scholarly journals Kinetics of pressure solution at halite-silica interfaces and intergranular clay films

1995 ◽  
Vol 100 (B7) ◽  
pp. 13113-13132 ◽  
Author(s):  
Stephen H. Hickman ◽  
Brian Evans
Keyword(s):  
Pressure Solution ◽  
Kinetics Of

On the Kinetics of Elementary Processes of Pressure Solution

1998 ◽  
Vol 152 (4) ◽  
pp. 667-683 ◽  
Author(s):  
V. Kruzhanov ◽  
B. Stöckhert
Keyword(s):  
Pressure Solution ◽  
Elementary Processes ◽  
Kinetics Of

A Discussion on natural strain and geological structure - The kinetics of rock deformation by pressure solution

1976 ◽  
Vol 283 (1312) ◽  
pp. 203-219 ◽  
Keyword(s):  
Grain Boundary ◽  
Geological Structure ◽  
Deformation Mechanisms ◽  
Rock Deformation ◽  
Pressure Solution ◽  
Mineral Solubility ◽  
Diffusive Mass Transfer ◽  
Diffusive Flow ◽  
Kinetics Of ◽  
Coble Creep

A simple model for rock deformation by pressure solution, assuming grain boundary diffusive mass transfer to be deformation rate controlling, is presented. The model leads to a constitutive flow law which is of the same form as that for Coble creep. It is argued that the presence of a fluid film in stressed grain boundaries leads to enhanced diffusivity of solute particles in the grain boundary. Some simple experiments are described, which demonstrate rapid diffusion in solutions in pores, much slower diffusion in stressed interfaces and deformation by pressure solution. By using the theoretical model, and by assuming that the pressure of the interfacial solution is equal to the applied normal stress, so that available experimental data on the effect of pressure on mineral solubility could be used, rates of deformation by pressure solution have been calculated. These are compared with rates of deformation by crystal plastic and high temperature diffusive flow processes, by using deformation mechanism maps. Predicted transition conditions between various deformation mechanisms are found to be consistent with those inferred from the study of textures of naturally deformed rocks.

Molecular dynamics simulations of diffusive properties of stressed water films in quartz and clay grain contacts

2020 ◽  
Author(s):  
Floris Teuling ◽  
Marthe G. Guren ◽  
François Renard ◽  
Martyn R. Drury ◽  
Suzanne J.T. Hangx ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Fluid Film ◽  
Pressure Solution ◽  
Fluid Films ◽  
Self Diffusion ◽  
Water Films ◽  
Fluid Film Thickness ◽  
Dynamics Simulations ◽  
Kinetics Of ◽  
Quartz Block

<p><strong>Molecular dynamics simulations of diffusive properties of stressed water films in quartz and clay grain contacts</strong></p><p>Floris S.R. Teuling<sup>1</sup>, Marthe G. Guren<sup>2</sup>, François Renard<sup>2</sup>, Martyn R. Drury<sup>1</sup>, Suzanne J.T. Hangx<sup>1</sup>, Helen E. King<sup>1</sup>, Oliver Plümper<sup>1</sup>, Henrik A. Sveinsson<sup>2</sup></p><ol><li>Utrecht University, Department of Earth Sciences, Princetonlaan 8a, 3584 CB Utrecht, the Netherlands</li> <li>University of Oslo, Departments of Geosciences and Physics, The Njord Centre, box 1048, Blindern, 0316 Oslo, Norway</li> </ol><p>Hydrocarbon extraction can increase effective normal stresses in geological reservoirs, potentially inducing deformation and seismicity<sup>1</sup>. The kinetics of time-dependent creep processes that could persist long after production has ended, such as pressure solution and stress corrosion, are poorly quantified. These processes can be limited by diffusion efficiency at stressed grain contacts, which depends strongly on fluid film thickness as well as interfacial and surface energies. The diffusive properties of stressed fluid films between various crystallographic surfaces of the rock forming minerals clay and quartz are critical to predict long term deformation of reservoir. Due to the small length scales of grain contacts, experimental data on these quantities are difficult to acquire. Therefore, we use molecular dynamic simulations to elucidate the physico-chemical behaviour of fluid films at different mineral interfaces.</p><p>We apply large-scale classical molecular dynamics in LAMMPS to numerically resolve fluid film behaviour in grain contacts. The silicate-water system is modelled using a modified ClayFF force field<sup>2</sup>. A β-quartz block was placed within a water-filled nanopore with either hydroxylated  β-quartz or basal illite clay surfaces as walls.  This geometry was built using the software packages Atomic Simulation Environment, Ovito and Packmol. The system was first equilibrated using an NVT thermostat and an NPT barostat for tens of picoseconds under conditions of 8 MPa fluid pressure and a temperature of 100°C. Then, a force was applied on the quartz block, corresponding to 10-200 MPa normal contact stress, such that a thin water film is squeezed at the interface between two grains. Self-diffusion constants were calculated by mean square displacements and velocity autocorrelation in films at steady state thicknesses.</p><p>Simulations reach a steady state after several nanoseconds run time. Under reservoir conditions, fluid film thicknesses are reduced to less than one nanometre. Two to three layers of adsorbed water remain in the grain contact, a result consistent with reported fluid film properties for grain contacts in upper crustal systems. Our results quantify how various juxtaposed quartz surfaces and quartz-clay interfaces influence fluid film thickness, self-diffusion and the dynamics of the water layer, which allows for constraining the kinetics of pressure solution creep in sandstone reservoirs.</p><p>Acknowledgements</p><p>This project received funding from the DeepNL programme</p><ol><li>Pijnenburg, R. P. J., Verberne, B. A., Hangx, S. J. T., & Spiers, C. J. (2019). Intergranular clay films control inelastic deformation in the Groningen gas reservoir: Evidence from split‐cylinder deformation tests. Journal of Geophysical Research: Solid Earth, 124.</li> </ol><p> </p><ol><li>Cygan, R. T., Liang, J. J., & Kalinichev, A. G. (2004). Molecular models of hydroxide, oxyhydroxide, and clay phases and the development of a general force field. The Journal of Physical Chemistry B, 108(4), 1255-1266.</li> </ol>

Kinetics of crack-sealing, intergranular pressure solution, and compaction around active faults

2000 ◽  
Vol 22 (10) ◽  
pp. 1395-1407 ◽  
Author(s):  
François Renard ◽  
Jean-Pierre Gratier ◽  
Bjørn Jamtveit
Keyword(s):  
Active Faults ◽  
Pressure Solution ◽  
Crack Sealing ◽  
Kinetics Of ◽  
Intergranular Pressure

scholarly journals Kinetics of precipitation of gypsum and implications for pressure‐solution creep

2000 ◽  
Vol 157 (2) ◽  
pp. 269-281 ◽  
Author(s):  
SIESE DE MEER ◽  
CHRISTOPHER J. SPIERS ◽  
COLIN J. PEACH
Keyword(s):  
Pressure Solution ◽  
Kinetics Of Precipitation ◽  
Kinetics Of

Direct observations of radiation-enhanced transformations in glass

1983 ◽  
Vol 41 ◽  
pp. 354-355
Author(s):  
J. F. DeNatale ◽  
D. G. Howitt
Keyword(s):  
Glass Matrix ◽  
Diffusion Mechanism ◽  
Bubble Formation ◽  
Silicate Glasses ◽  
Phase Decomposition ◽  
Direct Observations ◽  
Thin Foils ◽  
Oxygen Bubble ◽  
Electron Energy Loss ◽  
Kinetics Of

The electron irradiation of silicate glasses containing metal cations produces various types of phase separation and decomposition which includes oxygen bubble formation at intermediate temperatures figure I. The kinetics of bubble formation are too rapid to be accounted for by oxygen diffusion but the behavior is consistent with a cation diffusion mechanism if the amount of oxygen in the bubble is not significantly different from that in the same volume of silicate glass. The formation of oxygen bubbles is often accompanied by precipitation of crystalline phases and/or amorphous phase decomposition in the regions between the bubbles and the detection of differences in oxygen concentration between the bubble and matrix by electron energy loss spectroscopy cannot be discerned (figure 2) even when the bubble occupies the majority of the foil depth.The oxygen bubbles are stable, even in the thin foils, months after irradiation and if van der Waals behavior of the interior gas is assumed an oxygen pressure of about 4000 atmospheres must be sustained for a 100 bubble if the surface tension with the glass matrix is to balance against it at intermediate temperatures.

Irradiation behavior of pyrolytic silicon carbide

1983 ◽  
Vol 41 ◽  
pp. 72-73
Author(s):  
R. J. Lauf
Keyword(s):  
Silicon Carbide ◽  
Fission Products ◽  
Thermodynamics And Kinetics ◽  
Neutron Fluences ◽  
Fuel Particles ◽  
Sic Coatings ◽  
Irradiation Behavior ◽  
Kinetics Of ◽  
Htgr Fuel

Fuel particles for the High-Temperature Gas-Cooled Reactor (HTGR) contain a layer of pyrolytic silicon carbide to act as a miniature pressure vessel and primary fission product barrier. Optimization of the SiC with respect to fuel performance involves four areas of study: (a) characterization of as-deposited SiC coatings; (b) thermodynamics and kinetics of chemical reactions between SiC and fission products; (c) irradiation behavior of SiC in the absence of fission products; and (d) combined effects of irradiation and fission products. This paper reports the behavior of SiC deposited on inert microspheres and irradiated to fast neutron fluences typical of HTGR fuel at end-of-life.

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