| abstract |
The invention relates to a method for recovering oil from a fractured reservoir having an oil-wettable matrix and comprising at least one injection well and one production well, both of which arc in communication with the fractures and the matrix, wherein the method comprises the following steps in the following order: a) during a first stage, the injection, by an injection well, of a solution of viscosity-enhancing surfactants, capable of penetrating into the array of fractures, having limited interaction with the matrix, and creating a plug in situ so as to substantially and selectively reduce the perviousness of the fractures and to promote the passage of the solution of step b) into the matrix; b) during a second stage, the injection, by an injection well, of a solution of surfactants, capable of interacting with the matrix in order to make same preferably water-wettable and to extract the oil therefrom, said solution preferably flowing through the matrix; and after a latency period of at least 24 hours, c) during a third stage, the injection, by an injection well, of an aqueous solution with a view to increasing the surface tension, impregnating the matrix and, after the plug formed in step a) is dissolved by said oil, driving the oil toward the production well. |