Screening of the Effective Additive to Inhibit Surfactin from Forming Precipitation with Divalent Cations for Surfactin Enhanced Oil Recovery

Abstract

Surfactin, which is an anionic bio-surfactant, can be effective for enhanced oil recovery because it decreases interfacial tension between oil and water. However, it forms precipitation by binding with divalent cations. This study examined the countermeasure to prevent surfactin from forming precipitation for applying it to enhanced oil recovery. Alcohols, chelating agents, a cationic surfactant and an ion capturing substance were selected as the candidates for inhibiting surfactin from forming precipitation. Citric acid and trisodium citrate were selected as promising candidates through the measurements of turbidity of the mixture of the candidate, surfactin and calcium ions. Those chemicals also had a function as a co-surfactant for surfactin. However, the permeability of the Berea sandstone core into which the solution containing surfactin and trisodium citrate was injected was decreased significantly, whereas citric acid could be injected into the core without significant permeability reduction. Citric acid was therefore selected as the best inhibitor and subjected to the core flooding experiments. High enhancement of oil recovery of 9.4% (vs. original oil in place (OOIP)) was obtained and pressure drop was not increased during the injection of surfactin and citric acid. Those results suggest that citric acid has a dual role as the binding inhibitor and co-surfactant for surfactin.

The Surfactin-Like Lipopeptides From Bacillus spp.: Natural Biodiversity and Synthetic Biology for a Broader Application Range

“…Thus, they display as physico-chemical properties foaming (Razafindralambo et al, 1998 ; Fei et al, 2020 ), emulsifying (Deleu et al, 1999 ; Liu et al, 2015 ; Long et al, 2017 ; Fei et al, 2020 ) and dispersing properties, solid surface wetting and surface hydrophobicity modification performance (Ahimou et al, 2000 ; Shakerifard et al, 2009 ; Marcelino et al, 2019 ; Fei et al, 2020 ), and chelating ability (Mulligan et al, 1999 ; Grangemard et al, 2001 ; Eivazihollagh et al, 2019 ). This strong surface activity leads to detergent applications (Zezzi do Valle Gomes and Nitschke, 2012 ), but they also show promising perspectives of applications in the environmental sector to enhance oil recovery in oil-producing wells (Liu et al, 2015 ; Joshi et al, 2016 ; Long et al, 2017 ; de Araujo et al, 2019 ; Alvarez et al, 2020 ; Miyazaki et al, 2020 ), to increase the biodegradation rate of linear and aromatic hydrocarbons (Wang et al, 2020 ), and for metal removal from soil or aqueous solutions (Zouboulis et al, 2003 ; Eivazihollagh et al, 2019 ). Very recently, it was also suggested that surfactin can effectively demulsify waste crude oil (Yang et al, 2020 ).…”

Application of Alcohols to Inhibit the Formation of Ca(II) Dodecyl Sulfate Precipitate in Aqueous Solutions

“…Tri-sodium citrate was used to sequester calcium in a study published by Miyazaki et al The experimental data confirmed that tri-sodium citrate prevents the precipitation caused by calcium ions up to 900 ppm in solutions containing surfactin (a class of biosurfactant with an uncommon cyclic lipopeptide as a head group) [12].…”

Molecular Dynamics Studies on Effective Surface-Active Additives: Toward Hard Water-Resistant Chemical Flooding for Enhanced Oil Recovery

“…Surfactant precipitation can not only cause its retention but also block small pores, which can severely hinder further oil production. 8 Theoretical 9 and simulation 10 studies suggest that such in-plane aggregations hinder surfactant pressure build-up at the interface region, thereby increasing interfacial tension (IFT). On the other hand, high oil-brine IFT is unfavorable during chemical flooding.…”

“…A detailed literature review of the studies on the cation bridging formed by anionic surfactants and divalent cations is listed in Supporting Information S1. Surfactant precipitation can not only cause its retention but also block small pores, which can severely hinder further oil production . Theoretical and simulation studies suggest that such in-plane aggregations hinder surfactant pressure build-up at the interface region, thereby increasing interfacial tension (IFT).…”

“…Enormous efforts have been dedicated to improving the hard water (water containing a high concentration of multi-valent ions) resistance of surfactant formulas during chemical flooding, − which can be classified into either removing divalent ions using ion capturing agents − (chelating agents or ion exchangers) or inhibiting cation bridging formation , (Gemini surfactant and surfactant blend). Surfactant blending is an economically friendly and convenient approach without expensive and time-consuming chemical synthesis.…”