontal Well Production Forecast 330
20.4.3 Gas Gathering and Processing 330
20.4.3.1 Gathering Gases 331
20.4.3.2 Gas Processing 331
20.4.3.3 Water Management 332
20.5 Economic Analysis 333
20.5.1 Cash Flow Method 333
20.5.2 Net Present Value Method 336
20.5.3 Discounted Cash Flow Rate of Return Method 336
Problem 336
References 341

The economics of coal mine degasification can be viewed in two different ways: (1)
overall cost and benefit of degasification and (2) gas drainage/production as a stand-
alone business. Main benefits of coal mine degasification are three-fold: (1) safety
of the mine workers, (2) reduced cost of mining through improved productivity, and
(3) revenues from the marketing of produced gases. The chapter will discuss the three
benefits and the related costs of degasification in detail.

20.1 Safety in Mines

A good mine degasification plan can minimize, if not eliminate, chances of a mine ex-
plosion. It is not possible to place a monetary value on human life. It is truly priceless.
The economic gravity of a mine disaster can be realized by the fact that the companies,
that owned Sago Mine (2006 disaster) and Upper Big Branch (2010 disaster) mines,

Advanced Mine Ventilation. https://doi.org/10.1016/B978-0-08-100457-9.00020-1
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