Gas Permeability of Shale
- Authors
- Ahmad Sakhaee-Pour (The University of Texas at Austin) | Steven Bryant (The University of Texas at Austin)
- DOI
- https://doi.org/10.2118/146944-PA
- Document ID
- SPE-146944-PA
- Publisher
- Society of Petroleum Engineers
- Source
- SPE Reservoir Evaluation & Engineering
- Volume
- 15
- Issue
- 04
- Publication Date
- August 2012
- Document Type
- Journal Paper
- Pages
- 401 - 409
- Language
- English
- ISSN
- 1094-6470
- Copyright
- 2012. Society of Petroleum Engineers
- Disciplines
- 5.8.2 Shale Gas, 1.10 Drilling Equipment
- Downloads
- 19 in the last 30 days
- 7,212 since 2007
- Show more detail
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Summary
Permeability is one of the most fundamental properties of any reservoir rock required for modeling hydrocarbon production. However, shale permeability has not yet been understood fully because of the complexities involved in modeling flow through nanoscale throats. In this paper, we analyze the effects of adsorbed layers of methane (CH4) and of gas slippage at pore walls on the flow behavior in individual conduits of simple geometry and in networks of such conduits. The network is based on the scanning-electron-microscopy (SEM) image and drainage experiment of shale. To represent the effect of adsorbed gas, the effective size of each throat in the network depends on the pressure. The hydraulic conductance of each throat is determined on the basis of the Knudsen-number (Kn) criterion (Knudson 1909). The combined effects of adsorption and slip depend strongly on pressure and on conduit diameter. The results indicate that laboratory measurements made with N2 at ambient temperature and 5-MPa pressure, which is typical for a transient pulse-decay (TPD) method, overestimate the gas permeability at early life of production by a factor of four. This ratio increases if the measurement is run at ambient condition because the low pressure enhances the slippage and reduces the thickness of the adsorbed layer. Moreover, the permeability increases nonlinearly as the in-situ pressure decreases during production. This effect contributes to mitigating the decline in the production rate of shale-gas wells. Laboratory data available in the literature for CH4 permeability at pressures below 7 MPa agree with model predictions of the effect of pressure.
| File Size | 1 MB | Number of Pages | 9 |
References
Ambrose, R.J., Hartman, R.C., Diaz-Campos, M. et al. 2010. New Pore-scaleConsiderations in Shale Gas in Place Calculations. Paper SPE 131772 presentedat the SPE Unconventional Gas Conference, Pittsburgh, Pennsylvania, USA, 23-25February. http://dx.doi.org/10.2118/131772-MS.
Bennett, C.O. and Myers, J.E. 1962. Momentum, Heat, and MassTransfer. New York: Series in Chemical Engineering, McGraw-Hill.
Billiotte, J., Yang, D., and Su, K. 2008. Experimental study on gaspermeability of mudstones. Physics and Chemistry of the Earth, PartsA/B/C 33 (Supplement 1): S231-S236. http://dx.doi.org/10.1016/j.pce.2008.10.040.
Cipolla, C.L., Lolon, E.P., Erdle, J.C. et al. 2010. Reservoir Modeling inShale-Gas Reservoirs. SPE Res Eval & Eng 13 (4):638-653. SPE-125530-PA. http://dx.doi.org/10.2118/125530-PA.
Cui, X., Bustin, A.M.M., and Bustin, R.M. 2009. Measurements of gaspermeability and diffusivity of tight reservoir rocks: different approaches andtheir applications. Geofluids 9 (3): 208-223. http://dx.doi.org/10.1111/j.1468-8123.2009.00244.x.
Graham, T. 1833. On the law of the diffusion of gases. J. Membr.Sci. 100 (1): 17-21. http://dx.doi.org/10.1016/0376-7388(94)00228-Q.
Graham, T. 1846. On the Motion of Gases. Phil. Trans. R. Soc. Lond. A 136 (1846): 573-631.
Graham, T. 1849. On the Motion of Gases. Part II. Phil. Trans. R. Soc.Lond. A 139 (1849): 349-391.
Graham, T. 1863. On the Molecular Mobility of Gases. Phil. Trans.R. Soc. Lond. A 153 (1863): 385-405.
Javadpour, F., Fisher, D., and Unsworth, M. 2007. Nanoscale Gas Flowin Shale Gas Sediments. J Can Pet Technol 46 (10): 55-61.JCPT Paper No. 07-10-06. http://dx.doi.org/10.2118/07-10-06.
Karniadakis, G., Beskök, A., and Aluru, N. 2005. Microflows andNanoflows: Fundamentals and Simulation, Vol. 29. New York:Interdisciplinary Applied Mathematics, Springer. ISBN 0387221972.
Klinkenberg, L.J. 1941. The permeability of porous media to liquids andgases. API Drilling & Production Practice (1941): 200-213.
Knudsen, M. 1909. Die Gesetze der Molekularströmung und der innerenReibungsströmung der Gase durch Röhren (The laws of molecular and viscous flowof gases through tubes). Ann. Phys. 333 (1): 75-130. http://dx.doi.org/10.1002/andp.19093330106.
Letham, E.A. 2011. Matrix permeability measurements of gas shales: gasslippage and adsorption as sources of systematic errors. BSc thesis,University of British Columbia, Vancouver, Canada.
Luffel, D.L., Hopkins, C.W., and Schettler Jr., P.D. 1993. MatrixPermeability Measurement of Gas Productive Shales. Paper SPE 26633 presented atthe SPE Annual Technical Conference and Exhibition, Houston, 3-6 October. http://dx.doi.org/10.2118/26633-MS.
Mallon, A.J. and Swarbrick, R.E. 2008. How should permeability be measuredin fine-grained lithologies? Evidence from the chalk. Geofluids 8 (1): 35-45. http://dx.doi.org/10.1111/j.1468-8123.2007.00203.x.
Mason, E.A. and Malinauskas, A.P. 1983. Gas Transport in Porous Media:The Dusty-Gas Model. Amsterdam, The Netherlands: Chemical EngineeringMonographs, Elsevier Science.
Mendenhall, W., Reinmuth, J.E., and Beaver, R. 1989. Statistics forManagement and Economics. Boston, Massachusetts: PWS-Kent PublishingCompany.
Philip, Z.G., Jennings Jr., J.W., Olson, J.E. et al. 2005. Modeling CoupledFracture-Matrix Fluid Flow in Geomechanically Simulated Fracture Networks.SPE Res Eval & Eng 8 (4): 300-309. SPE-77340-PA. http://dx.doi.org/10.2118/77340-PA.
Polczer, S. 2009. Shale expected to supply half of North America's gas.Calgary Herald, 9 April 2009.
Reinecke, S.A. and Sleep, B.E. 2002. Knudsen diffusion, gas permeability,and water content in an unconsolidated porous medium. Water Resour. Res. 38 (12): 1280. http://dx.doi.org/10.1029/2002wr001278.
Roy, S., Raju, R., Chuang, H.F. et al. 2003. Modeling gas flow throughmicrochannels and nanopores. J. Appl. Phys. 93 (8):4870-4879. http://dx.doi.org/10.1063/1.1559936.
Sakhaee-Pour, A. 2012. Gas flow through shale. PhD dissertation (inprogress), The University of Texas at Austin, Austin, Texas.
Urbina, I. 2011. Insiders Sound an Alarm Amid a Natural Gas Rush. N.Y.Times, 25 June 2011, http://www.nytimes.com/2011/06/26/us/26gas.html?_r=1&pagewanted=all.
Wang, F.P. and Reed, R.M. 2009. Pore Networks and Fluid Flow in Gas Shales.Paper SPE 124253 presented at the SPE Annual Technical Conference andExhibition, New Orleans, 4-7 October. http://dx.doi.org/10.2118/124253-MS.
