Shale gas
ENPE 573 – Unconventional Gas Exploitation
Introduction to Shale Gas Classification, Formation, & Extraction
Abstract
The production of conventional gas has been declining over the last few years due to dwindling reserves. To counter-act this decline, companies are quickly turning to unconventional gas plays that can offer even greater reserves as shown in figure 1. Unfortunately, recovering unconventional gas is a very difficult process that requires advanced stimulation and/or completion methods as compared to conventional gas wells. The various forms of unconventional gas include tight gas, coal bed methane (CBM), shale gas, and gas hydrates. This paper will present a general overview of shale gas while providing insight into specific shale gas plays located in Canada and the United States. Specifically, it will discuss how the increase in shale gas production in the United States has validated the commercial viability of shale gas drilling through the use of new technological processes including hydraulic fractures in horizontal wells. This technology is then being applied to Canada where according to the NEB, over 1000 tcf of shale gas has been discovered to date.
Introduction
Shale rock is considered by the ERCB as “lithostratigraphic unit having less than 50% by weight organic matter, with: less than 10% of the sedimentary clasts having a grain size greater than 62.5 micrometers; and more than 10% of the sedimentary clasts having a grain size less than 4 micrometers”(Section 1.020(2)(27.1), Oil and Gas Conservation Regulations(OGCR)). In conventional terms this means, a shale gas reservoir consists of very fine grained particles that are filled with organic-rich material. Shale reservoirs are able to store gas in numerous ways. According to Centre for Energy, natural gas can be adsorbed onto insoluble organic matter called kerogen, trapped in pore spaces of fine grained sediments interbedded with shale and
Introduction to Shale Gas Classification, Formation, & Extraction
Abstract
The production of conventional gas has been declining over the last few years due to dwindling reserves. To counter-act this decline, companies are quickly turning to unconventional gas plays that can offer even greater reserves as shown in figure 1. Unfortunately, recovering unconventional gas is a very difficult process that requires advanced stimulation and/or completion methods as compared to conventional gas wells. The various forms of unconventional gas include tight gas, coal bed methane (CBM), shale gas, and gas hydrates. This paper will present a general overview of shale gas while providing insight into specific shale gas plays located in Canada and the United States. Specifically, it will discuss how the increase in shale gas production in the United States has validated the commercial viability of shale gas drilling through the use of new technological processes including hydraulic fractures in horizontal wells. This technology is then being applied to Canada where according to the NEB, over 1000 tcf of shale gas has been discovered to date.
Introduction
Shale rock is considered by the ERCB as “lithostratigraphic unit having less than 50% by weight organic matter, with: less than 10% of the sedimentary clasts having a grain size greater than 62.5 micrometers; and more than 10% of the sedimentary clasts having a grain size less than 4 micrometers”(Section 1.020(2)(27.1), Oil and Gas Conservation Regulations(OGCR)). In conventional terms this means, a shale gas reservoir consists of very fine grained particles that are filled with organic-rich material. Shale reservoirs are able to store gas in numerous ways. According to Centre for Energy, natural gas can be adsorbed onto insoluble organic matter called kerogen, trapped in pore spaces of fine grained sediments interbedded with shale and
References: Aguilera, R. (2012). Unconventional Gas Exploitation: Introduction. [PP Slide 48]. Aguilera, R. (2012). Shale Gas in Naturally Fractured Reservoirs & their Link to Unconventional Gas Exploitation [PP Slide 7] Horizontaldrilling.org, (2012). Horizontal – Directional Oil & Gas Well Drilling. Retrieved from http://www.horizontaldrilling.org/ Canadian Centre for Energy Information, (2002-2012). Shale Gas: Overview. Retrieved from http://www.centreforenergy.com/AboutEnergy/ONG/ShaleGas/Overview.asp Rokoksh, C.D., Pawlowicz, J.G., Berhane, H., Anderson, S.D.A. and Beaton, A.P. (2009). What is Shale Gas? An Introduction to Shale-Gas Geology in Alberta National Energy Board. (2009). Energy Briefing Note: A Primer for Understanding Canadian Shale Gas. (ISSN Publication No. 1917-506X) Deshpande, V.P. (2008). General Screening Criteria for Shale Gas Reservoirs and Production Data Analysis of Barnett Shale. p. 23-28, 55-57. Hayden, J., and Pursell, D. (2005). Pickering Energy Partners Inc. The Barnett Shale. Visitor’s Guide to the Hottest Gas Play in the US Kohl, K. (2007, September 27). Our Future in Unconventional Natural Gas. Energy & Capital. Retrieved from http://www.energyandcapital.com/articles/barnett+shale-devon+energy-natural+gas/521 United States Energy Information Administration (2008). Annual Energy Outlook 2008 (Early Release). Retrieved from http://www.eia.doe.gov/oiaf/aeo/production.html CSUG, (2010). UCG Facts: Shale Gas. Retrieved from http://www.csug.ca/index.php?option=com_content&task=view&id=60&Itemid=66#shale Kaufman, P., Penny, G.S., (2008). SPE 119900 Critical Evaluations of Additives Used in Shale Slickwater Fracs. SPE International Hoch, O. (2012). Tight Gas Sands: Completion and Stimulation. [Powerpoint Slide 4, 29] Pflug, G Uhryn, J. (2008). Technology in Western Canadian Tight Gas. [Powerpoint Slide 5, 13]. Retrieved from http://www.energyandcapital.com/articles/barnett+shale-devon+energy-natural+gas/521 Halliburton. (2010). The Halliburton Advantage: The Canadian Montney. [Powerpoint Slide 3]. Retrieved from http://www.halliburton.com/public/solutions/contents/Shale/related_docs/Canadian_Montney.pdf Byfield, M. (2008). Montney and Horn River: Two Superplays Drive Drilling and Technology. Oil & Gas Inquirer. Retrieved from http://www.oilandgasinquirer.com/article.asp?article=%5Cmagazine%5C081014%5Cmag2008_oe0001.html Cardott, B. (2008). Gas Shale Committee Report; Annual Leadership Meeting, Energy and Minerals Division. American Association of Petroleum Geologists.