scholarly journals Numerical Simulation on Non-Darcy Flow in a Single Rock Fracture Domain Inverted by Digital Images

Geofluids ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-13 ◽  
Author(s):  
Jianli Shao ◽  
Qi Zhang ◽  
Wenbin Sun ◽  
Zaiyong Wang ◽  
Xianxiang Zhu
Keyword(s):  
Numerical Simulation ◽  
Fluid Flow ◽  
Digital Images ◽  
Rock Fracture ◽  
Inertial Force ◽  
Darcy Flow ◽  
Fracture Aperture ◽  
Rock Fractures ◽  
Single Rock Fracture ◽  
Fracture Domain

The influence of rock seepage must be considered in geotechnical engineering, and understanding the fluid flow in rock fractures is of great concern in the seepage effect investigation. This study is aimed at developing a model for inversion of rock fracture domains based on digital images and further study of non-Darcy flow. The visualization model of single rock fracture domain is realized by digital images, which is further used in flow numerical simulation. We further discuss the influence of fracture domain geometry on non-Darcy flow. The results show that it is feasible to study non-Darcy flow in rock fracture domains by inversion based on digital images. In addition, as the joint roughness coefficient (JRC) increases or the fracture aperture decreases, distortion of the fluid flow path increases, and the pressure gradient loss caused by the inertial force increases. Both coefficients of the Forchheimer equation decrease with increasing fracture aperture and increase with increasing JRC. Meanwhile, the critical Reynolds number tends to decrease when JRC increases or the fracture aperture decreases, indicating that the fluid tends to non-Darcy flow. This work provides a reference for the study of non-Darcy flow through rock fractures.

Coupled hydromechanical modeling of rock fractures under normal stress

2004 ◽  
Vol 41 (4) ◽  
pp. 686-697 ◽  
Author(s):  
M Bart ◽  
J F Shao ◽  
D Lydzba ◽  
M Haji-Sotoudeh
Keyword(s):  
Experimental Data ◽  
Normal Stress ◽  
Rock Fracture ◽  
Fluid Pressure ◽  
Fracture Aperture ◽  
Rock Fractures ◽  
Compression Tests ◽  
Void Space ◽  
Progressive Fracture ◽  
Single Rock Fracture

In this paper, a nonlinear poromechanical model is developed for a single rock fracture under normal stress. The fracture is represented by a set of voids, and the progressive fracture displacement is considered as a modification process of void space. Based on experimental data obtained from three representative rock fractures, the constitutive model is formulated through an extension of Biot poroelasticity theory to a saturated fracture. A generalized poroelastic coupling coefficient is introduced to describe the interaction between pore fluid pressure and fracture deformation. This coefficient is expressed as a function of fracture aperture. Five parameters involved in the model have been determined from mechanical and poromechanical compression tests. The validity of the model is checked on fluid flow tests under different normal stresses. Comparisons between numerical simulations and experimental data are provided.Key words: hydromechanical coupling, interfaces, joints, poroelasticity, rock mechanics, fractures.

scholarly journals Numerical Modeling of Fluid Flow in Single Rock Fracture during Shear with Special Algorism for Contact Areas

2008 ◽  
Vol 124 (2) ◽  
pp. 129-136 ◽  
Author(s):  
Yujing JIANG ◽  
Tomofumi KOYAMA ◽  
Bo LI ◽  
Yusuke TASAKU ◽  
Ryousuke SAHO ◽  
...  
Keyword(s):  
Numerical Modeling ◽  
Fluid Flow ◽  
Rock Fracture ◽  
Contact Areas ◽  
Single Rock Fracture

Investigation of Proppant Distributions in Rock Fractures With Applications to Hydraulic Fracturing

2021 ◽  
Author(s):  
Amir A. Mofakham ◽  
Farid Rousta ◽  
Dustin M. Crandall ◽  
Goodarz Ahmadi
Keyword(s):  
Fluid Flow ◽  
Hydraulic Fracturing ◽  
Oil And Gas ◽  
Fluid Dynamic ◽  
Rock Fracture ◽  
Experimental Investigations ◽  
Rock Fractures ◽  
Fracture Geometry ◽  
Injection Process ◽  
Fracking Fluid

Abstract Hydraulic fracturing or fracking is a procedure used extensively by oil and gas companies to extract natural gas or petroleum from unconventional sources. During this process, a pressurized liquid is injected into wellbores to generate fractures in rock formations to create more permeable pathways in low permeability rocks that hold the oil. To keep the rock fractures open after removing the high pressure, proppant, which typically are sands with different shapes and sizes, are injected simultaneously with the fracking fluid to spread them throughout rock fractures. The extraction productivity from shale reservoirs is significantly affected by the performance and quality of the proppant injection process. Since these processes occur under the ground and in the rock fractures, using experimental investigations to examine the process is challenging, if not impossible. Therefore, employing numerical tools for analyzing the process could provide significant insights leading to the fracking process improvement. Accordingly, in this investigation, a 4-way coupled Computational Fluid Dynamic and Discrete Element Method (CFD-DEM) code was used to simulate proppant transport into a numerically generated realistic rock fracture geometry. The simulations were carried out for a sufficiently long period to reach the fractures’ steady coverage by proppant. The proppant fracture coverage is a distinguishing factor that can be used to assess the proppant injection process quality. A series of simulations with different proppant sizes as well as various fracking fluid flow rates, were performed. The corresponding estimated fracture coverages for different cases were compared. The importance of proppant size as well as the fluid flow rate on the efficiency of the proppant injection process, were evaluated and discussed.

Numerical Simulation of Solute Transport Instantaneously Injected in a Single Rock Fracture System: Inclusion of a Nonlinear Sorption Term

1994 ◽  
Vol 353 ◽  
Author(s):  
Yoko Fujikawa ◽  
M. Fukui
Keyword(s):  
Numerical Simulation ◽  
Solute Transport ◽  
Nonlinear Term ◽  
Transport Model ◽  
Rock Fracture ◽  
Porous Matrix ◽  
Nonlinear Sorption ◽  
The Laplace Transform ◽  
Single Rock Fracture ◽  
System Inclusion

AbstractThe effect of nonlinear Freundlich sorption isotherm on the transport of sorptive solute in a system of fracture and porous matrix was investigated through numerical simulation. To solve a set of partial differential equations of solute transport with nonlinear term, use of the Laplace transform Galerkin (LTG) technique was investigated. It was shown that the LTG method could be applied successfully to solve quasi-linearized transport equation. Sensitivity analysis showed that nonlinear sorption in porous matrix with order less than 1 increased the skewness of the breakthrough curve. The fitting of experimental effluent data using a transport model with nonlinear isotherms was also conducted.

Research Advance in Fluid Flow through a Single Rock Fracture

2012 ◽  
Vol 204-208 ◽  
pp. 628-634
Author(s):  
Bao Hua Guo ◽  
Cai Xia Tian
Keyword(s):  
Fluid Flow ◽  
Fractured Rock ◽  
Rock Fracture ◽  
Research Work ◽  
Engineering Practice ◽  
Flow Through ◽  
Research Advance ◽  
Single Rock Fracture ◽  
Fractured Rock Masses ◽  
Channeling Flow

Flow properties through a single rock fracture are the foundation of researching fluid flow in fractured rock masses. Many researchers at home and abroad are engaging in this subject for the urgent need of engineering practice. This article mainly introduces concepts of roughness, aperture, tortuosity, channeling flow, and influencing factors of stress, temperature, anisotropic, inlet head, scale effect, solution etc. Finally, some research work should be done in future are given.

scholarly journals Experimental Study and Numerical Simulation on Fluid Flow Mechanism through Rock Fracture

2011 ◽  
Vol 127 (3) ◽  
pp. 145-150
Author(s):  
Yujing JIANG ◽  
Bo LI ◽  
Xiangbin XIONG ◽  
Tomofumi KOYAMA
Keyword(s):  
Numerical Simulation ◽  
Experimental Study ◽  
Fluid Flow ◽  
Rock Fracture ◽  
Flow Mechanism

Evaluation Of Fluid Flow Field In Single Rock Fracture During Frictional Sliding

2008 ◽  
Author(s):  
K. Nemoto ◽  
N. Watanabe ◽  
N. Tsuchiya ◽  
Kazuyuki Tohji ◽  
Noriyoshi Tsuchiya ◽  
...  
Keyword(s):  
Fluid Flow ◽  
Flow Field ◽  
Rock Fracture ◽  
Frictional Sliding ◽  
Single Rock Fracture

scholarly journals Evaluation of equivalent hydraulic aperture (EHA) for rough rock fractures

2019 ◽  
Vol 56 (10) ◽  
pp. 1486-1501 ◽  
Author(s):  
Fei Xiao ◽  
Zhiye Zhao
Keyword(s):  
Fluid Flow ◽  
Rock Fracture ◽  
Fluid Velocity ◽  
Surrogate Models ◽  
Rock Fractures ◽  
Parallel Plates ◽  
Characteristic Parameters ◽  
Fracture Roughness ◽  
Hydraulic Aperture ◽  
The Impact

Most existing models for fluid transportation within a single rock fracture tend to use a channel with two smooth parallel plates, whereas real fracture surfaces are usually rough and tortuous, which can produce a flow field significantly different from the smooth plate model. For fluid flow in a rough fracture, there are surface concave areas (SCA), where the fluid velocity is extremely low, contributing little to the fluid transportation. It is of great significance to quantitatively evaluate the impact of rough surfaces on fluid flow. Therefore, a numerical model for simulating Newtonian fluid through rough fractures is proposed, where synthetic surfaces are generated according to statistical analysis of natural rock fractures and can be quantified by several characteristic parameters. Equivalent hydraulic aperture (EHA) is proposed as one quantitative indicator for evaluating the impact of fracture roughness. Systematic studies were conducted for evaluating EHAs of rough fractures, which, combined with characteristic parameters of fractures, are used to build surrogate models for EHA prediction. It is found that the EHA is directly correlated with the fracture roughness, the mean mechanical aperture, and the standard deviation of aperture distribution. The developed surrogate models were verified to have a high accuracy for EHA prediction.

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