The
spiral drill collar is one of our product families. Three RH spiral
grooves is
made in outside surface of drill collar in order to reduce the
contract area with the
well face and the steering resistance, which can
prevent differential pressure
sticking. The weight of spiral drill collar is 4% lighter than
drill collar of the same
size. The shapes of both ends are the same as
round drill collars. Spiral drill collars are classified into
typeⅠand typeⅡaccording to the difference of
spiral
grooves.
