WASHING UNIT OF DRILLING BIT Russian patent published in 2003 - IPC

FIELD: drilling of oil and gas wells, particularly, drilling rock-cutting tools, more specifically, jet-type rolling- cutter drilling bits. SUBSTANCE: washing unit of drilling bit includes body with channel and socket to which nozzle is secured with hollow member with screw blades installed on nozzle internal wall. Hollow member is made in form of sleeve and screw blades are located so that they provide for twisting of drilling mud flow through 1.5-2.5 revolutions. Length of immersed jet from nozzle outlet hole to contact with well rock is selected from equality L=(5-6)d, where L is length of immersed jet, mm; d is diameter of nozzle outlet hole, mm. EFFECT: improved drilling bit parameters (footage per bit, penetration rate). 1 dwg