S.m.f. International

Boulet Jean Gilbert

The profiled element or portion ( ) exhibits a shape which is overall of revolution with straight or curved generatrices and an axis directed along the axis of rotation of drilling. It includes projecting parts or ribs ( ) and recessed parts or grooves ( ) arranged in helixes with, as their axis, the axis of the rotary drilling. Over at least part ( ) of the length of the profiled element ( ) in the axial direction, at least one of the geometric and dimensional characteristics of the recessed parts ( ) and of the projecting parts ( ) varies in the axial direction of the profiled element ( ). As a preference, the profiled element ( ) includes, in at least one variable profiled part ( ), passages in the shape of grooves ( ) with a cumulative cross section which decreases in a direction of flow of the drilling fluid. This thus yields a hydrodynamic bearing effect, by forming a circumferential leakage flow ( ) of the drilling fluid.

Growing community of inventors

Paris, France

Boulet Jean Gilbert