Method for modifying the permeability of a geological formation zone

Process for modifying the permeability distribution of a geological formation zone that has portions of rock material with different permeabilities, including first portions with low permeability and second portions with high permeability, said geological formation zone being located between a fluid injection well and a fluid production well, said process comprising the following successive steps:

• a) injecting a solution containing at least one hydrophobically associative polymer HAP into the injection well, so that said solution circulates in said geological formation zone and at least partially plugs the permeability of the first portions of low permeability by forming a first HAP gel,
• b) injecting a solution containing at least one sol into the injection well so that said sol circulates in said zone and at least partially plugs the permeability of the second portions of high permeability-left free by forming a second gel,
• c) injecting a solution containing at least one surfactant into the injection well, said surfactant(s) circulating in said zone and interacting with the first HAP gel so that the permeability plugged in step a) of the first low-permeability portions becomes at least partially accessible to fluids again.