The diffusion mechanism of slurry in fractured rock is affected by geological environment and slurry performance, which should be revealed and characterized better. Browse these subsurface flow module updates in more detail below. However, most numerical studies on coupled flow and heat transfer are still based on the darcy flow hypothesis, and only a few studies on rough single fracture seepage and heat transfer tests mentioned the nonlinear flow slightly huang et al. How to model fracture flow in stress field in comsol. The interaction of hydro fractures with natural fractures expanded the fluid flow network and stimulated the volumetric strain of the srv as shown in pore pressure contours in fig. Finite element simulation of fluid flow in fractured rock. It shows how to use experimental data interpolated to a function used in the equation. Modeling of flow characteristics in 3d rough rock fracture. A computational method of productivity forecast of a. The discrete fracture network is established by the comsol multiphysics 5. Based on the twophase flow diffusion theory, a slurry diffusion model considering flowing water condition was established for a. Cleats are the systematic fractures in coal that are equivalent to joints in other sedimentary rocks10,11. Small scale yielding model for fracture mechanics comsol.
The fracture flow is added to a 2d surface in the 3d domain. Sep 01, 2015 based on various rock fracture surface roughness values, a set of single fracture numerical models were produced using the weierstrassmandelbrot functions to test the seepage flow performance. The discrete fracture network dfn form part of a regional characterization of the host. Model mass, momentum, and energy transport in porous.
Subsurface flow in saturated and variably saturated porous media. This could happen during a thermal recovery process. The foam model in the simulator was used to apply the mobility reduction. The following form of darcys law is solved in the fracture pipe. In this study, we focused on determining the effect of several operational parameters on co 2 foam behavior to control fast co 2 flow through fractures and to improve oil flow in a rock. Fractures within a porous media effect the flow properties through the porous matrix. I want to know the threshold value of that pressure from top which allows flow of fluid in fracture. Understanding the hydraulic response of fractured rock masses with respect to. Six single fractures, with various surface roughnesses characterized by the fractal dimension, were built using comsol multiphysics software. Analysis of bingham fluid radial flow in smooth fractures. Oct 01, 2020 an empirical model was developed to describe the heat transfer coefficient in a 3d rock fracture with heterogeneous apertures. This tutorial model demonstrates the capability of the comsol multiphysics software for estimating the permeability of a porous material by creating a detailed fluid flow model in a small unit cell. Modeling thermal breakthrough in fractured geothermal. The fracture flow interface was used along with darcys law due.
The fracture in this case the piping channel is represented as a 2d internal or external boundary rather than a 3d domain or a 1d boundary rather than a 2d domain, in twodimensional modelling. Groundwater flow in the fractured system surrounding. In the other setup the flow field is sandwiched between two impermeable strata. In this paper, the numerical modelling software comsol is used to. The change will be more obvious if the stresses caused by a combination of structural, flow, and thermal loads yield the rock and create discontinuities, fractures or abnormal porosities.
For nuclear waste disposal, for the enhancement of hydrocarbon recovery from a field, or the development of an enhanced geothermal system egs, it is fundamental to constrain the fractures and the fracture network. Download product updates download evaluation license restricted to customers with active subscription. Fully coupled hydromechanical modeling of hydraulic. Mathematical modeling of methane in matrix using comsol. Numerical modeling of thermal breakthrough induced by geothermal. In order to simulate hm behavior of a shaft seal using comsol, the following challenges must be solved. Heat transfer in a 3d rough rock fracture with heterogeneous.
The subsurface flow module is for engineers and scientists who want to simulate fluid flow below ground or in other porous media and also connect this flow with other phenomena, such as poroelasticity, heat transfer, chemistry, and electromagnetic fields. See the model rock fracture flow in the comsol multiphysics model library for an example using data interpolation. Effects of nondarcy flow on heatflow coupling process in. Grouting is always used in mine water plugging, reinforcement, and other disaster prevention projects. Matrix rock hot rock fracture asperity a b figure 1. The numerical results also reveal that the pressure gradient through a rock fracture is nonlinear and depends on the fracture. In order to understand the complex phenomena associated with induced seismic activity, the combination of reservoir fluid flow with. I am new to comsol and i want to model fluid flow in stress field. Chapter 11 3, point 3 is for example the withdrawal of groundwater or.
The numerical results also reveal that the pressure gradient through a rock fracture is nonlinear and depends on the fracture profile. A fracture flow permeability and stress dependency. Modeling fracture flow in stress field in comsol physics. In this set of eight tutorial models and associated documentation, you can investigate the resistive, capacitive, inductive, and thermal properties of a standard threecore leadsheathed xlpe hvac submarine cable with twisted magnetic armor 500 mm2, 220 kv. The acoustics module users guide comsol multiphysics. Effect of shear displacement on the directivity of permeability in 3d. Fluid flow through the fracture is simulated using the comsol multiphysics. Numerical simulations of seepage flow in rough single rock. As starting point i want a simple 2d box having a fracture from right to left while pressure gradient vertically. Gemex, egs, fluid, flow, fracture, stress field, dfm, fem. Aug 23, 2019 the use of the subsurface and the exploitation of subsurface resources require prior knowledge of fluid flow through fracture networks. The knowledge of fluid flow through rock fractures is directly related to hydrocarbon migration, waste disposal, and carbon dioxide sequestration. Using comsol multiphysics we examine two constellations of a fracture in a porous medium. Access to the comsol exchange online model sharing.
The average flow velocity is calculated by equation 2 as the boundary condition of the fracture. Simulations are computed in 2d, using comsol multiphysics finite ele. Grouting mechanism in waterbearing fractured rock based on. For users of the subsurface flow module, comsol multiphysics version 5. The fracture flow interface solves for pressure on internal 2d boundaries within a 3d matrix, based on a userdefined aperture. An integrated approach to simulate fracture permeability and. The fracture network generated is characterized by heterogeneous hydraulic and transport properties such as. An integrated approach to simulate fracture permeability. Modeling heat and fluid flow in discrete fracture networks rero doc. A potential flow model of fluid flow in a rock fracture uses the socalled reynolds equation.
Grouting mechanism in waterbearing fractured rock based. Analysis of oil flow in fractured oil reservoir using. Fracture flow, darcy law and free and porous media flow physics interfaces of comsol subsurface flow module have been used in simulating a fractured core flooding test data to achieve a better understanding of fracture matrix flow partitioning. Brinkman equations to represent flow in porous media that quickens toward a. Numerical simulation of laminar flow through a pipe using. Coupled flow heat transfer modeling in rock fractures2. Rock fracture roughness and tortuosity caused by contact asperities produce extra resistance for fluid flow in comparison with the channel consisting of two smooth parallel plates.
Applicability of the fracture flow interface to the. The present study is relevant to the operation period of fracture geothermal reservoirs when fluid flow and heat transport are under a steady state. Feb 01, 2021 fractures are intrinsically heterogeneous, and the complicated geometries void spaces and asperity contacts existing nonuniformly between two contacting fracture surfaces are easily altered thermally, geochemically and deformed under applied stress, which complicates the flow process and significantly affect fluid flow through rock fractures pyraknolte and nolte 2016 fig. According to the results, the comsol numerical model can simulate the flow characteristics through the rock fracture with more than 90% accuracy compared to the experimental data. Injectioninduced slip heterogeneity on faults in shale. Chemical reaction engineering module comsol multiphysics.
Modeling fracture flow in stress field in comsol physics forums. In one setup the fracture is located in a free in principle unbounded flow field within the porous medium. The computed pressure is automatically coupled to the physics describing the porous media flow in the surrounding matrix, an approximation that saves time and computational. Fully coupled thermohydromechanical modeling by comsol. The computed pressure is automatically coupled to the physics describing the porous media flow in the surrounding matrix, an approximation that saves time and computational resources involved in meshing the fractures. First, the shaftsealing components are unsaturated at installation, so coupling the unsaturated flow formulation with structural analysis is required.
The principal natural fractures permeability is the pathways for the flow of gas and water through the cleat systems. A discrete fracture network dfn based on geological data 1 was imported from file to comsol multiphysics using a comsol utility app. Presented at the comsol conference 2010 china i modeling two. The computed permeability can be used in homogenized models using darcys law or the brinkman equations. With this concept, we proposed a novel model named discrete fracture vug network model dfvn. On the opposite extreme, limit load analysis is used to determine failure when fracture toughness is high and failure is governed by the plastic flow characteristics of the material. Therefore, it is appropriate to represent the host rock considering only the fracture network. Horizontal distance m vug rock matrix fracture vertical distance m dfvn model is an extension of classic discrete fracture. In this study, we focused on determining the effect of several operational parameters on co 2 foam behavior to control fast co 2 flow through fractures and to improve oil flow in a rock matrix by.
Jul 11, 2009 fluid dynamics models are used by the petroleum industry to model single andor multiphase flow within fractured rock formations, in order to facilitate extraction of fluids such as oil and natural gas, and in other areas of engineering to study groundwater flow, as well as to estimate contaminant seepage and transport. This model is relevant for those interested in subsurface flow and transport of contaminants, including radioactive materials. Presented at the comsol conference 2010 china i modeling. Comsol multiphysics ability to accurately predict cleavage fracture in brittle materials where fracture toughness is low and ssy conditions are met. When comsol multiphysics evaluates the function, the software performs a structured interpolation from the data values on the grid to the coordinates where the function is evaluated. Comsol, the comsol logo, comsol multiphysics, comsol desktop, comsol server, and. The module also treats the transport of chemicals and their reactions with the. It has a number of physics interfaces to model chemical reaction kinetics, mass transport in dilute. The fracture permeability is estimated by investigating the 2 di mensional. It is well known that the complicated channeling of fluid flow and heat transfer is. A fracture flow permeability and stress dependency simulation. The next example adds the navierstokes equations in the well to. At high rates, the thermal front in the fracture moves at a higher rate in the fracture than in the rock matrix. The simulation results and analysis will be shown in section 3 and section 4.
The novelty of this study was to show the poroelastic response of the shale rock formation with different hydro fracture s orientation with respect to wellbore. Learn more about these subsurface flow updates below. Most groundwater is channeled through these fractures. Correlation of joint roughness coefficient and permeability of a fracture. Groundwater flow paths in fractured crystalline bedrock diva. Pdf a model for water flow through rock fractures based on. Simulation performed with ifemopenfrac, using quadratic isogeometric analysis. Numerical analysis of fluid flow in single rock fracture. Mar 15, 2017 i am new to comsol and i want to model fluid flow in stress field. Coupled processes and comsol multiphysics flow in porous medium darcys law continuum equation fracture permeability according to the cubic law poisseuille flow porosity change due to volumetric strain viscosity change due to temperature mechanics rock matrix. Introduction to fracture mechanics david roylance department of materials science and engineering massachusetts institute of technology cambridge, ma 029.
939 205 197 1277 947 1199 1229 994 408 832 1183 256 726 211 825 1388 1385 1064 1430 286 1263 404 1035 968 932 1087 1092 1203 740 1261 104 826 758 305 419 1412