COMPOSITION FOR DECLAYING OF BOTTOM-HOLE FORMATION ZONE Russian patent published in 2005 - IPC

FIELD: oil recovery industry, in particular buildup of reservoir recovery of low permeable, clay-containing beds.

SUBSTANCE: declaying composition contains clay dispersing reagent, peroxide compound and water, wherein as peroxide compound potassium fluoride peroxysolvate in activated form, comprising 1-3 mass % of oxalic or salicylic acid; and includes two sequential technological solutions. More specifically claimed composition contains (mass %): technological solutions 1: potassium fluoride peroxysolvate 1-2.5; hydrochloric acid as clay dispersing reagent 3-8.0; and balance: water; technological solutions 2: potassium fluoride peroxysolvate 1-2.5; sodium hydroxide as clay dispersing reagent 4-6.0; and balance: water. In addition said solution contain 0.1-1.0 mass % of water soluble surfactant. After treatment with disclosed solutions and well exposure dispersed reaction products are removed from bottom-hole formation zone.

EFFECT: bottom-hole formation zone of improved permeability due to effective removing of clayish and other mudding materials.

3 cl, 19 ex, 3 tbl