Application of Stress-pore Pressure Coupling Theory for Porous Media to the Xinfengjiang Reservoir Earthquakes

1995 ◽  
pp. 123-137
Author(s):  
Li-Ying Shen ◽  
Bao-Qi Chang
Keyword(s):  
Porous Media ◽  
Pore Pressure ◽  
Coupling Theory

scholarly journals Propagation of pore pressure diffusion waves in saturated porous media

2015 ◽  
Vol 117 (13) ◽  
pp. 134902 ◽  
Author(s):  
Duoxing Yang ◽  
Qi Li ◽  
Lianzhong Zhang
Keyword(s):  
Porous Media ◽  
Pore Pressure ◽  
Saturated Porous Media ◽  
Diffusion Waves ◽  
Pressure Diffusion

On the effect of pore pressure on the isotropic behavior of saturated porous media

1997 ◽  
Vol 81 (11) ◽  
pp. 7148-7152 ◽  
Author(s):  
H. Kytömaa ◽  
M. Kataja ◽  
J. Timonen
Keyword(s):  
Porous Media ◽  
Pore Pressure ◽  
Saturated Porous Media

Pressure-driven gas flow in viscously deformable porous media: application to lava domes

2019 ◽  
Vol 869 ◽  
pp. 85-109 ◽  
Author(s):  
David M. Hyman ◽  
M. I. Bursik ◽  
E. B. Pitman
Keyword(s):  
Porous Media ◽  
Steady State ◽  
Pore Pressure ◽  
Gas Flow ◽  
Lava Dome ◽  
Steady State Solution ◽  
Pore Fluid ◽  
State Solution ◽  
Deformable Porous Media ◽  
Lava Domes

The behaviour of low-viscosity, pressure-driven compressible pore fluid flows in viscously deformable porous media is studied here with specific application to gas flow in lava domes. The combined flow of gas and lava is shown to be governed by a two-equation set of nonlinear mixed hyperbolic–parabolic type partial differential equations describing the evolution of gas pore pressure and lava porosity. Steady state solution of this system is achieved when the gas pore pressure is magmastatic and the porosity profile accommodates the magmastatic pressure condition by increased compaction of the medium with depth. A one-dimensional (vertical) numerical linear stability analysis (LSA) is presented here. As a consequence of the pore-fluid compressibility and the presence of gravitation compaction, the gradients present in the steady-state solution cause variable coefficients in the linearized equations which generate instability in the LSA despite the diffusion-like and dissipative terms in the original system. The onset of this instability is shown to be strongly controlled by the thickness of the flow and the maximum porosity, itself a function of the mass flow rate of gas. Numerical solutions of the fully nonlinear system are also presented and exhibit nonlinear wave propagation features such as shock formation. As applied to gas flow within lava domes, the details of this dynamics help explain observations of cyclic lava dome extrusion and explosion episodes. Because the instability is stronger in thicker flows, the continued extrusion and thickening of a lava dome constitutes an increasing likelihood of instability onset, pressure wave growth and ultimately explosion.

Capturing the Dynamics of Foam Coarsening in a HPHT Microfluidic System

2021 ◽  
Author(s):  
Wei Yu ◽  
Xianmin Zhou ◽  
Mazen Yousef Kanj
Keyword(s):  
Porous Media ◽  
Pore Pressure ◽  
Foam Stability ◽  
Microfluidic System ◽  
Linear Increase ◽  
Gas Phases ◽  
Co2 Foam ◽  
Reservoir Conditions ◽  
Ultralow Interfacial Tension ◽  
Two Stages

Abstract The foam coarsening process is significant to foam stability in porous media. This study provides, for the first time, direct visualization of the foam coarsening process in porous media under realistic reservoir conditions. Foam coarsening behavior in porous media has shown a similar linear increase in the average bubble area to that in an open system but differs in two stages. The average bubble area increases with a faster rate in stage 1 and then increases with a slower rate in stage 2 and stage 2 dominates the foam coarsening process. The transition between the two stages occurs as the inner bubbles disappear when the edge bubbles start feeling the effects of the walls. The foam at steady-state shows a bimodal size distribution with bubbles trapped in the pore bodies and pore throats. The effects of pore pressure (600-3200 psi) and temperature (22-100 °C) were studied. Foam coarsening dynamics are sensitive to pore pressure and temperature, where higher pore pressure and lower temperature are more favorable to maintain a stable foam. Finally, the coarsening rates of foams generated with different gas phases were compared. In contrast to N2 foam and gas CO2 foam, supercritical CO2 foam exhibits the slowest coarsening rate because of its ultralow interfacial tension.

scholarly journals Numerical Simulation on Hydromechanical Coupling in Porous Media Adopting Three-Dimensional Pore-Scale Model

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Jianjun Liu ◽  
Rui Song ◽  
Mengmeng Cui
Keyword(s):  
Finite Element ◽  
Porous Media ◽  
Pore Pressure ◽  
Three Dimensional ◽  
Confining Pressure ◽  
Scale Model ◽  
Micro Ct ◽  
Pore Scale ◽  
Hydromechanical Coupling ◽  
Rock Matrix

A novel approach of simulating hydromechanical coupling in pore-scale models of porous media is presented in this paper. Parameters of the sandstone samples, such as the stress-strain curve, Poisson’s ratio, and permeability under different pore pressure and confining pressure, are tested in laboratory scale. The micro-CT scanner is employed to scan the samples for three-dimensional images, as input to construct the model. Accordingly, four physical models possessing the same pore and rock matrix characteristics as the natural sandstones are developed. Based on the micro-CT images, the three-dimensional finite element models of both rock matrix and pore space are established by MIMICS and ICEM software platform. Navier-Stokes equation and elastic constitutive equation are used as the mathematical model for simulation. A hydromechanical coupling analysis in pore-scale finite element model of porous media is simulated by ANSYS and CFX software. Hereby, permeability of sandstone samples under different pore pressure and confining pressure has been predicted. The simulation results agree well with the benchmark data. Through reproducing its stress state underground, the prediction accuracy of the porous rock permeability in pore-scale simulation is promoted. Consequently, the effects of pore pressure and confining pressure on permeability are revealed from the microscopic view.

scholarly journals Propagation of Pore Pressure and Stress in Saturated Porous Media Based on a Darcy-Brinkman Formulation

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Duoxing Yang ◽  
Lianzhong Zhang
Keyword(s):  
Porous Media ◽  
Phase Velocity ◽  
Pore Pressure ◽  
Characteristic Frequency ◽  
Mathematic Model ◽  
Compressional Wave ◽  
Damping Factor ◽  
Phase Lag ◽  
Saturated Porous Media ◽  
Viscous Shear

Propagation of pore pressure and stress in water-saturated elastic porous media is theoretically investigated when considering the Darcy-Brinkman law. The wave mode, phase velocity, phase lag, damping factor, and characteristic frequency are found from the updated mathematic model. The Brinkman term describes the fluid viscous shear effects and importantly contributes to the dispersion relation and wave damping. The coincidence of the properties of Biot waves of the first and second kinds occurs at a characteristic frequency, which is remarkably influenced by the Brinkman term. A key finding is that, compared to the Darcy-Brinkman law, Darcy’s law overestimates the phase velocity, damping, and phase lag of the first wave, while underestimates the phase velocity, damping, and phase difference of the second wave. The introduction of the Darcy-Brinkman law yields an improved description of the damping of the compressional wave modes in saturated porous media.

From red cells to soft lubrication, an experimental study of lift generation inside a compressible porous layer

2017 ◽  
Vol 818 ◽  
pp. 5-25 ◽  
Author(s):  
T. Gacka ◽  
Z. Zhu ◽  
R. Crawford ◽  
R. Nathan ◽  
Q. Wu
Keyword(s):  
Experimental Study ◽  
Porous Media ◽  
Pore Pressure ◽  
Layer Thickness ◽  
Porous Layer ◽  
Endothelial Glycocalyx ◽  
Porous Media Flow ◽  
Pressure Transducers ◽  
Porous Sheet ◽  
Trailing Edges

It is a new concept for porous media flow that a hydrodynamic lifting force is generated inside a highly compressible porous layer as a planing surface glides over it. The concept originated from the observation of the pop-out phenomena of red blood cells over the endothelial glycocalyx layer (EGL) lining the inner surface of our blood vessels (Feng & Weinbaum, J. Fluid Mech., vol. 422, 2000, pp. 282–317). In the current paper, we report an experimental study to examine this concept. A novel testing set-up was developed that consists of a running conveyer belt covered with a soft porous sheet, and a fully instrumented upper planar board, i.e. planing surface. The generation of pore pressure was observed and captured by pressure transducers when the planing surface glides over the porous sheet. Its distribution strongly depends on the relative velocity between the planing surface and the running belt, the mechanical and transport properties of the porous sheet as well as the compression ratios at the leading and trailing edges. The relative contribution of the transiently trapped air to the total lift was evaluated by comparing the pore pressure to the total lifting pressure measured by a load cell mounted between two adjacent pressure transducers. For a typical running condition with a polyester porous material ($k=h_{2}/h_{1}=5$, $\unicode[STIX]{x1D706}=h_{2}/h_{0}=1$, $U=3.8~\text{m}~\text{s}^{-1}$, where $h_{2}$, $h_{1}$, are the porous layer thickness at the leading and trailing edges, respectively; $h_{0}$ is the un-deformed porous layer thickness; and $U$ is the velocity of the running belt), over 68 % of the local lift is generated by the pore pressure. The results conclusively verified the validity of lift generation in a highly compressible porous layer as a planing surface glides over it. This study provides the foundation for the application of highly compressible porous media for soft lubrication with minimal frictional losses. It also sheds some light on the biophysics study of the EGL.

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