PROCESS OF BOREHOLE DRILLING Russian patent published in 1999 - IPC

FIELD: gas and oil production, drilling of vertical and inclined boreholes. SUBSTANCE: in accordance with invention rock breaking tool is rotated relative to face of borehole with speed ω, axial force on rock-breaking tool is fixed, speed ω is varied till its nonresonance value determined from solution of linear differential equation of fourth order with regard to sagging of arrangement of bottom part of drill pipe string with which lateral force acting on drill bit does not exceed deviation of drill bit on face is established. After this deviation of drilling of borehole from previous value is corrected by increase or decrease of axial force with preservation of drilling azimuth. Usage of invention ensures reduction of amplitude of lateral vibrations of bottom part of drill pipe string and 12% increase on the average of speed of drilling of borehole. EFFECT: reduced amplitude of lateral vibrations of bottom part of drill pipe string and increased speed of drilling. 2 dwg, 1 tbl