New Albany Shale, Illinois Basin, southwestern Indiana
By Bei Liu, Indiana University, Bloomingdale, IN, USA
The New Albany Shale of the Illinois Basin was deposited in an epicontinental sea during the Late Devonian. It occurs in central and southern Illinois, southwestern Indiana, and western Kentucky. Stratigraphically, the New Albany Shale overlies the Middle Devonian North Vernon Limestone and is overlain by the Rockford Limestone. Internally, it is composed of five members; they are the Blocher, Selmier, Morgan Trail, Camp Run, and Clegg Creek Members in ascending order (Figure 1). The thickness of the New Albany Shale ranges from less than 6 to 140 m (Figure 2), and its depth ranges from 0 to 1585 m, with the deepest part located in southern Illinois[2, 3]. The New Albany Shale is a time-equivalent stratigraphic unit to the Ohio Shale of the Appalachian Basin, the Antrim Shale of the Michigan Basin, the Bakken Shale of the Williston Basin, the Chattanooga Shale of the southeastern US, and the Woodford Shale of the southcentral US.
The New Albany Shale consists largely of black laminated to banded shales with interbedded greenish-gray bioturbated shales. The average total organic carbon content is 6−7 wt. %, ranging from < 1 to 20 wt. %. Based on bulk geochemistry, organic matter in the New Albany Shale belongs to oil-prone type II kerogen, but petrographic studies suggest that it is composed of organic matter of different origins[2, 4]. The New Albany Shale is dominantly within the oil window, with vitrinite reflectance (Ro) ranging from < 0.5% to 1.5% (Figure 3), and it is the primary source rock for traditional clastic and carbonate reservoirs in the Illinois Basin. The New Albany Shale itself produces both oil and gas[2, 6]. Natural gas produced from the New Albany Shale is a mixture of thermogenic and microbial gas[7].
Commercial gas production from the New Albany Shale began as early as 1863 from the Moreman well drilled in Meade County, Kentucky [8]. Drilling activities were later expanded to other areas of the basin and mostly occur in Indiana and Kentucky (Figure 4). Many of the recent wells were drilled with horizontal boreholes[3]. The initial potential of the NAS gas wells ranged from 567 to 11,327 m3/day (average 5295 m3/day), but the initial production to the pipeline is significantly lower [3, 8]. The New Albany Shale was historically exploited as a gas play. Four wells drilled and completed by Endeavor Energy Resources LP and two wells completed by Hard Rock Drilling in Kentucky produced both oil and gas. These six wells produced 23,649 barrels of oil and 246 MMcf of gas in approximately 18 months[6].
Gas-in-place in the New Albany Shale ranges from 86−160 trillion cubic feet based on the 1980 and 1992 National Petroleum Council estimates[9]. The U.S. Geological Survey (USGS) completed an assessment of the undiscovered oil and gas potential of the Illinois Basin in 2007[10]. The New Albany Shale was identified as a continuous assessment unit. In this unit, undiscovered technically recoverable gas ranges from 1.30 to 8.12 (average 3.79) trillion cubic feet, and natural gas liquids range from 1 to 13 (average 5) million barrels, respectively. The EIA estimate of undeveloped technically recoverable shale gas resources in the New Albany Shale is 10.95 trillion cubic feet as of January 1, 2009[11].
The New Albany Shale is not as productive as other time-equivalent shale plays such as the Bakken Shale and the Woodford Shale. The reasons for low productivity are still not well understood yet, but may include both geological (relatively low level of maturity, low reservoir pressure, lack of understanding of natural fracture systems, hydrocarbon depletion due to migration into other formations, etc.) and engineering factors (water encroachment, uncertainties in well performances, etc.)[3, 12]. Because the New Albany Shale is generally within the oil window throughout the basin, it may become a promising shale oil play (in addition to shale gas play) when the issues that inhibit oil and gas development are resolved. But whether the New Albany Shale is an emerging play or only a prolific source remains to be seen[12].
References[edit]
1. Lazar, O.R., 2007, Redefinition of the New Albany Shale of the Illinois Basin: An integrated, stratigraphic, sedimentologic, and geochemical study (Ph.D. Dissertation): Indiana University, Bloomington, 336 p.
2. Strąpoć, D., M. Mastalerz, A. Schimmelmann, A. Drobniak, and N.R. Hasenmueller, 2010, Geochemical constraints on the origin and volume of gas in the New Albany Shale (Devonian–Mississippian), eastern Illinois Basin: AAPG Bulletin, v. 94, no. 11, p. 1713−1740.
3. Drobniak, A., M. Mastalerz, J.E. Crockett, B.C. Nuttall, and K.P. Russell, et al., 2016, New Albany Shale: Indiana Geological Survey Digital Information 07. https://igws.indiana.edu/IGSMap/?map=NAS
4. Liu, B., J. Schieber, and M. Mastalerz, 2019, Petrographic and micro-FTIR study of organic matter in the Upper Devonian New Albany Shale during thermal maturation: Implications for kerogen transformation, in W. Camp, K. Milliken, K. Taylor, N. Fishman, P. Hackley, and J. Macquaker, eds., Mudstone Diagenesis: Research Perspectives for Shale Hydrocarbon Reservoirs, Seals, and Source Rocks: AAPG Memoir 120, p. 165–188.
5. Mastalerz, M., A. Schimmelmann, A. Drobniak, and Y. Chen, 2013, Porosity of Devonian/Mississippian New Albany Shale across a maturation gradient – Insights from organic petrology, gas adsorption, and mercury intrusion: AAPG Bulletin, v. 97, no. 10, p. 1621−1643.
6. Nuttall B.C., T.M. Parris, G. Beck, D.C. Willette, M. Mastalerz, and J. Crockett, 2015, Oil Production from Low-maturity Organic-rich Shale: An Example from the Devonian New Albany Shale in the Illinois Basin, Breckinridge County, Kentucky: AAPG Search and Discovery Article 51196. https://www.searchanddiscovery.com/pdfz/documents/2015/51196nuttall/ndx_nuttall.pdf.html
7. Martini, A.M., L.M. Walter, and J.C. McIntosh, 2008, Identification of microbial and thermogenic gas components from Upper Devonian black shale cores, Illinois and Michigan basins: AAPG Bulletin, v. 92, no.3, p. 327−339.
8. Hamilton-Smith, T., N.R. Hasenmueller, W.S. Boberg, Z. Smidchens, and W.T. Frankie, 1994, Gas production, in N.R. Hasenmueller, and J.B. Comer, eds., Gas Potential of the New Albany Shale (Devonian and Mississippian) in the Illinois Basin: Gas Research Institute, GRI-92/0391, Illinois Basin Studies 2, p. 23–40.
9. Hill, D.G., and C.R. Nelson, 2000, Gas productive fractured shales: An overview and update: Gas Tips, v. 6, p. 4–13.
10. Swezey, C.S., 2007, Assessment of undiscovered oil and gas resources of the Illinois Basin: U.S. Geological Survey Fact Sheet 2007-3058, 2 p. https://pubs.er.usgs.gov/publication/fs20073058
11. U.S. EIA, 2011, Review of Emerging Resources: U.S. Shale Gas and Shale Oil Plays, 105 p. https://www.eia.gov/analysis/studies/usshalegas/pdf/usshaleplays.pdf
12. Crockett, J., and D.E. Morse, 2010, The New Albany Shale in Illinois: emerging play or prolific source: Oil & Gas Journal, v. 108, no. 33, 72–79.
13. Liu, B., J. Schieber, M. Mastalerz, and J. Teng, 2020, Variability of rock mechanical properties in the sequence stratigraphic context of the Upper Devonian New Albany Shale, Illinois Basin: Marine and Petroleum Geology, v. 112, 104068.