Abstract: A sinker bar includes a cylindrical body having an outer surface terminating at a pin end. The pin includes a transition surface extending from an outer surface of the sinker bar and including a chamfered surface extending from the outer surface, an arcuate surface extending from the chamfered surface, and a straight-line surface extending from the arcuate surface, a tapered section extending from the straight-line surface, and a threaded section extending from the tapered section and terminating at a pin face.

Abstract: A sinker bar includes a cylindrical body having an outer surface terminating at a pin end. The pin includes a transition surface extending from an outer surface of the sinker bar and including a chamfered surface extending from the outer surface, an arcuate surface extending from the chamfered surface, and a straight-line surface extending from the arcuate surface, a tapered section extending from the straight-line surface, and a threaded section extending from the tapered section and terminating at a pin face.

Abstract: Centralizers for stabilizing production tubing within a well may include a mandrel for securing within a section of production tubing and having a gland mounting surface; a gland mounted to the gland mounting surface of the mandrel, and having a cylindrical body and two or more lobes extending radially outward from the cylindrical body and comprised of an abrasion resistant material. Downhole assemblies may include a production string receivable within a cased well; a tubing anchor catcher positioned within the production string; a downhole pump coupled to the production string and located axially below the tubing anchor catcher; and a centralizer coupled to the production string.

Abstract: Centralizers for stabilizing production tubing within a well may include a mandrel for securing within a section of production tubing and having a gland mounting surface; a gland mounted to the gland mounting surface of the mandrel, and having a cylindrical body and two or more lobes extending radially outward from the cylindrical body and comprised of an abrasion resistant material. Downhole assemblies may include a production string receivable within a cased well; a tubing anchor catcher positioned within the production string; a downhole pump coupled to the production string and located axially below the tubing anchor catcher; and a centralizer coupled to the production string.

Abstract: The present invention is a tubing centralizer for use within casing within a wellbore. The tubing centralizer has a tubing centralizer cage comprising a top ring, a middle ring, and a bottom ring and a plurality of springs, where each spring connects the top ring to the middle ring and the middle ring to the bottom ring and where each spring has a double arcuate shape such that the springs arc radially outward between the top ring and the middle ring and again between the middle ring and the bottom ring. The springs may be sized such that they exert outward pressure against the inside wall of the casing such that the tubing centralizer resists movement along the casing. The tubing centralizer may further comprise a tubing centralizer mandrel, where the tubing centralizer mandrel is part of the tubing string and extends through the tubing centralizer cage.

Abstract: The present invention is a tubing centralizer for use within casing within a wellbore. The tubing centralizer has a tubing centralizer cage comprising a top ring, a middle ring, and a bottom ring and a plurality of springs, where each spring connects the top ring to the middle ring and the middle ring to the bottom ring and where each spring has a double arcuate shape such that the springs arc radially outward between the top ring and the middle ring and again between the middle ring and the bottom ring. The springs may be sized such that they exert outward pressure against the inside wall of the casing such that the tubing centralizer resists movement along the casing. The tubing centralizer may further comprise a tubing centralizer mandrel, where the tubing centralizer mandrel is part of the tubing string and extends through the tubing centralizer cage.