METHOD OF TREATMENT OF BOTTOM-HOLE ZONE OF HIGH- TEMPERATURE LOW-PERMEABILITY SAND RESERVOIRS Russian patent published in 2002 - IPC

FIELD: methods of treatment of bottom-hole zone of high-temperature low-permeability sand reservoirs for raising of oil well production rate. SUBSTANCE: method includes successive injection of water-repellant buffer fluid, acid composition and subsequent buffer fluid into formation. Injection is carried out under dynamic conditions without leaving injected reagents in bottom-hole zone for reaction. Main dissolving fluid is used in form of mixture of hydrochloric acid or mud acid with oxygen-containing solvent capable of intensive mixing with water and oil and presenting mixtures of monobasic alcohols, or glycols, or cellosolves. Preliminary repellant-water buffer fluid is used in form of solution of compounds of organosilicate or organosiloxane class in oxygen-containing solvent. Subsequent buffer fluid is used in form of oxygen-containing solvent. EFFECT: increased well production rate by a factor of 1.4-1.8. 3 cl