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Characterization of Crude Oil Wetting Behavior by Adhesion Tests

1990; Linguagem: Inglês

10.2523/20263-ms

J.S. Buckley, N.R. Morrow,

Reservoir Engineering and Simulation Methods

Characterization of Crude Oil Wetting Behavior by Adhesion Tests J.S. Buckley; J.S. Buckley New Mexico Petroleum Recovery Research Center Search for other works by this author on: This Site Google Scholar N.R. Morrow N.R. Morrow New Mexico Petroleum Recovery Research Center Search for other works by this author on: This Site Google Scholar Paper presented at the SPE/DOE Enhanced Oil Recovery Symposium, Tulsa, Oklahoma, April 1990. Paper Number: SPE-20263-MS https://doi.org/10.2118/20263-MS Published: April 22 1990 Cite View This Citation Add to Citation Manager Share Icon Share Twitter LinkedIn Get Permissions Search Site Citation Buckley, J.S., and N.R. Morrow. "Characterization of Crude Oil Wetting Behavior by Adhesion Tests." Paper presented at the SPE/DOE Enhanced Oil Recovery Symposium, Tulsa, Oklahoma, April 1990. doi: https://doi.org/10.2118/20263-MS Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex Search nav search search input Search input auto suggest search filter All ContentAll ProceedingsSociety of Petroleum Engineers (SPE)SPE Improved Oil Recovery Conference Search Advanced Search AbstractWettability in a rock/oil/brine system determines the distribution of fluids and can have a dramatic effect on oil recovery. A better understanding of the state of wetting in the presence of a crude oil is required for design of displacement presence of a crude oil is required for design of displacement experiments and interpretation of results for satisfactory prediction of oil recovery by waterflooding. The adhesion test has been developed to characterize interactions between a crude oil and brines of varying composition.Adhesion maps show several consistent trends for most of the crude oils examined which are unlike those for refined mineral oils. At low salinity, there is a characteristic pH above which adhesion does not occur. This pH has been shown to correspond reasonably well with the cutoff predicted by calculations based on electrostatic forces and DLVO theory. In higher salinity brines, electrostatic forces are less important, and the adhesion test results indicate that other mechanisms must be responsible for determining wetting behavior. In this area of greatest practical interest, the adhesion test provides an empirical measure of the interactions between oil and solid. The effects of temperature, surface preparation, oil composition, and oxidation are reported.II.IntroductionThe importance of wettability in determining the outcome of displacements of oil by water is well established, even if the effects of wettability alteration are not always well understood. An adhesion test has been applied as part of an effort on several fronts to generate and study a range of wettability conditions intermediate to the more often investigated cases of strongly water wet and strongly oil wet. Early in this effort, we observed changes in wetting conditions, as measured by imbibition tests similar to that described by Amott, occurring in the presence of a particular crude oil. Weakly water wet conditions gave particular crude oil. Weakly water wet conditions gave improved recovery of this oil as compared to the strongly wetted case. Similar improvements in displacement efficiency under conditions believed to be other than strongly water wet have been reported by Rathnell et al., and by Wang.The key to altered wettability appears to be exposure of the rock surface to crude oil. The question then arises whether oils can be characterized by a test that is simpler and less time consuming than coreflooding and imbibition experiments. Crude oils are complex mixtures of hundreds of components, thus chemical characterization does not qualify as simple, nor would complete chemical analysis be likely to provide the characteristics of interest, unless the many interactions between the species were much better understood than they are at present. Asphaltene precipitation gives a simple chemical separation and an estimate of the heavy polar fraction likely to participate in wettability altering interactions with solid surfaces. However, no quantitative link between amount of asphaltenes and tendency to alter wetting has been established. In fact, freshly mined Athabasca tar sands, containing high concentrations of asphaltenes, have been shown to be strongly water wet.Contact angles measured at the three-phase line of contact (brine/oil/solid) provide another method of characterization. Low angles measured through the water phase correspond to strong water wetting; high angles in the water phase (low angles through the oil phase) indicate strong oil wetting. Problems arise, however, phase) indicate strong oil wetting. Problems arise, however, because measurements of crude oil/brine/solid contact angles, unlike contact angles for mineral oils, are often dependent on the method of measurement and show extreme hysteresis. Angles measured when water first covers the surface and is displaced by oil (receding angle,) are usually low; those measured when oil is displaced by water (advancing angle,) may vary from values comparable to to much higher angles. Observations of both these cases using a captive bubble techniques similar to a test of film thickness and stability reported by Aronson and Prince led to development of the adhesion test which can distinguish broadly between the low and high cases.In the present work, we use the adhesion test to study some of the variables which can affect wettability in corefloods.p. 871 Keywords: enhanced recovery, asphaltene, precipitation, moutray, crude oil, adhesion map, oxygen, brine, adhesion test, oil recovery Subjects: Improved and Enhanced Recovery, Waterflooding This content is only available via PDF. 1990. Society of Petroleum Engineers You can access this article if you purchase or spend a download.