ACTIVE CELLULOSE FLOUR FOR ISOLATING WATER INFLOWS IN PRODUCING WELLS AND BLOCKING WATERED RESERVOIRS IN INJECTION WELLS Russian patent published in 2018 - IPC E21B33/138 C09K8/50 

FIELD: chemistry.

SUBSTANCE: active cellulose flour for isolating water inflows in producing wells and blocking watered reservoirs in injection wells comprises 3.0-30.0 wt % of modified polysaccharide containing carboxyl groups in the amount of not less than 15 wt % and the molecular weight of, at least, 3.0⋅10⁶, 95.5-61.0 wt % of dolomite flour with a content of calcium cations of, at least, 35 wt % and 1.5-9.0 wt % of potassium dichromate.

EFFECT: creating an extended waterproof screen with high strength characteristics, which ultimately leads to an increase in the oil selection.

4 dwg, 2 tbl, 3 ex