Specific surface area and pore‐size distribution in clays and shales

Geophysical Prospecting - Tập 61 Số 2 - Trang 341-362 - 2013
Utpalendu Kuila1, Manika Prasad1
1Colorado School of Mines; 1500 Illinois St. Golden CO 80401

Tóm tắt

ABSTRACTOne of the biggest challenges in estimating the elastic, transport and storage properties of shales has been a lack of understanding of their complete pore structure. The shale matrix is predominantly composed of micropores (pores less than 2 nm diameter) and mesopores (pores with 2–50 nm diameter). These small pores in the shale matrix are mainly associated with clay minerals and organic matter and comprehending the controls of these clays and organic matter on the pore‐size distribution is critical to understand the shale pore network. Historically, mercury intrusion techniques are used for pore‐size analysis of conventional reservoirs. However, for unconventional shale reservoirs, very high pressures (> 414 MPa (60 000 psi)) would be required for mercury to access the full pore structure, which has potential pitfalls. Current instrumental limitations do not allow reliable measurement of significant portions of the total pore volume in shales. Nitrogen gas‐adsorption techniques can be used to characterize materials dominated by micro‐ and mesopores (2–50 nm). A limitation of this technique is that it fails to measure large pores (diameter >200 nm). We use a nitrogen gas‐adsorption technique to study the micro‐ and mesopores in shales and clays and compare the results from conventional mercury porosimetry techniques.Our results on pure clay minerals and natural shales show that (i) they have a multiscale pore structure at different dimensions (ii) fine mesopores, with a characteristic 3 nm pore size obtained with N2 gas‐adsorption are associated with an illite‐smectite group of clays but not with kaolinite; (iii) compaction results in a decrease of pore volume and a reduction of pore size in the ‘inter‐aggregate’ macropores of the illite‐smectite clays while the fine ‘intra‐tachoid’ mesopores are shielded from compaction; (iv) for natural shales, mineralogy controls the pore‐size distributions for shales and the presence of micropores and fine mesopores in natural shales can be correlated with the dominance of the illite‐smectite type of clays in the rock. Our assessment of incompressible 3 nm sized pores associated with illite‐smectite clays provides an important building block for their mineral modulus.

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Tài liệu tham khảo

10.1016/0148-9062(74)91784-7

10.1046/j.1365-2478.2003.00405.x

10.2136/sssaj1971.03615995003500040046x

10.1016/0032-5910(74)80031-8

10.1021/ja01269a023

BustinR.M. BustinA.M. CuiX. RossD. MurthyJ.K. andPathiV.S.2008.Impact of Shale Properties on Pore Structure and Storage Characteristics.SPE 119892‐MS. Presented at the SPE Shale Gas Production Conference Fort Worth Texas USA 16–18 November 2008.

10.1021/la00047a025

Clay Mineral Society Source Clay Information:http://www.clays.org/SOURCE%20CLAYS/SCdata.html.

ComiskyJ. SantiagoM. McCollomB. BuddhalaA.andNewshamK.2011.Sample Size Effects on the Application of Mercury Injection Capillary Pressure for Determining the Storage Capacity of Tight Gas and Oil Shales. SPE‐149432‐MS Presented at the Canadian Unconventional Resources Conference 15–17 Nov Alberta Canada

10.4095/222398

10.1346/CCMN.1970.0180103

10.1016/0008-8846(71)90058-5

10.1346/CCMN.2007.0550104

Dubinin M.M., 1966, Chemistry and Physics of Carbon, 51

10.1016/0021-9797(74)90265-3

10.1046/j.1365-2389.1999.00261.x

EIA's Energy in Brief: What is shale gas and why is it important?http://www.eia.gov/energy_in_brief/about_shale_gas.cfm.

10.2118/116139-PA

10.1088/0268-1242/16/12/301

GreggS.J.andSingK.S.W.1983.Adsorption Surface Area and Porosity (2nd ed.). New York: Academic press.

10.1016/S1387-1811(03)00339-1

10.1190/1.1443546

ISO 9277:2010.2010. Determination of the specific surface area of solids by gas adsorption – BET method.

Jaffe A., 2010, Shale gas will rock the world, The Wall Street Journal

10.2118/09-08-16-DA

10.1021/ja01151a046

10.2516/ogst:2005007

KataharaK.W.1996.Clay mineral elastic properties. SEG Technical Program Expanded Abstracts: pp. 1691–1694.

10.1346/CCMN.1995.0430106

KuilaU. PrasadM. DerkowskiA.andMcCartyD.K.2012.Compositional Controls on Mudrock Pore‐Size Distribution: An Example from Niobrara Formation. SPE 160141‐PP. Presented at presentation at the SPE Annual Technical Conference and Exhibition held in San Antonio Texas USA 8–10 October 2012.

10.2110/jsr.2009.092

10.1007/978-1-4020-2303-3_8

10.2118/20571-PA

10.1016/0021-9797(82)90153-9

10.2138/am.2011.3558

10.1016/S0169-1317(02)00146-1

10.1346/CCMN.2006.0540609

10.1139/t99-121

PollastroR.M.1992.Natural fractures composition cyclicity and diagenesis of the Upper Cretaceous Niobrara Formation Berthoud field Colorado .

10.1029/2001GL014054

10.1016/j.marpetgeo.2008.06.004

10.1016/S0167-2991(08)63059-1

10.1016/S0167-2991(07)80008-5

Rouquerol J., 1998, Absorption by Powders and Porous Solids

10.1346/CCMN.1997.0450405

SarkerR.2010.Elastic and flow properties of shales.PhD Dissertation Colorado School of Mines.

10.1111/j.1365-2478.2005.00495.x

SharpA.G.1981. Design curves for oceanographic pressure‐resistant housings. (WHOI Technical Memorandum 3‐81). Woods Hole Massachusetts: Woods Hole Oceanographic Institution. Retrieved from WHOAS: Woods Hole Open Access Serverhttp://hdl.handle.net/1912/1427.

10.1088/0957-0233/20/4/045108

10.2136/sssaj1973.03615995003700040021x

10.1351/pac198557040603

10.1346/CCMN.2001.0490604

10.1346/CCMN.2008.0560203

10.1046/j.1365-246X.2003.02046.x

Webb P.A., 1997, Analytical Methods in Fine Particle Technology

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Geophysical Prospecting

Tập 61 Số 2

341-362

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