A study of natural gas extraction in Marcellus shale

Abstract

With the dramatic increases in crude oil prices there has been a need to find reliable energy substitutions. One substitution that has been used in the United States is natural gas. However, with the increased use of natural gas, conventional sources are being depleted rapidly. Due to the strong use of conventional gas sources people have turned to unconventional gas sources. Unconventional gas sources are deemed economically infeasible to produce at the current price of natural gas. The reason some sources are unconventional is because the formation that holds the natural gas is highly impermeable, eg shale. Sources of unconventional natural gas in the United States are found in shales across the country; the Marcellus shale is one of these sources. The Marcellus shale is the largest natural gas source in the United States and is quickly becoming a major gas play. Estimates show that there are trillions of cubic feet of natural gas stored within the Marcellus shale, and energy companies are flocking to the area to extract it. This paper will discuss the techniques used by operators to extract natural gas in the Marcellus Shale. The focus will be on the drilling and hydraulic fracturing processes. A discussion regarding the environmental concerns when extracting natural gas follows. It was found that the methods used to extract natural gas, while effective, can harm the areas water supply. New technologies are being developed that use less water, are safer for the environment, and just as effective as the older methods in most situations.