GEL-FORMING COMPOUND FOR RESTRICTION OF WATER INFLOW TO WELL Russian patent published in 2011 - IPC C09K8/512 

FIELD: oil and gas industry.

SUBSTANCE: gel-forming compound for restriction of water inflow to the well contains sodium silicate, concentrated acid and fresh water, includes orthophosphoric or chlorhydric acid as concentrated acid, or sulphuric acid and additionally acrylic acid and initiator of its polymerisation - potassium persulphate or ammonium persulphate at the following component ratio, wt %: sodium silicate 3.0-6.0; the above concentrated acid (in terms of basic substance) 0.1-0.6, acrylic acid (in terms of basic substance) 4.0-10.0, the above polymerisation initiator 0.4-1.5, and fresh water is the rest.

EFFECT: decrease of corrosive activity in relation to steel, enlargement of time for gel formation at increased bed temperatures, increase of deformation-strength characteristics, and increase of duration of period of waterproof effect.

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