Numerical estimation of the degree of reservoir permeability heterogeneity using pressure drawdown tests

Tayfun Babadagli, Ali Al-Bemani, Khamis Al-Shammakhi

Research output: Contribution to journalArticle

3 Citations (Scopus)

Abstract

This study aims to correlate the response of pressure transient test to permeability distribution type. For this purpose, correlated permeability distributions in x-y direction are generated using fractional Brownian motion (fBm) as it has been shown in literature that permeability in carbonate reservoirs exhibits an fBm type distribution horizontally. 2-D fBm permeability distributions created using mid point displacement method are employed as data to a black oil simulator. The intermittence exponent, H or fractal dimension of the distribution, D, as defined by D = 2-H, characterizes the distribution type. All permeability distributions are normalized to represent the same arithmetic mean (20, 100, and 500 mD) and uniform variance so that only their fractal dimension that underlies the smoothness of the distribution distinguishes them. Many different realizations of permeability distributions are generated based on the random number seeds used and pressure transient (drawdown) tests are simulated using a black oil simulator package (ECLIPSE 100). Pressure transient analysis is performed using PanSystem package. As a base case and for the comparison purpose, the same procedure is repeated for the totally homogeneous case (the same permeability for all grids) and a random (normally distributed) permeability distribution with the same mean and uniform variance. The effects of permeability distribution type on the pressure response are clarified. A strong impact of heterogeneity is observed as an increase in skin effect with increasing fractal dimension of permeability distribution. This additional (or pseudo) skin effect due to heterogeneity is correlated to the fractal dimension of the permeability distribution. As a further step, the procedure is repeated for different flow rates applied during the drawdown test. The correlation between the fractal dimension of permeability distribution and additional skin is improved by incorporating the rate into it. The methodology followed can be used in the assessment of reservoir heterogeneity quantitatively using pressure transient response.

Original languageEnglish
Pages (from-to)313-331
Number of pages19
JournalTransport in Porous Media
Volume57
Issue number3
DOIs
Publication statusPublished - Dec 2004

Fingerprint

Fractal dimension
Brownian movement
Skin effect
Transient analysis
Oils
Simulators
Carbonates
Seed
Skin
Flow rate

Keywords

  • Degree of heterogeneity
  • Drawdown test
  • Fractal dimension
  • Fractional Brownian motion
  • Horizontal permeability distribution
  • Pressure transient analysis
  • Pseudo skin factor
  • Skin due to heterogeneity

ASJC Scopus subject areas

  • Catalysis
  • Chemical Engineering(all)

Cite this

Numerical estimation of the degree of reservoir permeability heterogeneity using pressure drawdown tests. / Babadagli, Tayfun; Al-Bemani, Ali; Al-Shammakhi, Khamis.

In: Transport in Porous Media, Vol. 57, No. 3, 12.2004, p. 313-331.

Research output: Contribution to journalArticle

@article{2a0fdbc2257e4576a2034a75ef46cf6b,
title = "Numerical estimation of the degree of reservoir permeability heterogeneity using pressure drawdown tests",
abstract = "This study aims to correlate the response of pressure transient test to permeability distribution type. For this purpose, correlated permeability distributions in x-y direction are generated using fractional Brownian motion (fBm) as it has been shown in literature that permeability in carbonate reservoirs exhibits an fBm type distribution horizontally. 2-D fBm permeability distributions created using mid point displacement method are employed as data to a black oil simulator. The intermittence exponent, H or fractal dimension of the distribution, D, as defined by D = 2-H, characterizes the distribution type. All permeability distributions are normalized to represent the same arithmetic mean (20, 100, and 500 mD) and uniform variance so that only their fractal dimension that underlies the smoothness of the distribution distinguishes them. Many different realizations of permeability distributions are generated based on the random number seeds used and pressure transient (drawdown) tests are simulated using a black oil simulator package (ECLIPSE 100). Pressure transient analysis is performed using PanSystem package. As a base case and for the comparison purpose, the same procedure is repeated for the totally homogeneous case (the same permeability for all grids) and a random (normally distributed) permeability distribution with the same mean and uniform variance. The effects of permeability distribution type on the pressure response are clarified. A strong impact of heterogeneity is observed as an increase in skin effect with increasing fractal dimension of permeability distribution. This additional (or pseudo) skin effect due to heterogeneity is correlated to the fractal dimension of the permeability distribution. As a further step, the procedure is repeated for different flow rates applied during the drawdown test. The correlation between the fractal dimension of permeability distribution and additional skin is improved by incorporating the rate into it. The methodology followed can be used in the assessment of reservoir heterogeneity quantitatively using pressure transient response.",
keywords = "Degree of heterogeneity, Drawdown test, Fractal dimension, Fractional Brownian motion, Horizontal permeability distribution, Pressure transient analysis, Pseudo skin factor, Skin due to heterogeneity",
author = "Tayfun Babadagli and Ali Al-Bemani and Khamis Al-Shammakhi",
year = "2004",
month = "12",
doi = "10.1007/s11242-004-1409-3",
language = "English",
volume = "57",
pages = "313--331",
journal = "Transport in Porous Media",
issn = "0169-3913",
publisher = "Springer Netherlands",
number = "3",

}

TY - JOUR

T1 - Numerical estimation of the degree of reservoir permeability heterogeneity using pressure drawdown tests

AU - Babadagli, Tayfun

AU - Al-Bemani, Ali

AU - Al-Shammakhi, Khamis

PY - 2004/12

Y1 - 2004/12

N2 - This study aims to correlate the response of pressure transient test to permeability distribution type. For this purpose, correlated permeability distributions in x-y direction are generated using fractional Brownian motion (fBm) as it has been shown in literature that permeability in carbonate reservoirs exhibits an fBm type distribution horizontally. 2-D fBm permeability distributions created using mid point displacement method are employed as data to a black oil simulator. The intermittence exponent, H or fractal dimension of the distribution, D, as defined by D = 2-H, characterizes the distribution type. All permeability distributions are normalized to represent the same arithmetic mean (20, 100, and 500 mD) and uniform variance so that only their fractal dimension that underlies the smoothness of the distribution distinguishes them. Many different realizations of permeability distributions are generated based on the random number seeds used and pressure transient (drawdown) tests are simulated using a black oil simulator package (ECLIPSE 100). Pressure transient analysis is performed using PanSystem package. As a base case and for the comparison purpose, the same procedure is repeated for the totally homogeneous case (the same permeability for all grids) and a random (normally distributed) permeability distribution with the same mean and uniform variance. The effects of permeability distribution type on the pressure response are clarified. A strong impact of heterogeneity is observed as an increase in skin effect with increasing fractal dimension of permeability distribution. This additional (or pseudo) skin effect due to heterogeneity is correlated to the fractal dimension of the permeability distribution. As a further step, the procedure is repeated for different flow rates applied during the drawdown test. The correlation between the fractal dimension of permeability distribution and additional skin is improved by incorporating the rate into it. The methodology followed can be used in the assessment of reservoir heterogeneity quantitatively using pressure transient response.

AB - This study aims to correlate the response of pressure transient test to permeability distribution type. For this purpose, correlated permeability distributions in x-y direction are generated using fractional Brownian motion (fBm) as it has been shown in literature that permeability in carbonate reservoirs exhibits an fBm type distribution horizontally. 2-D fBm permeability distributions created using mid point displacement method are employed as data to a black oil simulator. The intermittence exponent, H or fractal dimension of the distribution, D, as defined by D = 2-H, characterizes the distribution type. All permeability distributions are normalized to represent the same arithmetic mean (20, 100, and 500 mD) and uniform variance so that only their fractal dimension that underlies the smoothness of the distribution distinguishes them. Many different realizations of permeability distributions are generated based on the random number seeds used and pressure transient (drawdown) tests are simulated using a black oil simulator package (ECLIPSE 100). Pressure transient analysis is performed using PanSystem package. As a base case and for the comparison purpose, the same procedure is repeated for the totally homogeneous case (the same permeability for all grids) and a random (normally distributed) permeability distribution with the same mean and uniform variance. The effects of permeability distribution type on the pressure response are clarified. A strong impact of heterogeneity is observed as an increase in skin effect with increasing fractal dimension of permeability distribution. This additional (or pseudo) skin effect due to heterogeneity is correlated to the fractal dimension of the permeability distribution. As a further step, the procedure is repeated for different flow rates applied during the drawdown test. The correlation between the fractal dimension of permeability distribution and additional skin is improved by incorporating the rate into it. The methodology followed can be used in the assessment of reservoir heterogeneity quantitatively using pressure transient response.

KW - Degree of heterogeneity

KW - Drawdown test

KW - Fractal dimension

KW - Fractional Brownian motion

KW - Horizontal permeability distribution

KW - Pressure transient analysis

KW - Pseudo skin factor

KW - Skin due to heterogeneity

UR - http://www.scopus.com/inward/record.url?scp=7244251831&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=7244251831&partnerID=8YFLogxK

U2 - 10.1007/s11242-004-1409-3

DO - 10.1007/s11242-004-1409-3

M3 - Article

AN - SCOPUS:7244251831

VL - 57

SP - 313

EP - 331

JO - Transport in Porous Media

JF - Transport in Porous Media

SN - 0169-3913

IS - 3

ER -