Patent ID: 7520344
Filing Date: 2009-04-21
Classification: E21B

Abstract:
1. An apparatus for protecting a subassembly with a body having a body outer diameter for use inside a borehole of a well comprising: a collar having a collar axis, an inner side and an outer side and a collar outer diameter larger than the body outer diameter, a collar top square cut edge and a collar bottom beveled edge; a plurality of offset indentations formed on the outer side of the collar, wherein each offset indentation in rows of four to eight offset indentations along an angle sloping from about 7.5 degrees to about 45 degrees from the collar axis; a plurality of a metal carbide inserts, each fitted into an offset indentation with an interference fit forming a wear resistant pad on the outer side of the collar; a sealing means disposed between the collar bottom beveled edge and the body; and at least two spring locking apparatus disposed in inner side of the collar, wherein each spring locking apparatus engages a locking portion on the body thereby forming a sealed wear protected subassembly.