Mass Transfer & Porous Media (MTPM) - Andra

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P/MTPM/42Figure 2: Model of pore structure built with the pore-cor code from mercury injection curve and SEMobservations.three main magnetic axis, samples are cored for mercury injection. These measurements show that eachmagnetic axis has a specific threshold and void volume value indicating a potential anisotropy of flowingparameter. Ferro fluid injections give information about the void shape and void orientation. Thesemeasurements are performed for increasing fluid pressure giving access to decreasing threshold values.For clayey material, void orientation and shape are controlled by clay orientation, for silty samples, largervoids are controlled by silt grain and smaller ones are controlled by clay fractionPORE NETWORK MODEL AND INFERRED PERMEABILITYThe software “Pore-Cor”(www.pore-cor.com) is used to build a pore network model from mercury injectiondata (Matthews et al., 2006). This model implies the description of the porous network at a microscopic scalefrom mercury injection test and at mesoscopic scale from SEM observation. Two kinds of voids are defined,threshold in blue in the fig. 2, controlling the access to voids in orange giving the porosity volume, spaceswithout voids are associated to volume cemented by calcite (figure 2). Using this geometry a set of transferproperties could be inferred and involves from 10 -19 m 2 to 10 -21 m 2 with regard to the direction.References:Esteban, L. 2006. Anisotropies magnétique et de porosité des argilites du Callovo-Oxfordien du laboratoiresouterrain de l'Andra (Meuse/Haute-Marne, Bassin de Paris). Thèse Univ. Toulouse.Esteban, L., Bouchez, J.L. and Trouiller, A. 2006. The Callovo-Oxfordian argilites from eastern Parisbasin: magnetic data and petrofabrics. C . Rend. Acad . Sci ., Paris , Géosciences, 338, 867-881.Esteban, L., Géraud, Y. and Bouchez, J.L. (2006). Pore network connectivity in low permeabilitysediments from magnetic fabric data and oriented mercury injections. Geophysical Research Letters,vol. 33, L18311, doi :10.1029/2006GL026908.Esteban, L., Géraud, Y. and Bouchez, J.-L., 2007. pore network connectivity anisotropy in Jurassic argillitespecimens from eastern Paris Basin (France). physics and chemistry of the Earth, in press.Matthews, G.P., Canouville, C.F. and Moss, A.K., 2006. use of a void network model to correlate porosity,mercury porosimetry, thin section, absolute permeability and NMR relaxation time data for sandstonerocks. Physical Review, E(73): 031307.Page 506INTERNATIONAL MEETING, SEPTEMBER 17...>...18, 2007, LILLE, FRANCECLAYS IN NATURAL & ENGINEERED BARRIERSFOR RADIOACTIVE WASTE CONFINEMENT
P/MTPM/43IDENTIFICATION AND QUANTIFICATIONOF LARGE-SCALE DIFFUSION IN A DEEPCLAYSTONE FORMATION (OPALINUS CLAYOF MONT RUSSELIN, SWITZERLAND)M. Koroleva 1 , M. Mazurek 1 , A.M. Fernández 2 , A. Gautschi 3 , H.N.Waber 11. RWI, Institute of Geological Sciences, University of Bern, Baltzerstrasse 3, CH-3012 Bern,Switzerland (koroleva@geo.unibe.ch; mazurek@geo.unibe.ch; waber@geo.unibe.ch )2. CIEMAT, Avda. Complutense 22, 28040 Madrid, Spain (anamaria.fernandez@ciemat.es)3. Nagra, Hardstr. 70, CH-5430 Wettingen, Switzerland ( andreas.gautschi@nagra.ch )INTRODUCTIONNatural tracers in pore water of the Opalinus Clay, a claystone formation dating from the earliest Dogger(Aalenian), have been studied in cores drilled from the Mont Russelin emergency exit tunnel near St-Ursanne in the Canton of Jura, Switzerland. The tunnel penetrates an anticline of the thin-skinned belt ofthe Jura Mountains. Opalinus Clay occurs in the core of the anticline and contains a complex system ofthrust faults. In 1991, during the Mont Russelin tunnel construction, a water with a Cl - content similar tothat of present-day sea water was collected from an extensometer borehole in a Liassic slice in the centreof the anticline. Water seepages into the tunnel containing fresh water were collected in the Doggerlimestone stratigraphically overlying Opalinus Clay. The horizontal distance between the locations wherethe saline and the fresh water samples were taken is approximately 400 m. The interval between the twolocations is largely constituted of Opalinus Clay.EXPERIMENTAL CONCEPTIn the emergency exit tunnel, 17 boreholes were drilled perpendicular to the tunnel wall, approximately 4 mdeep, to cover a profile from the core of the anticline to its southeastern limb. Samples were collected fromthe Liassic claystone, the Opalinus Clay and the Dogger limestone. Samples for pore-water analysis weretaken from the deepest parts of each core, in order to minimize artifacts due to the presence of the tunnel(e.g. evaporation, oxidation and outgassing). The tracers considered included chloride, stable waterisotopes and helium. Chloride data were obtained from aqueous leaching and a small number of squeezingtests. The stable isotopic composition of water was obtained by the diffusive isotope exchange technique(Rübel et al., 2002). The amount of 4 He was measured by mass spectrometry (Pfeiffer QMS 422) afteroutgassing of the rock samples in a vacuum container over about 3 months.RESULTS AND DISCUSSIONThe chloride-accessible porosity in Opalinus Clay is about 0.55 times the water-loss porosity based on thecomparison of the Cl - concentration in the squeezed water with that in the aqueous extract solutions. Thisvalue is near-identical to that found for Opalinus Clay in the Mont Terri underground rock laboratory,which is located only 5 km to the northwest in the neighbouring anticline (Pearson et al., 2003). The Cl -distribution in pore water shows a regular and well defined profile, with a conspicuous decrease towardsthe limestone aquifer in the hanging wall (Fig. 1a). The highest values (approximately 20 g/kg H 2 O, similarto the value in present sea water) are found in the centre of the anticline in the underlying Liassicclaystones close to the contact with Opalinus Clay.The spatial distributions of δ 18 O, δ 2 H and helium concentrations also show systematic variations (Fig.1bfor δ 18 O). The values are highest in the centre of the anticline and decrease towards the Dogger in the limb.However, in contrast to the Cl - distribution, the stable water isotopes and helium show an anomaly relatedto a major fault zone close to the contact between Opalinus Clay and a tectonic slice of underlying Liassicclaystone.INTERNATIONAL MEETING, SEPTEMBER 17...>...18, 2007, LILLE, FRANCECLAYS IN NATURAL & ENGINEERED BARRIERSFOR RADIOACTIVE WASTE CONFINEMENTPage 507
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Poster [MTPM]Mass Transfer & Porous
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P/MTPM/1The free energy cost of for
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P/MTPM/3DIFFUSION OF IONS IN UNSATU
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P/MTPM/4POROUS MEDIA CHARACTERIZATI
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P/MTPM/5Oxalate ionsQuartzQuartz +P
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P/MTPM/6borehole was capped with a
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P/MTPM/7Initial state with glass an
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P/MTPM/8The mesh of the elementary
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P/MTPM/9Moreover, using another sam
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P/MTPM/10Figure 1: Horizontal cross
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P/MTPM/11n t (mol)as received8 10 -
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P/MTPM/1210,9Degree of saturation (
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P/MTPM/13RESULTSFirst, we estimated
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P/MTPM/142.5Energy (M eV)1.6 1.7 1.
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P/MTPM/15C/Co10.90.80.70.60.50.40.3
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P/MTPM/16ModelIrmayvG-M1vG-M2vG-M3T
Page 36 and 37: P/MTPM/17Figure 1: Experimental HTO
Page 38 and 39: P/MTPM/18Diffusion experiments were
Page 40 and 41: P/MTPM/19Figure 1: Used mesh for co
Page 42 and 43: P/MTPM/201.81.61.41.2upstream compa
Page 44 and 45: P/MTPM/21490Pressure [bar]0 10 20 3
Page 46 and 47: 134P/MTPM/22through-diffusion exper
Page 48 and 49: P/MTPM/23HA (µg/g)3002001000(a):pH
Page 50 and 51: P/MTPM/24through each sample. The p
Page 52 and 53: P/MTPM/25FIRST RESULTSPreliminary c
Page 54 and 55: P/MTPM/26heterogeneous distribution
Page 56 and 57: P/MTPM/27Relative concentration (C-
Page 58 and 59: P/MTPM/280.75m0.25mTable 1: Cross s
Page 60 and 61: P/MTPM/29Figure 1: A. Scheme of the
Page 62 and 63: P/MTPM/30The presented theory is ex
Page 64 and 65: P/MTPM/31Furthermore, Van Loon et a
Page 66 and 67: P/MTPM/32RESULTSResults show that,
Page 68 and 69: P/MTPM/33Clay modellingPore size di
Page 70 and 71: P/MTPM/341.60E-11f H2-d total (kg.m
Page 72 and 73: P/MTPM/350.50η R ()0.400.300.200.1
Page 74 and 75: P/MTPM/36200Bq/g1801601401201008060
Page 76 and 77: P/MTPM/37Argilite (ionic strength 0
Page 78 and 79: P/MTPM/38-Samples cored at 12m were
Page 80 and 81: P/MTPM/39APPLICATIONSCORE 2D has be
Page 82 and 83: P/MTPM/40Figure 1: Sketch drawing o
Page 84 and 85: P/MTPM/41Figure 1: Thermal conducti
Page 88 and 89: P/MTPM/43The available data are con
Page 90 and 91: P/MTPM/44Figure 1: Spatial extensio
Page 92 and 93: P/MTPM/45Relative concentration / (
Page 94 and 95: P/MTPM/46Figure 2: Swelling pressur
Page 96 and 97: P/MTPM/47then used in the transport
Page 98: P/MTPM/4820181614121086Gas pressure
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