scholarly journals Experimental observation of fluid flow channels in a single fracture

1998 ◽  
Vol 103 (B3) ◽  
pp. 5125-5132 ◽  
Author(s):  
Stephen Brown ◽  
Arvind Caprihan ◽  
Robert Hardy
Keyword(s):  
Fluid Flow ◽  
Experimental Observation ◽  
Single Fracture ◽  
Flow Channels

scholarly journals Analysis of Fracture Roughness Control on Permeability Using SfM and Fluid Flow Simulations: Implications for Carbonate Reservoir Characterization

Geofluids ◽  
2019 ◽  
Vol 2019 ◽  
pp. 1-19 ◽  
Author(s):  
Miller Zambrano ◽  
Alan D. Pitts ◽  
Ali Salama ◽  
Tiziano Volatili ◽  
Maurizio Giorgioni ◽  
...  
Keyword(s):  
Fluid Flow ◽  
Reservoir Characterization ◽  
Flow Simulation ◽  
Carbonate Reservoir ◽  
Single Fracture ◽  
Parallel Plates ◽  
Surface Mapping ◽  
Navier Stokes Equation ◽  
Hydraulic Aperture ◽  
Fracture Modeling

Fluid flow through a single fracture is traditionally described by the cubic law, which is derived from the Navier-Stokes equation for the flow of an incompressible fluid between two smooth-parallel plates. Thus, the permeability of a single fracture depends only on the so-called hydraulic aperture which differs from the mechanical aperture (separation between the two fracture wall surfaces). This difference is mainly related to the roughness of the fracture walls, which has been evaluated in previous works by including a friction factor in the permeability equation or directly deriving the hydraulic aperture. However, these methodologies may lack adequate precision to provide valid results. This work presents a complete protocol for fracture surface mapping, roughness evaluation, fracture modeling, fluid flow simulation, and permeability estimation of individual fracture (open or sheared joint/pressure solution seam). The methodology includes laboratory-based high-resolution structure from motion (SfM) photogrammetry of fracture surfaces, power spectral density (PSD) surface evaluation, synthetic fracture modeling, and fluid flow simulation using the Lattice-Boltzmann method. This work evaluates the respective controls on permeability exerted by the fracture displacement (perpendicular and parallel to the fracture walls), surface roughness, and surface pair mismatch. The results may contribute to defining a more accurate equation of hydraulic aperture and permeability of single fractures, which represents a pillar for the modeling and upscaling of the hydraulic properties of a geofluid reservoir.

THEORETICAL ANALYSES FOR LASER MACHINING MICROCHANNELS AND DEMONSTRATION OF THEIR USES IN MANUFACTURE OF A MICROFLUIDIC OPTICAL SWITCH

2006 ◽  
Vol 13 (06) ◽  
pp. 795-802 ◽  
Author(s):  
DANIEL LIM ◽  
ERNA GONDO SANTOSO ◽  
KIM MING TEH ◽  
STEPHEN WAN ◽  
H. Y. ZHENG
Keyword(s):  
Fluid Flow ◽  
Optical Switch ◽  
Low Cost ◽  
Microfluidic Devices ◽  
Cost Effective ◽  
Laser Machining ◽  
Machining Parameters ◽  
Flow Channels ◽  
Cost Effective Method ◽  
Theoretical Analyses

Silicon has been widely used to fabricate microfluidic devices due to the dominance of silicon microfabrication technologies available. In this paper, theoretical analyses are carried out to suggest suitable laser machining parameters to achieve required channel geometries. Based on the analyses, a low-power CO 2 laser was employed to create microchannels in Acrylic substrate for the use of manufacturing an optical bubble switch. The developed equations are found useful for selecting appropriate machining parameters. The ability to use a low-cost CO 2 laser to fabricate microchannels provides an alternative and cost-effective method for prototyping fluid flow channels, chambers and cavities in microfluidic lab chips.

scholarly journals SIZE EFFECT ON THE PERMEABILITY AND SHEAR INDUCED FLOW ANISOTROPY OF FRACTAL ROCK FRACTURES

Fractals ◽  
2018 ◽  
Vol 26 (02) ◽  
pp. 1840001 ◽  
Author(s):  
NA HUANG ◽  
YUJING JIANG ◽  
RICHENG LIU ◽  
YUXUAN XIA
Keyword(s):  
Fluid Flow ◽  
Stable State ◽  
Simulation Method ◽  
Shear Direction ◽  
Direction Parallel ◽  
Flow Channels ◽  
Fracture Size ◽  
Flow Through ◽  
Model Size ◽  
Induced Flow

The effect of model size on fluid flow through fractal rough fractures under shearing is investigated using a numerical simulation method. The shear behavior of rough fractures with self-affine properties was described using the analytical model, and the aperture fields with sizes varying from 25 to 200[Formula: see text]mm were extracted under shear displacements up to 20[Formula: see text]mm. Fluid flow through fractures in the directions both parallel and perpendicular to the shear directions was simulated by solving the Reynolds equation using a finite element code. The results show that fluid flow tends to converge into a few main flow channels as shear displacement increases, while the shapes of flow channels change significantly as the fracture size increases. As the model size increases, the permeability in the directions both parallel and perpendicular to the shear direction changes significantly first and then tends to move to a stable state. The size effects on the permeability in the direction parallel to the shear direction are more obvious than that in the direction perpendicular to the shear direction, due to the formation of contact ridges and connected channels perpendicular to the shear direction. The variances of the ratio between permeability in both directions become smaller as the model size increases and then this ratio tends to maintain constant after a certain size, with the value mainly ranging from 1.0 to 3.0.

Fluid Flow and Solute Transport though a Fracture Intersecting a Canister - Analytical Solutions for the Parallel Plate Model

2003 ◽  
Vol 807 ◽  
Author(s):  
L. Liu ◽  
I. Neretnieks
Keyword(s):  
Fluid Flow ◽  
Solute Transport ◽  
Flow Rate ◽  
Analytical Solutions ◽  
Parallel Plate ◽  
Spent Nuclear Fuel ◽  
Volumetric Flow Rate ◽  
Single Fracture ◽  
Plate Model ◽  
Specific Scenario

ABSTRACTIn this paper, we are concerned with a specific scenario where a large fracture intersects, at its center, a canister that contains spent nuclear fuel. Assuming that a nuclide is free to release from the canister into groundwater flowing through the fracture, a detailed formulation of the volumetric flow rate and the equivalent flow rate are made for the parallel plate model. The formulas proposed have been validated by numerical examinations; they are not only simple in forms but also universal in applications where the flow may be taken normal, inclined or parallel to the axis of the canister. Of great importance, they provide a convenient way to predict the average properties of fluid flow and solute transport through a single fracture with spatially variable apertures.

Smart proppant concept for monitoring hydraulic fractures

2011 ◽  
Vol 51 (1) ◽  
pp. 527 ◽  
Author(s):  
Arcady Dyskin ◽  
Elena Pasternak ◽  
Greg Sevel ◽  
Rachel Cardell-Oliver
Keyword(s):  
Fluid Flow ◽  
Random Distribution ◽  
Energy Content ◽  
Low Frequency ◽  
Hydraulic Fractures ◽  
Low Frequencies ◽  
Flow Channels ◽  
Monitoring Technique ◽  
Smart Actuators ◽  
Subsurface Fluid

Monitoring subsurface fluid flow is important in mapping hydraulic fractures and identifying flow channels in reservoirs. A new monitoring technique is proposed whereby fluid is injected with smart actuators capable of organising their pulses to create a combined output with a higher proportion of energy at low frequencies. Ideally, the best results occur when actuators are sequentialised so each next actuator emits its pulse immediately after the previous actuator. The low frequency energy content achieved using sequentialisation is much higher than that achieved with a random distribution of pulses, but is relatively insensitive to practical errors in scheduling and irregular attenuations of amplitudes. Simulations show that actuators can be self-organised into a sequential state by monitoring other actuators’ pulses using the algorithm presented in this paper.

A Cut-Cell Polyhedral Finite Element Model for Coupled Fluid Flow and Mechanics in Fractured Reservoirs

2021 ◽  
Author(s):  
Igor Shovkun ◽  
Hamdi A. Tchelepi
Keyword(s):  
Finite Element ◽  
Fluid Flow ◽  
Fractured Reservoirs ◽  
Computational Cost ◽  
Mechanical Deformation ◽  
Naturally Fractured Reservoirs ◽  
Fracture Model ◽  
Single Fracture ◽  
Cut Cell ◽  
Flux Approximation

Abstract Mechanical deformation induced by injection and withdrawal of fluids from the subsurface can significantly alter the flow paths in naturally fractured reservoirs. Modeling coupled fluid-flow and mechanical deformation in fractured reservoirs relies on either sophisticated gridding techniques, or enhancing the variables (degrees-of-freedom) that represent the physics in order to describe the behavior of fractured formation accurately. The objective of this study is to develop a spatial discretization scheme that cuts the "matrix" grid with fracture planes and utilizes traditional formulations for fluid flow and geomechanics. The flow model uses the standard low-order finite-volume method with the Compartmental Embedded fracture Model (cEDFM). Due to the presence of non-standard polyhedra in the grid after cutting/splitting, we utilize numerical harmonic shape functions within a Polyhedral finite-element (PFE) formulation for mechanical deformation. In order to enforce fracture-contact constraints, we use a penalty approach. We provide a series of comparisons between the approach that uses conforming Unstructured grids and a Discrete Fracture Model (Unstructured DFM) with the new cut-cell PFE formulation. The manuscript analyzes the convergence of both methods for linear elastic, single-fracture slip, and Mandel’s problems with tetrahedral, Cartesian, and PEBI-grids. Finally, the paper presents a fully-coupled 3D simulation with multiple inclined intersecting faults activated in shear by fluid injection, which caused an increase in effective reservoir permeability. Our approach allows for great reduction in the complexity of the (gridded) model construction while retaining the solution accuracy together with great saving in the computational cost compared with UDFM. The flexibility of our model with respect to the types of grid polyhedra allows us to eliminate mesh artifacts in the solution of the transport equations typically observed when using tetrahedral grids and two-point flux approximation.

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