THE SIGNIFICANCE OF COLLOIDAL HYDROCARBONS IN CRUDE-OIL PRODUCTION .1. NEW ASPECTS OF THE STABILITY AND RHEOLOGICAL PROPERTIES OF WATER-CRUDE OIL-EMULSIONS

The compositions of paraffinic deposits obtained from oil wells and pi pelines were studied. It was established that, besides the well-known asphaltene, malthene, resin and paraffin, a hydrophobic paraffin deriv ative (solid hydrophobic fraction) of higher molar mass and melting po int, containing polar end-groups (C=O and COO-), can also be isolated. X-ray analyses showed this material to be an organocolloid of lamella r structure. Small angle X-ray scattering measurements demonstrated th at the substance readily swells in toluene. When its solutions and its suspensions prepared by cooling are studied in aromatic/aliphatic sol vent mixtures, they exhibit a great variety of structural characterist ics. Optical measurements indicate that its tendency to aggregate is v ery sensitively affected by the polarity of the hydrocarbon mixture, a nd by temperature. Its presence at a concentration of 1-2% stabilizes water-in-oil emulsions, which is explained by changes in the colloidal state of the paraffin derivative.