Abstract: A mandrel for mounting a stabiliser to drilling or casing drilling or running casing tubulars. The mandrel may be formed of a base component that is one of an elastomer, semi-crystalline or amorphous polymer, a thermoset material, or a cross-linked material. The mandrel may be formed or repaired by melting a base material in a high temperature melter and delivering it to a mould placed around a drill pipe etc. A stabiliser may be formed on a sleeve by covering the sleeve with a dissolvable substance, moulding the stabiliser over the sleeve, and separating the sleeve and stabiliser so that it can freely rotate relative to the sleeve. A stabiliser for a well tubular having a cylindrical body about a well tubular having stand-off ribs extending radially outwards from the cylindrical body and a protruding ring configured to run circumferentially around and extend radially outwards from the body.

Abstract: The present invention is directed to a tubular centralization system for completing oil, gas, geothermal and other types of wells where the temperatures may be high or the side loads are high, or both. A centralizer has a ring-shaped main body having an inner surface and an outer surface, with a central axis of rotation that passes through the open or hollow centre of the ring from a first open end to a second open end. A plurality of elongate blades extend from the outer surface of the body with each blade forming a wave form with at least two peaks and troughs along the length of the blade.

Abstract: A friction reducing tool (1) having a generally tubular body (2) and three or more groups of rotatable castors (3) provided about the periphery of the body, wherein the castors of each group are substantially aligned in a longitudinal direction, and wherein each group of castors has at least one castor offset relative to at least one other castor of the same group.

Abstract: A pipe assembly (5) for use in a wellbore (3) having a plurality of outlets (6) positioned about the periphery of the pipe at longitudinally spaced apart intervals for allowing fluid to pass from the interior to the exterior of the pipe.

Abstract: A centralizer having a first group of rollers (5) for reducing friction between the centralizer and an oil field tubular (7) and a second group of rollers (4) for reducing friction between the centralizer and the wall of a well. The axles of the first group of rollers (5) are generally aligned with the axis of the bore (2) to reduce rotational friction. The axles of the rollers of the second group of rollers (4) are generally transversed to the bore (2). The arrangement reduces rotational and axial drag between an oil field tubular (7) and the walls of a well, particularly when initiating rotation of an oil field tubular.

Abstract: A drill pipe (1; 12) has a journal (2; 15) formed thereon. Integrally formed stop collars (10, 11; 16, 17) are provided at each end of the journal (2; 15). The arrangement enables rotatable tools (18) to be fitted directly to a journal (2; 15) to reduce friction between the rotatable tool (18) and the journal (2; 15). The journal (2; 15) may be of a substantially greater length than the length of the rotatable tool (18) to facilitate lubrication and cooling. Alternatively removable stop collars (30; 31) are secured adjacent the ends of a journal (28) formed on the drill pipe (25). Methods of forming the journal surface (2; 15) during manufacture of a drill pipe are disclosed. There are also disclosed methods for reconditioning an existing drill pipe (20) to form a journal (21) thereon.

Abstract: A friction reducing fitting for downhole applications. The fitting has a body portion (3) for securement about a tubular member, the body portion having a pair of apertures (5, 6). A roller (1) is provided, and an axle (4, 11) passing through said roller and said apertures in the body at either end of said roller. The axle is deformed at at least one end to prevent movement of the end of the axle through the aperture in the body.

Abstract: A friction reducing tool for drilling applications having a plurality of rollers for about the periphery of the tool (3). The rollers (4) have extensions (7) which locate within cavities (8) to prevent the rollers from passing from cavity (10) to the exterior of the tool. The tool is formed in multiple parts (3a and 3b) having interengaging tongues (5 and 6) which are joined together by passing a rod (15) through bore (13). A groove (14) is provided in outer component (2) to enable rod (15) to be inserted in bore (13).

Abstract: A fitting for reducing friction between a drilling string and the wall of a well. In a first aspect the fitting has recesses (6) provided along the bore of the fitting to lubricate the interface between the fitting and the drill string to minimise friction. In a second aspect a fitting is provided on a drill string having rotatable roller means (21) which can rotate about a point of rotation (23) so as to minimise both axial and rotational friction. According to a third aspect the fitting comprises an inner section (30) secured to a drill pipe (35) or other fitting and an outer section (31) rotatable about the inner section (30). Preferably a sealed bearing (36, 42-47, 37, 38) is provided between the inner section (30) and outer section (31).

Abstract: Improvements in casing installation components are described. The modified construction comprises radial support pedestals (2) incorporating rollers (3) on the outside of the support pedestals so that the rollers reduce longitudinal friction between the component and the well bore. The improvements described may be adapted for use in the construction of casing centralizers, float shoes, float collars and similar equipment which is inserted into the well bore.