METHOD FOR LIMITING WATER INFLOW IN PRODUCING OIL WELLS AND LEVELLING THE INJECTIVITY PROFILE, REDUCING INJECTIVITY IN INJECTION WELLS Russian patent published in 2023 - IPC E21B33/138 C09K8/508 E21B43/32 

FIELD: oil industry.

SUBSTANCE: invention can be used in the treatment of production and injection wells with heterogeneous permeability flooded formations in order to limit water inflows in oil production wells and equalize the injectivity profile, reduce injectivity in injection wells. The method includes preparation of a gel-forming composition containing polyacrylamide (PAA) and chromium acetate in a process vessel filled with water with constant stirring. In this case, a non-ionic surfactant is first added to the water, then polyacrylamide (PAA). After that, chromium acetate is added to the resulting mixture and stirred until uniform colouring. The prepared gel-forming composition is pumped into the well under the condition of continuous injection. At the same time, the gel-forming composition contains in % wt.: polyacrylamide (PAA) - 0.3-1.5, chromium acetate - 0.03-0.15, non-ionic surfactant - 0.2-0.5, water - the rest.

EFFECT: increased efficiency of isolation of water-saturated porous and/or fractured channels during operations to limit water inflow.

1 cl, 1 dwg, 1 tbl