METHOD OF WELLBORE CLEANING Russian patent published in 2001 - IPC

FIELD: drilling and major repairs of wells of various applications including those filled with fluid. SUBSTANCE: method includes formation of continuous jet from full flow of drilling mud with help of jet giant lowered down to lower boundary of interval to be cleaned. Jet giant has slotted nozzle closed over perimeter of cross-section with opening determined by mathematical inequality. Continuous jet is formed in direction from axis of pipe string between external surface of jet giant and wellbore. Starting part of continuous jet from full flow of drilling mud from fixed jet giant is directed at angle to side of upper boundary of interval to be cleaned relative to axis of pipe string. Angle value is determined by mathematical inequality. Lifting of giant on pipe string is carried out at speed calculated with consideration of mathematical inequality. Upon reaching of upper boundary of interval to be cleaned by jet giant, well is washed. EFFECT: improved quality of wellbore cleaning.