Use of compounds of alkylamidobetaine type in assisted oil recovery, and microemulsions containing such compounds

Use in assisted oil recovery of compounds of alkylamidobetaine type corresponding to the general formula: in which R is a monovalent aliphatic hydrocarbon radical with 7 to 23 carbon atoms, R and R are saturated monovalent aliphatic hydrocarbon radicals with 1 to 4 carbon atoms, n is an integer from 2 to 4 and m an integer from 1 to 5. These compounds are employed to form aqueous solutions of varied concentrations as well as microemulsions, to be injected into oil deposits. ON DECRIT L'UTILISATION EN RECUPERATION ASSISTEE DU PETROLE DE COMPOSES DE TYPE ALKYLAMIDO-BETAINIQUE, REPONDANT A LA FORMULE GENERALE :(CF DESSIN DANS BOPI)DANS LAQUELLE R EST UN RADICAL HYDROCARBONE ALIPHATIQUE MONOVALENT DE 7 A 23 ATOMES DE CARBONE, R ET R SONT DES RADICAUX HYDROCARBONES ALIPHATIQUES MONOVALENTS SATURES DE 1 A 4 ATOMES DE CARBONE, N EST UN ENTIER DE 2 A 4 ET M UN ENTIER DE 1 A 5.CES COMPOSES SONT UTILISES POUR FORMER DES SOLUTIONS AQUEUSES DE CONCENTRATIONS VARIEES AINSI QUE DES MICROEMULSIONS, A INJECTER DANS LES GISEMENTS DE PETROLE.