Surface tension, interfacial tension and emulsification of sodium dodecyl sulfate extended surfactant

In enhanced oil recovery, not only the low‐tension performance, but also the robustness at optimum formulation is an important issue. The fourth part of our review series is dedicated to robustness, defined as the width of the zone exhibiting three‐phase behavior around the optimum formulation, whatever the scanned variable. It is first corroborated from a screening of the available data in the literature that the tension minimum is inversely proportional to the square of the three‐phase range in the HLD scale. However, since there is still an inaccuracy of about a factor 10 in the tension minimum, some significant improvement can be attained in some cases by increasing the three‐phase behavior width in two ways. The first approach consists of finding systems that are insensitive to some formulation variable such as temperature, surfactant mixture composition or concentration, and water‐to‐oil ratio. The second way is to produce an artifact through which the optimum formulation is produced twice in a scan. If the distance between the two events in the scan is reduced down to be zero, their corresponding three‐phase behavior zones merge and result in a wider WIII region with a low tension. Several cases of such events are reported: alkaline scans, anionic‐nonionic and anionic‐cationic mixture changes, linear change in composition in three‐surfactant mixture, partial precipitation from a surfactant mixture in a salinity scan, and excessive partitioning of polyethoxylated nonionics. More complex transitions with three effects in a single scan or three concomitantly scanned variables show even more possibilities in practice.

Section: Insensitivity To a Formulation Variable Change Reduced Sensimentioning

confidence: 99%

How to Attain Ultralow Interfacial Tension and Three‐Phase Behavior with Surfactant Formulation for Enhanced Oil Recovery: A Review. Part 4: Robustness of the Optimum Formulation Zone Through the Insensibility to Some Variables and the Occurrence of Complex Artifacts

Salager

Antón

Arandia

et al. 2017

“…The result indicated that PP 9 S exhibits the best surface activity among the extended surfactants because of the optimal number of inserted PO chains. The surface tension, IFT, and emulsification of sodium dodecyl PO sulfate (C 12 P m S, m = 4, 8, and 12) were investigated (Liu, Zhao, Li, & Niu, ). Therefore, extended surfactants can produce ultralow IFT and are the foremost candidates for microemulsion and EOR.…”

Section: Introductionmentioning

confidence: 99%

Effects of the Polypropylene Oxide Number on the Surface Properties of a Type of Extended Surfactant

Zhou

Wang

et al. 2018

The surface properties of 5 extended surfactant C12–14P mE2S solutions in pure water and 0.1 M NaCl were investigated through surface tension and electrical conductivity measurements. The surface properties measured include the critical micelle concentration (CMC), critical surface tension (γcmc), maximum surface excess concentration (Γmax), minimum area occupied per surfactant molecule (Amin), and efficiency in surface tension reduction (pC20). The CMC values of the 5 surfactants decreased with increasing polypropylene oxide number (PON) and were higher than those obtained in 0.1 M NaCl. The Γmax values showed a downward trend whereas the Amin values exhibited an upward trend with increasing PON without NaCl. The Γmax values were higher and the Amin values were lower than those obtained without 0.1 M NaCl. The CMC values increased at elevated temperatures. The CMC values of C12–14P3E2S, C12–14P5E2S, and C12–14P8E2S were similar but were markedly lower than those of C12–14E2S at different temperatures. When PON was less than 12, the log CMC value decreased linearly with increasing PON in the absence of salt, and the relationship between pC20 and PON was linear. But in the presence of 0.1 M NaCl, the log CMC value decreased exponentially with increasing PON.

“…Effect of polypropylene oxide intermediate size (PON) on the CMC and adsorption area(He et al, 2014;Lange and Schwuger, 1968;Liu et al, 2016;Witthayapanyanon et al, 2006) …”

mentioning

confidence: 99%

Extended Surfactants Including an Alkoxylated Central Part Intermediate Producing a Gradual Polarity Transition—A Review of the Properties Used in Applications Such as Enhanced Oil Recovery and Polar Oil Solubilization in Microemulsions

Salager

Forgiarini

Márquez

2019

The research published in the past half century indicates that surfactant interfacial performance in producing low tension or high solubilization with polar oils is not generally attained with pure conventional species exhibiting well‐defined polar and nonpolar parts. The improvement trends reached with surfactant mixtures as well as the introduction of additives like cosurfactants and linkers lead to the introduction of the so‐called extended surfactants, whose structure includes an intermediate polarity spacer between the hydrophilic head and the lipophilic tail. Recent investigations on different kinds of surfactants in a variety of applications—such as detergency, cosmetics, enhanced oil recovery or crude demulsifying, and vegetable oil extraction—indicate that these extended surfactants are likely to be particularly performing with oils containing polar groups, such as triacylglycerols and asphaltenic crudes. Possible applications of extended surfactants in enhanced oil recovery, crude emulsion breaking, detergency and cleaning, medicine and cosmetics vehicles, and natural oil extraction as well as some other cases are quickly reviewed.