METHOD FOR MUDDING FORMATION REMOVING FROM BOTTOMHOLE ZONE OF TERRIGENOUS FORMATION Russian patent published in 2006 - IPC E21B43/27 

FIELD: oil production industry, particularly methods for mudding formation removal from bottomhole zone.

SUBSTANCE: method involves injecting technological acid solution in formation; holding the solution in formation to provide chemical reaction and removing reaction products from formation. The solution includes acid-surfactant reagent comprising emulsifier Neftenol K taken in amount of 0.1-1.0% by weight, sulfanic acid in amount of 0.1-1.0% by weight, corrosion inhibitor IKU-1 or acetophenone or methyl-ethyl ketone in amount of 0.05-3.0% by weight, monohydric or polyatomic alcohol in amount of 0.0-40.0% by weight, remainder is water. The solution includes 1.0-5.0% by weight of sodium or ammonium persulphate, 10.5-50.0% by weight of acid-surfactant reagent, remainder is water.

EFFECT: increased efficiency and technological efficiency, prevention of secondary deposit and emulsion forming.

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