FIELD: mining.
SUBSTANCE: invention relates to technical means for drilling side holes from the horizontal part of an open-hole, in particular to drilling devices using long-length flexible pipes (coiled tubing). Assembly of the bottom of the drill string – ABDS for drilling of offshoots includes serially arranged from the bottom upwards a bit, a screw downhole motor – SDM, long flexible pipes – LFP, after the bit there is an oscillator-turbulence promoter, after the damper there is a unit for change of the bit misalignment to the specified range of angles α from 0 to 3°, a telesystem with a connecting unit. Bit displacement change unit consists of upper and lower adapters, core and gear clutch, which is reinforced with hard-alloy teeth. Telesystem consists of a housing made from an alloyed drill pipe; in the housing, in series, from bottom to top, there are assemblies: a deflector, a load module, an inclination meter, a power supply and communication unit. Note here that three flexible centralizers are arranged in telesystem housing in the form of a ring with three spring-loaded canopies made of sheet steel welded on its outer surface. Body of the telesystem on the outside at both ends is equipped with rigid centralizers, which are made in the form of rings, on the external surface of which corresponding overflow channels are made in the form of longitudinal cylindrical grooves with possibility of working fluid overflow. Telesystem is connected by geophysical cable, stored inside LFP column through geophysical tip with ground equipment. At that, above the geophysical tip on the inner surface of the body of the telesystem there are notches, which enable to capture the body of the telesystem. Connecting assembly is made in form of mechanical disconnector, which is a shear pin, destructing at design load.
EFFECT: technical result is monitoring of downhole parameters and determination of position of assembly of bottom of drill string (ABDS) in real time, adjustment of intensity of borehole deviation depending on angle of skewing of engine and diameter of well, increased speed of drilling bit during drilling of offshoot, which reduces time of works and reduces costs.
1 cl, 3 dwg
