Comparative porosity and pore structure assessment in shales: Measurement techniques, influencing factors and implications for reservoir characterization

Porosity and pore size distribution (PSD) are essential petrophysical parameters controlling permeability and storage capacity in shale gas reservoirs. Various techniques to assess pore structure have been introduced; nevertheless, discrepancies and inconsistencies exist between each of them. This s...

Full description

Bibliographic Details
Main Authors: Yuan, Yujie, Rezaee, Reza
Format: Journal Article
Language:English
Published: MDPI 2019
Subjects:
Online Access:http://hdl.handle.net/20.500.11937/89583
_version_ 1848765252024401920
author Yuan, Yujie
Rezaee, Reza
author_facet Yuan, Yujie
Rezaee, Reza
author_sort Yuan, Yujie
building Curtin Institutional Repository
collection Online Access
description Porosity and pore size distribution (PSD) are essential petrophysical parameters controlling permeability and storage capacity in shale gas reservoirs. Various techniques to assess pore structure have been introduced; nevertheless, discrepancies and inconsistencies exist between each of them. This study compares the porosity and PSD in two different shale formations, i.e., the clay-rich Permian Carynginia Formation in the Perth Basin, Western Australia, and the clay-poor Monterey Formation in San Joaquin Basin, USA. Porosity and PSD have been interpreted based on nuclear magnetic resonance (NMR), low-pressure N2 gas adsorption (LP-N2-GA), mercury intrusion capillary pressure (MICP) and helium expansion porosimetry. The results highlight NMR with the advantage of detecting the full-scaled size of pores that are not accessible by MICP, and the ineffective/closed pores occupied by clay bound water (CBW) that are not approachable by other penetration techniques (e.g., helium expansion, low-pressure gas adsorption and MICP). The NMR porosity is largely discrepant with the helium porosity and the MICP porosity in clay-rich Carynginia shales, but a high consistency is displayed in clay-poor Monterey shales, implying the impact of clay contents on the distinction of shale pore structure interpretations between different measurements. Further, the CBW, which is calculated by subtracting the measured effective porosity from total porosity, presents a good linear correlation with the clay content (R2 = 0.76), implying that our correlated equation is adaptable to estimate the CBW in shale formations with the dominant clay type of illite.
first_indexed 2025-11-14T11:32:17Z
format Journal Article
id curtin-20.500.11937-89583
institution Curtin University Malaysia
institution_category Local University
language English
last_indexed 2025-11-14T11:32:17Z
publishDate 2019
publisher MDPI
recordtype eprints
repository_type Digital Repository
spelling curtin-20.500.11937-895832022-11-14T05:36:32Z Comparative porosity and pore structure assessment in shales: Measurement techniques, influencing factors and implications for reservoir characterization Yuan, Yujie Rezaee, Reza Science & Technology Technology Energy & Fuels gas shale NMR helium porosimetry clay bound water porosity pore size distribution low-pressure gas adsorption MICP ANGLE NEUTRON-SCATTERING CLAY BOUND WATER GAS-ADSORPTION SIZE DISTRIBUTION SURFACE-AREA LOW-PRESSURE POROSIMETRY DISTRIBUTIONS COAL Porosity and pore size distribution (PSD) are essential petrophysical parameters controlling permeability and storage capacity in shale gas reservoirs. Various techniques to assess pore structure have been introduced; nevertheless, discrepancies and inconsistencies exist between each of them. This study compares the porosity and PSD in two different shale formations, i.e., the clay-rich Permian Carynginia Formation in the Perth Basin, Western Australia, and the clay-poor Monterey Formation in San Joaquin Basin, USA. Porosity and PSD have been interpreted based on nuclear magnetic resonance (NMR), low-pressure N2 gas adsorption (LP-N2-GA), mercury intrusion capillary pressure (MICP) and helium expansion porosimetry. The results highlight NMR with the advantage of detecting the full-scaled size of pores that are not accessible by MICP, and the ineffective/closed pores occupied by clay bound water (CBW) that are not approachable by other penetration techniques (e.g., helium expansion, low-pressure gas adsorption and MICP). The NMR porosity is largely discrepant with the helium porosity and the MICP porosity in clay-rich Carynginia shales, but a high consistency is displayed in clay-poor Monterey shales, implying the impact of clay contents on the distinction of shale pore structure interpretations between different measurements. Further, the CBW, which is calculated by subtracting the measured effective porosity from total porosity, presents a good linear correlation with the clay content (R2 = 0.76), implying that our correlated equation is adaptable to estimate the CBW in shale formations with the dominant clay type of illite. 2019 Journal Article http://hdl.handle.net/20.500.11937/89583 10.3390/en12112094 English http://creativecommons.org/licenses/by/4.0/ MDPI fulltext
spellingShingle Science & Technology
Technology
Energy & Fuels
gas shale
NMR
helium porosimetry
clay bound water
porosity
pore size distribution
low-pressure gas adsorption
MICP
ANGLE NEUTRON-SCATTERING
CLAY BOUND WATER
GAS-ADSORPTION
SIZE DISTRIBUTION
SURFACE-AREA
LOW-PRESSURE
POROSIMETRY
DISTRIBUTIONS
COAL
Yuan, Yujie
Rezaee, Reza
Comparative porosity and pore structure assessment in shales: Measurement techniques, influencing factors and implications for reservoir characterization
title Comparative porosity and pore structure assessment in shales: Measurement techniques, influencing factors and implications for reservoir characterization
title_full Comparative porosity and pore structure assessment in shales: Measurement techniques, influencing factors and implications for reservoir characterization
title_fullStr Comparative porosity and pore structure assessment in shales: Measurement techniques, influencing factors and implications for reservoir characterization
title_full_unstemmed Comparative porosity and pore structure assessment in shales: Measurement techniques, influencing factors and implications for reservoir characterization
title_short Comparative porosity and pore structure assessment in shales: Measurement techniques, influencing factors and implications for reservoir characterization
title_sort comparative porosity and pore structure assessment in shales: measurement techniques, influencing factors and implications for reservoir characterization
topic Science & Technology
Technology
Energy & Fuels
gas shale
NMR
helium porosimetry
clay bound water
porosity
pore size distribution
low-pressure gas adsorption
MICP
ANGLE NEUTRON-SCATTERING
CLAY BOUND WATER
GAS-ADSORPTION
SIZE DISTRIBUTION
SURFACE-AREA
LOW-PRESSURE
POROSIMETRY
DISTRIBUTIONS
COAL
url http://hdl.handle.net/20.500.11937/89583