Shale Gas: Nanometer-Scale Observations and Well Modelling
- Dmitriy Silin (Shell International Exploration and Production Incorporated) | Timothy J. Kneafsey (Lawrence Berkeley Laboratory)
- Document ID
- Society of Petroleum Engineers
- Journal of Canadian Petroleum Technology
- Publication Date
- November 2012
- Document Type
- Journal Paper
- 464 - 475
- 2012. Society of Petroleum Engineers
- 5.8.2 Shale Gas, 4.3.4 Scale
- 1 in the last 30 days
- 1,283 since 2007
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Our studies of the underlying fundamental gas-recovery mechanisms from shale gas are motivated by expectations of the increasing role of shale gas in national energy portfolios worldwide. We use pore-scale analysis of reservoir shale samples to identify critical parameters to be employed in a gas-flow model used to evaluate well-production data. We exploit a number of 3D-imaging technologies to study the complexity of shale pore structure: from low-resolution X-ray computed tomography (CT) to focused ion beam and scanning electron microscopy (FIB/SEM). We observe that heterogeneity is present at all scales. The CT data show fractures, thin layers, and density heterogeneity. The nanometer-scale-resolution FIB/SEM images show that various mineral inclusions, clays, and organic matter are dispersed within a volume of few-hundred µm3. Samples from different regions differ sharply in the shape, size, and distribution of pores, solid grains, and the presence of organic matter. Although the samples have clearly distinguishable signatures related to the regions of origin, extremely low permeability is a common feature. This and other pore-scale observations suggest a bounded-stimulated-domain model of a horizontal well within fractured shale that accounts for both compression and adsorption gas storage. Using the method of integral relations, we obtain an analytical formula approximating the solution to the pseudopressure diffusion equation. This formula makes fast and simple evaluation of well production possible without resorting to complex computations. It ss a decline curve, which predicts two stages of production. During the early stage, the production rate declines with the reciprocal of the square root of time, whereas later, the rate declines exponentially. The model has been verified by successfully matching monthly production data from a number of shale-gas wells collected over several years of operation. With appropriate scaling, the data from multiple wells collapse on a single type curve. Pore-scale image analysis and the mesoscale model suggest a dimensionless adsorption-storage factor (ASF) to characterize the relative contributions of compression and adsorption gas storage.
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Al Ahmadi, H., Almarzooq, A., and Wattenbarger, R. 2010. Application of Linear Flow Analysis to Shale Gas Wells -Field Cases. Presented at the SPE Unconventional Gas Conference, Pittsburgh,Pennsylvania, USA, 23-25 February. SPE-130370-MS. http://dx.doi.org/10.2118/130370-MS.
Ambrose, R.J., Hartman, R.C., Diaz-Campos, M. et al. 2010. New Pore-scaleConsiderations in Shale Gas in Place Calculations. Presented at the SPEUnconventional Gas Conference, Pittsburgh, Pennsylvania, USA, 23-25 February.SPE 131772. http://dx.doi.org/10.2118/131772-MS.
Arps, J.J. 1945. Analysis of Decline Curves. In Transactions of theAmerican Institute of Mining and Metallurgical Engineers: Petroleum Developmentand Technology 1945, Vol. 160, SPE-945228-G, 228-247. New York: AIME.
Barenblatt, G.I. 1954. On some approximate methods in the theory ofone-dimensional unsteady filtration in the elastic drive regime (in Russian).Izvestiya (Bulletin), USSR Academy of Sciences, Division of TechnicalSciences 9: 35-49.
Barenblatt, G.I., Entov, V.M., and Ryzhik, V.M. 1990. Theory ofFluid Flows Through Natural Rocks. Dordrecht, The Netherlands: KluwerAcademic Publishers.
Brunauer, S., Deming, L.S., Deming, W.E. et al. 1940. On a Theory of the vander Waals Adsorption of Gases. Journal of the American Chemical Society 62 (7): 1723-1732. http://dx.doi.org/10.1021/ja01864a025.
Bumb, A.C. and McKee, C.R. 1988. Gas-Well Testing in the Presence ofDesorption for Coalbed Methane and Devonian Shale. SPE Form Eval 3 (1): 179-185. SPE-15227-PA. http://dx.doi.org/10.2118/15227-PA.
Civan, F., Rai, C., and Sondergeld, C. 2011. Shale-Gas Permeabilityand Diffusivity Inferred by Improved Formulation of Relevant Retention andTransport Mechanisms. Transport Porous Media 86 (3):925-944. http://dx.doi.org/10.1007/s11242-010-9665-x.
Cracknell, R.F., Gordon, P., and Gubbins, K.E. 1993. Influence of poregeometry on the design of microporous materials for methane storage. TheJournal of Physical Chemistry 97 (2): 494-499. http://dx.doi.org/10.1021/j100104a036.
Curtis, J.B. 2002. Fractured Shale-Gas Systems. AAPG Bull. 86 (11): 1921-1938. http://dx.doi.org/10.1306/61eeddbe-173e-11d7-8645000102c1865d.
Curtis, M.E., Ambrose, R.J., Sondergeld, C.S. et al. 2010. StructuralCharacterization of Gas Shales on the Micro- and Nano-Scales. Presented at theCanadian Unconventional Resources and International Petroleum Conference,Calgary, 19-21 October. SPE-137693-MS. http://dx.doi.org/10.2118/137693-MS.
Donohue, M.D. and Aranovich, G.L. 1998. Adsorption Hysteresis in PorousSolids. Journal of Colloid and Interface Science 205 (1):121-130. http://dx.doi.org/10.1006/jcis.1998.5639.
Elgmati, M.M., Zhang, H., Bai, B. et al. 2011. Submicron-PoreCharacterization of Shale Gas Plays. Presented at the North AmericanUnconventional Gas Conference and Exhibition, The Woodlands, Texas, USA, 14-16June. SPE-144050-MS. http://dx.doi.org/10.2118/144050-MS.
Gale, J.F.W., Reed, R.M., and Holder, J. 2007. Natural fracturesin the Barnett Shale and their importance for hydraulic fracture treatments.AAPG Bull. 91 (4): 603-622. http://dx.doi.org/10.1306/11010606061.
Goodman, T.R. 1958. The heat-balance integral and its application toproblems involving a change of phase. Transactions of the ASME 80: 335-342.
Ilk, D., Rushing, J.A., Perego, A.D. et al. 2008. Exponential vs. HyperbolicDecline in Tight Gas Sands—Understanding the Origin and Implications forReserve Estimates Using Arps' Decline Curves. Presented at the SPE AnnualTechnical Conference and Exhibition, Denver, SPE-116731-MS. http://dx.doi.org/10.2118/116731-MS.
Javadpour, F. 2009. Nanopores and Apparent Permeability of Gas Flow inMudrocks (Shales and Siltstone). J Can Pet Technol 48 (8):16-21. JCPT Paper No. 09-08-16-DA. http://dx.doi.org/10.2118/09-08-16-DA.
Lee, W.J. and Sidle, R.E. 2010. Gas Reserves Estimation in Resource Plays.Presented at the SPE Unconventional Gas Conference, Pittsburgh, Pennsylvania,USA, 23-25 February. SPE-130102-MS. http://dx.doi.org/10.2118/130102-MS.
Lewis, A.M. and Hughes, R.G. 2008. Production Data Analysis of Shale GasReservoirs. Presented at the SPE Annual Technical Conference and Exhibition,Denver, 21-24 September. SPE-116688-PA. http://dx.doi.org/10.2118/116688-MS.
Loucks, R.G., Reed, R.M., Ruppel, S.C. et al. 2009. Morphology,Genesis, and Distribution of Nanometer-Scale Pores in Siliceous Mudstones ofthe Mississippian Barnett Shale. Journal of Sedimentary Research 79 (12): 848-861. http://dx.doi.org/10.2110/jsr.2009.092.
Mahle, J.J. 2002. An adsorption equilibrium model for Type 5 isotherms.Carbon 40 (15): 2753-2759. http://dx.doi.org/10.1016/s0008-6223(02)00201-4.
Mota, J.P.B. 2008. Adsorbed Natural Gas Technology. In Recent Advances inAdsorption Processes for Environmental Protection and Security, ed. J.P.Mota and S. Lyubchik, 177-192. Dordrecht, The Netherlands: NATO Science forPeace and Security Series C: Environmental Security, Springer Science+BusinessMedia B.V.
Neimark, A.V., Ravikovitch, P.I., and Vishnyakov, A. 2000. Adsorptionhysteresis in nanopores. Physical Review E 62 (2):R1493-R1496. http://dx.doi.org/10.1103/PhysRevE.62.R1493.
Okiongbo, K.S., Aplin, A.C., and Larter, S.R. 2005. Changes in Type IIKerogen Density as a Function of Maturity:? Evidence from the Kimmeridge ClayFormation. Energy & Fuels 19 (6): 2495-2499. http://dx.doi.org/10.1021/ef050194+.
Pirverdian, A.M. 1953. About a method of approximate solution ofelastic-drive filtration problems (in Russian). Inzhenernyj Sbornik 14: 189-191.
Polubarinova-Kochina, P.Y. 1953. About unsteady coal-bed gas filtration (inRussian). Prikladnaya Matematika i Mekhanika (Applied Mathematics andMechanics (PMM)) 17 (6): 735-738.
Rouquerol, J., Rouquerol, F., and Sing, K.S.W. 1999. Adsorption byPowders and Porous Solids: Principles, Methodology and Applications London:Academic Press.
Schamp, J.H.W., Mason, E.A., Richardson, A.C.B. et al. 1958. Compressibilityand Intermolecular Forces in Gases: Methane. Physics of Fluids 1 (4): 329-337. http://dx.doi.org/10.1063/1.1705891.
Silin, D., Ajo-Franklin, J.B., Cabrini, S. et al. 2009. Pore-scale studiesof unconventional reservoir rocks. Poster presented at the American GeophysicalUnion Fall Meeting 2009, San Francisco, California, USA, 14-18 December.Abstract H23F-1018.
Silin, D., Ajo-Franklin, J.B., Cabrini, S. et al. 2010a. Pore-scale studiesof gas shale. Presented at the American Geophysical Union Fall Meeting 2010,San Francisco, California, USA, 13-17 December. Abstract MR22C-03.
Silin, D., Kneafsey, T.J., Ajo-Franklin, J.B. et al. 2010b.Three-dimensional imaging of tight gas host rock - Observations and conceptualmodels (Goldschmidt Abstracts 2010-S). Geochimica et Cosmochimica Acta 74 (12, Supplement): A962. http://dx.doi.org/10.1016/j.gca.2010.04.045.
Sing, K.S.W. 1985. Reporting physisorption data for gas/solid systems withspecial reference to the determination of surface area and porosity(Recommendations 1984). Pure and Applied Chemistry 57 (4):603-619. http://dx.doi.org/10.1351/pac198557040603.
Solar, C., Blanco, A.G., Vallone, A. et al. 2010. Adsorption of Methane inPorous Materials as the Basis for the Storage of Natural Gas. In NaturalGas, P. Potocnik. Rijeka, Croatia: Sciyo. http://www.intechopen.com/books/natural-gas.
Sondergeld, C.H., Ambrose, R.J., Rai, C.S. et al. 2010. Micro-StructuralStudies of Gas Shales. Presented at the SPE Unconventional Gas Conference,Pittsburgh, Pennsylvania, USA, 23-25 February. SPE-131771-MS. http://dx.doi.org/10.2118/131771-MS.
Tomutsa, L. and Radmilovic, V. 2003. Focused ion beam assistedthree-dimensional rock imaging at submicron scale. Presented at theInternational Symposium of the Society of Core Analysts, Pau, France, 21-24September. SCA 2003-47.
Tomutsa, L., Silin, D.B., and Radmilovic, V. 2007. Analysis of ChalkPetrophysical Properties By Means of Submicron-Scale Pore Imaging andModeling. SPE Reservoir Evaluation & Engineering 10(3): 285-293. SPE-99558-PA. http://dx.doi.org/10.2118/99558-PA.
Wegrzyn, J. and Gurevich, M. 1996. Adsorbent storage of natural gas.Applied Energy 55 (2): 71-83. http://dx.doi.org/10.1016/s0306-2619(96)00015-3.