METHOD OF BOTTOM-HOLE ZONE TREATMENT Russian patent published in 2016 - IPC E21B43/27 E21B43/22 

FIELD: oil and gas industry.

SUBSTANCE: invention is referred to oil and gas industry. The method of bottom-hole zone treatment in formation includes injection of hydrocarbon solvent, injection of acid composition containing halogen acid, organic acid, anionic, non-ionic and cationic surfactants, flush of the acid compound to the formation depth by displacing fluid, process withhold and extraction of waste solvent by generating depression in the well. At that before injection of the acid composition its reaction rate is adjusted for the type of rock in the treated zone, and adjustment of the reaction rate for the type of rock in the treated zone is considered as reached when ratio of maximum and minimum reaction rate for certain rock types is not more than two; interfacial tension value is decreased up to the value at which a channel is generated for penetration of the acid composition to the formation as a dominant bore hole; value of man-caused load is decreased up to maintenance of sludge complex at less than 1% by complexing and change in content of anionic, non-ionic and cationic surfactants at obtained values for slow-down of acid reaction and interfacial tension.

EFFECT: improved efficiency of acid stimulation of carbonaceous reservoirs due to adjusted rates of acid reactions with different generic structure of limestone contained in the rock of producing formation, development of fluid channels made as bore holes, prevented generation of sludge complexes formed in process of acid stimulation.

3 cl, 6 tbl, 7 dwg