SEDIMENT-FORMING COMPOUND FOR LIMITING WATER INFLOW AND LEVELING THE INJECTIVITY PROFILE OF INJECTION WELLS Russian patent published in 2023 - IPC C09K8/508 E21B33/138 

FIELD: oil industry.

SUBSTANCE: invention relates to compositions for limiting water inflow into production wells by reducing the permeability of flooded formation intervals and levelling the injectivity profile of injection wells by reducing the permeability of the most washed-out sections of the formation. The precipitate-forming composition includes 10.0-20.0 wt.% aluminium salt, 0.5-20.0 wt.% urea, 0.5-10.0 wt.% urotropine, 0.01-5.0 wt.% water-soluble polymer, while the composition additionally contains 0.25-2.5 wt.% cationic surfactant (SAS) in the form of derivatives of higher carboxylic acids containing amines and acyl derivatives of amines in one molecule, 0.25-2.5 wt.% non-ionic surfactant (NSA) in the form of cyclic amidines of higher carboxylic acids composition and water (the rest). Moreover, the ratio of these surfactants in the composition is 1:1. In this case, polymers of natural or synthetic origin are used as a water-soluble polymer.

EFFECT: increasing the efficiency of the formation isolation due to the increased hardness, strength and adhesion of the sediment formed by the composition to the rock, as well as long-term action of the composition due to the stability of the resulting volumetric sediment, including at temperatures up to 300°C.

2 cl, 1 tbl