The Experimental Rock Deformation Group conducts research on the mechanical behaviour and transport properties of Earth materials at conditions pertaining to the crust and upper mantle. Our research involves experimental work, coupled with microstructural study of the active microscale processes, plus microphysical and numerical modelling of these processes.
Experimental rock deformation
The research activities of the Experimental Rock Deformation Group aim to provide fundamental data on rock properties and deformation mechanisms. The group runs the High Pressure and Temperature (HPT) lab, equipped with facilities that allow experiments to be conducted under conditions representative for the deep subsurface (crust and upper mantle). Combining the experimental work with microstructural analysis and microphysical modelling studies, we develop process-based, quantitative descriptions of the deformation behaviour and transport properties of rocks and allied materials. Our findings help to understand, model and predict a wide range of geological, geotechnical and geodynamical processes, such as the compaction of sedimentary rocks, bulk deformation of the crust, or localisation of deformation in lithospheric scale fault zones. In this context, most research activities of the Experimental Rock Deformation Group can be broadly placed in one (or more) of the following themes:
- Fault and earthquake mechanics
- Effects of geo-energy production and geological storage
- Ductile flow and transport in the mantle, crust and ice sheets
Fault and earthquake mechanics
Fault zones form the principal sites at which deformation of the lithosphere (the crust and uppermost mantle) is accommodated during plate tectonics. Movement along fault zones can occur in a stable, creeping manner or can be sudden and unstable, resulting in an earthquake. The type of mechanical behaviour exhibited depends on the deformation and fluid transport processes occurring within the core of the fault. One of our main activities is research on the internal brittle, frictional and plastic processes that control the mechanical behaviour and slip stability of faults. Using our purpose-built facilities, we aim to quantify the physical and chemical mechanisms involved, through friction experiments at the full range of pressure-temperature conditions relevant for major earthquakes as well as those induced by human activities in the sub-surface. Pre-, co- and post-seismic slip phenomena are addressed, including the measurement of acoustic waves generated in laboratory earthquakes (stick-slips). Together with microstructural investigations, the experimental results are used to develop models describing fault rock rheology. These models describe the time and rate dependence of fault strength or friction. They provide input needed for modelling large scale plate tectonic and seismogenic processes, and for seismic hazard assessment. Topics currently addressed include:
- The rheological and transport properties of seismogenic subduction zone faults
- The rheology of continental faults including the San Andreas Fault
- Effects of CO2 on fault friction and sealing/healing
- Frictional behaviour of simulated fault rocks from the lithologies present in the sub-surface of the Groningen gas field
- Location and size distribution of laboratory earthquakes
Effects of geo-energy production and geological storage
Exploitation of the subsurface for production or injection of fluids perturbs the natural physical and chemical equilibrium of the reservoir system. However, with energy demands soaring and the impact of CO2 emissions on climate increasing, the subsurface is progressively being targeted for low-carbon resources like natural gas and geothermal energy, as well as for storage of renewable energy, such as in the form of hydrogen fuel and compressed air, and injection of CO2 to mitigate climate change. The Experimental Rock Deformation Group applies its expertise to address the mechanical and chemical response of upper crustal rock systems to the production and injection of such fluids.
Natural gas production: In the transition to sustainable energy sources, low-carbon natural-gas will play an important role as an alternative to coal and oil. However, adverse effects of prolonged gas production, such as surface subsidence and seismicity, are becoming apparent in gas fields worldwide, such as the giant Dutch Groningen Gas field. This may impact the potential for natural gas to contribute to the energy transition. It is widely believed that the principal processes occurring in depleting gas reservoirs involve compaction of the reservoir rock, as the vertical effective stress increases. In a faulted and/or mechanically heterogeneous reservoir, gradients in compaction and associated deviations in shear and normal stress in the neighbourhood of pre-existing faults and other heterogeneities can trigger fault slip or other rock failure phenomena, and potentially induced seismicity. We aim to provide a microphysical models and quantitative descriptions of rock and fault behaviour to advance understanding of reservoir compaction and fault behaviour in the context of induced seismicity and subsidence in sandstone reservoirs, like the Groningen Gas field. We are also investigating the impact mitigation strategies, such as the injection of fluids, may have on halting reservoir compaction.
CO2 storage: Carbon dioxide capture at fossil fuel power plants, coupled with geological storage in empty hydrocarbons reservoirs, saline aquifers or unminable coal seams, presents one of the most promising ways of reducing CO2 emissions. The feasibility of geological storage is determined by the response of the subsurface to CO2 injection. Particularly important is the coupled chemical-mechanical response of the reservoir formation, of the overlying caprocks, and of faults bounding the reservoir. We study the potential of subsurface mineralization of reservoirs and hydro-fractured peridotites, the effects CO2 may have on the compaction of reservoir rocks, and the integrity of wellbore systems, caprocks and faults, as well as the potential for CO2 uptake by coal and the associated effects of stress and strain thereupon.
Ductile flow and transport in the mantle, crust and ice sheets
The rheological and transport properties of rock materials constituting Earth’s crust and mantle exert a strong control on a wide range of geological phenomena. The dynamics of large-scale tectonic processes such as rifting, continental break-up, subduction and orogenesis, for example, are in part controlled by the mechanical behaviour of the upper mantle. In turn, the physical properties of rock materials are controlled by micro-scale processes such as crystal defect motion, recrystallisation or diffusion. Of particular importance is the rate of deformation due to these processes, which is typically described in terms of creep equations or flow laws. One of the aims of the Experimental Rock Deformation Group is to gain insight into these microphysical processes and to quantify them. This is done by performing deformation experiments at in-situ temperature and pressure, e.g. using our 1-GPa gas deformation apparatus and high-temperature, controlled-atmosphere conductivity system. Visit the HPT-lab facilities webpage for more information.
Key research topics include solid state flow of the lithospheric upper mantle and asthenosphere, the development of shear zones, dynamic recrystallisation, and the effects of trace amounts of water, as well as the electrical conductivity of upper mantle rocks and partially molten systems. Our mechanical results consist of rheological flow laws that can be included in numerical models addressing the dynamics of plate tectonic processes. Our work on conductivity aims to provide a basis for interpreting large scale electrical measurements in terms of active deformation phenomena. The rheology of ice and the flow ice sheets are controlled by similar microphysical processes. In the last few years, the Experimental Rock Deformation Group has extended its studies of flow and recrystallisation to address the rheology of ice, to be included in geodynamic models of icy planetoids and for better constraining polar ice flow on Earth.
SEISMIC: Slip and earthquake nucleation in experimental and numerical simulations: a multi-scale, integrated and coupled approach
SEISMIC is a research project led by dr. André Niemeijer, funded by the EU through an ERC starting grant, and by the NWO through a VIDI grant. The 5-year project (2013-2018) is aimed at understanding earthquake nucleation and propagation by obtaining a better understanding of the microphysical processes that control friction of fault rocks under in-situ conditions of pressure, temperature and fluid pressure. The complete proposal is available on request. See also the NARCIS and CORDIS pages on SEISMIC.
Contact: dr. André Niemeijer
Reservoir deformation and fault mechanical behaviour in the Groningen Gas field
A major research programme is underway in the HPT Laboratory at Utrecht University (2015-2019) aimed at providing a fundamental, physically based understanding and quantitative description of reservoir deformation and fault mechanical behaviour in the Groningen gas field. It involves an integrated approach employing experimental rock and fault mechanics work conducted at in-situ conditions, microscale observational studies to determine the physical processes that control reservoir rock deformation and fault slip in the field and in the laboratory, plus modelling and experimental work aimed at establishing upscaling rules between laboratory and field scales. The results obtained are providing constitutive laws describing reservoir deformation and fault friction behaviour. These are being included in geomechanical models aimed at coupling reservoir compaction and fault reactivation to investigate fault rupturing and seismogenic behaviour at the reservoir scale. The work is being executed by a team of eight senior scientists, five postdoctoral researchers and three PhD students with expertise ranging from experimental rock and fault mechanics to electron microscopy, geophysics and numerical modelling. Important collaborations with earthquake science groups across the world include the CalTech Seismological Laboratory, CA, USA, the National Research Institute for Earth Science and Disaster Resilience (NIED), Tsukuba, Japan and the Laboratory for Earthquake Dynamics, China Earthquake Administration (CEA), Beijing, China. The programme is funded by the Nederlandse Aardolie Maatschappij (NAM) with full freedom to publish all results in the open scientific literature.
Contact: prof. dr. Chris Spiers
Marie Skłodowska Curie Action ITN ‘CREEP’: Complex Rheologies in Earth Dynamics and Industrial Processes
The CREEP Innovative Training Network is a coherent platform for training and career development of young scientists in Geodynamics, Mineral Physics, Seismology, Fluid Mechanics, and Materials Sciences. It aims to structure the collaboration in research and training between 10 leading academic centres in Solid Earth Sciences in Europe and 11 industrial partners. Within the CREEP programme, 16 Early Stage Researchers (ESRs) study the origin of rheological complexity in Earth and analogous materials and how it controls the dynamics of our planet, including natural and human-induced seismicity, and affects a large range of industrial applications, from energy production and waste storage to production of high-performance glasses. At the Experimental Rock Deformation Group, we host the following two projects (2015-2019):
- ESR2: Effects of fault rheology on microseismicity
- ESR3: Quantifying the role of coupled solution transfer and brittle processes in controlling the rheology, transport and containment properties of rocksalt
The HPT laboratory run by the Experimental Rock Deformation Group is equipped with a wide variety of facilities. These involve apparatus for deformation at high pressure and temperature, high temperature furnaces and apparatus for thermal, microstructural and IR analysis.
Visit the HPT lab facilities website
- Triaxial compression apparatus (Heard apparatus)
- Rotary shear apparatus
- Gas medium, high precision servo-controlled triaxial testing machine (gas apparatus)
- Triaxial compression apparatus (Shuttle vessel)
- Uniaxial (oedometer) compaction cell (Monel vessel)
- Uniaxial compaction cell
- 3D Dilatometer
- Transient step gas permeameter
- Contact resistivity cell
- Pressurised conductivity cell
The staff members (and PhD students) of the Experimental Rock Deformation Group are involved in teaching several Bachelor and Master courses. In addition, we are involved in the supervision of Bachelor, honours and Master projects and internships.
- Structure and properties of Earth materials (GEO3-1304)
- Continuum mechanics and rheology (GEO3-1302)
- Structural geology and tectonics (GEO3-1307)
- Water in geo processes (GEO3-1330)
- Fieldwork 2: Pyrenees (GEO3-1210)
- Introduction Porous Media (GEO3-1336)
- Kinetic processes (GEO4-1426)
- Structural analysis of deformed rocks (GEO4-1411)
- Mechanisms of deformation and transport in rocks (GEO4-1410)
- Earth resources (GEO4-1425)
- Fossil resources: past, present and future (GEO4-2325)
- Sustainable and unconventional geo-resources (GEO4-1437)
- Field research instruction geology (GEO4-1430)
- Modelling of crust and lithosphere deformation (Geo4-1442)
Research projects in the Experimental Rock Deformation Group (HPT Lab) at Utrecht are funded by a number of agencies, organisations and companies. The following provide major research funding:
- NWO (The Netherlands Organisation for Scientific Research)
- NWO/ALW (Earth and Life Sciences Division)
- NWO/SRON (Space Sciences Division)
- ISES (Netherlands Centre for Integrated Solid Earth Sciences)
- CATO (Dutch National Research Programme on Carbon Capture and Storage)
- NAM (Nederlandse Aardolie Maatschappij)
- Shell Global Solutions
- TNO Built Environment and Geosciences
- European Commission Framework Programmes (e.g. ERC)
Ningbo Newanton Rubber & Plastics Products Co., Ltd, Ningbo, China: Newanton sponsors research on geological storage of CO2 at the HPT Lab by developing and supplying CO2 – resistant rubber sealing products and sample jacketing materials without charge.