masse-tige spiralée et cannelée

Désignations

Codes : pays ou zone où la désignation a cours (CH, FR, DE, EU = Union européenne, INT = usage international). Une désignation barrée est déconseillée.

Définitions

anglais

A drill collar with a round cross section that has a long continuous groove or flute machined helically into its outer surface. The spiralled 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 collar; thus the possibility of differential pressure sticking is reduced.