Characterization of Pore Space of Cement-Based Materials by Combined Mercury and Wood's Metal Intrusion

Abstract Capillary condensation is the condensation of the gas inside nano-pore space at a pressure lower than the bulk dew point pressure as the result of multilayer adsorption due to the high capillary pressure inside the small pore throat of unconventional rocks. The condensation of liquid in nano-pore space of rock changes its mechanical and acoustic properties. Acoustic properties variation due to capillary condensation provides us a tool to monitor phase change in reservoir as a result of nano-confinement as well as mapping the area where phase change occurs as well as characterize pore size distribution. This is particularly important for tight formations where confinement has a strong effect on phase behavior that is challenging to measure experimentally. Theoretical studies have examined the effects of capillary condensation; however, these findings have not been verified experimentally. The main objective of this study is to experimentally investigate the effect of capillary condensation on the mechanical and acoustic properties of shale samples. The mechanical and acoustic characterization of the samples was carried out experimentally using a state-of-the-art tri-axial facility at the Colorado School of Mines. The experimental set-up is capable of the simultaneous acquisition of coupled stress, strain, resistivity, acoustic and flow data. Carbon dioxide was used as the pore pressure fluid in these experiments. After a comprehensive characterization of shale samples, experiments were conducted by increasing the pore pressure until condensation occurs while monitoring the mechanical and acoustic properties of the sample to quantify the effect of capillary condensation on the mechanical and acoustic properties of the sample. Experimental data show a 5% increase in Young's Modulus as condensation occurs. This increase is attributed to the increase in pore stiffness as condensation occurs reinforcing the grain contact. An initial decrease in compressional velocity was observed as pore pressure increases before condensation occurs which is attributed to the expansion of the pore volume when pore pressure increases. After this initial decrease, compressional velocity slightly increases at a pressure around 750 - 800 psi which is close to the condensation pressure. We also observed a noticeable increase in shear velocity when capillary condensation occurs, this could be due to the immobility of the condensed liquid phase at the pore throats. The changes of geomechanical and acoustic signatures were observed at around 750 - 800 psi at 27°C, which is the dew point pressure of the fluid in the nano-pore space of the sample at this temperature. While the unconfined bulk dew point pressure of carbon dioxide at the same temperature is 977 psi. Hence, this study marks the first measurement of the dew point of fluid in nano-pore space and potentially leads to the construction of the phase envelope of fluid under confinement.

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3D Confocal Imaging Methodology Optimized for Pore Space Characterization of Microporous Carbonate Reservoirs

10.2523/iptc-19615-ms ◽

2020 ◽

Author(s):

A. Hassan ◽

V. Chandra ◽

M. P. Yutkin ◽

T. W. Patzek

Keyword(s):

Pore Space ◽

Confocal Imaging ◽

Carbonate Reservoirs ◽

Imaging Methodology ◽

Space Characterization

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Advances in low-field nuclear magnetic resonance (NMR) technologies applied for characterization of pore space inside rocks: a critical review

Petroleum Science ◽

10.1007/s12182-020-00488-0 ◽

2020 ◽

Vol 17 (5) ◽

pp. 1281-1297 ◽

Cited By ~ 1

Author(s):

Jian-Chun Guo ◽

Hang-Yu Zhou ◽

Jie Zeng ◽

Kun-Jie Wang ◽

Jie Lai ◽

...

Keyword(s):

Pore Space ◽

Structure Characterization ◽

Fluid Identification ◽

Low Field ◽

Signal Collection ◽

History Of ◽

Nmr Techniques ◽

Future Work ◽

Result Interpretation

Abstract NMR serves as an important technique for probing rock pore space, such as pore structure characterization, fluid identification, and petrophysical property testing, due to the reusability of cores, convenience in sample processing, and time efficiency in laboratory tests. In practice, NMR signal collection is normally achieved through polarized nuclei relaxation which releases crucial relaxation messages for result interpretation. The impetus of this work is to help engineers and researchers with petroleum background obtain new insights into NMR principals and extend existing methodologies for characterization of unconventional formations. This article first gives a brief description of the development history of relaxation theories and models for porous media. Then, the widely used NMR techniques for characterizing petrophysical properties and pore structures are presented. Meanwhile, limitations and deficiencies of them are summarized. Finally, future work on improving these insufficiencies and approaches of enhancement applicability for NMR technologies are discussed.

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Computational topology-based characterization of pore space changes due to chemical dissolution of rocks

Applied Mathematical Modelling ◽

10.1016/j.apm.2020.06.037 ◽

2020 ◽

Vol 88 ◽

pp. 21-37 ◽

Cited By ~ 1

Author(s):

Vadim Lisitsa ◽

Yaroslav Bazaikin ◽

Tatyana Khachkova

Keyword(s):

Pore Space ◽

Computational Topology ◽

Chemical Dissolution

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Methods for Porosity Characterization of Cement Based Materials

MRS Proceedings ◽

10.1557/opl.2012.1550 ◽

2012 ◽

Vol 1488 ◽

Author(s):

M.M. Canut ◽

M. R. Geiker

Keyword(s):

Pore Size ◽

Pore Volume ◽

Mercury Intrusion Porosimetry ◽

Degree Of Hydration ◽

Cement Based Materials ◽

Porosity Estimation ◽

Portland Cement Paste ◽

Low Temperature Calorimetry ◽

Porosity Characterization

ABSTRACTImportant pore structure parameters related to mechanical properties and durability of cement-based materials can be determined by techniques such as scanning electron microscopy (SEM), mercury intrusion porosimetry (MIP), and low temperature calorimetry (LTC). The methods provide information on porosity characteristics as pore volume, pore thresholds and/or pore size distribution in different size ranges and do therefore to a large extent supplement each other. Pastes of w/b=0.4 with 0%, 40% or 70% slag by volume were cured saturated at 20ºC for up to two years. The porosity was characterized by LTC, MIP, and SEM. Higher volume of pores was obtained by MIP compared to results obtained using LTC and SEM. Measured porosity was correlated with predicted porosity using information on the density and degree of hydration of the cement and slag. Porosity estimation showed best agreement with the porosity data measured by MIP. The use of slag showed the same trend for all tests: a higher total volume of pores, but a lower threshold pore size when compared with Portland cement paste. The findings illustrate the importance of measuring not only pore volume but also threshold pore sizes when characterizing porosity of cement-based materials with different binder compositions.

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Characterization of Chemically Modified Pore Surfaces by Small Angle Neutron Scattering

MRS Proceedings ◽

10.1557/proc-166-415 ◽

1989 ◽

Vol 166 ◽

Cited By ~ 11

Author(s):

C. J. Glinka ◽

L. C. Sandert ◽

S. A. Wiset ◽

N. F. Berk

Keyword(s):

Neutron Scattering ◽

Small Angle ◽

Small Angle Neutron Scattering ◽

Pore Space ◽

Silica Particles ◽

Microporous Silica ◽

Hydrocarbon Chains ◽

Phase Liquid ◽

Internal Pore

ABSTRACTSmall angle neutron scattering has been used to characterize the structure of linear hydrocarbon chains chemically grafted to the internal pore surfaces of microporous silica particles. The aim of this work has been to relate the structure of the bonded adsorbate layers in these particles to their performance in, for example, reverse-phase liquid chromatography. By filling the pore space in the modified silica with a solution that matches the scattering density of the silica framework, the scattering from the adsorbate layers is enhanced and provides a sensitive probe of the effective thickness, uniformity and degree of solvent penetration in the layers. Results are presented for both monomeric and polymeric phases of alkyl chains ranging from C8 to C30 bonded to silica particles with a mean pore size of 100 nm.

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Characterization of hydration depths of cement particles with different sizes in hardened cement-based materials

Construction and Building Materials ◽

10.1016/j.conbuildmat.2021.123986 ◽

2021 ◽

Vol 300 ◽

pp. 123986

Author(s):

Xiaohang Zhang ◽

Xinchun Guan ◽

Chongzhi Ma

Keyword(s):

Hardened Cement ◽

Cement Based Materials

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Characterization of Cement Microstructure for the Immobilization of Nuclear Waste Using Advanced Imaging Methods

MRS Proceedings ◽

10.1557/opl.2012.626 ◽

2012 ◽

Vol 1475 ◽

Author(s):

D.L. Engelberg ◽

J.A. Duff ◽

L. Murray ◽

L. Dodds ◽

N. Mobasher ◽

...

Keyword(s):

Nuclear Waste ◽

Pore Space ◽

Imaging Techniques ◽

Image Correlation ◽

Advanced Imaging ◽

Comprehensive Picture ◽

X Ray Computed ◽

Matrix Fraction ◽

Nuclear Waste Immobilization

ABSTRACTA range of advanced imaging techniques have been brought together to provide a comprehensive picture of cement microstructure for nuclear waste immobilization. Image analysis of Nirex Reference Vault Backfill (NRVB) has been used to characterize the Calcium-Silicate-Hydrate (C-S-H) matrix fraction. Through weight loss measurements and digital image correlation of OPC-based cement blends we have quantified the development of microstructure surface strains during the initial 48 hrs hardening period. The build-up of displacements on the microstructure scale indicated grain-like compressive areas, surrounded by a network of tensile regions. Serial sectioning of NRVB using ultra-microtome cutting has been explored for advanced high-resolution 3D microstructure characterization, while X-ray Computed Tomography (XCT) has been used to obtain information of the 3-D pore space and size distribution of air pores in NRVB non-destructively.

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