Abstract: A sucker rod guide for attachment to a sucker rod or the like has a body comprising a circumferential edge at each end, wherein one or both of the circumferential edges is non-linear. The shape of the non-linear circumferential edge can be symmetrically varying, asymmetrically varying, sinusoidal, castellated or stepped, undulating or randomly or pseudo-randomly profiled, to produce a turbulence stabilization effect. At least a portion of the body of the sucker rod guide, and in particular, a region around one or both of the non-linear circumferential edges comprises a textured surface or a surface structure.

Abstract: A thread protector for use with sucker rods and other downhole tools is pushable onto an end of the sucker rod for secure retention. The thread protector is optionally squeezed and rotated for release from the end of the sucker rod. Included on the protector is a sleeve having a closed end and an opposite open end for receiving and pushably engaging with the end of the sucker rod. The sleeve has one or more first regions around a circumference of the sleeve having reduced diameter for engagement with one or more regions of the end of the sucker rod and one or more second regions around the circumference of the sleeve having enlarged diameter. Application of pressure to the one or more second regions of the sleeve causes disengagement of the one or more first regions from the end of the sucker rod for removal of the thread protector.

Abstract: A centralising assembly for a downhole device in the mining or oil well field, a method of manufacture therefor and to a coupling device including a centralising device.

Abstract: A wear prevention system for a pumping system of a oil or gas well, the system comprising a sucker rod string comprising a plurality of rod components, a production pipe string, couplers for the rod components and centralizers for the rod components within the production pipe wherein centralizers are on the couplers. The centralizers contain integral signal mediums which are released as the centralizer becomes worn. The sucker rod string comprises rod components of different lengths and the rod components of relative shortest length are positioned at points of greatest curvature in the well. The rod components of relative shortest length have centralizers which contain different signal mediums to the rod components of relative longest length.