COMPOSITION FOR SEDIMENT REMOVAL FROM OIL WELLS AND RESERVOIR BOTTOMHOLE ZONE Russian patent published in 2015 - IPC C09K8/52 

FIELD: oil and gas industry.

SUBSTANCE: composition for sediment removal from oil wells and bottomhole zone of reservoir includes aqueous solution A containing ammonium salt, surfactant and reaction trigger, and aqueous solution B of sodium nitrite, at volume ratio of the solutions 1:1. Solution A includes ammonium nitrate as ammonium salt, Netrol as reaction trigger, Nonoxynol as surfactant at the following component ratio, wt %: ammonium nitrate 10-40, Netrol 1-5, Nonoxynol 0.01-0.5, the rest is water; and solution B contains additionally Trilon B at the following component ratio, wt %: sodium nitrite 15-30, Trilon B 3-5, the rest is water.

EFFECT: improved efficiency of both organic and inorganic sediment removal and destruction in oil wells and bottomhole zone of reservoir, at low temperatures as well.

2 tbl, 9 ex