METHOD OF TREATMENT OF BOTTOMHOLE FORMATION ZONE Russian patent published in 2003 - IPC

FIELD: oil producing industry, particularly, methods of treatment of bottomhole formation zone of wells drilled into terrigenous low-permeability reservoirs. SUBSTANCE: method includes injection into formation of solution of hydrochloric acid, solution of mixture of mineral acids, organic solvent and allowing time for reaction process. Solution of hydrochloric acid is injected into formation under dynamic regime, then, organic solvent is injected and, further on, solution of mineral acids mixture with time delay required for attaining pH 4-5 of said solution. In this case, organic solvent and/or solution of mineral acids mixture additionally contains mutual solution in form of glycal ethers, including ethyl cellosolve, butyl cellosolve or dioxane. EFFECT: higher efficiency of treatment of bottomhole formation zone and intensified recovery of oil from low- permeability reservoirs. 3 cl, 3 ex