METHOD OF CONTROL OVER AXIAL LOAD ON BORE BIT AT BORING HORIZONTAL AND DIRECTIONAL WELLS WITH SCREW BOTTOMHOLE MOTOR Russian patent published in 2009 - IPC E21B4/06 

FIELD: oil and gas industry.

SUBSTANCE: invention refers to boring oil and gas wells. The method consists in determination of pressure on a stand pipe of a boring rig in an idle mode of operation of the screw bottomhole motor (bore bit above bottomhole), in creating required load onto the bore bit unloading weight of the boring column to bottomhole till pressure on the stand pipe grows to a value of difference of pressure in working and idle modes of motor operation determined by its characteristic. Upon start of the motor (above bottomhole) during its operation in the idle mode there is performed turning the boring column over with following measurement of value of moment M_i.m. Further axial load is applied to the bore bit and turn over of boring column is performed with following measurement of value of moment on a rotor M_w.m. Actual axial load on the bore bit is determined from the mathematic formula.

EFFECT: increased efficiency of boring horizontal and directional wells, also increased reliability of screw bottomhole motor and of rock destroying tool.