Study on Mechanism of Surfactant Adsorption at Oil–Water Interface and Wettability Alteration on Oil-Wet Rock Surface

With the depletion of conventional light crude oil reserves in China, the demand for heavy oil exploitation has grown, highlighting the increasing significance of enhanced heavy oil recovery. Surfactants reduce oil–water interfacial tension, modify the wettability of reservoir rocks, and facilitate...

Full description

Saved in:
Bibliographic Details
Main Authors: Xinyu Tang, Yaoyao Tong, Yuhui Zhang, Pujiang Yang, Chuangye Wang, Jinhe Liu
Format: Article
Language:English
Published: MDPI AG 2025-06-01
Series:Molecules
Subjects:
Online Access:https://www.mdpi.com/1420-3049/30/12/2541
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1849425488061136896
author Xinyu Tang
Yaoyao Tong
Yuhui Zhang
Pujiang Yang
Chuangye Wang
Jinhe Liu
author_facet Xinyu Tang
Yaoyao Tong
Yuhui Zhang
Pujiang Yang
Chuangye Wang
Jinhe Liu
author_sort Xinyu Tang
collection DOAJ
description With the depletion of conventional light crude oil reserves in China, the demand for heavy oil exploitation has grown, highlighting the increasing significance of enhanced heavy oil recovery. Surfactants reduce oil–water interfacial tension, modify the wettability of reservoir rocks, and facilitate the emulsification of heavy oil. Consequently, investigating the adsorption behavior of surfactants at oil–water interfaces and the underlying mechanisms of wettability alteration is of considerable importance. In this study, the surface tension of four surfactants and their interfacial tension with Gudao heavy oil were measured. Among these, BS-12 exhibited a critical micelle concentration (CMC) of 6.26 × 10<sup>−4</sup> mol·dm<sup>−3</sup>, a surface tension of 30.15 mN·m<sup>−1</sup> at the CMC, and an adsorption efficiency of 4.54. In low-salinity systems, BS-12 achieved an ultralow interfacial tension on the order of 10<sup>−3</sup> mN·m<sup>−1</sup>, demonstrating excellent surface activity. Therefore, BS-12 was selected as the preferred emulsifier for Gudao heavy oil recovery. Additionally, FT-IR, SEM, and contact angle measurements were used to elucidate the interfacial adsorption mechanism between BS-12 and aged cores. The results indicate that hydrophobic interactions between the hydrophobic groups of BS-12 and the adsorbed crude oil fractions play a key role. Core flooding experiments, simulating the formation of low-viscosity oil-in-water (<i>O</i>/<i>W</i>) emulsions under reservoir conditions, showed that at low flow rates, crude oil and water interact more effectively within the pores. The extended contact time between heavy oil and the emulsifier led to significant changes in rock wettability, enhanced interfacial activity, improved oil recovery efficiency, and increased oil content in the emulsion. This study analyzes the role of surfactants in interfacial adsorption and the multiphase flow behavior of emulsions, providing a theoretical basis for surfactant-enhanced oil recovery.
format Article
id doaj-art-d91dcf2edf254e16b54057cbe1012b27
institution Kabale University
issn 1420-3049
language English
publishDate 2025-06-01
publisher MDPI AG
record_format Article
series Molecules
spelling doaj-art-d91dcf2edf254e16b54057cbe1012b272025-08-20T03:29:45ZengMDPI AGMolecules1420-30492025-06-013012254110.3390/molecules30122541Study on Mechanism of Surfactant Adsorption at Oil–Water Interface and Wettability Alteration on Oil-Wet Rock SurfaceXinyu Tang0Yaoyao Tong1Yuhui Zhang2Pujiang Yang3Chuangye Wang4Jinhe Liu5College of Chemistry and Chemical Engineering, China University of Petroleum, Qingdao 266580, ChinaCollege of Chemistry and Chemical Engineering, China University of Petroleum, Qingdao 266580, ChinaCollege of Chemistry and Chemical Engineering, China University of Petroleum, Qingdao 266580, ChinaCollege of Chemistry and Chemical Engineering, China University of Petroleum, Qingdao 266580, ChinaCollege of Chemistry and Chemical Engineering, China University of Petroleum, Qingdao 266580, ChinaCollege of Chemistry and Chemical Engineering, China University of Petroleum, Qingdao 266580, ChinaWith the depletion of conventional light crude oil reserves in China, the demand for heavy oil exploitation has grown, highlighting the increasing significance of enhanced heavy oil recovery. Surfactants reduce oil–water interfacial tension, modify the wettability of reservoir rocks, and facilitate the emulsification of heavy oil. Consequently, investigating the adsorption behavior of surfactants at oil–water interfaces and the underlying mechanisms of wettability alteration is of considerable importance. In this study, the surface tension of four surfactants and their interfacial tension with Gudao heavy oil were measured. Among these, BS-12 exhibited a critical micelle concentration (CMC) of 6.26 × 10<sup>−4</sup> mol·dm<sup>−3</sup>, a surface tension of 30.15 mN·m<sup>−1</sup> at the CMC, and an adsorption efficiency of 4.54. In low-salinity systems, BS-12 achieved an ultralow interfacial tension on the order of 10<sup>−3</sup> mN·m<sup>−1</sup>, demonstrating excellent surface activity. Therefore, BS-12 was selected as the preferred emulsifier for Gudao heavy oil recovery. Additionally, FT-IR, SEM, and contact angle measurements were used to elucidate the interfacial adsorption mechanism between BS-12 and aged cores. The results indicate that hydrophobic interactions between the hydrophobic groups of BS-12 and the adsorbed crude oil fractions play a key role. Core flooding experiments, simulating the formation of low-viscosity oil-in-water (<i>O</i>/<i>W</i>) emulsions under reservoir conditions, showed that at low flow rates, crude oil and water interact more effectively within the pores. The extended contact time between heavy oil and the emulsifier led to significant changes in rock wettability, enhanced interfacial activity, improved oil recovery efficiency, and increased oil content in the emulsion. This study analyzes the role of surfactants in interfacial adsorption and the multiphase flow behavior of emulsions, providing a theoretical basis for surfactant-enhanced oil recovery.https://www.mdpi.com/1420-3049/30/12/2541chemical floodingsurfactantinterface propertiesheavy oil emulsion
spellingShingle Xinyu Tang
Yaoyao Tong
Yuhui Zhang
Pujiang Yang
Chuangye Wang
Jinhe Liu
Study on Mechanism of Surfactant Adsorption at Oil–Water Interface and Wettability Alteration on Oil-Wet Rock Surface
Molecules
chemical flooding
surfactant
interface properties
heavy oil emulsion
title Study on Mechanism of Surfactant Adsorption at Oil–Water Interface and Wettability Alteration on Oil-Wet Rock Surface
title_full Study on Mechanism of Surfactant Adsorption at Oil–Water Interface and Wettability Alteration on Oil-Wet Rock Surface
title_fullStr Study on Mechanism of Surfactant Adsorption at Oil–Water Interface and Wettability Alteration on Oil-Wet Rock Surface
title_full_unstemmed Study on Mechanism of Surfactant Adsorption at Oil–Water Interface and Wettability Alteration on Oil-Wet Rock Surface
title_short Study on Mechanism of Surfactant Adsorption at Oil–Water Interface and Wettability Alteration on Oil-Wet Rock Surface
title_sort study on mechanism of surfactant adsorption at oil water interface and wettability alteration on oil wet rock surface
topic chemical flooding
surfactant
interface properties
heavy oil emulsion
url https://www.mdpi.com/1420-3049/30/12/2541
work_keys_str_mv AT xinyutang studyonmechanismofsurfactantadsorptionatoilwaterinterfaceandwettabilityalterationonoilwetrocksurface
AT yaoyaotong studyonmechanismofsurfactantadsorptionatoilwaterinterfaceandwettabilityalterationonoilwetrocksurface
AT yuhuizhang studyonmechanismofsurfactantadsorptionatoilwaterinterfaceandwettabilityalterationonoilwetrocksurface
AT pujiangyang studyonmechanismofsurfactantadsorptionatoilwaterinterfaceandwettabilityalterationonoilwetrocksurface
AT chuangyewang studyonmechanismofsurfactantadsorptionatoilwaterinterfaceandwettabilityalterationonoilwetrocksurface
AT jinheliu studyonmechanismofsurfactantadsorptionatoilwaterinterfaceandwettabilityalterationonoilwetrocksurface