Abstract: A wellbore sealing system includes a dart retained in a top plug and deployable through a bore defined in the top plug and through a bore defined in the bottom plug to sealingly engage float equipment abutting the bottom plug. The dart and float equipment bear wellbore pressure directly. The dart latches with the float equipment and sealing features provide bi-directional sealing.

Abstract: A centralizer sub, and system, for enhanced access to subterranean zones from the surface as used in oil and gas wellbore installations to center a pipe or casing within a wellbore or previous casing string during run-in, installation, or cementing procedures. In under-reamed applications, casing strings and centralizers pass through a smaller casing string before opening up to a larger hole where repeated compressions and decompressions of bow strings of centralizers can compromise integrity and reliability. A centralizer sub, system, and method reduces and controls insertion and running forces to preserve centralizer integrity and down-bore surfaces and equipment.

Abstract: A centralizer having asymmetrical bow springs defining a more gradual lead-in angle and a steeper retreat angle to reduce the required insertion and running forces. The centralizer comprises two end bands and a plurality of bow springs connecting the two shaped to gradually contact the surrounding hole or well casing. The bow springs are arranged such that a least two of them are asymmetric and positioned such that the apex of each is the same distance from an end band.

Abstract: Asymmetric casing centralizers are provided with varying flow resistances caused by a combination of straight vanes and spiral vanes; as a result, the casing centralizer has varying pressure drops thereacross when the casing centralizer is positioned within a preexisting structure such as, for example, a horizontal wellbore section that traverses one or more subterranean formations.

Abstract: A centralizer sub, and system for enhanced access to subterranean zones from the surf ace as used in oil and gas wellbore installations to center a pipe or casing within a wellbore or previous casing string during run-in, installation, or cementing procedures. In under-reamed applications, casing strings and centralizers pass through a smaller casing string before opening up to a larger hole where repeated compressions and decompressions of bow strings of centralizers can compromise integrity and reliability. A centralizer sub, and system reduces and controls insertion and running forces to preserve centralizer integrity and down-bore surfaces and equipment.

Abstract: A centralizer having asymmetrical bow springs defining a more gradual lead-in angle and a steeper retreat angle to reduce the required insertion and running forces. The centralizer comprises two end bands and a plurality of bow springs connecting the two shaped to gradually contact the surrounding hole or well casing. The bow springs are arranged such that a least two of them are asymmetric and positioned such that the apex of each is the same distance from an end band.

Abstract: A stage tool apparatus and components for same are described. In several exemplary embodiments, the stage tool apparatus is part of tubular string or casing positioned within a preexisting structure such as, for example, a wellbore.

Abstract: Casing centralizers and methods are described. In several exemplary embodiments, a casing centralizer has varying flow resistances; as a result, the casing centralizer has varying pressure drops thereacross when the casing centralizer is positioned within a preexisting structure such as, for example, a horizontal wellbore section that traverses one or more subterranean formations.

Abstract: A centralizer sub, system, and method for enhanced access to subterranean zones from the surface as used in oil and gas wellbore installations to center a pipe or casing within a wellbore or previous casing string during run-in, installation, or cementing procedures. In under-reamed applications, casing strings and centralizers pass through a smaller casing string before opening up to a larger hole where repeated compressions and decompressions of bow strings of centralizers can compromise integrity and reliability. A centralizer sub, system, and method reduces and controls insertion and running forces to preserve centralizer integrity and down-bore surfaces and equipment.

Abstract: A convertible valve having a conversion element retained in a seat to convert a valve gate from bidirectional flow to unidirectional flow. The convertible valve includes a valve gate moveable between a first open position and a second closed position, a seat moveable between a first position and a second position, and a conversion element retained in the seat. The seat, in its first position, maintains the valve gate in its first open position. With the valve gate in the first open position, the convertible valve allows bi-directional fluid flow. Fluid flowing through the convertible valve creates downward force on the conversion element and the seat. Upon reaching a predetermined force, the seat moves to its second position allowing the valve gate to move to its second closed position. With the valve gate in the second closed position, the convertible valve allows only unidirectional fluid flow.

Abstract: A wellbore sealing system includes a dart retained in a top plug and deployable through a bore defined in the top plug and through a bore defined in the bottom plug to sealingly engage float equipment abutting the bottom plug. The dart and float equipment bear wellbore pressure directly. The dart latches with the float equipment and sealing features provide bi-directional sealing.

Abstract: A convertible valve having a conversion element retained in a seat to convert a valve gate from bidirectional flow to unidirectional flow. The convertible valve includes a valve gate moveable between a first open position and a second closed position, a seat moveable between a first position and a second position, and a conversion element retained in the seat. The seat, in its first position, maintains the valve gate in its first open position. With the valve gate in the first open position, the convertible valve allows bi-directional fluid flow. Fluid flowing through the convertible valve creates downward force on the conversion element and the seat. Upon reaching a predetermined force, the seat moves to its second position allowing the valve gate to move to its second closed position. With the valve gate in the second closed position, the convertible valve allows only unidirectional fluid flow.

Abstract: An easy-start centralizer having asymmetrical bow springs defining a more gradual lead-in angle and a steeper retreat angle to reduce the required insertion and running forces. The reduced-slope approach of the bow spring centralizer provides for smoother, more controlled compression and engagement of the bow springs with the casing opening or other wellbore restriction.

Abstract: A method comprises providing a laminated countertop workpiece with at least one unfinished end and a profile front edge, and providing a profile edge workpiece in the same color and profile design scheme as the laminated countertop workpiece. Additionally, the method includes cutting a corner molding piece from the profile edge workpiece, and attaching the corner molding piece to a front corner area of the laminated countertop workpiece adjacent and at an angle to the profile front edge and the unfinished end. The method further includes attaching at least a portion of the profile edge workpiece to the laminated countertop workpiece along the unfinished end to continue the profile edge about the laminated countertop workpiece.

Abstract: An improved hinge is provided for interconnecting window panes or the like, wherein the hinge is particularly adapted for use in a folding rear window of an automotive vehicle having a fold-down convertible top. The hinge comprises an elongated one-piece extrusion of flexible elastomer material shaped to define a back-to-back pair of generally U-shaped channel strips joined together by a short hinge segment along one side thereof. The channel strips are respectively secured with substantial bond area to adjacent edges of a pair of window panes, with the hinge segment acccommodating relatively free swinging movement of the panes betweeen a normal position lying generally in a common plane and a folded or stacked position for compact storage.

Abstract: An improved method and related apparatus are provided for making convertible top for automobiles and the like, wherein top deck and side quarter panels of fabric-based material cooperatively form rain gutters extending along the opposite sides of the top deck panel. The top deck and each side quarter panel for a convertible top are initially sewn together in overlying relation near one side margin whereupon the side margin is folded over with the side quarter panel folded back upon itself to define a pair of directly overlying side edge strips. This folded side margin is advanced through a folding fixture adapted to insert an elongated rod substantially into the base of the fold between the side edge strips of the side quarter panel. An adhesive material is applied between the side edge strips which are then pressed together to obtain a secure bond therebetween and to lock the rod in place.