Open Access

ARTICLE

Effect of Salinity on Imbibition-Based Oil Production

Xiong Liu¹, Yueqi Cui^1,*, Yirui Ren¹, Lingxuan Peng², Yuchan Cheng¹, Zhiyuan Du¹, Yu Chen¹, Lishan Cao³

1 School of Petroleum Engineering, Xi’an Shiyou University, Xi’an, 710065, China
2 College of Carbon Neutrality Future Technology, China University of Petroleum, Beijing, 102249, China
3 The Third Gas Production Plant of PetroChina Changqing Oilfield Branch, Wushenqi, Ordos, 017000, China

* Corresponding Author: Yueqi Cui. Email:

(This article belongs to the Special Issue: Subsurface Fluid Flow Dynamics and Applications in Carbon Reduction Technologies)

Fluid Dynamics & Materials Processing 2025, 21(11), 2815-2828. https://doi.org/10.32604/fdmp.2025.073775

Received 25 September 2025; Accepted 06 November 2025; Issue published 01 December 2025

Abstract

This study explores the impact of salinity on fluid replacement during imbibition-driven oil recovery through a series of core self-imbibition experiments. By integrating key parameters such as interfacial tension, contact angle, and oil displacement efficiency, we systematically examine how variations in salinity level, ion type, and ion concentration affect the imbibition process. The results demonstrate that the salinity of the injected fluid exerts a strong influence on the rate and extent of oil recovery. Compared with high-salinity conditions, low-salinity injection, particularly below 5000 mg·L⁻¹, induces pronounced fluctuations in the replacement rate, achieving the highest recovery at approximately 1000 mg·L⁻¹. The interplay between interfacial tension and displacement efficiency is jointly governed by both ion type and concentration. Moreover, changes in ionic composition can alter rock wettability from oil-wet toward water-wet states, thereby enhancing imbibition efficiency. Among the tested ions, Mg²⁺ and SO₄²⁻ at low concentrations were found to be especially effective in promoting oil displacement.

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Keywords

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