scholarly journals Pore-Pressure Rise, Frictional Strength, and Fault Slip: One-Dimensional Interaction Models

1996 ◽  
Vol 125 (2) ◽  
pp. 371-384 ◽  
Author(s):  
Tien-Chang Lee
Keyword(s):  
Pore Pressure ◽  
Pressure Rise ◽  
Fault Slip ◽  
Interaction Models ◽  
One Dimensional ◽  
Dimensional Interaction ◽  
Frictional Strength

scholarly journals Perturbation Solution for One-Dimensional Flow to a Constant-Pressure Boundary in a Stress-Sensitive Reservoir

2021 ◽  
Author(s):  
Amarjot Singh Bhullar ◽  
Gospel Ezekiel Stewart ◽  
Robert W. Zimmerman
Keyword(s):  
Approximate Solution ◽  
Pore Pressure ◽  
Constant Pressure ◽  
Initial Permeability ◽  
Order Perturbation ◽  
Zeroth Order ◽  
One Dimensional ◽  
First Order ◽  
Outflow Boundary ◽  
Perturbation Solutions

Abstract Most analyses of fluid flow in porous media are conducted under the assumption that the permeability is constant. In some “stress-sensitive” rock formations, however, the variation of permeability with pore fluid pressure is sufficiently large that it needs to be accounted for in the analysis. Accounting for the variation of permeability with pore pressure renders the pressure diffusion equation nonlinear and not amenable to exact analytical solutions. In this paper, the regular perturbation approach is used to develop an approximate solution to the problem of flow to a linear constant-pressure boundary, in a formation whose permeability varies exponentially with pore pressure. The perturbation parameter αD is defined to be the natural logarithm of the ratio of the initial permeability to the permeability at the outflow boundary. The zeroth-order and first-order perturbation solutions are computed, from which the flux at the outflow boundary is found. An effective permeability is then determined such that, when inserted into the analytical solution for the mathematically linear problem, it yields a flux that is exact to at least first order in αD. When compared to numerical solutions of the problem, the result has 5% accuracy out to values of αD of about 2—a much larger range of accuracy than is usually achieved in similar problems. Finally, an explanation is given of why the change of variables proposed by Kikani and Pedrosa, which leads to highly accurate zeroth-order perturbation solutions in radial flow problems, does not yield an accurate result for one-dimensional flow. Article Highlights Approximate solution for flow to a constant-pressure boundary in a porous medium whose permeability varies exponentially with pressure. The predicted flowrate is accurate to within 5% for a wide range of permeability variations. If permeability at boundary is 30% less than initial permeability, flowrate will be 10% less than predicted by constant-permeability model.

Pore Pressure Rise During Cyclic Loading of Sands

1982 ◽  
Vol 108 (2) ◽  
pp. 315-319
Author(s):  
Christos P. Tsatsanifos ◽  
Sarada K. Sarma
Keyword(s):  
Cyclic Loading ◽  
Pore Pressure ◽  
Pressure Rise

Effect of Carbon Dioxide on the Laminar Burning Speed of Propane–Air Mixtures

2019 ◽  
Vol 141 (8) ◽  
Author(s):  
Sai C. Yelishala ◽  
Ziyu Wang ◽  
Hameed Metghalchi ◽  
Yiannis A. Levendis ◽  
Kumaran Kannaiyan ◽  
...  
Keyword(s):  
High Speed ◽  
Pressure Rise ◽  
Gas Temperature ◽  
Cmos Camera ◽  
Primary Input ◽  
One Dimensional ◽  
Schlieren System ◽  
Co2 Concentrations ◽  
Constant Volume Chamber ◽  
Laminar Burning Speed

This experimental research examined the effect of CO2 as a diluent on the laminar burning speed of propane–air mixtures. Combustion took place at various CO2 concentrations (0–80%), different equivalence ratios (0.7<ϕ<1.2) and over a range of temperatures (298–420 K) and pressures (0.5–6.2 atm). The experiments were performed in a cylindrical constant volume chamber with a Z-shaped Schlieren system, coupled with a high-speed CMOS camera to capture the propagation of the flames at speeds up to 4000 frames per second. The flame stability of these mixtures at different pressures, equivalence ratios, and CO2 concentrations was also studied. Only laminar, spherical, and smooth flames were considered in measuring laminar burning speed. Pressure rise data as a function of time during the flame propagation were the primary input of the multishell thermodynamic model for measuring the laminar burning speed of propane-CO2-air mixtures. The laminar burning speed of such blends was observed to decrease with the addition of CO2 and to increase with the gas temperature. It was also noted that the laminar burning speed decreases with increasing pressure. The collected experimental data were compared with simulation data obtained via a steady one-dimensional (1D) laminar premixed flame code from Cantera, using a detailed H2/CO/C1–C4 kinetics model encompassing 111 species and 784 reactions.

One-Dimensional Consolidation Modelling for Unlayered Soil

2014 ◽  
Vol 580-583 ◽  
pp. 123-128
Author(s):  
Issam Hanafi ◽  
Fouad Dimane ◽  
Francisco Mata Cabrera ◽  
José Tejero Manzanares
Keyword(s):  
Numerical Solution ◽  
Pore Pressure ◽  
Effective Stress ◽  
Finite Strain ◽  
Total Stress ◽  
Linear Solution ◽  
One Dimensional ◽  
Soil Skeleton ◽  
Fluid Pore Pressure ◽  
Extra Stress

In this work, one-dimensional problem has a well-known linear solution and, thus, provides a simple verification of the consolidation capability using numerical solution. The coupling is approximated by the effective stress principle, which treats the saturated soil as a continuum, assuming that the total stress at each point is the sum of an effective stress carried by the soil skeleton and a pore pressure in the fluid permeating the soil. This fluid pore pressure can change with, and the gradient of the pressure through the soil that is not balanced by the weight of fluid between the points in question will cause the fluid to flow: the flow velocity is proportional to the pressure gradient in the fluid according to Darcy's law. A typical case is a consolidation problem. Here the addition of a load to a body of soil causes pore pressure to raise initially; then, as the soil skeleton takes up the extra stress, the pore pressures decay as the soil consolidates. The Terzaghi problem is the simplest example of such a process. For illustration purposes, the problem is treated with and without finite-strain effects. The numerical solution agrees reasonably well with the analytical solution, with some loss of accuracy at later times.

Sign in / Sign up

Export Citation Format

Share Document