METHOD OF SOUR WELL INTERVENTION IN TERRIOGENOUS RESERVOIR Russian patent published in 2011 - IPC E21B43/27 C09K8/74 

FIELD: oil and gas production.

SUBSTANCE: method of sour well intervention in a terriogenous reservoir involves injecting into a productive formation a first processing medium containing, wt %: hydrazine hydrochloride N₂H₄·2HCl 10.8, organic phosphonic acid derivative 0.5, surface-active substance 0.5, corrosion inhibitor 0.5, water the rest. Further, after curing of the processing medium, a buffer liquid containing the surface-active substance in the concentration 0.5-0.8 % is injected into the reaction mixture. It is followed with injection of a second processing medium containing, wt %: hydrazine hydrochloride N₂H₄·2HCl 10.8, ammonium bifluoride NH₄F·HF 4.3, organic phosphonic acid derivative 0.5, surface-active substance 0.5, corrosion inhibitor 0.5, water the rest. Further, after curing of the second processing medium, well completion is performed.

EFFECT: prevented sedimentation in processing of terriogenous reservoirs having carbonate impurities with providing a high degree of filter cake removal ensured by a higher degree of dissolution and dispersion of a clay matter.

2 cl, 3 tbl