DEVELOPMENT METHOD OF WATER-FLOODED OIL DEPOSIT Russian patent published in 2019 - IPC E21B43/22 

FIELD: oil, gas and coke-chemical industries.

SUBSTANCE: invention relates to oil and gas industry, in particular, to methods for development of water-flooded oil deposit in low-permeable terrigenous reservoir flooding. In method of development of water-flooded oil deposit with low-permeable terrigenous reservoir by successive injection of injection screening fringes into injection wells and an intermediate fringe of the low-viscosity gel-forming composition, the screening buffer fringes are a water-polymer solution containing the following in wt. %: high-molecular sulphonated polyacrylamide AN 125 with degree of sulphonation of 25 mol. %, 8 million units, 0.01–0.3, chromium acetate 0.001–0.03, fresh water - balance, and as intermediate fringe of low-viscosity gel-forming composition there used is composition containing, wt. %: aluminum chloride or polyoxychloride 2.0–10.0, sodium acetate 0.25–5.0, carbamide 0.25–15.0, fresh or mineralized water - the rest; each screening buffer rim is used in the volume equal to 10–100 % of the volume of the intermediate rim.

EFFECT: result is prevention of dilution of gel-forming composition by formation and pumped water; increased coverage of formation by flooding due to provision of maximum depth of penetration into reservoir of intermediate fringe of low-viscosity gel-forming composition with increased time of gel formation and high structural-mechanical properties that is a consequence of use of specified set of fringes with optimized recipes.

1 cl, 3 tbl