METHOD OF SELECTIVELY INHIBITING GELATION OF HYDROPHOBICALLY ASSOCIATING SUBSTANCES

FIELD: polymer materials. ^ SUBSTANCE: invention, in particular, relates to hydrophobically modified water-soluble polymers or complexes of the latter with surfactants and discloses a method for selectively inhibiting gelation of hydrophobically associating gel-forming liquid containing hydrophobically associating water-soluble polymers or complexes of the latter with surfactants. Advantage of invention resides in that, when thus inhibited liquid contacts with a hydrocarbon medium, inhibitory effect is preserved and gelation does not occur and, when liquid contacts with an aqueous medium, inhibitory effect is cancelled and gelation takes place. Inhibitor is selected such that it is well soluble in aqueous media but insoluble in hydrocarbon media, for example ethanol or methanol. Hydrophobically associating substance in associating gel-forming liquid is, in particular, hydrophobically modified water-soluble polymer based on polyacrylamide containing 84.4 or 88.8 mol % acrylamide units, 1.5 mol % n-dodecylacrylamide units, and 14.1 or 9.7 mol % sodium acrylate units. Surfactant used in polymer complexes is, in particular, cetylpyridinium chloride. Invention further discloses associating gel-forming liquid containing 1 to 10% by weight of hydrophobically associating substances and also composition for treating oil well, which comprises associating liquid. Disclosed is also a method for selectively blocking water entry into producing oil well from underground water-bearing formations. Invention can thus be used in oil production to control water inflows in oil-production well allowing restriction of water entry into well without unfavorably affecting oil production process. ^ EFFECT: facilitated gelation control in polymer-containing liquids. ^ 4 cl, 2 dwg, 1 tbl