PERMEABILITY MODELS FOR TWO-PHASE FLOW IN FRACTAL POROUS-FRACTURE MEDIA WITH THE TRANSFER OF FLUIDS FROM POROUS MATRIX TO FRACTURE

Fractals ◽  
2021 ◽  
Vol 29 (06) ◽  
pp. 2150148
Author(s):  
TONGJUN MIAO ◽  
AIMIN CHEN ◽  
YAN XU ◽  
SUJUN CHENG ◽  
LIWEI ZHANG ◽  
...  
Keyword(s):  
Fractal Dimension ◽  
Two Phase Flow ◽  
Structural Parameters ◽  
Porous Matrix ◽  
Fracture Aperture ◽  
Phase Flow ◽  
Relative Permeabilities ◽  
Two Phase ◽  
Dimension Formula ◽  
Phase Saturation

Study of transport mechanism of two-phase flow through porous-fracture media is of considerable importance to deeply understand geologic behaviors. In this work, to consider the transfer of fluids, the analytical models of dimensionless relative permeabilities for the wetting and non-wetting phases flow are proposed based on the fractal geometry theory for porous media. The proposed models are expressed as functions of micro-structural parameters of the porous matrix and fracture, such as the fractal dimension ([Formula: see text] for pore area, the fractal dimensions [Formula: see text] for wetting phase and for non-wetting phase, porosity ([Formula: see text], the total saturations ([Formula: see text], the porous matrix saturation ([Formula: see text] of the wetting and non-wetting phases, fractal dimension ([Formula: see text] for tortuosity of tortuous capillaries, as well as the ratio ([Formula: see text] of the maximum pore size in porous matrix to fracture aperture. The ratio ([Formula: see text] has a significant impact on the relative permeabilities and total saturations of wetting phases. The results reveal that the flow contribution of wetting phase from the porous matrix to both the seepage behavior of the fracture and total wetting phase saturation can be neglected as [Formula: see text]. The models may shed light on the fundamental mechanisms of the wetting and non-wetting phase flow in porous-fracture media with fluid transfer.

ANALYSIS OF FRACTIONAL FLOW FOR TRANSIENT TWO-PHASE FLOW IN FRACTAL POROUS MEDIUM

Fractals ◽  
2016 ◽  
Vol 24 (01) ◽  
pp. 1650013 ◽  
Author(s):  
TING Lu ◽  
YONGGANG DUAN ◽  
QUANTANG FANG ◽  
XIAOLU DAI ◽  
JINSUI WU
Keyword(s):  
Porous Medium ◽  
Fractal Dimension ◽  
Chemical Engineering ◽  
Two Phase Flow ◽  
Structural Parameters ◽  
Phase Flow ◽  
Fractional Flow ◽  
Two Phase ◽  
Fluid Properties ◽  
Fractal Characteristics

Prediction of fractional flow in fractal porous medium is important for reservoir engineering and chemical engineering as well as hydrology. A physical conceptual fractional flow model of transient two-phase flow is developed in fractal porous medium based on the fractal characteristics of pore-size distribution and on the approximation that porous medium consist of a bundle of tortuous capillaries. The analytical expression for fractional flow for wetting phase is presented, and the proposed expression is the function of structural parameters (such as tortuosity fractal dimension, pore fractal dimension, maximum and minimum diameters of capillaries) and fluid properties (such as contact angle, viscosity and interfacial tension) in fractal porous medium. The sensitive parameters that influence fractional flow and its derivative are formulated, and their impacts on fractional flow are discussed.

New Experimental Data and Analysis for Two-Phase Flow-Induced Vibration of Tube Bundles: Preliminary Results

2003 ◽  
Author(s):  
Deepanjan Mitra ◽  
Vijay K. Dhir ◽  
Ivan Catton
Keyword(s):  
Two Phase Flow ◽  
Structural Parameters ◽  
Cross Flow ◽  
Instability Criterion ◽  
Phase Flow ◽  
Flow Induced Vibration ◽  
Two Phase ◽  
Void Fractions ◽  
Comparison Of The Results ◽  
Square Array

In the past, fluid-elastic instability in two-phase flow has been largely investigated with air-water flow. In this work, new experiments are conducted in air-water cross-flow with a fully flexible 5 × 3 normal square array having pitch-to-diameter ratio of 1.4. The tubes have a diameter of 0.016 m and a length of 0.21 m. The vibrations are measured using strain gages installed on piano wires used to suspend the tubes. Experiments are carried out for void fractions from 0%–30%. A comparison of the results of the current tests with previous experiments conducted in air-water cross-flow shows that instability occurs earlier in a fully flexible array as compared to a flexible tube surrounded by rigid tubes in an array. An attempt is made to separate out the effects of structural parameters of three different experimental datasets by replotting the instability criterion by incorporating the instability constant K, in the reduced velocity parameter.

A FRACTAL PERMEABILITY MODEL FOR POROUS–FRACTURE MEDIA WITH THE TRANSFER OF FLUIDS FROM POROUS MATRIX TO FRACTURE

Fractals ◽  
2019 ◽  
Vol 27 (06) ◽  
pp. 1950121 ◽  
Author(s):  
TONGJUN MIAO ◽  
AIMIN CHEN ◽  
YAN XU ◽  
SUJUN CHENG ◽  
BOMING YU
Keyword(s):  
Fractal Dimension ◽  
Geothermal Energy ◽  
Theoretical Foundation ◽  
Flow Behavior ◽  
Porous Matrix ◽  
Fracture Aperture ◽  
Permeability Model ◽  
Microstructural Parameters ◽  
Dimension Formula ◽  
Proposed Model

The transfer of fluids from porous matrix to fracture is a key issue to accurately predict the fluid flow behavior in porous–fracture media. In this work, to take into account the transfer of fluids, the analytical model of dimensionless permeability is proposed based on the fractal geometry theory for porous media. The proposed model is expressed as a function of microstructural parameters of the porous matrix and fracture, such as the pore area fractal dimension [Formula: see text], fractal dimension [Formula: see text] for tortuosity of tortuous capillaries, the ratio [Formula: see text] of the maximum pore size in porous matrix to fracture aperture, as well as the ratio [Formula: see text] of the pressure difference along the fracture to that along the porous matrix layers. The model reveals that the ratios [Formula: see text] and [Formula: see text] have significant influences on the permeability contribution from the porous matrix to the seepage behavior of the fracture. While the contribution of porosity of leak-wall porous surface of the fracture to the permeability is less than 10%. The present results may provide an important theoretical foundation for exploration of petroleum, gas and geothermal energy extraction systems.

Pressure Drop Fluctuation and Flow Regime Identification for Air-Water Two-Phase Flow

2000 ◽  
Author(s):  
Bofeng Bai ◽  
Tiejun Wu ◽  
Liejin Guo ◽  
Xuejun Chen
Keyword(s):  
Fractal Dimension ◽  
Pressure Drop ◽  
Two Phase Flow ◽  
Pressure Fluctuations ◽  
Flow Regimes ◽  
Superficial Velocity ◽  
Phase Flow ◽  
Two Phase ◽  
Propagation Network ◽  
First Time

Abstract The fluctuating pressure drop for air-water two-phase flow was measured in the vertical upward section of U-type tube with 0.05m I.D. The feature of the fluctuations was extracted by means of statistical and chaotic theories. The influence of liquid superficial velocity on the features was also investigated. The results showed that the mean, root mean square, fractal dimension of pressure drop fluctuations is function of flow regimes. The fractal dimension can be larger than 1.5 in annular flow with great liquid superficial velocity which is reported for the first time. Furthermore, the present paper provided a feasible solution, which the gas-liquid two-phase flow regimes can be recognized automatically and objectively on basis of the combination of the Counter Propagation Network (CPN) and the FFT coefficients of the differential pressure fluctuations. The recognition possibility is determined by the clustering results of the Kohonen layer in the CPN. With the presented test cases, the possibility can be greater than 90 percent for different liquid phase velocity.

Pulsating localised fluid expulsions

2020 ◽  
Author(s):  
Ludovic Räss ◽  
Nina S.C. Simon ◽  
Yury Y. Podladchikov
Keyword(s):  
Gas Flow ◽  
Two Phase Flow ◽  
Porous Matrix ◽  
Pore Fluid ◽  
Three Dimensions ◽  
Model Parameters ◽  
Phase Flow ◽  
Two Phase ◽  
Natural Systems ◽  
Natural Outcome

<p>A wide variety of fluid-rich natural systems exhibit a distinct pulsating signature on geophysical measurements. Identifying the processes leading to these observed pulses are key to further understand important multi-scale and multi-physics valve-like dynamics in natural environments such as gas flow in volcanic systems, magma transport in the crust, tremors and slip or subsurface flow migration. These natural two-phase systems share common features as they can be described as viscously deforming saturated porous media. They exhibit a time-dependant deformation of their porous matrix, buoyant pore-fluid, an effective pressure dependant bulk viscosity and a nonlinear porosity-permeability relation.</p><p>We here investigate the role of coupled hydro-mechanical processes to trigger pulsating localised fluid expulsions. We show that the pulsating regime may be a natural outcome of the interactions between a viscously deforming porous matrix and a nonlinear pore-fluid flow. We rely on high-resolution direct numerical two-phase flow calculations in three dimensions to explore what parameters control the main characteristics of the pulsating signal. We are particularly interested in how amplitudes, wave lengths and frequencies of the signal relate to the input model parameters.</p><p>We show that repeated fluid pulses are a natural outcome of the coupled Stokes and Darcy equations within the nonlinear viscous two-phase flow regime. We discuss the relevance of our findings in light of the valve-like behaviour in a variety of natural fluid-rich environments. We propose to use the characteristic of the pulsating signal to gain further insight in the dynamics of complex natural systems.</p>

Sign in / Sign up

Export Citation Format

Share Document