CPC E21B 17/1042 (2013.01) [E21B 17/1014 (2013.01)] | 27 Claims |
1. A downhole apparatus for reducing rotational and linear friction between a downhole tool and/or a downhole tool string comprising said downhole tool and a wall of a wellbore, the downhole apparatus comprising:
an annular body portion configured for location on a mandrel of the downhole tool;
one or more rib portions extending radially from the annular body portion, and configured to engage the wall of the wellbore;
wherein the annular body portion and the one or more rib portions are integrally formed from a non-metallic material;
wherein the annular body portion has a first inner diameter smaller than a maximum outer diameter of the mandrel;
wherein the annular body portion is elastically reconfigurable between a first configuration in which the annular body portion defines said first inner diameter and a second configuration in which the annular body portion defines a second inner diameter, the second inner diameter being larger than the first inner diameter so as to permit location of the apparatus around and along the mandrel; and
and wherein the annular body portion is elastically reconfigurable between the second configuration and a third configuration in which the annular body portion defines a third inner diameter, the third inner diameter being smaller than the second inner diameter and larger than a minimum outer diameter of the mandrel so as to permit the apparatus to be located on the mandrel such that the mandrel is rotatable within the apparatus and/or the apparatus is rotatable around the mandrel.
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