Marcellus Shale

Santoro, R. Howarth, R.W. Ingraffea, T. Life cycle greenhouse gas emissions inventory of Marcellus shale gas. Technical Report of the Agriculture, Energy, Environment Program, Cornell University, Ithaca, NY, 2011. To be archived and made available on-line. 

Figure 2. Tracing of paper chromatogram showing amino acids separated from an H2SO4 extract of MarceUus shale and Onondaga shale. 1 and 5 are standards 2 and 4 are Marcellus shale 3 is Newton Hamilton (Onondaga) shale...

Amino Acids. Traces of amino acids were found in the Devonian Newton Hamilton and Marcellus Formations in a previous study (7). In the present work (Table V) small quantities of amino acids were isolated from the Marcellus shale. In both the earlier work and the present study an amino acid that chromatographed as arginine was found. Other amino acids in the Marcellus black shale are histidine( ), methionine, alanine, tyrosine, valine, leucine or isoleucine, and two unknowns, possibly including aminobutyric acid of nonprotein origin in the Newton Hamilton Formation histidine( ). Ammonia was also present in both the Marcellus and the Newton Hamilton. 

In the Whitby Formation, the available FA oil yields (59 samples) are less than 60 litres/tonne (14 U.S. gallons/ton). This oil has a specific gravity in the range 0.893 to 0.942. Twenty FA determinations on Kettle Point samples revealed oil yields up to 72 1/t (17 gal/ton) with specific gravity in the range 0.896 to 0.956. Few FA analyses of Marcellus shales are available the highest oil yield to date is 64 1/t (15.4 gal/ton). 

The cost of energy varies quite a bit from plant to plant. In some locations, energy sources are plentiful and inexpensive. For example, in Saudi Arabia, gas coming from an oil well is sometimes simply flared (burned). In other locations, fuel is quite expensive because it must be transported long distances. For example, in Japan, some of the natural gas is shipped in from Indonesia on liquefied natural gas (LNG) tankers, which are very expensive. Therefore, energy costs depend on location. The recent drastic drop in namral gas prices in the United States due to increased production from Marcellus shale has lowered (temporarily at least) energy costs. 

Natural gas is produced Ifom a variety of shale formations in the U.S., including the Barnett and Marcellus shales in Texas and the U.S. Northeast, respectively. As these resources have been developed, there has been an increasing public interest in greenhouse gas (GHG) emissions and water consumption associated with their extraction and use. 

To quantify this variability, we have assessed the carbon and water footprints of Barnett and Marcellus shale gases, which are geologically and geographically distinct, and feature different drilling and completion practices as well as treatment and processing requirements. 

The ISO guidelines specify four phases of an LCA (a) Definition of the goal and scope of a study, (b) Inventory analysis, (c) Environmental impact assessment, and (d) Interpretation. In this study, we employed the methodology described in our previous work on Marcellus shale gas [2]. 

Figure 4 Life cycle GHG emissions associated with rich gas produced from the Marcellus shale...

One may consider the effect of the variability of EURs and other operational characteristics over a shale play using Monte Carlo. We describe the procedure in detail in our previous work (2). In brief, we conduct N (e.g. 5000) trials in which we select input data from their distributions at random and conduct the LCA. This results in N sets of results (e.g. carbon footprints, water footprints), which constitute distributions for those results in lieu of single point estimates. We report 80% confidence intervals (CIs) for these estimates in Table 2. From the overlap of the CIs, it is evident that there is no statistically significant difference among the carbon footprints, water footprints, and other characteristics of Barnett and Marcellus shale gases. 

Landfill and biogas are often small and localized operations where the methane is at low pressure and requires compression for membrane treatment. The methane gathered in these operations is often locally consumed. Both coal gasification and natural gas from Marcellus Shale on the East Coast have recently been championed in the United States as additional sources of fuels to help in the transition from a dependence on foreign oil to alternative energy sources. 

Until recently, many oil and gas companies considered natural gas locked in tight, impermeable shale uneconomical to produce. Advanced drilling and reservoir stimulation methods have dramatically increased gas production from unconventional shales. The Barnett Shale formation in Texas has experienced the most rapid development. The Marcellus Shale formation of the Appalachian basin, in the northeastern United States, potentially represents the largest unconventional gas resource in the United States. Other shale formations, such as the Haynesville Shale, straddling Texas and Louisiana, have also attracted interest, as have some formations in Canada. The resource potential of these shales has significantly increased the natural gas reserve estimates in the United States (Andrews, 2009). 

As shown earlier in Figure 4.2 in Chapter 4, shale gas is present across much of the lower 48 states. Figure 4.2 shows the approximate locations of current producing gas shales and prospective shales. To date, the most active of these shales are the Barnett Shale, Haynesville/Bossier Shale, Antrim Shale, Fayetteville Shale, Marcellus Shale, and New Albany Shale. This chapter does not discuss all of the unconventional gas shales rather, discussion here is limited to these most active shale gas plays. Each of these shale gas plays or basins is different, and each has a unique set of exploration criteria and operational challenges. Because of these differences, the development of shale gas resources in each of these areas faces potentially unique challenges. The Antrim and New Albany Shales, for example, are shallower shales that produce significant volumes of formation water, unlike most of the other gas shales. Development of the Fayetteville Shale is occurring in rural areas of north-central Arkansas, while development of the Barnett Shale is focused in the area of Forth Worth, Texas, in an urban and suburban environment. 

The Marcellus Shale is the most expansive shale gas play, spanning six states in the northeastern United States. The estimated depth of production for the Marcellus is between 4000 and 8500 feet (Table 5.5). The Marcellus Shale is a Middle Devonian-age shale bounded by shale (Hamilton Group) above and limestone (Tristates Group) below (Figure 5.5). 

The Marcellus Shale covers an area of 95,000 square miles at an average thickness of 50 to 200 feet. Whereas the Marcellus is lower in relative gas content at 60 to 100 scf/ton, the much larger area of this play compared to the other shale gas plays results in a higher original gas-in-place estimate of... 

Stratigraphy of the Marcellus Shale. (Adapted from Arthur, J.D. et al.. An Overview of Modem... 

Up to 1500 Tcf. The average well spacing in the Marcellus Shale is 40 to 160 acres per well. The data in Table 5.5 show technically recoverable resources for the formation to be 262 Tcf, although much like the Haynesville Shale the potential estimates for this play are frequently being revised upward due to its early stage of development. 

Sumi, L. (2008). Shale Gas Focus on the Marcellus Shale. Oil and Gas AccoimtabiUty Project (OGAP)/Earthworks, Washington, DC, 25 pp. 

Catskill Mountainkeeper. (2008). The Marcellas Shale—American s Next Super Giant. Catskill Mountainkeeper, Youngsville, NY (www.catskillmountainkeeper.org/ our-programs/fracking/marcellus-shale/). 

Marshall Miller Associates. (2008). Marcellus Shale, pap>er presented to Fireside Pumpers, Bradford, PA. 

Santoro, R.L., Howarth, R.W., and Ingraffea, A.R. (2011). Indirect Emissions cf Carbon Dioxide from Marcellus Shale Gas Development, Technical Report. Agriculture, Energy, and Environment Program, Cornell University, New York. 

Marcellus Shale) water contamination from a spill of fracturing fluids Methane contamination of multiple drinking water wells methane in private wells Transferable results due to common types of impacts ... 

Marcellus Shale) suspected contamination Stray gas in wells, surface spills contaminated Determine if surface spills affect surface and ground water If contamination exists, determine potential source of contaminants in drinking water Atlas Energy, LP... 

Note Some estimates show that hydraulic fracturing in Marcellus Shale regions can require up to eight million gallons of water per month. With this type of drilling, only about ten percent of the water returns to the surface but even so, that creates up to 800,000 gallons of wastewater each month. 

Marcellus Directory. 2010. Houston Hart Energy Publishing. Covers the oil and gas activity in the Marcellus Shale Natural Gas Field Formation, which extends through Pennsylvania, New York, Ohio, and West Virginia, part of the Devonian Black Shale Field. Provides the same coverage as all Hart directories. More information at http //www.hartenergy.com/ directories/marcellus.php (accessed July 23, 2010). 

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