Effects of swelling-clay and surface roughness on the wettability of transitional shale

Wettability in unconventional reservoirs is poorly understood. However, it plays a fundamental role in fluid-rock interactions, and an understanding of wetting behavior is essential for capillary seal assessments and hydrocarbon reserve estimation and recovery in clay-rich reservoirs. In this study,...

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Main Authors: Li, Pei, Zhang, J., Rezaee, Reza, Dang, W., Li, Xuekai, Fauziah, Cut Aja, Nie, H., Tang, X.
Format: Journal Article
Language:English
Published: ELSEVIER 2021
Subjects:
Online Access:http://hdl.handle.net/20.500.11937/89547
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author Li, Pei
Zhang, J.
Rezaee, Reza
Dang, W.
Li, Xuekai
Fauziah, Cut Aja
Nie, H.
Tang, X.
author_facet Li, Pei
Zhang, J.
Rezaee, Reza
Dang, W.
Li, Xuekai
Fauziah, Cut Aja
Nie, H.
Tang, X.
author_sort Li, Pei
building Curtin Institutional Repository
collection Online Access
description Wettability in unconventional reservoirs is poorly understood. However, it plays a fundamental role in fluid-rock interactions, and an understanding of wetting behavior is essential for capillary seal assessments and hydrocarbon reserve estimation and recovery in clay-rich reservoirs. In this study, the wetting behavior of transitional Shanxi-Taiyuan shale from the southern North China basin was examined via the contact angle (CA) and spontaneous imbibition (SI) measurement methods. Under water-air-shale conditions, water-wet and neutral-wet behaviors were observed, whereas neutral-wet and oil-wet behaviors were observed under water-oil-shale conditions (Young's equation was used to convert the water-air-shale system to the water-oil-shale system). When the CA method was used, the shale was shown to be hydrophobic, whereas when the SI test was used, the shale was observed to be hydrophilic. The water-air CAs are negatively correlated with the total organic content (TOC), carbonate and clay mineral contents (excluding those of illite). Furthermore, iron-containing compounds, such as pyrite and siderite, were shown to decrease the water wetness. A linear negative correlation was found between the surface roughness and the CA value. The relationship between these parameters can be used to predict the CAs at different surface roughness values for a given sample. The contradictory wetting behaviors between the results of SI and CA methods can be explained by: (i) differences between the CAs formed under water-air-shale conditions and those formed under hydrocarbon-brine-shale conditions; (ii) differences in the surface roughness, which is dependent on the texture and mineralogy of the shale sample; and (iii) clay swelling after water sorption and the formation of microfractures due to water–rock interactions.
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spelling curtin-20.500.11937-895472023-01-16T03:46:52Z Effects of swelling-clay and surface roughness on the wettability of transitional shale Li, Pei Zhang, J. Rezaee, Reza Dang, W. Li, Xuekai Fauziah, Cut Aja Nie, H. Tang, X. Science & Technology Technology Energy & Fuels Engineering, Petroleum Engineering Shale Spontaneous imbibition Contact angle Wettability Surface roughness Clay swelling MISSISSIPPIAN BARNETT SHALE MIDDLE YANGTZE PLATFORM SOUTHERN NORTH CHINA PORE STRUCTURE SPONTANEOUS IMBIBITION INTERFACIAL-TENSION MULTIPHASE FLOW SICHUAN BASIN GAS ADSORPTION Wettability in unconventional reservoirs is poorly understood. However, it plays a fundamental role in fluid-rock interactions, and an understanding of wetting behavior is essential for capillary seal assessments and hydrocarbon reserve estimation and recovery in clay-rich reservoirs. In this study, the wetting behavior of transitional Shanxi-Taiyuan shale from the southern North China basin was examined via the contact angle (CA) and spontaneous imbibition (SI) measurement methods. Under water-air-shale conditions, water-wet and neutral-wet behaviors were observed, whereas neutral-wet and oil-wet behaviors were observed under water-oil-shale conditions (Young's equation was used to convert the water-air-shale system to the water-oil-shale system). When the CA method was used, the shale was shown to be hydrophobic, whereas when the SI test was used, the shale was observed to be hydrophilic. The water-air CAs are negatively correlated with the total organic content (TOC), carbonate and clay mineral contents (excluding those of illite). Furthermore, iron-containing compounds, such as pyrite and siderite, were shown to decrease the water wetness. A linear negative correlation was found between the surface roughness and the CA value. The relationship between these parameters can be used to predict the CAs at different surface roughness values for a given sample. The contradictory wetting behaviors between the results of SI and CA methods can be explained by: (i) differences between the CAs formed under water-air-shale conditions and those formed under hydrocarbon-brine-shale conditions; (ii) differences in the surface roughness, which is dependent on the texture and mineralogy of the shale sample; and (iii) clay swelling after water sorption and the formation of microfractures due to water–rock interactions. 2021 Journal Article http://hdl.handle.net/20.500.11937/89547 10.1016/j.petrol.2020.108007 English ELSEVIER restricted
spellingShingle Science & Technology
Technology
Energy & Fuels
Engineering, Petroleum
Engineering
Shale
Spontaneous imbibition
Contact angle
Wettability
Surface roughness
Clay swelling
MISSISSIPPIAN BARNETT SHALE
MIDDLE YANGTZE PLATFORM
SOUTHERN NORTH CHINA
PORE STRUCTURE
SPONTANEOUS IMBIBITION
INTERFACIAL-TENSION
MULTIPHASE FLOW
SICHUAN BASIN
GAS
ADSORPTION
Li, Pei
Zhang, J.
Rezaee, Reza
Dang, W.
Li, Xuekai
Fauziah, Cut Aja
Nie, H.
Tang, X.
Effects of swelling-clay and surface roughness on the wettability of transitional shale
title Effects of swelling-clay and surface roughness on the wettability of transitional shale
title_full Effects of swelling-clay and surface roughness on the wettability of transitional shale
title_fullStr Effects of swelling-clay and surface roughness on the wettability of transitional shale
title_full_unstemmed Effects of swelling-clay and surface roughness on the wettability of transitional shale
title_short Effects of swelling-clay and surface roughness on the wettability of transitional shale
title_sort effects of swelling-clay and surface roughness on the wettability of transitional shale
topic Science & Technology
Technology
Energy & Fuels
Engineering, Petroleum
Engineering
Shale
Spontaneous imbibition
Contact angle
Wettability
Surface roughness
Clay swelling
MISSISSIPPIAN BARNETT SHALE
MIDDLE YANGTZE PLATFORM
SOUTHERN NORTH CHINA
PORE STRUCTURE
SPONTANEOUS IMBIBITION
INTERFACIAL-TENSION
MULTIPHASE FLOW
SICHUAN BASIN
GAS
ADSORPTION
url http://hdl.handle.net/20.500.11937/89547