Abstract: A method for injecting water into fluid storing rocks containing clay minerals, in particular in hydrocarbon sites formed by sandstones, sands, marlaceous sandstones, water storing rocks, geothermic circulation sites, in zones in the vicinity of wells, extending to large sites. Continuously or discontinuously compounds are introduced into the storing rocks having a hydrated cation diameter in the range between 0.13 and 0.15 nm, a coordination number 12. The compounds are preferably potassium-, and/or ammonium-, and/or zirconium salts. Depending on the clay content of the storing rock, stabilization is performed by using a solution of the enumerated salts in a concentration of 0.1-500 g/l, advantageously 0.1 to 300 g/l, and in a quantity of 0.5 to 5000 m.sup.3, preferably 50 to 3000 m.sup.3, which is related to the vertical dimension of the rock, expressed in meters.

Abstract: A process for the enhanced oil recovery in oil reservoirs having a significant cation exchange capacity. A displacement slug is injected into an injection well formed from several successive zones, the solubility in the injection water of the anionic surfactant which it contains being adjusted so as to increase, for compensating the rock-micellar solution interactions, from one zone of the slug to the next considering the order of introducing the different zones of the slug.