METHOD OF BOREHOLE DESLUDGING Russian patent published in 2003 - IPC

FIELD: hole drilling. SUBSTANCE: method includes hole washing with mud with rotation and reciprocating of drill stem assembly with eccentrics. Borehole is cleaned from sludge by lifting drill stem assembly at depths with distance between them determined by length of drill stem assembly with eccentrics plus length of working rod for time required for carrying-out of sludge to surface with mud flow from interval of residence of said assembly with eccentrics. In borehole sections with zenith angle up to 15- 20 deg., washing of borehole is carried out within intervals of caverns. In inclined and horizontal sections of borehole, washing with mud is effected from hole bottom to depth at which zenith angle becomes less than 15-20 deg. EFFECT: higher efficiency of cleaning of inclined, horizontal and cavernous sections of boreholes.