The role of chitosan salt as a sustainable corrosion inhibitor in acidizing operations
Author Identifier (ORCID)
Abstract
Acidizing is a major method of well stimulation widely employed in the petroleum industry to improve the hydrocarbons flow from a reservoir to the wellbore by dissolving portions of the rock matrix. However, conventional acidizing fluids are highly corrosive and reactive, posing significant risks to downhole equipment. Moreover, wormhole formations can result from dissolution of carbonate formations in presence of strong acids. Chitosan salt (CS) is an environmentally sustainable and cost-effective biopolymer that have been used as corrosion inhibitors and wettability modifying agents. However, its utilization for slowing down acid-rock reactions and enhancing the efficiency of acidizing operations has not been reported in any existing literature. Thus, this study evaluates the effects of combining in-house synthesized water-soluble CS with citric acid (CA) as an acidizing fluid for limestone core samples, focusing on pH stabilization and wormhole generation, as well as flow characteristics during core flooding. The impact of 1000 ppm CS on different concentrations of citric acid (CA) (5%, 7.5%, and 10%) acidizing fluid was evaluated through coreflooding experiments. The experiments were conducted at pore pressure of 1100 psi, a confining pressure of 2500 psi, temperature of 50 °C and a constant flow rate of 1 cc/min. Results showed that the addition of chitosan salt resulted in a negligible change in pH of citric acid solutions, indicating a pH-stabilizing effect that may also contribute to corrosion inhibition. The CS-CA mixture significantly suppressed the formation of irregular wormholes compared to CA alone, promoting more uniform and controlled dissolution patterns within the rock matrix. Moreover, higher concentrations of CA (7.5 wt% and 10 wt%) in the presence of CS led to increased pressure drops during injection, which can be attributed to enhanced fluid viscosity and regulated acid-rock interactions. These findings highlight the potential of chitosan salt as a novel multifunctional additive for enhancing acidizing efficiency and controlling wormhole propagation in carbonate reservoirs.
Keywords
acidizing, carbonate reservoirs, chitosan salt, citric acid, inhibitor, wormhole
Document Type
Journal Article
Date of Publication
10-1-2026
Article Number
129829
E-ISSN
18733166
ISSN
01677322
Volume
459
Publication Title
Journal of Molecular Liquids
Publisher
Elsevier
School
School of Engineering
Copyright
subscription content
Recommended Citation
Al-Yaseri, A., Yekeen, N., Al-Yasiri, A. K., & Alameedy, U. (2026). The role of chitosan salt as a sustainable corrosion inhibitor in acidizing operations. Journal of Molecular Liquids, 459, 129829. https://doi.org/10.1016/j.molliq.2026.129829