BOTTOMHOLE DRILLING STRING ASSEMBLY FOR INCLINED AND HORIZONTAL WELL DRILLING WITH THE USE OF DOWNHOLE SCREW MOTOR

摘要

FIELD: well drilling equipment, particularly equipment for directional drilling.;SUBSTANCE: bottomhole assembly comprises drilling string, drilling bit, downhole screw motor and telescopic system installed between lower drilling string pipe and downhole screw motor. The telescopic system comprises cylinder provided with orifices in lower part thereof and connected with drilling string and hollow piston located in the cylinder. The hollow piston is attached to downhole screw motor body. The bottomhole assembly comprises fixed valve made as bush with elastic shank and installed in the cylinder over cylinder orifices. The elastic shank has conical surface to permit piston passage in the shank and annular grooves adapted to receive annular sealing members made of elastomeric material.;EFFECT: increased service life due to improved bottomhole assembly reliability.;4 dwg