Abstract: Systems for controlling deviations during drilling operations, including a transmission housing and a bearing assembly secured between a stator housing and a drill bit. Two stabilizers are secured to the transmission housing, and one stabilizer is secured to the bearing assembly to provide enhanced stability to the lower portion of the drill string. The stabilizers can have a triangular shaped body for increasing flow area, reducing annular velocity, and increasing stiffness of the system. The stabilizers can be rotationally offset from one another to facilitate maintaining the gauge of the borehole. The transmission housing can be a one-piece construction to minimize connections within the system and improve reliability. The stabilizers can include laser clad metal surfaces and diamond dome inserts to prevent wear and erosion. A triangular reamer can be included beneath the stabilizers to further prevent wear to the stabilizers and to add stability to the drill bit.

Abstract: Disclosed is a downhole apparatus including a tubular and at least one line passage extending along an outer surface of the tubular. At least one end clamp is located at least one end of the line passage. The at least one end clamp includes a clamp body and at least one standoff located between the clamp body and the outer surface of the tubular defining a clamp protected space therebetween. Further disclosed is a downhole tubular system including a least two tubular apparatus, each tubular apparatus including at least one tubular and at least one line passage extending along an outer surface of the tubular. At least one end clamp is located at least one end of the line passage. The tubular system further includes at least one coupling clamp disposed at a coupling of the at least two tubular apparatus.

Abstract: A transport assembly configured to be attached to downhole apparatus has a support assembly configured to be attached to the downhole apparatus and a ground engaging assembly, which may be a roller wheel configured to contact with and move in relation to a surface of a wellbore. The roller wheel may engage with the support assembly so as to provide for their relative rotation. The transport assembly also includes a retaining member disposed between the roller wheel and the support assembly, and the retaining member is operable to resist separation of the roller wheel from the support assembly. The transport assembly is further configured such that, when the transport assembly is in use moving along a wellbore, the roller wheel bears against the retaining member, which in turn bears against the support assembly. The retaining member is a ball-bearing.

Abstract: A close-tolerance expandable bow spring centralizer 8 having a first expandable collar 10A coupled to and spaced apart from a second expandable collar 10B through a plurality of bow springs 30 wherein expandable collars 10A, 10B comprise a plurality of slidably coupled links 16 that separate to expand the diameter of the collars 10A, 10B, e.g., upon expansion of an expandable pipe string 80 on which the centralizer 8 is received. Expandable bow spring centralizer 8 may grip the expandable pipe string 80 when in the collapsed configuration to eliminate the need for a stop collar. Additionally or alternatively, a fin 32 may be connected to each bow spring 30, and then connected to one or more adjacent fins 32 upon collapse of the bow springs 30 to form a restraining band 39 that may be ruptured, e.g., upon expansion of the expandable pipe string 80.

Abstract: A centraliser segment (11) comprising a first collar portion(15), a second collar portion (17) and bow element (19) extending between said first collar portion and said second collar portion to maintain the collar portions in spaced relation to each other, said bow portions having an intermediate portion which lies to one side of the plane accommodating the collar portions, a first connector element (21) provided at one end of the collar portions and second connector element (23) provided at the other end of the collar portions, said first connector elements are engagable with said second connector elements of the same or another centraliser segment such that one or more said centraliser segments are connectable together to form a centraliser which in use is capable of being received around a borehole casing, said first and second connector element having an adjustment element which can cause the diameter of the centraliser can be varied by operation of the adjustment element (41) wherein the adjustment is co

Abstract: An example of a caisson system that surrounds a conductor that extends from a head member positioned above a water surface to below a mud line includes a caisson positioned about the conductor, the caisson having a lowest end; a lower centralizer connected within the caisson proximate the lowest end of the caisson; and a second centralizer connected within the caisson above the lower centralizer relative to the mud line; wherein each centralizer includes a plurality of bow members extending between a first and a second collar, the first collar immovably connected within the caisson and the second collar moveable relative to the first collar, and each bow member curving inward from the caisson defining a bore disposing the conductor.

Abstract: A bow-spring centralizer (6) includes bow springs (34), moving collars (20) secured to each end of each bow spring, and interlocked stop collars (10). Extendable collars (8) may each be formed of a moving collar (20) movably interlocked with a stop collar (10). The centralizer (6) may be formed from a tube cut using a laser to create two extendable collars coupled by bow springs. Each extendable collar may include heads (12) integrally formed on extensions (26) protruding from a collar (stop collar or moving collar). The heads may be generally rectangular, arrow, or teardrop-shaped head or some other shape. Each head may be slidably captured within a chamber (24) on the interlocked collar (moving collar or stop collar). The extensions of each interlocked tubular member define the outer walls of the chamber in which a head of the interlocked tubular member is slidably captured.

Abstract: An example method comprises securing a sleeve around at least a portion of a downhole tool, deploying the sleeve and the downhole tool into a wellbore penetrating a subterranean formation, and retrieving the sleeve and the downhole tool from the wellbore. The step of securing the sleeve around the at least portion of the downhole tool may be performed at the well site.

Abstract: An adjustable centering tool for use in pipes of varying inner diameter. The centering tool being provided with a number of identical and steplessly adjustable, radially protruding wings having guiding lugs and chamfered end faces. The wings, having been set, are retained by an upper lock mandrel with a safety pin and a lower lock mandrel with a safety nut. The outer circumference of a cylindrical tool body is fitted with longitudinal grooves having sloped terminations cooperating with the wing dimensions, the chamfered end faces of the wings, and the guiding lugs.

Abstract: An attachment and fastener system rigidly secures a rotatable drill pipe protector (RDPP) to a drill pipe. The RDPP comprises a sleeve which is split axially along at least one side. Parallel hinge bars are contained in first and second hinge sections which wrap around the hinge bars along opposite sides of the opening in the RDPP. One hinge bar is rotatable in the first hinge section. A series of axially spaced apart bolts are held in corresponding threaded openings in the rotatable hinge bar which rotates about its axis to swing the bolts in unison between open and closed positions. The other hinge bar has a series of threaded receptor openings facing outwardly from slotted openings in the second hinge section and aligned with the bolts on the other hinge bar. The rotating hinge bar swings the bolts into alignment with the slotted openings in the other hinge, after which the bolts are tightened in the threaded receptor openings for applying a holding force around the drill pipe.

Abstract: A well bore fluid recovery system and method is disclosed for recovering a column of well bore fluid within a stand of casing before cutting the casing. The recovery system relates to a system for preventing fluids from being spilled when casing is being finished for a well bore. After being run the casing must be cut and finished at an appropriate level to install rig equipment such as blow out preventers along with other equipment. However, because of earlier operations, the entire length of casing is typically filled with drilling fluid. Depending on conditions, the length of casing which is to be cut and removed may therefore over a 100-foot (27.4 meter) column of drilling fluid therein. The drilling fluid in this section must be properly drained before the casing is cut and removed.

Abstract: A centraliser segment (11) which can, by itself or in combination with one or more corresponding centraliser segments, be used to form a centraliser (13) which can in use be clampingly engaged around an element (10) which is receivable in a borehole, said centraliser segment comprising a first collar portion (15), a second collar portion (17) and at least one bow element (19) extending between said first collar portion and said second collar portion to maintain the collar portions in spaced relation to each other, wherein the collars have an inner face which in use is to bear against the element and wherein said bow element has a curvature along its length to define an intermediate portion which extends laterally from the centraliser segment away from the inner faces of the collars, at least the intermediate portion of the bow elements having a convex transverse profile, a first connection element (21) provided at one end of the collar portions and second connection element (23) provided at the other end of t

Abstract: There is disclosed an improved tool, e.g. adapted to comprise at least part of a well completion assembly or well drilling assembly. The invention provides an improved downhole tool (or device) having a friction factor of the order of ten times less than those known from the prior art, e.g. of the order of 0.100 or less. Accordingly the invention provides a downhole tool (10; 10a; 10b; 10c; 10d), at least part of the downhole tool or device being made from Tungsten Disulphide (Tungsten Disulfide). In a disclosed embodiment the at least part comprises at least one surface of the downhole tool, the at least one surface comprising a bearing surface, e.g. a journal bearing surface and/or a thrust bearing surface.

Abstract: A tool and its operating procedure are provided to protect any device while lowering into a well, and especially hydraulic devices such as sensors with expandable arms or inflatable elements such as packers. The protection is mainly important in the open hole of highly deviated or horizontal wells, for any device equipped with external seal element, delicate sensor or articulated parts. This tool features an automatic sequence controlled by a single dart or a single ball launched into the running string from the surface: when the dart or the ball lands on its seat, the pressure build-up is initially applied to a piston to extract the device from the protector without exposing it to any differential pressure, then it is automatically applied to the device itself for actuation as soon as the device is entirely pulled out of the protector.

Abstract: First and second centralizer portions, comprising a first end collar coupled to a plurality of first bow spring segments and a second end collar coupled to a plurality of second bow spring segments, respectively, may be received onto the pipe segment on opposite sides of an installed stop collar. The plurality of first bow spring segments are coupled to the plurality of second bow spring segments, such as by welding, to form a bow spring centralizer with a plurality of bow springs extending between the first and second end collars, the bow spring centralizer movable along the pipe segment within a limited range defined by the separation of the first and second end collars. In one embodiment, the first centralizer portion and the second centralizer portion may be formed by cutting through the bow springs of a bow spring centralizer.

Abstract: A centralizer for an instrument such as an in-place inclinometer is described. The centralizer has a clamp with an inner receptacle configured for coupling to the instrument housing, and a plurality of elongate fingers extending from the clamp that center the instrument in the casing. The fingers carry rollers that fit into grooves in the instrument casing. The fingers are arcuate and provide a spring-like contact force that causes the rollers to abut the instrument casing and stabilize the instrument.

Abstract: A close-tolerance expandable bow spring centralizer 8 having a first expandable collar 10A coupled to and spaced apart from a second expandable collar 10B through a plurality of bow springs 30 wherein expandable collars 10A, 10B comprise a plurality of slidably coupled links 16 that separate to expand the diameter of the collars 10A, 10B, e.g., upon expansion of an expandable pipe string 80 on which the centralizer 8 is received. Expandable bow spring centralizer 8 may grip the expandable pipe string 80 when in the collapsed configuration to eliminate the need for a stop collar. Additionally or alternatively, a fin 32 may be connected to each bow spring 30, and then connected to one or more adjacent fins 32 upon collapse of the bow springs 30 to form a restraining band 39 that may be ruptured, e.g., upon expansion of the expandable pipe string 80.

Abstract: There is disclosed an improved expandable centraliser (20;120;220;320), which may optionally also be adjustable, and a related downhole assembly and a method of completing a well. Previous art has suffered from a number of problems and essentially attempted to mitigate the effect of pipe expansion, i.e. using tension caused in the centraliser body. The centraliser (20;120;220;320) of the invention uses the expansion of the tubing to cause compressive forces, which are exerted over known distances to energise blades of the centraliser by using relative motion caused by said expansion. The expandable centraliser (20;120;220;320) comprises at least one first member (30;130;230;330), and at least one second member (35;135;235;335), wherein, in use, relative circumferential motion of the at least one first and second members (30,35;130,135;230,235;330,335) causes radial motion of at least one portion (40;140;240;340) of the expandable centraliser (20;120;220;320).

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 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.

Abstract: An apparatus according to one or more aspects of the present disclosure comprises at least two centralizers, each centralizer having a circumferential stand-off portion and a second circumferential portion defining 360 degrees, at least two bows extending between opposing collars within the stand-off circumferential portion; wherein the at least two centralizers are spaced axially apart and fixedly attached to the tubular with the respective circumferential stand-off portions angularly offset from one another to provide 360 degrees of standoff. According to one or more aspects of the present disclosure, one or both of the collars of each centralizer may be rotationally stationary relative to the tubular and axially moveable relative to the tubular.

Abstract: 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.

Abstract: A line retention system includes a positionally fixed retainer having one or more recesses therein that are receptive to one or more lines. The system further includes one or more spline recesses in the positionally fixed retainer receptive to one or more position splines and one or more position splines that are receivable in the one or more spline recesses. A method for retaining one or more lines is included.

Abstract: A drilling system employs a set of bushings that protect seats used for casing hangers. The system includes one or more seat protectors that attach to a running tool. The running tool is lowered down the wellbore with the seat protectors attached and deposits a bushing at each surface to be protected. The running tool may retrieve the bushings as the running tool is withdrawn from the wellbore.

Abstract: Drilling apparatuses and methods for limiting precession are provided. According to one embodiment, a drilling apparatus includes a non-rotating stabilizer. The non-rotating stabilizer includes a first blade and a second blade, the first blade being arranged opposite the second blade. The first blade is biased radially outwardly by a force of a first value. The second blade is not biased radially outwardly by a force corresponding to the first value. The second blade may be a blade which is slidable along the non-rotating stabilizer in an axial direction and allow free sliding axial contact with the formation.

Abstract: A bow-spring centralizer (6) includes bow springs (5), moving collars (11) secured to each end of each bow spring, and interlocked stop collars (10). Extendable collars (8) may each be formed of a moving collar (11) movably interlocked with a stop collar (10). The centralizer (6) may optionally be formed from a tube cut using a laser to create two extendable collars coupled by bow springs. Each extendable collar may include heads integrally formed on extensions protruding from a collar (stop collar or moving collar). The heads may be generally rectangular, arrow, or teardrop-shaped head or some other shape. Each head may be slidably captured within a chamber on the interlocked collar (moving collar or stop collar). The extensions of each interlocked tubular member define the outer walls of the chamber in which a head of the interlocked tubular member is slidably captured.

Abstract: An apparatus and method is provided for protecting control lines used with tool strings in a downhole environment. A control line protector assembly comprises a plurality of components formed into a unitary piece which includes a guard section having a first end section and a second end section, a slot on each of the first end section and the second end section, and a securing mechanism for coupling the guard section having the first end section and the second end section to the coupling. A control line protector assembly is formed using a metal stamping process.

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: Apparatus for cleaning the inner wall of wellbore tubulars, and for capturing downhole debris in the wellbore An elongated, tubular central mandrel has threaded connections on either end for makeup into a tubular string The mandrel has recesses on its outer circumference into which split rings are mounted Various service elements are then attachable to the central mandrel, by sliding them over the mandrel and holding them in place with stabilizer elements which connect to the split rings Different embodiments of the service elements include a brush assembly, a junk basket, and a magnet The stabilizer elements may be mounted onto the split rings so as to either be rotationally locked with respect to the mandrel, or so as to be capable of rotating with respect to the mandrel, since the service elements are held in place on the central mandrel by the stabilizer elements.

Abstract: The invention relates to an apparatus for connecting a control line to a tubular string. In one embodiment, the apparatus includes a guide boom pivotable around a location adjacent the string and with a guide member at an end thereof to guide the control line. The apparatus further includes a clamp boom that is independently pivotable and includes a clamp housing at an end thereof for clamping the control line against the tubular string. The guide boom and the clamp boom each have a center line which is substantially aligned with the center line of the tubing string permitting the control line to be aligned adjacent the tubular string prior to clamping.

Abstract: A centralizer includes two stop collars configured to be affixed to an exterior surface of a pipe. A plurality of circumferentially spaced apart spacers is each coupled at each end to one of the stop collars, a first plurality of circumferentially spaced apart bow springs is each coupled at one end thereof to the first stop collar and at an opposite end thereof to a first floating collar disposed between the first and second stop collars. A second plurality of circumferentially spaced apart bow springs is each coupled at one end thereof to the second stop collar and at an opposite end thereof to a second floating collar disposed between the first and second stop collars. A shape of the bow springs is selected to cooperatively engage the spacers and the floating collars such that when compressed the centralizer provides a substantially fluid-tight seal.

Abstract: A centralizer having a body with an inner surface provided with a friction-reducing slider, typically located in an annular recess on the inner surface of the body of the slider, spaced from the ends of the body. The slider can be formed separately from a body of the centralizer and subsequently attached thereto on the inner surface so that it is adapted to bear between the outer surface of the tubing to be centralized and the inner surface of the centralizer. This reduces rotational torque transmitted between the centralizer and the tubing, and assists in maneuvering of the tubular string into the desired position in the well.

Abstract: A temperature activated actuator installed on a tubular to actuate an adjacent device may include one or more shape-memory alloy elements. The elements may be coupled between a first portion and a second portion of a device, or the elements may be coupled between the tubular and a portion of the device. The elements are activated by raising the temperature to a transition temperature to cause metallurgical phase transformation, causing the elements to shrink and displace at least a portion of the device. The actuator may be used, for example, to actuate a centralizer from a run-in mode to a deployed mode or, alternately, to actuate a packing member from a run-in mode to an isolating mode. A nickel-titanium alloy, for example, may be used as the shape-memory alloy material from which the shape-memory element is made.

Abstract: A well bore fluid recovery system and method is disclosed for recovering a column of well bore fluid within a stand of casing before cutting the casing. The recovery system relates to a system for preventing fluids from being spilled when casing is being finished for a well bore. After being run the casing must be cut and finished at an appropriate level to install rig equipment such as blow out preventers along with other equipment. However, because of earlier operations, the entire length of casing is typically filled with drilling fluid. Depending on conditions, the length of casing which is to be cut and removed may therefore over a 100-foot (27.4 meter) column of drilling fluid therein. The drilling fluid in this section must be properly drained before the casing is cut and removed.

Abstract: A geophysical sensor apparatus, system, and method for use in, for example, oil well operations, and in particular using a network of sensors emplaced along and outside oil well casings to monitor critical parameters in an oil reservoir and provide geophysical data remote from the wells. Centralizers are affixed to the well casings and the sensors are located in the protective spheres afforded by the centralizers to keep from being damaged during casing emplacement. In this manner, geophysical data may be detected of a sub-surface volume, e.g. an oil reservoir, and transmitted for analysis. Preferably, data from multiple sensor types, such as ERT and seismic data are combined to provide real time knowledge of the reservoir and processes such as primary and secondary oil recovery.

Abstract: A wear resistant sub assembly with a sleeve with a sleeve outer diameter larger than the body outer diameter, a plurality of offset indentations formed on the outer side of the sleeve formed in rows of four to eight offset indentations along a diagonal orientation to a sleeve axis; a plurality of a metal carbide inserts providing an interference fit into each offset indentation thereby forming a wear resistant sleeve; a sealing means disposed between the sleeve and the body and at least two spring locking apparatus engaging locking indentations on the body.

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: A device (100, 200) is for centering a drill casing (7) within a wellbore (3). The device (100, 200) includes a generally tubular body (9) having an outer surface (11) facing the wellbore (3). A plurality of protrusions (4) is disposed on the outer surface (11) along a line (6). A gap region between the protrusions (4) along the line (4) improves the installation strength and improves the flow of cement (22) on installation.

Abstract: A downhole apparatus having a radially expanding portion and a support structure are described. The support structure comprises an attachment means for coupling to the apparatus and a support portion configured to be deployed from a first unexpanded condition to a second expanded condition by expansion of the apparatus. In one aspect of the invention, the downhole apparatus is expanded by exposing the swellable material to at least one predetermined fluid, and the support structure abuts the swellable material in its expanded form. A method of use and its application to a well packer, a hanging member, an anchor and a centralising apparatus are described.

Abstract: A downhole apparatus, for example a centraliser, comprises a swellable material which expands upon contact with at least one predetermined fluid. In a first aspect of the invention, a centraliser comprises a body and a plurality of formations upstanding from the body. In another aspect, a downhole apparatus comprises a throughbore configured to receive a tubular, a swellable member, and a rigid assembly integrally formed with the swellable member. The rigid assembly provides stand off to the apparatus in use. In a further aspect, the downhole apparatus has a first condition before expansion of the swellable member in which a rigid assembly defines a maximum outer diameter of the apparatus. In a second condition after expansion of the swellable member, the swellable member defines a maximum outer diameter of the apparatus. In a preferred embodiment, the rigid assembly is designed to flex or deform under an axial or radial load.

Abstract: A centralizer for tubular elements is provided which includes an inner part formed by a first material having high mechanical performance and chemical stability and an outer part arranged on said inner part, formed by a second material. The second material may be an autolubricating material. The second material may further possess a low coefficient of friction. The second material may additionally possess lower mechanical performance and chemical stability than the first material. A method of manufacturing the centralizer is also provided, including steps of injecting the first material on a tubular element to form the inner part on the tubular element and injecting the second material to form the outer part on the formed inner part.

Abstract: An improved centralizer is provided for centralization of tubulars such as casings, liners, production tubing, and production screens, in oil/gas wells. Such a centralizer comprises a tubular body, wherein a portion of an outermost surface of the tubular body is formed from a first material, and a portion of, or portion adjacent to, at least one end of the tubular body, and/or a portion of an innermost surface of the tubular body, is formed from at least one second material, in contrast to unitary construction centralizers disclosed by the prior art, and the first material has a lower Young's modulus than the at least one second material.

Abstract: An apparatus for protecting a sub assembly inside a borehole of a well, with a sleeve having a sleeve outer diameter larger than the body outer diameter; a plurality of offset indentations formed on the outer side of the sleeve formed in rows of 4 to 8 offset indentations along a diagonal orientation to a sleeve axis; a plurality of a metal carbide inserts providing an interference fit into each offset indentation thereby forming a wear resistant pad on the outer side of the sleeve; a sealing means disposed between the sleeve bottom beveled edge and the body forming a sealed sub assembly using at least two spring locking apparatus engaging locking indentations on the body.

Abstract: A unitary gravel pack multi-pathway tube includes a body; a gravel slurry flow passage defined within the body; and a control line protection projection extending from and supported by the body, the projection extending laterally from the body relative to an extent of the flow passage and method.

Abstract: A coiled tubing connector having a body and a plurality of entry or transition sections connected to the body wherein the connector has a low cycle fatigue life of at least 30%, more preferably at least 50% of the coiled tubing. A preferred embodiment contains two shoulders that form an annular void, a plurality of centralizers about an exterior of the body, and/or a plurality of elastomer molds separating the centralizers. The connector is preferably longer than the connectors of the prior art and is a composite of fluoroplastics or aluminum alloys.

Abstract: A through tubing centralizer is delivered below the tubing and expanded against a surrounding tubular for fixation. In a window milling through tubing application, a whipstock is delivered through tubing and anchored. One or more centralizers are then delivered through tubing and expanded so that their inside diameter when set exceeds their outside diameter during run in. They are placed below the tubing and above the whipstock to help a through tubing mill stay on the whipstock ramp while milling the window. After the window is started, the centralizer can be expanded fully against the surrounding tubular to allow subsequent removal of the whipstock. Optionally, the centralizer can be collapsed for removal through tubing.

Abstract: A centralizer includes a first stop collar configured to be affixed to an exterior surface of a pipe. A second stop collar is spaced apart from the first stop collar and is configured to be affixed to the exterior surface of the pipe. A plurality of circumferentially spaced apart longitudinal spacers is included and each is coupled at each longitudinal end to one of the stop collars. A first plurality of circumferentially spaced apart bow springs is each coupled at one longitudinal end thereof to the first stop collar and at an opposite longitudinal end thereof to a first floating collar disposed between the first and second stop collars. A second plurality of circumferentially spaced apart bow springs is each coupled at one longitudinal end thereof to the second stop collar and at an opposite longitudinal end thereof to a second floating collar disposed between the first and second stop collars.

Abstract: Centralizers including at least a portion formed of a first material and at least one end band secured to the first material and formed of a second material. The end band being installed to resist detachment from the portion formed of the first material.

Abstract: The invention relates to a device for control of the flow through a production tube placed in an oil well. The device comprising a portion of the production tube provided with through orifices and protection equipment for providing resistance to wear by erosion. The protection equipment comprises several add-on sectors assembled around the portion of the tube. Each add-on sector provided with an associated inner stiffener penetrating into the portion of the production tube through at least one through orifice. At least one of the add-on sectors provided with at least one opening extending through the sector and its associated inner stiffener.

Abstract: A collar for protecting a body inside a borehole of a well, with a collar outer diameter larger than the body outer diameter, a plurality of offset indentations formed on the outer side of the collar formed in rows of four to eight offset indentations along a diagonal orientation to a collar axis. A metal carbide inserts engages each offset indentation with an interference fit forming a wear resistant pad on the outer side of the collar. A sealing means is disposed between a bottom beveled edge of a collar and the body forming a sealed sub assembly. At least two spring locking apparatus engaging a locking portion on the body.