Abstract: The drill string element has at least one bearing zone for bearing against the wall of the borehole during drilling. The bearing zone comprises at least one bearing segment extending in the axial direction and having an outside surface that is cylindrical and of constant diameter greater than the diameter of any other portion of the surface of the element, and also having a guide zone that is circularly symmetrical about the axis of the drill string element. The bearing zone preferably also has a drilling fluid activation zone extending axially in a disposition adjacent to the bearing segment. The guide zone presents a radius of curvature not less than one-third the outside diameter of the bearing segment.

Abstract: The stabilizer (1) has a tubular central body (3) having means for connection (3a, 3b) to a first and a second component of the string of drill rods and at least one external contact element (4) with a wall (2a) of the borehole (2). The external element (4) for contact of the stabilizer (1) with the wall (2a) of the borehole (2) has at least one means for activation (6) of a means (7) co-operating with the wall (2a) of the borehole (2) to limit the friction between the contact element (4) and the wall (2a) of the borehole (2). The activation means can consist of inter-blade spaces (6) for acceleration of the circulation (7) of the drilling liquid or by a means for coupling in rotation of the external element (4) and the central body (3) of the stabilizer (1).

Abstract: The drill string element has at least one bearing zone for bearing against the wall of the borehole during drilling. The bearing zone comprises at least one bearing segment extending in the axial direction and having an outside surface that is cylindrical and of constant diameter greater than the diameter of any other portion of the surface of the element, and also having a guide zone that is circularly symmetrical about the axis of the drill string element. The bearing zone preferably also has a drilling fluid activation zone extending axially in a disposition adjacent to the bearing segment. The guide zone presents a radius of curvature not less than one-third the outside diameter of the bearing segment.

Abstract: A profiled element for rotary drilling equipment and applications to components of a string of drill pipes has an area of abutment on the wall of a drilling hole having a maximum diameter constituting the maximum diameter of the rotary drilling equipment and a turbulence area for producing an activation of the circulation of a drilling fluid in the annulus. The profiled element also has a deflection area adjacent to the abutment area and to the turbulence area, having at least one surface inclined with respect to the axis of the rotary drilling, whose meridian line moves away from the axis in the direction going from bottom to top, in the service position of the profiled element in the drilling hole.

Abstract: The stabiliser (1) has a tubular central body (3) having means for connection (3a, 3b) to a first and a second component of the string of drill rods and at least one external contact element (4) with a wall (2a) of the borehole (2). The external element (4) for contact of the stabiliser (1) with the wall (2a) of the borehole (2) has at least one means for activation (6) of a means (7) co-operating with the wall (2a) of the borehole (2) to limit the friction between the contact element (4) and the wall (2a) of the borehole (2). The activation means can consist of inter-blade spaces (6) for acceleration of the circulation (7) of the drilling liquid or by a means for coupling in rotation of the external element (4) and the central body (3) of the stabiliser (1).

Abstract: A profiled element for rotary drilling equipment and applications to components of a string of drill pipes has an area of abutment on the wall of a drilling hole having a maximum diameter constituting the maximum diameter of the rotary drilling equipment and a turbulence area for producing an activation of the circulation of a drilling fluid in the annulus. The profiled element also has a deflection area adjacent to the abutment area and to the turbulence area, having at least one surface inclined with respect to the axis of the rotary drilling, whose meridian line moves away from the axis in the direction going from bottom to top, in the service position of the profiled element in the drilling hole.

Abstract: The shaped element has at least one stirring and entrainment zone in which the outside surface of the shaped element has recessed portions and projecting portions configured substantially in the form of helices about the axis of rotation of the drillrod, said portions being wound in a direction such as to encourage the flow of a drilling fluid in the upward direction in an annular space between the drillrod and the wall of a borehole under the effect of the drillrod rotating. The angle of inclination of the helices in which the recessed portions and the projecting portions of the shaped element are configured increases in the flow direction of the drilling fluid in the annular space.

Abstract: The profiled element or portion (3) 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 (14, 15, 20) and recessed parts or grooves (13, 16, 19) arranged in helixes with, as their axis, the axis of the rotary drilling. Over at least part (10, 11) of the length of the profiled element (3) in the axial direction, at least one of the geometric and dimensional characteristics of the recessed parts (13, 16, 19) and of the projecting parts (14, 15, 20) varies in the axial direction of the profiled element (3). As a preference, the profiled element (3) includes, in at least one variable profiled part (11), passages in the shape of grooves (16) 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 (18) of the drilling fluid.

Abstract: A rotating drill pipe string element (1) includes at least one portion (2a) of tubular shape whose external surface has at least one groove (8a, 8b, 8c, 8d, 8e) arranged in a helix having as an axis the axis (O) of the tubular portion (2a). The groove (8a, 8b, 8c, 8d, 8e) has a cross-section in a plane perpendicular to the axis (O) of the portion having an undercut part (10) lying to the rear of a radius (OA) of the cross-section of the tubular portion, (2a), the radius passing through the external end (A) of the area of the groove (8c) lying to the rear, with respect to the forward direction of rotation of the pipe string of the groove (8c) with respect to the forward direction of rotation (.OMEGA.) of the pipe string.

Abstract: An anchorage line comprising a large number of successive elements interconnected in an articulated way and each including a closed watertight tube delimitating an interior volume full of air. The anchorage line comprises a shallow depth extremity providing the link with a floating vehicle and a very deep anchorage extremity providing anchorage on an ocean bottom. The floatability of the anchorage line varies according to its length. The tubular essential parts of the anchorage line have a wall thickness related to their diameter and which is thicker the nearer these parts are to the anchorage extremity of the line. The anchorage line may be assembled on site and put in place by a suitable device.