دیکشنری تخصصی مهندسی نفت - نسخه آنلاین

n: two helical boards with the same angle

n: refer to double flute

n: the vertical rotating fluid channel on the bit or enlarger

n: see spirally grooved drill collar:

n: refer to “spiral dirll collar”

n: the rubber protection valve on whose outskirt there are several flowpath trough which benefits the fluid flowing

n: refer to “fluted kelly”

n: the drive rod on the top ofdrilling pipe of small rig，with troughs in the outskirt and able to move in the cirulator propelling the pipe moving

n: the difference between the indications of a measuring instrument when the same value of the quantity measured is reached by increasing or decreasing the quantity.

n: the phenomenon that the chips of rock lags flute in the reture when drilling.

n: a drill collar with a round cross section that has a long continuous groove or flute machined helically into its outer surface. The spiraled groove provides space between the wall of the hole and the body of the collar, minimizing the area of contact between the hole wall and the collar;thus the possibility of differential pressure sticking is reduced.