US 5,247,990 A · Centralizer

Abstract

A centralizer for downhole sucker rods such as those used in oil wells. The centralizer has a central axial aperture for rotatable mounting on a downhole rod of a rod string. The exterior surface of the centralizer is shaped to engage the well wall when brought into contact with the wall such that rotational movement of the centralizer is limited or stopped with respect to the wall. Generally, the exterior of the centralizer is shaped to match the shape of the wall of the well in which it is to be used. A centralizer for use with a well lined with a circular tubing thus has at least one exterior surface which in cross section defines an arc having a radius of curvature equal to that of the tubing interior. A disclosed embodiment has six lobes having surfaces defining in cross section portions of three such arcs arranged symmetrically about the central aperture.

Claims16

Dependent claims

A centralizer for use in a downhole well having a wall and a rotatable rod string connected to a downhole pump, which centralizer comprises:

a body having an opening for rotatable mounting to a rod of the rod string;
and
a plurality of exterior contact surfaces for engagement of the wall;
wherein the centralizer is shaped to have a cross-section such that the contact surfaces together define portions of an arc which is non-congruent with a circle concentric with a central axis of said opening in said body, so as to engage the wall when brought into abutting contact therewith to limit rotational movement of the centralizer with respect to the wall as the rod rotates.

1 more element

Dependencies are inferred from the claim text.

Centralizer

Life of this patent

Centralizer

Life of this patent

Abstract

Claims16