One-atmosphere foaming

Effects of Surfactant Chemical Structure on One-Atmosphere Foaming Properties... 

Cell size and uniformity are also important variables when studying foams. However, space limitations preclude discussions of these variables herein. Other surfactant properties critical to the success of an EOR process are surfactant adsorption and thermal stability. These questions, under study in our laboratory, are not considered in the short-term one atmosphere foam test experiment and therefore will not be discussed herein. 

Unlike previous one atmosphere foam test designs, the present test permits the effect of the oil phase on surfactant foaming properties to be determined. Refined hydrocarbons were used as model oil phases. Results summarized in Tables I and Figure 3 indicated that the presence of hydrocarbons decreased the foam stability. Examination of Table I indicated that the presence of a hydrocarbon substantially reduced the 75 C foam volumes produced by AES and AESo surfactants. 

The authors wish to acknowledge the important contributions of David Haseltine, Craig Yates and Tanya Balthazar who performed many of the one atmosphere foaming experiments and of Eugene F. Lutz, J. Dan Paiz and T. A. B. M. Bolsman who synthesized some of the test surfactants. The authors would like to thank Shell Development Company for permission to publish this work. 

Correlation equations relating surfactant chemical structure to performance characteristics and physical properties have been established. One atmosphere foaming properties of alcohol ethoxyl-ates and alcohol ethoxylate derivatives have been related to surfactant hydrophobe carbon chain length, ethylene oxide content, aqueous phase salinity, and temperature. Similar correlations have been established for critical micelle concentration, surfactant cloud point, and surfactant adsorption. 

However, there are potential objections to the use of a one atmosphere foaming experiment. These must be considered to determine the relevance of these experiments to surfactant performance in a formation. Bikerman has stated that in one atmosphere experiments the height and volume of the foam obtained depend on the details of the shaking procedure...and thus cannot be used to characterize the foaminess of a liquid in a (reasonably) absolute manner...the foam heights reproduced are specific for the test procedure selected and have no general validity. (10)... 

Foam Volume of Alcohol Ethoxylates - One Atmosphere Foaming Studies... 

Both the use of one atmosphere foaming experiments and the technique of multiple correlation analysis have a common purpose minimizing the effort required to develop new surfactants for mobility control and other EOR applications. Proper use of these techniques with due consideration of their limitations can substantially reduce the number of experiments required to develop new surfactants or to understand the effect of surfactant chemical structure on physical properties and performance parameters. ... 

The limitation of the use of one atmosphere foaming experiments to rank order the predicted surfactant performance in permeable media rather than in quantitatively or semi-quantitatively predicting the actual performance of the surfactants under realistic use conditions has already been mentioned. Multiple correlation analysis has its greatest value to predicting the rank order of surfactant performance or the relative value of a physical property parameter. Correlation coefficients less than 0.99 generally do not allow the quantitative prediction of the value of a performance parameter for a surfactant yet to be evaluated or even synthesized. Despite these limitations, multiple correlation analysis can be valuable, increasing the understanding of the effect of chemical structure variables on surfactant physical property and performance parameters. 

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