| 摘要 |
<p>A drill stem element for drilling a well with flow of a drilling fluid around the element and in a direction extending from a drilling well bottom towards the surface, including a member and a coupling mounted for rotation about the member. The coupling includes at least two abutment zones on a wall of the well during drilling, each abutment zone externally includes at least one abutment portion having an outer diameter greater than a diameter of other portions of the element, each abutment zone having a convex rounded shape generated by revolution, each abutment zone being axially remote from at least one other abutment zone. The coupling further includes an intermediate zone between the two abutment zones, an opening being provided between the coupling and the member for the flow of drilling fluid between the coupling and the member forming a fluid bearing.</p> |
