Abstract: A centralizer having bow springs in a retracted position to facilitate passage through a restriction. After passing through the restriction, the bow springs may be expanded to support a casing. In one embodiment, the bow springs may be expanded using a movable sleeve.

Abstract: Disclosed herein is a centralizer for being mounted around a centralizer sub body to form a centralizer sub. The centralizer comprises first and second opposing end collars arranged, in use, to be positioned around a longitudinal axis of the centralizer. The centralizer also comprises a plurality of spring bows extending from the first end collar to the second end collar. The first end collar may comprise first and second end regions arranged, in use, to face one another. The first and second opposing end regions may comprise first and second engaging elements respectively. The first end region may be configured to be connected, in use, to the second end region via the first and second engaging elements. Also disclosed is a centralizer sub and an engaging device for use in forming a centralizer.

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: A downhole tractor assembly that is configured for open-hole applications. The assembly includes a force monitoring mechanism to help monitor and control forces imparted through a drive mechanism of the tractor in real time. As such, damage to open-hole formations due to excessive tractoring forces may be minimized along with mechanical damage to the tractor. Furthermore, the drive mechanism of the tractor may include multiple sondes and bowsprings with gripping saddles specially configured for contacting the well wall across a large area in a non-point and line manner so as to avoid digging into and damaging the well wall during tractoring.

Abstract: A gripper assembly for anchoring a tool within a downhole passage and for possibly assisting movement of the tool within the passage. The gripper assembly includes an elongated mandrel and flexible toes that can be radially displaced to grip onto the surface of the passage. The toes are displaced by the interaction of a driver slidable on the mandrel and a driver interaction element on the toes. In one embodiment, the toes are displaced by the interaction of rollers and ramps that are longitudinally movable with respect to one another. In another embodiment, the toes are displaced by the interaction of toggles that rotate with respect to the toes.

Abstract: A centralizer comprises a first collar, a second collar, a plurality of bow springs coupling the first collar to the second collar, and a plurality of particulates disposed on an outer surface of at least one bow spring. One or more of the first collar, the second collar, and the bow springs comprises a composite material. In some embodiments, the centralizer comprises a third collar, wherein the plurality of bow springs comprise a first portion of bow springs and a second portion of bow springs, and wherein the first portion of the bow springs couple the first collar to the third collar and the second portion of the bow springs couple the second collar to the third collar.

Abstract: 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.

Abstract: A method comprising providing a centralizer disposed about a wellbore tubular, wherein the centralizer comprises a first collar, a second collar, a plurality of bow springs coupling the first collar to the second collar, and a plurality of particulates disposed on an outer surface of at least one bow spring, wherein one or more of the first collar, the second collar, and the bow springs comprise a composite material, and placing the wellbore tubular in a wellbore disposed in a subterranean formation.

Abstract: An apparatus and methods of spacing a tool from walls of tubing are provided as embodiments of the present invention. The apparatus can include a centralizer that is inserted in the tubing, the centralizer having inwardly arched sides or inwardly arched bow springs so that an inner diameter of the centralizer increases from a longitudinal midpoint to a longitudinal end point of the centralizer. The centralizer has a smaller diameter than the tubing so that it can be positioned inside of the tubing downstream of a seating ring in a relaxed position so that when the tool passes through the centralizer, the inwardly arched sides or inverted bow springs expand towards an inner wall of the tubing to centralize and inhibit radial movement of the tool when deployed through the inwardly arched sides of the centralizer.

Abstract: A tubing centralizing apparatus has a centralizer body including opposing end portions, a central passage extending through the opposing end portions, and a plurality of apertures extending therethrough between its exterior side surface and the central passage. The apertures are uniformly spaced about a longitudinal axis of the central passage. Bow springs are mounted on the exterior side surface of the centralizer body such that a central portion of each one of the bow springs is bowed away from the centralizer body. The tubing sub is slideably positioned within the central passage of the centralizer body. One of the tubing joint collars is attached to each end portion of the tubing sub. The tubing joint collars and the centralizer body are jointly configured such that the tubing joint collars engage the centralizer body for constraining the tubing sub within the central passage of the centralizer body.

Abstract: Methods and devices are provided for accurately determining depths of certain structures in downhole strings. Locator tools comprise a shaft and a plurality of locator springs longitudinally mounted on the shaft. The locator springs are biased to expand and are configured to compress to allow the tool to traverse past restrictions in the downhole string. Each locator spring includes a locating pad that allows it to engage with an internal locating notch in the downhole string. The internal locating notch is sized to mate with the locator tool, i.e., to allow the locator springs to engage the internal locating notch. In this way, the depth of internal locating notches may be determined precisely and accurately by sensing engagement of the tool with the internal locating notch. Advantages of certain embodiments include more accurate depth determination, repeatable engagements of the tool, and reduced false engagements.

Abstract: The invention concerns an independent measuring and processing probe designed to be lowered in a tube for temporarily installation at the bottom of a hydrocarbon well. It includes removable anchoring resources (3, 4) capable of anchoring the probe to a casing at the bottom of the well, a set of sensors, at least one of which is a seismic sensor, recording resources, resources for processing the measurements provided by the sensors, and a central body (1) integrally reamed throughout the whole of its length by an opening (2) so as to allow free passage through the probe when it is in the anchored position. Such a probe can be used in particular to effect a reliable preliminary study on the well before installing a more complete observation system.

Abstract: Embodiments of the invention generally relate to methods and apparatuses for anchoring progressing cavity (PC) pumps. In one embodiment, a method of anchoring a PC pump to a string of tubulars disposed in a wellbore which includes acts of inserting the PC pump and anchor assembly into the tubular. Running the PC pump and anchor assembly through the tubular to any first longitudinal location along the tubular string. Longitudinally and rotationally coupling the PC pump and the anchor assembly to the tubular and forming a seal between the PC pump and the tubular string at the first location and performing a downhole operation in the tubular.

Abstract: A method for securing a wellbore string device to a wellbore liner tubular employs a swelling elastomer to frictionally grip a gap between the wellbore string device and the liner tubular. The swelling elastomer is positioned between the wellbore string device and the wellbore liner tubular, then activated to cause it to swell to engage the wellbore string device with the wellbore liner tubular. The wellbore string device may be a centralizer, a wear band or a torque ring.

Abstract: A passive centralizer for stably centering within a well. The centralizer may be of a retracted profile for advancement within the well and deployable for centralization upon reaching an operation site. Deployment may be achieved in an automated manner without the requirement of operator interaction therefor. Furthermore, the centralizer may be truly passive in that energy for deployment may be stored entirely within the passive centralizer prior to its insertion within the well. The passive centralizer may also be compressed following centralization by any number of downhole restrictions. In this manner the passive centralizer may also be readily withdrawn from the well.

Abstract: A stop collar assembly used for axially securing and/or to resist axial sliding of a downhole tool device. The assembly provided on a housing of the downhole tool and includes a generally annular ring having an inner circumference beveled outward proximate to the ring edge. A clamp ring having a raised portion on its outer surface is disposed adjacent and substantially coaxial with the annular ring. Pushing the annular ring against the clamp ring compresses the clamp ring onto the housing to resist axial sliding of the annular ring.

Abstract: A downhole tool is provided that includes a grip assembly for contacting a well formation. The grip assembly includes a gripper body; and a centralizer that is attached to and radially expandable with respect to the gripper body and that has a geometry which is lockable by a locking device. The grip assembly also includes a force amplifier in force transmitting relation with the centralizer, wherein the force amplifier transfers a force in a first direction to a much larger force in a second direction when the centralizer is locked by the locking device.

Abstract: A gripper assembly for anchoring a tool within a downhole passage and for possibly assisting movement of the tool within the passage. The gripper assembly includes an elongated mandrel and flexible toes that can be radially displaced to grip onto the surface of the passage. The toes are displaced by the interaction of a driver slidable on the mandrel and a driver interaction element on the toes. In one embodiment, the toes are displaced by the interaction of rollers and ramps that are longitudinally movable with respect to one another. In another embodiment, the toes are displaced by the interaction of toggles that rotate with respect to the toes.

Abstract: A gripper assembly for anchoring a tractor within a downhole passage and for assisting movement of the tractor within the passage. The gripper assembly includes an elongated mandrel and flexible toes that can be radially displaced to grip onto the surface of the passage. The toes are displaced by the interaction of a driver slidable on the mandrel and a driver interaction element on the toes. In one embodiment, the toes are displaced by the interaction of rollers and ramps that are longitudinally movable with respect to one another. In another embodiment, the toes are displaced by the interaction of toggles that rotate with respect to the toes.

Abstract: A slip assembly apparatus is adapted (i) to be deployed into a wellbore (ii) to prevent axial movement of a downhole tool assembly in the wellbore when the slip assembly apparatus is actuated and external forces are imposed on the downhole tool assembly; (iii) to allow fluid flow past the slip assembly apparatus within the wellbore when the slip assembly apparatus is actuated or non-actuated; and (iv) to allow release of the slip assembly apparatus by use of a release load that is less than the axial capacity of the deployment mechanism. Different embodiments of the invention contain features such as claddings and treatments for surface hardness and wear resistance, and grooves or flutes for enhancing fluid flow between the outer diameter of the slip assembly and the inner diameter of the well casings.

Abstract: A gripper assembly for anchoring a tractor within a downhole passage and for assisting movement of the tractor within the passage. The gripper assembly includes an elongated mandrel and flexible toes that can be radially displaced to grip onto the surface of the passage. The toes are displaced by the interaction of a driver slidable on the mandrel and a driver interaction element on the toes. In one embodiment, the toes are displaced by the interaction of rollers and ramps that are longitudinally movable with respect to one another. In another embodiment, the toes are displaced by the interaction of toggles that rotate with respect to the toes.

Abstract: An anchor system for high expansion applications is described. It features a gripping member that holds together a pair of links. The movement of the links is regulated to assure the gripping member moves into proper contact with the casing. Meshing gears or a pin and slot can do this, for example. The gripping member is shaped such that it can still transmit load through the links even if the pin connections fail. The gripping member is preferably contoured to the shape of the casing inner wall to enhance grip.

Abstract: A gripper assembly for anchoring a tractor within a downhole passage and for assisting movement of the tractor within the passage. The gripper assembly includes an elongated mandrel and flexible toes that can be radially displaced to grip onto the surface of the passage. The toes are displaced by the interaction of a driver slidable on the mandrel and a driver interaction element on the toes. In one embodiment, the toes are displaced by the interaction of rollers and ramps that are longitudinally movable with respect to one another. In another embodiment, the toes are displaced by the interaction of toggles that rotate with respect to the toes.

Abstract: A borehole casing centralizer segment (1) including a first collar portion (3), a second collar portion (5), and bows (7) extending between the first collar portion (3) and the second collar portion (5). First connectors (9) are provided at first locations of the first collar portion (3) and the second collar portion (5), respectively. The first connections (9) are engageable with the second connectors (11) of the same or another centralizer segment (1). In this way, one or more centralizer segments (1) are connectable together to form a centralizer around a borehole casing.

Abstract: A gripper assembly for anchoring a tractor within a downhole passage and for assisting movement of the tractor within the passage. The gripper assembly includes an elongated mandrel and flexible toes that can be radially displaced to grip onto the surface of the passage. The toes are displaced by the interaction of a driver slidable on the mandrel and a driver interaction element on the toes. In one embodiment, the toes are displaced by the interaction of rollers and ramps that are longitudinally movable with respect to one another. In another embodiment, the toes are displaced by the interaction of toggles that rotate with respect to the toes.

Abstract: A packer is provided which reduces the number of components required in a retrievable packer. The packer is compact in size, and convenient and economical in use. In a described embodiment, the packer includes seal carrying and gripping assemblies mounted on a mandrel. Axial compression of the assemblies causes a seal and grip structures carried on the assemblies to radially outwardly deflect. Each of the assemblies may be integrally formed, thereby further reducing the number of components needed to construct the packer. Each of the assemblies is usable separately on the mandrel to produce apparatus which only grippingly engage or only sealingly engage a tubular member in a well. The packer or similar apparatus is retrieved by releasing the force axially compressing the assemblies.

Abstract: A downhole chemical cutting tool for use in a well bore to cut large diameter conduits including an elongated tool body having a chemical section adapted to contain a chemical cutting agent and a cutting section adapted to receive the cutting agent from the chemical section. The cutting section has a plurality of externally upset cutting heads extending circumferentially outwardly from the cutting section and terminating in outer cutting surfaces. Each of the cutting heads has a plurality of cutting ports extending radially inwardly from the outer cutting surface and in fluid communication with an internal chamber within the cutting section. The tool further comprises expansible slip and bow spring means in the elongated tool body for centering and anchoring the tool during cutting. The cutting heads are of a configuration having an inner spoke section which has a central bore opening into the interior chamber of the cutting section and a disk section secured to the outer portion of the spoke section.

Abstract: An emergency casing support utilizes a conventional casing hanger. Casing hanger lands on a wellhead housing internal landing shoulder. The emergency support secures to the lower end of the casing hanger. The emergency support has a body which carries a slips bowl. Body also carries a seal for sealing between the casing and the body. A sleeve nut is engaged by a setting tool lowered through the casing hanger into the body. The sleeve nut when rotated causes the bowl to move upward relative to the slips and also energizes the seal.

Abstract: A stop for an oil well swabbing device which is economical to use, is readily positioned in the well casing at the desired level, and is readily removable with a conventional fishing tool.

Abstract: An improved centralizer for well casing, comprising an externally threaded upper anchor fixed to the casing, an upper collar threaded to the upper anchor, a lower anchor fixed to the casing, a lower collar bearing against said lower anchor, and a plurality of relatively flexible metallic straps extending between the collars. The centralizer is assembled over a section of well casing as the casing is lowered into the well. When the casing reaches its final depth, it is rotated so that the anchors rotate with the casing, while the collars and the straps remain stationary, as the straps engage the wellbore. When the casing is thus rotated, the upper collar moves along the threads of the upper anchor towards the lower collar, axial movement of which is prevented by the lower anchor. This forces the straps to bulge outwardly away from the casing, urging the casing toward the center of the borehole.

Abstract: A liner hanger is shown of the type used to hang a well liner in a surrounding well bore. The hanger includes a tubular mandrel which is connectible in a liner string. A set of circumferentially-spaced gripping slips are mounted about the mandrel with each slip having a spring arm extending therefrom in alignment with the axis of the mandrel. A tapered, slip expander cone is mounted on the mandrel exterior above each of the slips for expanding the slips radially outwardly in the direction of the surrounding well bore responsive to opposite relative movement of the slips and cones. At least one channel guide is formed on the exterior of the mandrel in longitudinal alignment with one of the expander cones. The channel guide includes a slot portion for slidably receiving the spring arm of one of the gripping slips for supporting the slip on the exterior of the mandrel.

Abstract: In the mining of various minerals from the earth, large mining shafts extending from the surface down to the deposited mineral layers or seams in the earth can be provided through the use of large diameter bore hole drilling equipment. With the drilling equipment stationed on the surface of the earth, a drilling member is drilled down into the earth for forming a shaft in excess of 10 feet to a depth of at least 2000 feet. As the earth is broken up during the drilling operation, the broken fragments are removed from the drilled hole by a reverse circulation drilling operation. During the drilling operation, the drilling bit is maintained in proper alignment with the shaft being drilled by the use of non-rotating stabilizers having an outer diameter substantially equal to the diameter of the hole being drilled.

Abstract: A well anchor for use in a cased well having anchor members of bowed springs and a vertically reciprocable rod actuator movable from the surface to set the anchor.