Changes

^{TOC_o = original total organic carbon; HI_o = original hydrogen index.}

^{TOC_o = original total organic carbon; HI_o = original hydrogen index.}

The computed GOC values from these TOCo values are variable, ranging from about 25 (Bossier 2) to 62% (Haynesville 1). As previously suggested, such variation is good reason to segregate various organofacies of source rocks into percentages based on thickness instead of using a single average value. Differences in the Bossier and Haynesville shales have also been reported in the core-producing area of northwestern Louisiana on highly mature cuttings and core samples, although four facies were identified in the Bossier (Novosel et al., 2010). A dramatic difference in the amount of GOC exists between the two formations and within the Tithonian itself. These organofacies differences in the Tithonian may explain the dramatic difference in TOC values reported for the Bossier Shale in Freestone County, Texas (Rushing et al., 2004), and an unidentified location by Emme and Stancil (2002). Available data for the Tithonian Bossier Shale suggest an about 1% TOC value on average in central Texas, with a value nearer 4% in easternmost Texas and in Louisiana.

The computed GOC values from these TOCo values are variable, ranging from about 25 (Bossier 2) to 62% (Haynesville 1). As previously suggested, such variation is good reason to segregate various organofacies of source rocks into percentages based on thickness instead of using a single average value. Differences in the Bossier and Haynesville shales have also been reported in the core-producing area of northwestern Louisiana on highly mature cuttings and core samples, although four facies were identified in the Bossier.<ref>Novosel, I., K. Manzano-Kareah, and A. S. Kornacki, 2010, [http://www.searchanddiscovery.net/abstracts/pdf/2010/annual/abstracts/ndx_novosel.pdf Characterization of source rocks in the Greater Sabine Bossier and Haynesville formations, northern Louisiana, USA. (abs.)]: AAPG National Convention.</ref> A dramatic difference in the amount of GOC exists between the two formations and within the Tithonian itself. These organofacies differences in the Tithonian may explain the dramatic difference in TOC values reported for the Bossier Shale in Freestone County, Texas,<ref>Rushing, J. A., A. Chaouche, and K. E. Newsham, 2004, A mass balance approach for assessing basin-centered gas prospects: Integrating reservoir engineering, geochemistry, and petrophysics, in J. M. Cubitt, W. A. England, and S. R. Larter, eds., Understanding petroleum reservoirs: Toward an integrated reservoir engineering and geochemical approach: Geological Society (London) Special Publication 237, p. 373–390.</ref> and an unidentified location by Emme and Stancil.<ref>Emme, J. J., and R. Stancil, 2002, [http://www.searchanddiscovery.net/abstracts/pdf/2002/annual/SHORT/ndx_46627.pdf Anadarko's Bossier gas play: A sleeping giant in a mature basin (abs.)]: AAPG National Convention, March 10–13, 2002.</ref> Available data for the Tithonian Bossier Shale suggest an about 1% TOC value on average in central Texas, with a value nearer 4% in easternmost Texas and in Louisiana.

==Top 10 North American shale-gas plays==

==Top 10 North American shale-gas plays==

* Cooles, G. P., A. S. Mackenzie, and T. M. Quigley, 1986, Calculation of petroleum masses generated and expelled from source rocks: Organic Geochemistry, v. 10, p. 235–245.

* Cooles, G. P., A. S. Mackenzie, and T. M. Quigley, 1986, Calculation of petroleum masses generated and expelled from source rocks: Organic Geochemistry, v. 10, p. 235–245.

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* Emme, J. J., and R. Stancil, 2002, Anadarko's Bossier gas play: A sleeping giant in a mature basin (abs.): AAPG National Convention, March 10–13, 2002: http://www.searchanddiscovery.net/abstracts/pdf/2002/annual/SHORT/ndx_46627.pdf (accessed November 11, 2010).

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* Faqira, M., A. Bhullar, and A. Ahmed, 2010, Silurian Qusaiba Shale Play: Distribution and characteristics (abs.): Hedberg Research Conference on Shale Resource Plays, December 5–9, 2010, Austin, Texas, Book of Abstracts, p. 133–134.

* Faqira, M., A. Bhullar, and A. Ahmed, 2010, Silurian Qusaiba Shale Play: Distribution and characteristics (abs.): Hedberg Research Conference on Shale Resource Plays, December 5–9, 2010, Austin, Texas, Book of Abstracts, p. 133–134.

* Munoz, Y. A., R. Littke, and M. R. Brix, 2007, Fluid systems and basin evolution of the western Lower Saxony Basin, Germany: Geofluids, v. 7, no. 3, p. 335–355, doi:10.1111/j.1468-8123.2007.00186.x.

* Munoz, Y. A., R. Littke, and M. R. Brix, 2007, Fluid systems and basin evolution of the western Lower Saxony Basin, Germany: Geofluids, v. 7, no. 3, p. 335–355, doi:10.1111/j.1468-8123.2007.00186.x.

* Natural Gas for Europe, 2010, [http://naturalgasforeurope.com/category/news-by-country/other-countries/india First shale gas well in India spudded].

* Natural Gas for Europe, 2010, [http://naturalgasforeurope.com/category/news-by-country/other-countries/india First shale gas well in India spudded].

* Novosel, I., K. Manzano-Kareah, and A. S. Kornacki, 2010, [ http://www.searchanddiscovery.net/abstracts/pdf/2010/annual/abstracts/ndx_novosel.pdf Characterization of source rocks in the Greater Sabine Bossier and Haynesville formations, northern Louisiana, USA. (abs.)]: AAPG National Convention.

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* Oil amp Gas Journal, 2010a, [http://www.ogj.com/index/article-tools-template/_printArticle/articles/oil-gas-journal/drilling-production-2/2010/08/north-africa_gets.html North Africa gets first shale gas frac job], August 30, 2010.

* Oil amp Gas Journal, 2010a, [http://www.ogj.com/index/article-tools-template/_printArticle/articles/oil-gas-journal/drilling-production-2/2010/08/north-africa_gets.html North Africa gets first shale gas frac job], August 30, 2010.

* Oil amp Gas Journal, 2010b, [http://www.ogj.com/index/article-tools-template.articles.oil-gas-journal.exploration-development-2.2010.07.south-africa_karoo.html South Africa Karoo shale gas hunt growing].

* Oil amp Gas Journal, 2010b, [http://www.ogj.com/index/article-tools-template.articles.oil-gas-journal.exploration-development-2.2010.07.south-africa_karoo.html South Africa Karoo shale gas hunt growing].

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* Rullkotter, J., et al., 1988, Organic matter maturation under the influence of a deep intrusive heat source: A natural experiment for quantitation of hydrocarbon generation and expulsion from a petroleum source rock (Toarcian Shale, northern Germany): Advances in Organic Geochemistry 1987: Organic Geochemistry, v. 13, no. 1–3, p. 847–856, doi:10.1016/0146-6380(88)90237-9.

* Rullkotter, J., et al., 1988, Organic matter maturation under the influence of a deep intrusive heat source: A natural experiment for quantitation of hydrocarbon generation and expulsion from a petroleum source rock (Toarcian Shale, northern Germany): Advances in Organic Geochemistry 1987: Organic Geochemistry, v. 13, no. 1–3, p. 847–856, doi:10.1016/0146-6380(88)90237-9.

* Rushing, J. A., A. Chaouche, and K. E. Newsham, 2004, A mass balance approach for assessing basin-centered gas prospects: Integrating reservoir engineering, geochemistry, and petrophysics, in J. M. Cubitt, W. A. England, and S. R. Larter, eds., Understanding petroleum reservoirs: Toward an integrated reservoir engineering and geochemical approach: Geological Society (London) Special Publication 237, p. 373–390.

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* Zou, C.-n., S.-z. Tao, X.-h. Gao, Y. Li, Z. Yang, Y.-j. Gong, D.-z. Dong, X.-j. Le, et al., 2010, [http://www.searchanddiscovery.net/abstracts/pdf/2010/annual/abstracts/ndx_caineng.pdf Basic contents, geological features and evaluation methods of continuous oil/gas plays in China]: AAPG Search and Discovery Article 90104, 7 p.

* Zou, C.-n., S.-z. Tao, X.-h. Gao, Y. Li, Z. Yang, Y.-j. Gong, D.-z. Dong, X.-j. Le, et al., 2010, [http://www.searchanddiscovery.net/abstracts/pdf/2010/annual/abstracts/ndx_caineng.pdf Basic contents, geological features and evaluation methods of continuous oil/gas plays in China]: AAPG Search and Discovery Article 90104, 7 p.