Summary Results for Brine Migration Modeling Performed by LANL, LBNL, and SNL for the Used ...

105 Pages·2014·6.66 MB·English

Summary Results for
Brine Migration
Modeling Performed by
LANL, LBNL, and SNL
for the UFD Program

Prepared for
U.S. Department of Energy
Used Fuel Disposition Campaign
Kristopher L. Kuhlman
Sandia National Laboratories

September 25, 2014
FCRD-UFD-2014-000071
SAND2014-18217 R
DISCLAIMER
This information was prepared as an account of work sponsored by an
agency of the U.S. Government. Neither the U.S. Government nor any
agency thereof, nor any of their employees, makes any warranty,
expressed or implied, or assumes any legal liability or responsibility for
the accuracy, completeness, or usefulness, of any information, apparatus,
product, or process disclosed, or represents that its use would not infringe
privately owned rights. References herein to any specific commercial
product, process, or service by trade name, trade mark, manufacturer, or
otherwise, does not necessarily constitute or imply its endorsement,
recommendation, or favoring by the U.S. Government or any agency
thereof. The views and opinions of authors expressed herein do not
necessarily state or reflect those of the U.S. Government or any agency
thereof.

Prepared by:
Sandia National Laboratories
Albuquerque, New Mexico 87185

Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a
wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy’s National
Nuclear Security Administration under contract DE-AC04-94AL85000.
RECENT BRINE MODELING IN GEOLOGIC SALT
September 25, 2014 iii
RECENT BRINE MODELING IN GEOLOGIC SALT
iv September 25, 2014
Acknowledgments
The author thanks Lupe Argu¨ello and Frank Hansen from Sandia; Phil Stauffer and Florie Capor-
usciofromLosAlamos;JonnyRutqvistandLauraBlancoMart´ınfromBerkeley;andJo¨rgMo¨nig,
Jens Wolf, and Anke Schneider from GRS for providing reports and answering questions about
theirrecentsalt-relatedmodelingwork.
TheauthorthanksBwalyaMalama,DaveSassani,ErnieHardin,FrankHansen,andcolleagues
at the fifth US/German Workshop on Salt Repository Research, Design, and Operation for discus-
sions on facets of the topic of brine migration in salt. The author thanks Heeho Park and Glenn
HammondforassistancewiththePFLOTRANsimulations.
Finally,theauthorthanksErnieHardinforhisdetailedandinsightfulreviewoftheentirereport.
RECENT BRINE MODELING IN GEOLOGIC SALT
September 25, 2014 v
Summary
This report summarizes laboratory and field observations and numerical modeling related to cou-
pled processes involving brine and vapor migration in geologic salt, focusing on recent develop-
ments and studies conducted at Sandia, Los Alamos, and Berkeley National Laboratories. Interest
into the disposal of heat-generating waste in salt has led to interest into water distribution and
migrationinbothrun-of-minecrushedandintactgeologicsalt.
Ideally a fully coupled thermal-hydraulic-mechanical-chemical simulation is performed using
numerical models with validated constitutive models and parameters. When mechanical coupling
is not available, mechanical effects are prescribed in hydraulic models as source, boundary, or
initialconditions. Thisreportpresentsmaterialassociatedwithdevelopingappropriateinitialcon-
ditions for a non-mechanical hydrologic simulation of brine migration in salt. Due to the strong
coupling between the mechanical and hydrologic problems, the initial saturation will be low for
theexcavationdisturbedzonesurroundingtheexcavation.
Although most of the material in this report is not new, the author hopes it is presented in a
formatmakingitusefultoothersaltresearchers.
Thisreport(FCRD-UFD-2014-000071)satisfiesaLevel-2milestone(M2FT-14SN0818011)
in the DOE-NE Used Fuel Disposition Campaign in work package “DR Salt R&D – SNL” under
WBS1.02.08.18.
Thisreport(particularlySection5)alsosatisfiesaLevel-4milestonetitled“Summarizecurrent
THMCmodelingresultssupportingtestingofmechanicalandhydrologicbehaviorofthenear-field
host rock surrounding excavations” (M4FT-14SN0818053) in the “Salt R&D to Support Field
Studies–SNL”workpackageunderthesameWBS.
RECENT BRINE MODELING IN GEOLOGIC SALT
vi September 25, 2014
Contents
ListofFigures vii
ListofTables ix
Acronyms xi
1 Introduction 1
1.1 BrineinSalt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.2 CoupledTHMCProcessesinSalt . . . . . . . . . . . . . . . . . . . . . . . . . . 4
2 NumericalModelingofWaterinSalt 6
2.1 CurrentTHM,THC,andTHMCnumericalmodels . . . . . . . . . . . . . . . . . 6
2.1.1 CODE BRIGHT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
2.1.2 FEHM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
2.1.3 TOUGH-FLACandFLAC-TOUGH . . . . . . . . . . . . . . . . . . . . . 7
2.1.4 d3fandr3t . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
2.1.5 SIERRAMechanics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
2.1.6 PFLOTRAN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
2.2 Salt-RelevantModelBenchmarkingExercises . . . . . . . . . . . . . . . . . . . . 9
2.3 PointsofComparisonforCoupledProcessModels . . . . . . . . . . . . . . . . . 12
3 ProcessesAffectingWaterMovementinSalt 15
3.1 RepresentativeScalesinSalt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
3.2 WaterDistributioninIntactSalt . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
3.2.1 Intergranularbrineandvapor . . . . . . . . . . . . . . . . . . . . . . . . . 18
3.2.2 Intragranularbrine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
3.2.3 Brineinnon-saltlayers . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
3.2.4 Waterofhydration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
3.2.5 Waterinrun-of-minesaltvs. intactsalt . . . . . . . . . . . . . . . . . . . 21
3.3 WaterDrivingForcesinSalt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
3.3.1 Pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
3.3.2 Hygroscopy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
3.3.3 Capillarity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
3.3.4 Gravityanddensityeffects . . . . . . . . . . . . . . . . . . . . . . . . . . 28
3.3.5 Diffusivetransport . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
RECENT BRINE MODELING IN GEOLOGIC SALT
September 25, 2014 vii
3.3.6 Temperatureeffects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
3.4 DistributionofPermeabilityandPorosity . . . . . . . . . . . . . . . . . . . . . . 31
3.4.1 Permeabilityofheterogeneouslayers . . . . . . . . . . . . . . . . . . . . 31
3.4.2 DRZpermeabilitysurroundingexcavations . . . . . . . . . . . . . . . . . 31
3.4.3 Saltpermeabilityasafunctionofmechanicalproperties . . . . . . . . . . 33
3.4.4 Porositychangesduetodissolutionandprecipitation . . . . . . . . . . . . 38
3.4.5 Permeabilitychangesduetovariablesaturation . . . . . . . . . . . . . . . 39
3.5 ChemicalProcessesinSaltandBrine . . . . . . . . . . . . . . . . . . . . . . . . 39
3.6 BalanceofDimensionlessQuantities . . . . . . . . . . . . . . . . . . . . . . . . . 40
3.6.1 Thermalcharacteristictime . . . . . . . . . . . . . . . . . . . . . . . . . . 41
3.6.2 Hydrauliccharacteristictime . . . . . . . . . . . . . . . . . . . . . . . . . 42
3.6.3 Masstransportcharacteristictime . . . . . . . . . . . . . . . . . . . . . . 42
4 RecentHydrologicModelDevelopmentandLabTestingforWaterinSalt 45
4.1 LosAlamosNationalLaboratory . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
4.2 LawrenceBerkeleyNationalLaboratory . . . . . . . . . . . . . . . . . . . . . . . 46
4.3 SandiaNationalLaboratories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
5 HydrologicInitialConditionsinSaltRepositories 48
5.1 EvolutionoftheDRZAroundExcavations . . . . . . . . . . . . . . . . . . . . . . 49
5.2 EffectofDRZDry-outonHydrologicModelingInitialConditions . . . . . . . . . 52
5.3 WIPPObservationsofDRZDry-out . . . . . . . . . . . . . . . . . . . . . . . . . 56
5.3.1 MB139watertable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
5.3.2 WIPPsmall-scalemine-by . . . . . . . . . . . . . . . . . . . . . . . . . . 56
5.3.3 WIPPlarge-scalebrineinflow(RoomQ) . . . . . . . . . . . . . . . . . . 57
6 SummaryandConclusions 64
References 65
A PFLOTRANinputfiles 85
A.1 SaturatedInitialCondition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85
A.2 NonuniformSaturationInitialCondition . . . . . . . . . . . . . . . . . . . . . . . 89
RECENT BRINE MODELING IN GEOLOGIC SALT
viii September 25, 2014
List of Figures
1.1 MapofsaltdistributionintheUS(JohnsonandGonzales,1978) . . . . . . . . . . 1
1.2 Intragranular brine inclusions and intergranular pore fluids in salt (Olivella et al.,
1995) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.3 Cartoon representation of coupling in THMC systems (Cosenza and Ghoreychi,
1993). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
3.1 Relation between brine types and flow mechanisms. Adapted from Shefelbine
(1982)andSchlichandJockwer(1985). . . . . . . . . . . . . . . . . . . . . . . . 15
3.2 Proposed reduction of connectivity at constant porosity in intergranular porosity
duringsaltreconsolidationandhealing(Hansenetal.,2014a) . . . . . . . . . . . . 18
3.3 Characteristicthermogravimetricanalysesfrombeddedsaltsamples(Powersetal.,
1978) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
3.4 StaticformationporepressuresinterpretedfromWIPPtests(BeauheimandRoberts,
2002) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
3.5 Rangeofsaltporosityandporesize(CosenzaandGhoreychi,1993) . . . . . . . . 25
3.6 SaltpetrofabricstudyresultsforWIPPandAssesalt(Bechtholdetal.,2004). . . . 25
3.7 Capillary pressure data from WIPP anhydrite marker bed cores (Howarth and
Christian-Frear,1997) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
3.8 Capillary pressure data for fine-grained crushed salt (Cinar et al., 2006); Brooks
and Corey (1966) and van Genuchten (1980) model parameters indicated; MRSM
=steady-statemodifiedrestored-statemethod,CPDM=dynamicconstantpressure
desaturationmethod . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
3.9 Capillarypressuredataforfine-grainedcrushedsaltat5%and10%porosity(Olivella
etal.,2011);vanGenuchten(1980)modelparametersindicated . . . . . . . . . . 28
3.10 Correlation between intrinsic permeability and gas-threshold pressure; see Salzer
etal.(2007)forreferences. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
3.11 Idealizedlithologyofatypicalnon-saltcomponentofbeddedsalt: MB139(Borns,
1985) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
3.12 Permeability and porosity estimates from WIPP Small-scale Mine-by test (Stor-
montetal.,1991a);power-lawmodelsuggestedbyCosenza(1996) . . . . . . . . 33
3.13 Brine permeabilities interpreted from tests conducted at WIPP (Beauheim and
Roberts,2002) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
3.14 Typicalmacrofracturinganddamagesurroundingaroomexcavatedinbeddedsalt
(BornsandStormont,1988) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
RECENT BRINE MODELING IN GEOLOGIC SALT
September 25, 2014 ix
3.15 Trends in permeability and porosity for dilating (orange) and healing (blue) salt
(Hansenetal.,2014a) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
3.16 Salt permeability against net confining pressure (σ ) and octahedral shear stress
m
(τ )(Lai,1971). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
o
3.17 Experimental results showing redistribution of porosity due to precipitation and
dissolutionincrushedsalt,asafactorofinitialsaltporosityforinitialsaturationof
40% (left) and initial brine saturation for initial porosity of 30% (right) (Olivella
etal.,2011). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
5.1 Directional nature of damage surrounding a rectangular excavation in salt (Gram-
bergandRoest,1984;BornsandStormont,1988). . . . . . . . . . . . . . . . . . . 50
5.2 Numerical prediction of damage distribution around a WIPP disposal room (D
giveninEquation(5.1))(VanSambeeketal.,1993a) . . . . . . . . . . . . . . . . 50
5.3 Photo of en echelon (large aperture sub-parallel) fracturing at change in roof ele-
vation at WIPP (Hansen, 2003), with orientation drawings at left illustrating roof
geometryandrockbolts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
5.4 One-dimensionaltwo-phaseflowmodelinginbrineusingPFLOTRAN.Initialcon-
ditionsstartingfromnearlybrine-saturatedandhydrostatic(6MPa)pressure. . . . 54
5.5 One-dimensionaltwo-phaseflowmodelinginbrineusingPFLOTRAN.Initialcon-
ditionsfrom20%brinesaturationinDRZand100%brinesaturationinintactsalt,
withhydrostatic(6MPa)pressure. . . . . . . . . . . . . . . . . . . . . . . . . . . 55
5.6 Water table observed with shallow MB139 boreholes in the DRZ at WIPP. Modi-
fiedfrom(Dealetal.,1995,App.E). . . . . . . . . . . . . . . . . . . . . . . . . . 56
5.7 WIPPSmall-scaleMine-byboreholelayout(Stormontetal.,1991a) . . . . . . . . 57
5.8 WIPP Small-scale Mine-by brine (left) and gas (right) pressures in observation
boreholes before, during, and after excavation of the central borehole (Stormont
etal.,1991a) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
5.9 WIPPSmall-scaleMine-byexperimentresultsshowingextentofDRZ(bluedotted
line)anddesaturatedzone(greendashedline);modifiedfromStormontetal.(1991a) 59
5.10 WIPPRoomQinflowdata(Freezeetal.,1997) . . . . . . . . . . . . . . . . . . . 60
5.11 RoomQporosityincreasepredictedbySPECTROM-32(Freezeetal.,1997) . . . 61
5.12 Room Q TOUGH2 baseline porosity case inflow predictions, showing constant-
porositymodel(dashed),variableporositymodel(solid)(Freezeetal.,1997) . . . 62
5.13 Room Q TOUGH2 increased porosity case inflow predictions, showing baseline
porosityincrease(solid)and5%and10%additionalDRZporosity(dashed)(Freeze
etal.,1997) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
RECENT BRINE MODELING IN GEOLOGIC SALT
x September 25, 2014
List of Tables
3.1 Hydrous evaporite minerals in geologic salt; upper 4 minerals more common than
lower4. SeereferencesandnotesinRoedderandBassett(1981) . . . . . . . . . . 22
3.2 Values of characteristic times; characteristic length L = 1 m (Cosenza and Ghor-
eychi,1993;Cosenzaetal.,1998) . . . . . . . . . . . . . . . . . . . . . . . . . . 41
3.3 Typical thermal properties for salt (Cosenza and Ghoreychi, 1993; Cosenza et al.,
1998) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
3.4 ThermalPecletnumbersfordifferentsalttypes(Cosenzaetal.,1998) . . . . . . . 42
3.5 Typicalhydraulicpropertiesforsalt(CosenzaandGhoreychi,1993;Cosenzaetal.,
1998) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
3.6 Typicalmass-transportpropertiesforsalt(CosenzaandGhoreychi,1993;Cosenza
etal.,1998) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
3.7 TransportPecletnumbersfordifferentsalttypes(CosenzaandGhoreychi,1993) . 44