| Patent application number | Description | Published |
| 20080264629 | Field-Assemblable Bow-Spring Casing Centralizer and Method of Making A Centralizer - A casing centralizer is provided that may be shipped unassembled and is then assemblable at a well site. According to one embodiment, first and second collars each have a plurality of circumferentially spaced aligning slots and a corresponding plurality of threaded, extruded through-holes. A plurality of bow-springs each have a foot at each end. Each bow-spring axially extends between the first and second collars. The foot at one end of each bow-spring is disposed in one of the aligning slots of the first collar, and the foot at the other end is disposed in one of the aligning slots on the second collar. A plurality of threaded fasteners corresponding in number to the threaded extruded through-holes secure the ends of the bow-springs to the threaded extruded through-holes. The extruded through-holes have a flange height greater than a collar thickness adjacent to the extruded through-holes. The increased flange height allows more threads to be formed within the extruded holes, resulting in a stronger threaded connection with the threaded fasteners, and a correspondingly stronger, more durable centralizer. The foot is retained within the aligning slot to reinforce the coupling between the bow-spring and the collar. A method of manufacturing the casing centralizer is also provided. | 10-30-2008 |
| 20080283237 | Low Clearance Centralizer and Method of Making Centralizer - A bow-spring centralizer includes a center assembly having a plurality of bow springs and a pair of generally tubular moving collars secured one to each end of each bow spring, the center assembly formed intermediate a pair of generally tubular stop collars. Each moving collar/stop collar combination forms an interlocking and axially extendable collar. The centralizer is formed from a single tube. The tube is cut using a laser according to a cut pattern that creates interlocked stop collar/moving collar combinations that are rotatably locked but axially movable one relative to the other. Each of the interlocked stop collars and moving collars includes a plurality of circumferentially spaced heads, each head integrally formed on one of a plurality of circumferentially spaced extensions protruding from the stop collar or moving collar. The heads may have a variety of projected shapes, such as a rectangular, arrow or a teardrop shaped. Each head is axially slidably captured within one of a plurality of chambers on the other tubular member (stop collar or moving collar) to which the first member is coupled. The extensions of each interlocked tubular member define the outer walls of the chamber in which a head of the opposing tubular member is slidably captured. | 11-20-2008 |
| 20080283253 | Expandable Centralizer For Expandable Pipe String - A close-tolerance expandable bow spring centralizer | 11-20-2008 |
| 20090025929 | Apparatus for and Method of Deploying a Centralizer Installed on an Expandable Casing String - A method of and apparatus for deploying a bow spring centralizer installed on an expandable casing string and restrained in the collapsed configuration by restraining bands that rupture, upon expansion of the casing string, to deploy the bow spring centralizer and provide stand-off between the expanded casing string and the wall of the borehole. In one embodiment, the bow spring centralizer comprises landings for receiving and retaining the bands for restraining the centralizer in the collapsed configuration. In another embodiment, the bands are secured to the centralizer to prevent separation of the ruptured bands from the deployed centralizer. | 01-29-2009 |
| 20100218956 | APPARATUS FOR AND METHOD OF SECURING A CENTRALIZER TO A TUBULAR - A bow-spring centralizer ( | 09-02-2010 |
| 20100252274 | FRICTION REDUCING WEAR BAND AND METHOD OF COUPLING A WEAR BAND TO A TUBULAR - In one embodiment, a wear band comprises a rotating element having a bore receivable on a tubular, the bore comprising first and second bore portions slidably receiving first and second sleeve bearings. Outer surfaces of the sleeve bearings slidably engage the bore portions and the bores of the sleeve bearings slidably engage the tubular. A first and a second stop collars may be received on the tubular to together straddle the rotating element and sleeve bearings to longitudinally secure the rotating element in a position on the tubular. The tubular may be included within a tubular string run into a borehole or into the bore of an installed casing, such as in casing while drilling. The rotating element provides stand-off between a tubular and the wall of a bore, reduces frictional resistance to longitudinal sliding and also to rotation of the tubular string within the bore. | 10-07-2010 |
| 20100326671 | INTERFERENCE-FIT STOP COLLAR AND METHOD OF POSITIONING A DEVICE ON A TUBULAR - A stop collar is assembled using a method including the steps of receiving a bore of a base having a set of fingers extending along an exterior of a tubular, receiving a bore of a sleeve onto the tubular adjacent the set of fingers, and receiving the sleeve onto the set of fingers in an interference-fit. In alternate embodiments, the base comprises a plurality of angularly distributed fingers and/or the base comprises a gap to permit conformance of the base to the tubular. A fingerless base may cooperate with one or more separate fingers to form a base. In an embodiment of the method, the sleeve may be thermally expanded prior to the step of receiving the sleeve onto the set of fingers. The sleeve may be heated to expand the bore prior to being received onto the set of fingers. | 12-30-2010 |
| 20110146971 | Low Clearance Centralizer and Method of Making Centralizer - A bow-spring centralizer ( | 06-23-2011 |