Method for stimulating an effluent-producing zone adjoining an aquifer

Abstract

In a petroliferous zone surmounting an aquifer, a lateral sweep stimulation is achieved by means of a fluid capable of displacing the petroleum effluents (a warm fluid such as steam, a solvent, etc), which is injected into the formation through a deflected injection drain, i.e. a first drain, horizontal for example), and the oil displaced by the displacement fluid is withdrawn through a withdrawing drain, i.e. a second drain, laterally offset in relation to the first drain and substantially parallel to it. In order to prevent the oil from being displaced into the aquifer and remaining trapped therein, a third drain and possibly a fourth drain closer to the interface (I) with the aquifer than the first and the second drain are bored into the petroliferous zone. A water circulation (injection and/or withdrawal) established by means of the third drain and/or of the fourth drain considerably limits the trapping of the displacement fluid and of the displaced oil by diverting the displacement lines of the fluidized effluents towards the second drain.