Abstract: Betaines containing the morpholine nucleus, some of which are novel per se, are dissolved in sea water or formation water, the concentration of betaine being from 200 to 100,000 ppm to give a surfactant solution suitable for displacing crude oil from a formation in an enhanced oil recovery process. Included in the solution can be an anionic surfactant containing in its structure an ethoxylated benzene ring which shows a synergistic effect with the betaine in lowering the interfacial tension of the surfactant solution against oil. These betaines have high tolerance towards divalent metal cations and high temperature stability as compared with betaines previously proposed for enhanced oil recovery.

Abstract: An inflatable barrier for oil spilt on water consists of an air chamber and a water chamber which when inflated give a figure-of-eight cross-section, and in order to facilitate laying there is a pilot air tube attached to the air chamber preferably 1/500 the cross-sectional area of the air chamber. The pilot air tube is quickly inflated and prevents sinking or twisting of the barrier prior to inflation of the air and water chambers.