MICELLARSYSTEME MIT EINEM GEHALT AN N-ACYL-N-ALKYL-(ALPHA)-AMINOCARBONSAEUREVERBINDUNGEN, DIE SICH INSBESONDERE ZUR HILFSMITTEL-GEFOERDERTEN GEWINNUNG VON KOHLENWASSERSTOFFEN EIGNEN

In the preparation of miceller systems for enhanced hydrocarbon recovery, surfactants are used which consist of N-acyl N-alkyl- alpha -amino-carboxylic compounds. The considered products comply with the general formulas: wherein at least one of R1, R2 and R3 is a saturated or unsaturated C1-C22 aliphatic hydrocarbon radical (one of them having optionally a carboxylic group) the other or others being a hydrogen atom, R1, R2 and R3 having together from 4 to 22 carbon atoms, R4 is an alkyl radical of 1-5 carbon atoms, R5 an alkyl radical of 1-12 carbon atoms and M is an alkali or alkaline-earth metal, ammonium or a quaternary ammonium group. As used in the formation of micellar systems (aqueous solutions, emulsions or mirco-emulsions) for enhanced oil recovery, these surfactants have improved performances, particularly, in field waters of high polyvalent ion (Ca++ and Mg++) content, within relatively wide temperature and pH ranges.