Abstract: The present invention relates to the use of at least one compound of formula (I): (I) [P+(R1—Y—R2)4]zXz- wherein: Y is chosen from an oxygen atom or an NH group; R1 is a linear or branched alkyl radical having from 1 to 15 carbon atoms; R2 is chosen from a hydrogen atom or a linear or branched alkyl radical having from 1 to 14 carbon atoms; Xz- is a monovalent anion or a divalent anion, or a trivalent anion, or a tetravalent anion group; z is a number from 1 to 4; for enhancing the injectivity of an injection well, wherein the compound of formula (I) is added to an aqueous medium to form an injection stream which is injected into a subterranean formation which comprises at least one polymer, via said injection well.

Abstract: The present invention relates to a flow control valve to be connected to a pipe. The valve includes: a plurality of fluid transport tubes having a geometrically variable cross-section and placed in parallel with each other; and a means for connecting to the pipe and located at one end of the fluid transport tubes.

Abstract: The present invention relates to a flow control valve to be connected to a pipe. The valve includes: a plurality of fluid transport tubes having a geometrically variable cross-section and placed in parallel with each other; and a means for connecting to the pipe and located at one end of the fluid transport tubes.