METHOD OF CLEANING THE PRODUCING FORMATION BOTTOM-HOLE ZONE Russian patent published in 2002 - IPC

FIELD: development of oil and gas deposits by wells; applicable in cleaning of bottom-hole zone of producing formation after well drilling. SUBSTANCE: method includes successive injection of selected portions of chemical reagents into bottom-hole formation zone. In so doing, prior to treatment of bottom-hole formation zone and after supply of every chemical reagent, zone supersaturated with gas built up in bottom-hole formation zone by gas injection at pressure exceeding formation pressure. In this case, gas is supplied to bottom-hole zone at minimal flow rate, and supersaturated zone is built up with radius exceeding that of contaminated part of bottom-hole zone. After leaving the well to stand for time required for performance of reaction of chemical agents with producing well rocks and contents of porous medium, bottom-hole formation zone is cleaned from reaction products by putting well into operation. EFFECT: higher efficiency of cleaning of bottom-hole zone of producing formation from filtrate of drilling mud and reaction products. 1 ex