A FAST CALCULATION METHOD FOR ESTIMATING THE REPRESENTATIVE ELEMENTARY VOLUME OF A THREE-DIMENSIONAL FRACTURE NETWORK

2016 ◽  
Vol 7 (2) ◽  
pp. 99-106 ◽  
Author(s):  
Na Huang ◽  
Yujing Jiang ◽  
Richeng Liu ◽  
Bo Li
Keyword(s):  
Calculation Method ◽  
Three Dimensional ◽  
Fracture Network ◽  
Representative Elementary Volume ◽  
Elementary Volume ◽  
Fast Calculation

Fast calculation method for computer-generated cylindrical holograms based on the three-dimensional Fourier spectrum

2013 ◽  
Vol 38 (23) ◽  
pp. 5172 ◽  
Author(s):  
Yusuke Sando ◽  
Daisuke Barada ◽  
Boaz Jessie Jackin ◽  
Toyohiko Yatagai
Keyword(s):  
Calculation Method ◽  
Fourier Spectrum ◽  
Three Dimensional ◽  
Fast Calculation

scholarly journals REPRESENTATIVE ELEMENTARY VOLUME OF A REGION OF INTEREST OF A HETEROGENEOUS CARBONATE ROCK USING X-RAY COMPUTED MICROTOMOGRAPHY AND NUMERICAL SIMULATION

2018 ◽  
Vol 36 (4) ◽  
pp. 1 ◽  
Author(s):  
William Godoy de Azevedo Lopes de Silva ◽  
Edmilson Helton Rios ◽  
Fernanda Oliveira Hoerlle ◽  
Elizabeth May Braga Dulley Pontedeiro ◽  
Leonardo Fonseca Borghi de Almeida ◽  
...  
Keyword(s):  
Fluid Flow ◽  
Numerical Simulations ◽  
Three Dimensional ◽  
Region Of Interest ◽  
Representative Elementary Volume ◽  
Elementary Volume ◽  
Pore System ◽  
X Ray ◽  
Reservoir Evaluation ◽  
Computed Microtomography

ABSTRACT. Characterization of carbonate rocks presents several challenges regarding the acquisition of petrophysical parameters and the understanding of fluid-flow dynamics in their pore system. To face these challenges, techniques such as X-ray microtomography, three-dimensional digital model reconstruction and fluid-flow numerical simulations have been continuously developed and improved. This study analyzes the representative elementary volume (REV) of a region of interest (ROI) of a highly heterogeneous stromatolite sample. Porosity and permeability are estimated for different subvolumes of the sample based on digital petrophysics. All necessary steps for reconstruction and segmentation of the complex pore system of the sample, as well as numerical simulations of fluid flow, are presented and discussed. The workflow is promising for reservoir evaluation because it can be applied to any type of carbonate rock.Keywords: Stromatolite, mCT, segmentation, REV, digital petrophysicsRESUMO. A caracterização de rochas carbonáticas apresenta diversos desafios quanto à determinação de seus parâmetros petrofísicos e o entendimento da dinâmica de escoamento de fluidos em seus sistemas porosos. Técnicas como a microtomografia de raios X, a modelagem digital tridimensional e a simulação numérica do escoamento de fluidos têm sido continuamente desenvolvidas e aprimoradas para superar esses desafios. Este estudo analisa o volume elementar representativo (REV) em uma região de interesse (ROI) de uma amostra de estromatólito altamente heterogênea. A porosidade e a permeabilidade são estimadas em diferentes subvolumes da amostra através da petrofísica digital. São apresentadas e discutidas todas as etapas necessárias para a reconstrução e segmentação do sistema poroso e a simulação numérica do escoamento de fluidos. A metodologia é promissora para avalição de reservatórios visto que o fluxo de trabalho pode ser aplicado a qualquer tipo de rocha carbonática.Palavras-chave: Estromatólitos, mCT, segmentação, REV, petrofísica digital

INVESTIGATIONS ON REPRESENTATIVE ELEMENTARY VOLUME AND DIRECTIONAL PERMEABILITY OF FRACTAL-BASED FRACTURE NETWORKS USING POLYGON SUB-MODELS

Fractals ◽  
2020 ◽  
Vol 28 (05) ◽  
pp. 2050085
Author(s):  
JING ZHANG ◽  
RICHENG LIU ◽  
LIYUAN YU ◽  
HONGWEN JING ◽  
QIAN YIN
Keyword(s):  
Preferential Flow ◽  
Numerical Study ◽  
Length Distribution ◽  
Fracture Network ◽  
Representative Elementary Volume ◽  
Polar Coordinate System ◽  
Elementary Volume ◽  
Fracture Length ◽  
Directional Permeability ◽  
Dfn Model

Since the directional permeability of fractured rock masses is significantly dependent on the geometric properties of fractures, in this work, a numerical study was performed to analyze the relationships between them, in which fracture length follows a fractal distribution. A method to estimate the representative elementary volume (REV) size and directional permeability ([Formula: see text] by extracting regular polygon sub-models with different orientation angles ([Formula: see text] and side lengths ([Formula: see text] from an original discrete fracture network (DFN) model was developed. The results show that the fracture number has a power law relationship with the fracture length and the evolution of the exponent agrees well with that reported in previous studies, which confirms the reliability of the proposed fractal length distribution and stochastically generated DFN models. The [Formula: see text] varies significantly due to the influence of random numbers utilized to generate fracture location, orientation and length when [Formula: see text] is small. When [Formula: see text] exceeds some certain values, [Formula: see text] holds a constant value despite of [Formula: see text], in which the model scale is regarded as the REV size and the corresponding area of DFN model is represented by [Formula: see text] (in 2D). The directional permeability contours for DFN models plotted in the polar coordinate system approximate to circles when the model size is greater than the REV size. The [Formula: see text] decreases with the increment of fractal dimension of fracture length distribution ([Formula: see text]. However, the decreasing rate of [Formula: see text] (79.5%) when [Formula: see text] increases from 1.4 to 1.5 changes more significantly than that (34.8%) when [Formula: see text] increases from 1.5 to 1.6 for regular hexagon sub-models. This indicates that the small non-persistent fractures dominate the preferential flow paths; thereafter, the flow rate distribution becomes more homogeneous when [Formula: see text] exceeds a certain value (i.e. 1.5). A larger [Formula: see text] results in a denser fracture network and a stronger conductivity.

scholarly journals Determination of Fractured Rock’s Representative Elementary Volume by a Numerical Simulation Method

2019 ◽  
Vol 9 (4) ◽  
pp. 4448-4451
Author(s):  
H. Gasmi ◽  
M. Touahmia ◽  
A. Torchani ◽  
E. Hamdi ◽  
A. Boudjemline
Keyword(s):  
Wave Propagation ◽  
Simulation Method ◽  
Fracture Network ◽  
Homogenization Method ◽  
Representative Elementary Volume ◽  
Elementary Volume ◽  
Fractured Network ◽  
Numerical Program

The present study aims at developing a numerical program called DISSIM which can analyze the homogenization of rock massifs using a new subroutine which calculates Representative Elementary Volume (REV). The DISSIM methodology consists of two steps. The first step involves the modeling of the fractured network in order to provide a surface simulation that represents the real fracture of the examined front. The second step is to numerically model the wave propagation through the simulated fracture network while characterizing the attenuation of vibrations due to the effect of discontinuities. This part allows us to determine in particular the wave propagation velocity through the fractured mass, from which we can determine the homogenized Young's modulus. However, after extensive bibliographic research, it was realized that a third step appeared to be necessary. In fact, it is necessary to look for a representative elementary volume on which we apply the proposed homogenization method. Two types of the representative elementary volume are proposed in this article, the geometric REV and the mechanical REV. The presentation of these two types of REV and the DISSIM methodology are detailed in this paper. Then, this methodology was applied to the study of a real case. The present research provides a method allowing the calculation of both types of REV for fissured rocks. The case study yielded comparable results between the mechanical REV and the geometric REV, which is compatible with previous research studies.

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