Saturated paraffinic and naphthenic hydrocarbons without aromatics have been vapor-phase oxidized to produce cyclic ethers and lesser amounts of olefins. These cyclic ethers appear to be effective cosurfactants for the preparation of slugs containing petroleum sulfonate surfactants. The cyclic-ether/olefin mixture has been reacted with SO//3 from oleum or liquid SO//3 to form sulfonates comprising a mixture of mono-, di-, and polysulfonates. The reaction products consisting of the sulfonates, unreacted oxidized products, and residual hydrocarbons have been extracted with isopropanol (IPA) to give two sulfonate fractions. Recent studies show that by mixing the two IPA fractions of the sulfonation products, a remarkably new surfactant behavior is obtained. In contrast to the behavior of other surfactants that yield ultralow tensions over only a narrow range of values of EACN, this mixture of mono- and polysulfonates generates low IFT's over a wide range of EACN extending from C//5 to C//1//2. The salt tolerance of monosulfonates and polysulfonates, either alone or in mixtures, is rather high, and even at about 4 wt% NaCl, the surfactant solutions remain stable and yield low IFT's against crude oil.
All Science Journal Classification (ASJC) codes