Abstract: An apparatus and method for manufacture of a unitary centralizer forming Apertures are formed in a blank to create an intermediate blank having bow spring elements within a unitary centralizer and expanding a medial portion of the bow spring elements. An expansion element is inserted into the intermediate blank. An expansive force is applied to the expansion element, thereby expanding the medial portion of the bow spring elements. Mandrels placed against the upper and lower surfaces of the expansion element receive a compressive force for transfer to the expansion element. Set screw holes are placed on the unitary centralizer for attachment.

Abstract: An apparatus and method for manufacture of a unitary centralizer forming Apertures are formed in a blank to create an intermediate blank having bow spring elements within a unitary centralizer and expanding a medial portion of the bow spring elements. An expansion element is inserted into the intermediate blank. An expansive force is applied to the expansion element, thereby expanding the medial portion of the bow spring elements. Mandrels placed against the upper and lower surfaces of the expansion element receive a compressive force for transfer to the expansion element. Set screw holes are placed on the unitary centralizer for attachment.

Abstract: A float shoe/collar apparatus and method for multi-purpose use in running a tubular string such as a casing string or liner into a wellbore and for optimizing cementing operations. In one presently preferred embodiment, the apparatus permits auto filling of the tubular string as the string is lowered into the wellbore. Circulation can be effected through down jets for washing the wellbore as necessary. After the tubular string is positioned, the down jets can be blocked off and up jets opened to thereby direct cement upwardly to optimize cement placement. Check valves can also be activated to prevent flow from the wellbore into the tubular string. In one embodiment, the apparatus comprises an inner member and tubular member. The inner member is movable upon release of shear pins to cause longitudinal movement relative to the outer member. The movement of the inner member may close a plurality of downward jets and may also open a plurality of upward jets, if desired.

Abstract: A stand-off device for tubulars comprising a sleeve adapted to fit around a tubular, the sleeve comprising an outer surface and a plurality of blades extending along the outer surface of the sleeve, the blades comprising a bearing surface, wherein the bearing surface of each blade is curved longitudinally. The device may be metallic or non-metallic. Non-metallic devices further comprise a protective coating to inhibit abrasion, corrosion, sparking, and electrolysis. The stand-off device is particularly suitable for use with casing in deviated wellbores.

Abstract: A stand-off device for tubulars comprising a sleeve adapted to fit around a tubular, the sleeve comprising an outer surface and a plurality of blades extending along the outer surface of the sleeve, the blades comprising a bearing surface, wherein the bearing surface of each blade is curved longitudinally. The device may be metallic or non-metallic. Non-metallic devices further comprise a protective coating to inhibit abrasion, corrosion, sparking, and electrolysis. The stand-off device is particularly suitable for use with casing in deviated wellbores.

Abstract: An improved float shoe/collar apparatus is provided for use during casing run in or floated in. The apparatus has an inner tubular member and outer tubular member, movable upon release of shear pins to cause longitudinal movement relative to each other. The movement of the inner tubular member closes a plurality of downward jets and opens a plurality of upward jets. The apparatus also is equipped with a set of check valves, held open on run in, and activated to close upon cementing to prevent “u-tubing” of fluid back into the casing.

Abstract: A tool tie down system is provided which ties down a well tool inserted into the top end of a casing string being lowered into a well from upward movement caused by pressure forces from below the well tool inside the upper end of the casing string. The system includes a frictionally engageable clasp for supporting a tie down yoke on the bails connecting the traveling block and elevator slips assembly. A plurality of cords attached to the elevator on one end and the tie down yoke on the other end redirect forces from below to hold the well tool in place resisting these forces, the cords being fabricated, for example from an elastomer, a metal or metal alloy, a fiber, or combinations thereof.

Abstract: The apparatus of the present invention is a mechanism for use in cementing a casing string in a well bore comprising a float collar connectable to the casing string, a cement plug engagable to the float collar, and a wiper plug engagable to the cement plug, each element utilizing inclined plane J-slots for engagability. When engaged, the J-slots disallow not only rotational movement between the elements, but also vertical movement between the elements.

Abstract: A method and apparths for filling and circulating drilling fluid in a wellbore during casing running operations is disclosed. A fill/circulate tool is placed partially within the upper end of a casing string so that fluid may be pumped into the interior of the casing string. The tool has a self energizing seal element which engages the interior wall of the casing string when the tool is fully lowered therein, said seal element being energized by the pressure of the fluid in the casing string so that fluid pumped into the casing string through the tool is circulated through the casing string and explled from the lower end of the casing string.

Abstract: A casing joint is provided for use in landing a casing string in a well bore for an oil or gas well in a controlled manner so that movement of the casing string relative to the well bore does not cause the casing string to become damaged. The casing joint includes an inner tubular member disposed within an outer tubular member. The casing joint also includes a means for causing the inner tubular member to move axially relative to the outer tubular member in response to differential fluid pressures. The casing joint further includes a plurality of shear pins attaching the inner tubular member to the outer tubular member. The shear pins are selected to shear at a predetermined load so as to enable the inner tubular member to move axially relative to the outer tubular member. The casing joint also includes a pair of anti-rotation lugs which prevent the inner tubular member from rotating relative to the outer tubular member.

Abstract: A method and apparatus for cementing a casing string utilizes a port collar which may be hydraulically opened and mechanically closed, and permits the passage of downhole tools through the port collar, without opening the port collar.

Abstract: There is disclosed an assembly of parts for use in cementing a casing string in a well bore comprising a float collar connectible as part of the string, a cement plug lowerable onto the collar, and a wiper plug lowerable onto the cement plug, the lower end of the cement plug having threads for limited make-up with threads on the upper end of the collar and the lower end of the wiper plug having threads for limited make-up with the cement plug, so as to limit rotation between them.

Abstract: There is disclosed a well packer for use in closing off the annulus between a casing string in which the packer is connected and a well bore into which the casing string is lowered. The packer includes a mandrel connected as part of the casing string, a sleeve of elastomeric material surrounding an intermediate portion of the mandrel and adapted to be inflated into engagement with the well bore, and relatively short, substantially rigid but flexible, overlapping strips disposed about only upper and lower portions of the sleeve for expansion therewith into engagement with the well bore.

Abstract: There is disclosed apparatus for use in completing a well whose well bore has a substantially horizontally extending lower end into which a casing string is to be lowered, the apparatus including a tool adapted to be connected in the casing string and having a plug therein above a back pressure valve installed in the lower end of the string to form a buoyant chamber within the casing string which is filled with a low density fluid for lowering into the substantially horizontally extending lower end of the well bore.

Abstract: There is disclosed an oil or gas well having a well bore which penetrates a production zone and a casing string which is anchored in the well bore by a column of cement bonded to the casing string and well bore. Connectors are installed as part of the casing string to permit portions thereof opposite the production zone and above the production zone to be respectively contracted or extended in response to subsidence or other causes of axial loading of the string through the cement column.

Abstract: There is disclosed a through the tubing bridge plug adapted to close off a well bore beneath the lower end of a well tubing and which includes a tubular body connectable to a pipe string for lowering it through the well tubing, an elastomeric packing element surrounding the body, and upper and lower sets of thin, elongate metal strips surrounding the body respectively above and below the packing element. The upper strips are caused to move downwardly and the lower strips to move upwardly to cause their ends to slide over expander surfaces and outwardly against the well bore, on the body above and below the packing element, and the packing element is then inflated into engagement with the well bore intermediate the ends of the strip ends of the metal strips being forced outwardly against the well bore, and the packing element then being inflated to sealably engage the well bore intermediate the ends of the upper and lower metal strips.

Abstract: Apparatus is disclosed for use in placing cement within the annulus between a casing string and a well bore in which the casing string is suspended, such apparatus including a stage collar connectible as part of the casing string and having a packing element mounted thereon and adapted to be inflated into engagement with the well bore, one or more side ports through which cement may be circulated into the annulus above the packer, tubular members or sleeves for opening and closing the ports following inflation of the packing element.

Abstract: There is disclosed a casing centralizer which comprises a pair of longitudinally spaced collars adapted to be assembled about the casing, and bow springs which extend longitudinally between the collars. The ends of the bow springs are secured to the collars by means of outwardly bent portions at the ends of the bow springs which are adapted to fit within openings in the collars, and a tab on one side of each collar opening which extends inwardly from the inner surface of the collar and passes through an opening in the end of the bow spring adjacent its outwardly bent portion, whereby each tab may be bent over the inner surface of the bent portion at the end of the bow spring so as to hold the outer surface of the end of the bow spring against the inner surface of the collar.

Abstract: There are disclosed several embodiments of an inflatable tool of the type comprising a mandrel adapted to be raised and lowered within a well bore and an inflatable element including a sleeve of elastomeric material surrounding a tubular section of the mandrel and anchored at its ends to upper and lower heads which are disposed about the tubular section and relatively movable longitudinally toward and away from one another, upon inflation of the sleeve, as well as substantially flat reinforcing strips of sheet metal or other relatively rigid but flexible material which are arranged about the sleeve with their side edges in overlapping relation and with their ends anchored to the heads so that the strips flex outwardly with the sleeve to cause the inflatable element to engage a wall of the well bore.

Abstract: A re-entry cementing float shoe for use with sonar/TV underwater guide systems is a short inner and outer cylindrical housing members in concentric spaced relationship forming an annular space therebetween with a cementing core filling said annular space, said inner housing has its top below the top of the outer housing, the upper inner surface of the cement forming a taperal lining cone, the bottom of the cone ending at the top of the inner housing and the top of the cement cone ending at the inner surface of the outer housing below an inner top portion of the outer housing, said portion having an attachment means for accepting and attaching to a casing pipe.