1. Flow and transport of gases, CO2, NAPL and nano-particles in fracture systems on the local and multiple-fracture scales Auli Niemi, Chin-Fu Tsang Fritjof Fagerlund, Zhibing Yang, Prabhakar Sharma, Martin Larsson UPPSALA UNIVERSITY DEPARTMENT OF EARTH SCIENCES NGL ANNUAL SCIENCE MEETING Oskarshamn, 7-8th of November 2013

2. MAIN INTEREST: study of flow and transport of Gases, CO2, NAPL and Nano-particles in fracture systems on the local and multiple fracture scales LOCAL FRACTURE SCALE: Variable-aperture single fractures; Complex fractures (with internal structures); Fracture zones MULTIPLE FRACTURE SCALE; Fracture intersections; Fracture networks – sparse; Fracture networks – dense

3. Flow and Transport Gases; relative permeability, capillary pressure effects, etc. CO2: added effects of phase change, solubility, dense brine with dissolved CO2, possible presence of mixture gases, fluid immobilization and entrapment etc. NAPL: multiple components and multiple phase effects, fluid immobilization and entrapment, interface characterization, interface mass transfer, dissolution etc. Nano-particles: pore-scale effects, effect of roughness of fracture surfaces, mixing of solutes, colloids, effect of unsaturated fractures (can be coupled with gas injection), etc. Characterization of trapped fluids (NAPL or CO2) using, e.g., partitioning tracer techniques

4. Outline Examples of our recent/ongoing work on example topics; CO2 geological storage, solute and NAPL transport in fractures and nanoparticle transport Possibilities for NGL

5. Geological storage of CO2 CO 2 > 800 m Several kilometers Supercritical CO 2 Brine A sufficiently impermeable seal (cap rock) A sufficiently permeable reservoir rock

6. How is CO 2 stored in the deep aquifer?

7. CO 2 CO 2 gets physically trapped beneath the sealing cap-rock and low permeability layers

8. How is CO 2 stored in the deep aquifer? CO 2 gets trapped as immobile isolated residual ’blobs’ in the pore space CO 2 CO 2 gets physically trapped beneath the sealing cap-rock and low permeability layers

9. How is CO 2 stored in the deep aquifer? CO 2 gets trapped as immobile isolated residual ’blobs’ in the pore space CO 2 CO 2 gets physically trapped beneath the sealing cap-rock and low permeability layers CO 2 dissolves into water

10. How is CO 2 stored in the deep aquifer? CO 2 gets trapped as immobile isolated residual ’blobs’ in the pore space CO 2 CO 2 gets physically trapped beneath the sealing cap-rock and low permeability layers CO 2 dissolves into water CO 2 converts into solid minerals

11. CO2 Geological Storage Ongoing EU FP7 projects MUSTANG – large-scale integrating project for quantifying Saline Aquifers for CO2 Geological Storage (2009-2014) Panacea – project focusing on long term effects of CO2 Geological Storage (2012-2014) TRUST – project continuing and expanding the field experiment of MUSTANG (2012-2017) CO2QUEST – project focusing on effect of impurities of CO2 stream (2013- 2016) Pre-feasibility studies in Sweden financed by the Swedish Energy Authority SwedeStoreCO2; to look at possibilities for a pilot scale injection experiment in the Swedish territory BASTOR; to look at possibilities to store CO2 in the Baltic Sea region

12. Test sites MUSTANG is a large-scale integrating EU FP7 R&D project (2009-2014), with 19 partners and 25 affiliated organizatons (coordinated by Uppsala University) Objective: to develop methodology and understanding for the quantification of saline aquifers for CO2 geological storage 7 field sites including one deep injection experiment and one shallow injection experiment of CO2, as well as strong laboratory experiment, process understanding and modeling components Webb-site : www.co2mustang.eu MUSTANG project

13. Heletz deep CO 2 injection experiment Scientifically motivated CO2 injection experiment of scCO2 injection to a reservoir layer at 1600 m depth, with sophisticated monitoring and sampling

14. CO2 injection experiment Objectives To gain understanding and develop methods to determine the two key trapping mechanisms of CO2 (residual trapping and dissolution trapping) at field scale, impact of heterogeneity Validation of predictive models, measurement and monitoring techniques wells for field experiments

15. injection-withdrawal of scCO2 and brine zone of residual trapped scCO 2 1.2. Determine in-situ residual and dissolution trapping parameters  Reduced influence of formation heterogeneity scCO2, brine & tracers sc CO 2 push-pulldipole  Heterogeneity affects migration and trapping  Hydraulic tests  Thermal tests  Tracer tests residual trapping residual & dissolution trapping, (& interfacial area)

16. CO2 Geological Storage Ongoing EU FP7 projects MUSTANG – large-scale integrating project for quantifying Saline Aquifers for CO2 Geological Storage (2009-2014) Panacea – project focusing on long term effects of CO2 Geological Storage (2012-2014) (www. panacea-co2.org) TRUST – project continuing and expanding the field experiment of MUSTANG (2012-2017)(http://trust-co2.org) CO2QUEST – project focusing on effect of impurities of CO2 stream (2013- 2016) (www.co2quest.eu) Pre-feasibility studies in Sweden financed by the Swedish Energy Authority SwedeStoreCO2; to look at possibilities for a pilot scale injection experiment in the Swedish territory BASTOR; to look at possibilities to store CO2 in the Baltic Sea region

17. CO2 Geological Storage Ongoing EU FP7 projects MUSTANG – large-scale integrating project for quantifying Saline Aquifers for CO2 Geological Storage (2009-2014) Panacea – project focusing on long term effects of CO2 Geological Storage (2012-2014) TRUST – project continuing and expanding the field experiment of MUSTANG (2012-2017) CO2QUEST – project focusing on effect of impurities of CO2 stream (2013- 2016) Pre-feasibility studies in Sweden financed by the Swedish Energy Authority SwedeStoreCO2; to look at possibilities for a pilot scale injection experiment in the Swedish territory BASTOR; to look at possibilities to store CO2 in the Baltic Sea region

18. Possibilities to store CO2 in Sweden/Baltic two feasibility studies 2012-2013, financed by the Swedish Energy Authority SwedeStoreCO2; to look at possibilities for a pilot scale injection experiment in the Swedish territory BASTOR; to look at possibilities to store CO2 in the Baltic Sea - so far financing by Finland and Sweden - contact person Per Arne Nilsson, PanaWare Erlström et al, 2011 Vernon et al, 2013

19. NGL related questions – CO2 storage Integrity of the sealing cap-rock is crucial for the performance of the storage Need to understand the characteristics of fractures and fracture zones possibly intersecting the cap-rock -flow through existing fractures and the related hydro- mechanical-chemical processes (opening/sealing of the fractures) -possible creation of new fractures and re-activation of existing fractures/fracture zones due to mechanical effects NGL would provide opportunities observing gas/multiphase flow and trapping as well as brine migration in real fractures

20. Chemical alterations of caprock fracture fractures when brine saturated with CO2 flowing throuh Hydro-thermo-mechanical effects CO2 (supercritical and gaseous) flow through caprock fractures ; comparison of laboratory experments to natural analogue sites Gouze et al, 2012 Edlmann et al www.co2mustang.eu

21. Solute Transport in Fractures - study of flow-wetted surface as a function of fracture aperture statistics Larsson, M. et al (2013) A new approach to account for fracture aperture variability when modeling solute transport in fracture networks WRR 49(4), Pp. 2241-2252 A new approach to account for fracture aperture variability when modeling solute transport in fracture networks Larsson et al (2012) A study of flow-wetted surface area in a single fracture as a function of its hydraulic conductivity distribution WRR 48(1)DOI: 10.1029/2011WR010686 A study of flow-wetted surface area in a single fracture as a function of its hydraulic conductivity distribution WRR

22. Solute Transport in Fractures - determining of flow-wetted surface from SWIW tests Larsson, M et al (2013), Understanding the effect of single fracture heterogeneity from single well injection withdrawal (SWIW) tests. Hydrogeology Journal, DOI 10.1007/s10040-013- 0988-x. the specific flow-wetted surface, can be determined by matching the observed breakthrough curve for a heterogeneous fracture to that for a homogeneous fracture with an equivalent property parameter.

23. NAPL Transport in Fractures 23 Release Receptor Dissolved plume Trapped residual blobs in fractures DNAPL pool in dead-end fractures GW flow Fractured bedrock Two fundamental processes: Fluid displacement (How DNAPL migrates) Interphase mass transfer (How DNAPL dissolves) Variable-aperture fracture b g φ aperture

24. NAPL Transport in Fractures Modeling of NAPL infiltration and dissolution in heterogenenous fractures, develop a general approach for flow and dissolution How does fracture roughness influence NAPL distribution and the dissolution process? Estimation of NAPL presence from observations of dissolved concentrations in the water What fracture geometries lead to fast dissolutions and what geometries make dissolution difficult?

25. entrapment and dissolution in heterogeneous fractures NAPL Transport in Fractures Yang, Z et al (2012) Jour Cont Hydrol, 133:1-16. Yang, Z. et al (2012) WRR 48, W09507. Yang, Z. et al (2013) Two-phase flow in rough-walled fractures: Comparison of continuum and invasion- percolation models. WRR 49(2) Pp 993-1002

26. DNAPL dissolution experiment 26 Light transmission system Analog fracture cell Aperture field, mm Entrapped TCE Initial condition for DNAPL dissolution Yang, Z et al (2013) Dissolution of dense non-aqueous phase liquids in vertical fractures: Effect of finger residuals and dead- end pools. Journ Cont Hydrol Vol:149, Pp 88-99

27. Nanoparticles (NPs)  Use of nanoparticles is accelerating in a wide range products & technological applications  Toxicity and transport behaviour in the environment largely unknown, particularly in complex media such as fractured rocks  Particles can act as carriers of other contaminants, including e.g. radionuclides  Extreme surface area per unit weight:  extreme capacity for surface reactions  different behaviour than larger particles 2 mg, aggregated 2 mg, dispersed

28.  Critical to understand the mechanisms of NP transport & mobilization in fractures  Particle interactions with both rock surfaces and other contaminants  Particle-mediated transport e.g. from nuclear waste repository?  Density-driven flow, heterogeneity & channelling NP transport in fractures saturated system unsaturated system  Altered transport behaviour in the presence of a gas phase  NP attachment at the liquid-gas interfaces

29. computer relay / control unit background fluid pump injection fluid pump camera light panel fracture replica outflow Dark box Experiments & laboratory at UU  Light- transmission system to study 2D flow & transport processes – quantification of aperture, concentrations & fluid saturations  Experiments in well-characterized, variable aperture fractures

30. USE OF NGL FACILITY For local scale; selection of different types of fractures, complex fractures, and fracture zones in the Äspö tunnel For multiple fracture scale; selection of different types of fracture intersections, sparse fracture networks and dense fracture networks in the Äspö tunnel Study at locations at different depths from close to surface to 460-m depth Study at different scales Study of multiple locations to explore effects of spatial heterogeneity Use of Äspö tunnel as sink by injection into rocks and observing emergence in the tunnel (and also possibly land surface)

31. RELEVANT ONGOING PROJECTS CO2 geological storage Four major EU FP7 projects, as coordinator or WP leader; MUSTANG 2009-2014, Panacea 2012-2014, TRUST 2012- 2017, CO2QUEST 2013-2016 Two pre-feasibility studies investigating CO2 geological storage in Sweden/Baltic; SwedestoreCO2 and Bastor, both funded by Energimyndigheten Research Councils (VR) strategic funds for CO2 research (2011-2014) Deep hydrogeology of fractured rocks Coupled effects in deep hydrologelogical systems, funded by SGU (2013-2015) Some of the fracture studies presented above were funded by earlier FORMAS (flow welled surface analyses) and by VR (NAPL transport) projects

32. Thank you for your attention !