Abstract: A groundwater pumping apparatus includes an outer tube, an inner tube, a shield member, a vacuum unit and a pump unit. The outer tube is buried in ground, and has a water-passing portion at its lower part. The inner tube has a substantially same length as the outer tube, and is placed in the outer tube such that the inner tube is spaced from the outer tube. The inner tube has a groundwater inlet at its bottom end, which is provided at a position lower than a top end of the water-passing portion. The shield member shields top ends of the outer tube and the inner tube. The vacuum unit reduces a pressure in the inner tube. The pump unit pumps groundwater that comes in the inner tube through the groundwater inlet.

Abstract: A float apparatus for use in a casing string. The float apparatus includes an outer case having a check valve positioned therein. A body portion which may be comprised of high compressive strength cement affixes the check valve to the outer case. The check valve includes a valve body and a valve element. The valve body defines a valve seat and the valve element is deformable so that it will conform to the shape of the valve seat and seal against flow in the casing.

Abstract: An apparatus and method for cementing a casing string in a wellbore. A self-filling tubular cementing collar connected to the lower end of a casing string is provided with one-way flow valving that allows well fluid to enter and self-fill the casing string as it is lowered into the wellbore and automatically prohibits reverse fluid flow from the collar when washing or cementing during forward circulation through the collar. The one-way valving is carried by an axially movable support that can be shifted by a cementing plug moved by pump pressure to permanently seal the entry flow passage after the casing sting is properly positioned in the wellbore.

Abstract: A float shoe comprising an upper section having a casing connection at an upper end thereof, and a lower section slidably coupled to the upper section, the lower section comprising a closed lower end and having at least one port disposed therein.

Abstract: An apparatus to protect the mounting area of casing when subsequently attaching a tubular is disclosed. A sleeve that defines a sealed cavity having a loose incompressible material inside covers the mounting location on the casing. The cementing of the casing takes place through the sleeve. After the cementing, the sleeve is drilled out and the incompressible material is removed to the surface with the drill cuttings. A tubular is inserted in the casing and is preferably expanded into sealing contact with the mounting location on the casing. At the end of expansion, the run in shoe on the tubular is retrieved.

Abstract: An expandable float shoe and associated methods are provided. In a described embodiment, an expandable float shoe is attached to a leg of an expandable wellbore junction. The float shoe and leg are radially compressed, such as by folding along their axial lengths. The wellbore junction is conveyed into a well and expanded by applying pressure therein. The float shoe expands outward, along with the leg of the wellbore junction.

Abstract: An apparatus for preventing or limiting the rotation of cementing plugs in a casing string during drillout. The apparatus includes an outer housing with a sleeve disposed therein. The sleeve has an inner surface configured to engage cementing plugs received therein to cause an interference fit. The sleeve will hold the cementing plugs when rotational forces, such as drilling forces, are applied so that during drillout, rotation of the cementing plug is prevented or is at least limited.

Abstract: An apparatus for preventing or limiting the rotation of cementing plugs in a casing string during drillout. The apparatus includes an outer housing with a sleeve disposed therein. The sleeve has an inner surface configured to engage cementing plugs received therein to cause an interference fit. The sleeve will hold the cementing plugs when rotational forces, such as drilling forces, are applied so that during drillout, rotation of the cementing plug is prevented or is at least limited.

Abstract: An apparatus for preventing or limiting the rotation of cementing plugs in a casing string during drillout. The apparatus includes an outer housing with a sleeve disposed therein. The sleeve has an inner surface configured to engage cementing plugs received therein to cause an interference fit. The sleeve will hold the cementing plugs when rotational forces, such as drilling forces, are applied so that during drillout, rotation of the cementing plug is prevented or is at least limited.

Abstract: A float shoe comprising an upper section having a casing connection at an upper end thereof, and a lower section slidably coupled to the upper section, the lower section comprising a closed lower end and having at least one port disposed therein.

Abstract: A differential float and cementing valve assembly used to position and cement casing in a wellbore. A leaf spring and other components of the assembly are preferably constructed of composite materials and/or plastics that can be drilled up with polycrystalline diamond compact (PDC) bits. The valve components may be contained within a metallic housing.

Abstract: An apparatus and methods for preventing the accumulation of unwanted materials in an enlarged inner diameter portion of a casing or housing. In one aspect of the invention, a sleeve is disposed in the housing to isolate an annular area defined by the outer surface sleeve and the wall of the enlarged inner diameter portion. The sleeve prevents unwanted materials from being disposed in the annular area. The sleeve can later be expanded into the enlarged inner diameter portion, removed from the wellbore or destroyed. In another aspect of the invention, the sleeve is provided and disposed to cover the enlarged inner diameter portion. By covering the enlarged inner diameter portion, unwanted material is prevented from accumulating at said portion and from interfering with the expansion of the next casing into said portion to form a monobore. The sleeve can be made from materials that are dissolvable, elastically deformable, or retrievable.

Abstract: A cement float collar is disclosed that can be positioned downhole and used in a wellbore completion operation after drilling a wellbore with casing. A wellbore drilling and completion method is also disclosed. The cement float collar is made for pumping downhole and into engagement with a groove formed in the casing, called the profile nipple. As such, no restriction is needed in the casing for accepting or latching the float collar and the portion of casing including the groove can be installed at the start of the drilling operation. In addition, the profile nipple can be used to engage other drilling tools and, therefore, can already be in place when the final well depth (TD) is reached.

Abstract: A shoe (10) for guiding a string within a well-bore is described. The shoe comprises an annular body (12) of relatively hard material and a nose portion (16) of relatively soft material which are interlocked so that when the nose portion is drilled through, any remaining parts are held against the annular body. Interlocking is achieved by a dovetail thread (30). Embodiments are described for the shoe as a reamer shoe and as a drill bit to run in casing.

Abstract: An apparatus for preventing or limiting the rotation of cementing plugs in a casing string during drillout. The apparatus includes an outer housing with a sleeve disposed therein. The sleeve has an inner surface configured to engage cementing plugs received therein to cause an interference fit. The sleeve will hold the cementing plugs when rotational forces, such as drilling forces, are applied so that during drillout, rotation of the cementing plug is prevented or is at least limited.

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 tubing shoe (30) comprising: a body (32) for mounting on the end of a tubing string; and reaming members (36) extending longitudinally and helically around the body, the reaming members providing substantially complete circumferential coverage of the body whereby, in use, when the tubing shoe is advanced axially into a bore, the reaming members (36) provide reaming around the shoe circumference. A rotatable torque reducing sleeve or centraliser (38) may also be mounted on the body, rearwardly of the reaming members.

Abstract: The present invention provides a downhole cementing apparatus run into a borehole on a tubular. The apparatus is constructed on the pipe in such a way that pressure surge during run-in is reduced by allowing fluid to enter the pipe and utilize the fluid pathway of the cement. In one aspect of the invention, an inner member is provided that filters fluid as it enters the fluid pathway. In another aspect of the invention, various methods are provided within the cementing apparatus to loosen and displace sediment in the borehole prior to cementing.

Abstract: The present invention relates to a float collar apparatus for regulating the passage of fluid through a casing liner or sub-sea casing. Apparatus of the present invention is fabricated using plastic flapper valves and sleeve components in contrast to prior art float collar components which are fabricated almost entirely of hard metals. The use of plastic components in the float collar apparatus of the present invention provides a substantial reduction in time and resources expended during drilling out of the float collar once cementing operations are completed. Additionally, the float collar apparatus of the present invention is fabricated from a pre-determined combination of plastic components and metal components thereby ensuring that the improved float collar can still endure substantial hydrostatic stresses encountered during casing liner running in and cementing operations.

Abstract: A downhole cementing system employing a cement choke within the casing to reduce the downward velocity of cement through the casing and thereby inhibit formation fracturing caused by vibration of the casing.

Abstract: A differential float and cementing valve assembly used to position and cement casing in a wellbore. A poppet valve mounted in the flapper gate of a check valve provides a regulated back-flow of drilling fluid through the check valve. A leaf spring biases the poppet valve to its closed position. Drilling fluid pressure in the wellbore overcomes the spring force to open the poppet valve and permit drilling fluid to back-flow into the casing. The regulated admission of drilling fluid into the casing permits the casing to sink into the well at a controlled rate while automatically maintaining a desired level of drilling fluid in the casing. With the casing at the bottom of the well, a cement slurry is pumped through the casing. A setting ball moving in advance of the cement slurry deactivates the poppet valve and its flapper gate and activates a second check valve in the assembly to prevent cement back-flow.

Abstract: A composite landing collar is disclosed which is preferably adhesive bonded to the liner string using a high temperature epoxy. The spacing during bonding is maintained within dimensional limits using spacers. The body features a bi-directional material, with an appropriate ratio in the warp and fills directions, for about a quarter of the wall thickness. A unidirectional material with the fibers axially aligned aids in reduction of thermal stresses in the thick wall during curing, as well as reducing shear stress concentration along the adhesive bonding interface.

Abstract: A one trip method for drilling a wellbore below a cemented casing is disclosed. An apparatus for use in performing the method is also disclosed. The method comprises lowering a drill bit into a casing cemented in the wellbore. The casing has float equipment connected therein. The drill bit is rotated in the casing above the float equipment so that it expands radially outwardly to a diameter greater than the inner diameter of the casing.

Abstract: A casing drilling shoe adapted for attachment to a casing string and comprising an outer drilling section constructed of a relatively hard material such as steel and an inner section constructed of a readily drillable material such as aluminum. The drilling shoe further includes a device for controllably displacing the outer drilling section to enable the shoe to be drilled through using a standard drill bit and subsequently penetrated by a reduced diameter casing string or liner.

Abstract: An impervious metallic liner for the isolation of the well bore from the formations of an oil or gas well below a casing string; the liner being flattened to run through the casing string, but is inflated to occupy the space directly below the casing string rather than occupying the conventional area radially inward from the position occupied by the casing string.

Abstract: A composite landing collar is disclosed which is preferably adhesive bonded to the liner string using a high temperature epoxy. The spacing during bonding is maintained within dimensional limits using spacers. The body features a bi-directional material, with an appropriate ratio in the warp and fills directions, for about a quarter of the wall thickness. A unidirectional material with the fibers axially aligned aids in reduction of thermal stresses in the thick wall during curing, as well as reducing shear stress concentration along the adhesive bonding interface.

Abstract: A tubing shoe (30) comprising: a body (32) for mounting on the end of a tubing string; and reaming members (36) extending longitudinally and helically around the body, the reaming members providing substantially complete circumferential coverage of the body whereby, in use, when the tubing shoe is advanced axially into a bore, the reaming members (36) provide reaming around the shoe circumference. A rotatable torque reducing sleeve or centraliser (38) may also be mounted on the body, rearwardly of the reaming members.

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: Apparatus (10) for facilitating coupling and cementing of downhole tubulars (12, 28) comprises a tubing section (12, 10) for use in lining a bore. The tubing section has upper and lower ends and defines a tubing wall having cement outlets (20) spaced from the lower end of the tubing. The lower end of the tubing is selectively closed, and swab cups (22) are provided externally of the lower end of the tubing below the cement outlets (20) for restricting passage of cement.

Abstract: A float shoe/collar apparatus and method is disclosed 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 present invention permits auto filling of the tubular string as the string is lowered into the wellbore. If desired, 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 in accord with the present invention to prevent flow from the wellbore into the tubular string. In one embodiment, the invention 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.

Abstract: A downhole string includes a liner and devices positioned outside the liner. One or more control lines extend from the liner devices along the exterior of the liner to one or more connectors that provide connection points inside the liner. The one or more connectors may include electrical connectors (e.g., direct contact connectors), inductive connectors (e.g., inductive couplers), optical connectors (e.g., fiber optic connectors), and hydraulic connectors. The one or more control lines may be electrical lines, fiber optic lines, or hydraulic lines. The downhole string may also be used with a cement protector during cementing operations to protect both the inside of the liner as well as the one or more connectors attached to the liner. The cement protector includes a sleeve that isolates cement from the inside of the liner during a cementing operation so that a liner wiper plug is not needed. The cement protector is engageable to a pulling tool that is attached to a running tool.

Abstract: A method for locating a drill bit when drilling out cementing equipment from a casing of a wellbore. A first step involves placing in the casing of the wellbore at the time of placing cementing equipment, at least one coloured marker member. A second step involves monitoring cuttings during drilling for traces of colour. Penetration of a drill bit into the cementing equipment is indicated by coloured cuttings from the at least one coloured marker member.