Patent Application
20100116558
1. Field of the Invention
The present invention relates to an adjustable guide to position a portion of a pipe string within a pipe gripping assembly, such as an elevator assembly or a spider. The present invention relates to an adjustable guide to steer a pipe end into the bottom of an elevator assembly or to generally center a pipe connection so that it may pass through a spider on a drilling rig.
2. Background of the Related Art
Wells are drilled into the earth's crust and completed to establish a fluid conduit between the surface and a targeted geologic feature, such as a formation bearing oil or gas. Pipe strings used to drill or complete a well may be made-up as they are run into a drilled borehole. A casing string may be cemented into a targeted interval of a drilled borehole to prevent borehole collapse and/or formation fluid cross-flow, and to isolate the interior of the well from corrosive geologic fluids.
Generally, a pipe string may be suspended in a borehole from a rig using a pipe gripping assembly called a spider, and step-wise lengthened by threadably joining a pipe segment (which, for purposes of this disclosure, may be a pipe stand comprising a plurality of pipe segments) to the proximal end of the pipe string at the rig. The lengthened pipe string may then be suspended using a second type of gripping assembly called an elevator assembly that is movably supported from a draw works and a derrick above the spider. As the load of the pipe string is transferred from the spider to the draw works and the derrick, the spider may be unloaded and then disengaged from the pipe string by retraction of the spider slips. The lengthened pipe string may then be lowered further into the borehole using the draw works. The spider may again engage and support the pipe string within the borehole and an additional pipe segment may be joined to the new proximal end of the pipe string to further lengthen the pipe string.
Lengthening a pipe string generally involves adding one pipe segment at a time to an existing pipe string. Using one method, a pipe segment is secured to a lift line that hoists the pipe segment into the derrick to dangle the distal end of the pipe segment near the proximal end of the pipe string just above the spider. The distal end of the pipe segment may be, for example, an externally threaded male connection, or “pin end,” of the pipe segment, and it may be positioned by rig personnel to be received into and bear against the proximal end of the pipe string that is suspended by the spider. The proximal end of the pipe string may be, for example, an internally threaded female connection, or a “box end” connection.
A stabber is a member of the rig crew that works in the derrick. The stabber may be secured to a structural component of the derrick to prevent him from falling as he leans out to manually position the proximal end of the pipe segment (which may be an internally threaded connection) to align the distal end of the pipe segment with the proximal end of the pipe string. A power tong may be used to grip and rotate the pipe segment about its axis to make-up the threaded connection between the distal end of the pipe segment and the proximal end of the pipe string to thereby lengthen the pipe string. The proximal end of the now-connected pipe segment then becomes the new proximal end of the lengthened pipe string.
After threadably connecting the pipe segment to the pipe string, the stabber may then align the new proximal end of the pipe string with the inlet of a bell guide that is coupled to the bottom of an elevator assembly. The stabber attempts to position the proximal end of the pipe string to enter the inlet of the bell guide as the elevator assembly is controllably lowered toward the spider using the draw works. After the proximal end of the pipe string passes through the bell guide and then exits the bell guide at its outlet, the proximal end of the pipe string may then enter a bore between the outlet of the bell guide and the gripping zone of the elevator assembly. Further lowering of the elevator assembly will then cause the proximal end of the pipe string to enter and pass through the gripping zone defined by the slips within the elevator assembly.
After the proximal end of the pipe string is received through the gripping zone of the elevator assembly, the elevator assembly slips may be actuated to engage and grip the pipe string just below its proximal end. Subsequently raising the elevator assembly using the draw works lifts the pipe string and unloads the spider. The draw works may then be used to controllably lower the elevator assembly toward the spider to position the proximal end of the pipe string just above the gripping zone of the spider. The spider may reengage and support the pipe string to strategically position the proximal end of the pipe string to receive and threadably connect to a new pipe segment. This step-wise method of lengthening a pipe string is repeated until the pipe string reaches its desired length.
Most gripping assemblies include a tapered bowl having a stepped profile. A stepped profile tapered bowl may comprise a stepped or variable profile within the tapered bowl to provide a generally staged convergence of the slips on the exterior surface of the pipe string. The initial stage of convergence may be a rapid radial convergence of the slips on the exterior surface of a pipe string, generally followed by a more gradual convergence as the slips engage, tighten and grip the exterior surface of the pipe string. While the stepped-profile design affords a more vertically compact elevator assembly, it also substantially limits the range of pipe diameters that may be gripped by the gripping assembly. Pipe strings are generally uniform in diameter and wall thickness throughout their length because gripping assemblies are generally adapted to grip only one size of pipe. Some geological formations, such as salt zones or unconsolidated formations, are prone to movement relative to adjacent formations, and this relative movement may necessitate the use of stronger, thicker-walled pipe at critical intervals to prevent unwanted pipe string failures. Other formations may present a more corrosive environment, thereby necessitating a thicker-walled pipe string. One method of protecting the well against damage in these critical formations is to form the entire pipe string using the thicker and more expensive pipe, but this approach results in a substantial increase in cost.
An alternative method is to install a tapered pipe string, which is a pipe string that has one or more outer pipe diameter transitions along its length. For example, a tapered pipe string may have a first portion with a first pipe wall thickness and outside diameter, and a second portion with a second pipe wall thickness and outside diameter. The second portion of the tapered pipe string may be connected to extend the length of the tapered pipe string beyond the length of the first portion. A tapered pipe string may be installed in a well so that a thicker and stronger-walled portion of the tapered pipe string is strategically positioned within a more critical depth interval of the well. For example, but not by way of limitation, a thicker-walled first portion may be disposed within a tapered pipe string nearer to the surface so that the lower, thinner-walled second portion of the tapered pipe string will be adequately supported by the stronger first portion. As another example, but not by way of limitation, a thicker-walled second portion may be positioned adjacent to an unconsolidated formation or an unstable formation penetrated by the well to ensure that the tapered pipe string offers more resistance to movement or shear as a result of movement in the unconsolidated or unstable formation.
Using conventional, stepped profile tapered bowls, forming a tapered pipe string normally requires the use of two or more elevator assemblies and two or more spiders so that two or more diameters of pipe can be made-up and run in a single pipe string. This approach requires rig downtime to change out the elevator assembly or the spider, or both, for each outer diameter transition.
A different type of tapered bowl for a gripping assembly may comprise a tapered bowl having a smooth and non-stepped profile.
A tapered bowl having a non-stepped profile enables the gripping assembly to engage and grip a range of pipe diameters. The “gripping zone,” as that term is used herein, may be defined as the space within the tapered bowl and between the angularly distributed arrangement of slips, and it varies in size and shape according to the vertical elevation of the set of slips within the tapered bowl when they are engage and grip the pipe.
A limitation that may affect the utility of a spider, elevator assembly (e.g., string elevator, CRT) or other pipe gripping assembly (for example, one having a non-stepped profile) is the difficulty of positioning the proximal end of the pipe string within the gripping zone of the gripping assembly. Wear, warping and material imperfections in the pipe segments or connections may cause the pipe string to be non-linear. Imperfections in the derrick and/or the rig floor, and other factors such as wind and thermal expansion may all combine to cause the bore of the elevator assembly to be misaligned with the proximal end of the pipe string, or to cause the bore of the spider to be misaligned with a pipe connection within the pipe string. For these reasons, the rig crew often has to manually position the proximal end of a pipe string to enter the elevator assembly or to position a pipe connection towards the center of the bore of the spider. It is important that the slips of the tubular gripping apparatus, for example a spider, CRT or elevator assembly, engage and set against the exterior surface of the pipe string as simultaneously and evenly as possible to prevent damage to equipment or to the pipe string, and to ensure a positive grip.
Devices have been developed to assist the rig crew in aligning the proximal end of the pipe string with the elevator assembly. For example, a conventional bell guide is a rigid and generally inverted, funnel-shaped housing that may be coupled to the bottom of an elevator assembly and used to engage and steer the proximal end of the pipe string into the bore of the tapered bowl beneath the gripping zone of the elevator assembly. As the elevator assembly is lowered over the pipe string, the proximal end of a pipe string may engage the sloped interior surface of the bell guide. The reaction force imparted to the proximal end of the pipe string by the bell guide has a compressive component and a radial component. As the elevator assembly is lowered, the proximal end of the pipe string may slide along the interior surface of the bell guide until it reaches the outlet of the bell guide, enter the bore of the tapered bowl of the elevator assembly, and then pass through the gripping zone of the elevator assembly defined by the retracted slips.
A conventional bell guide may have a significant limitation when used with a elevator assembly with a smooth, non-stepped tapered bowl adapted for gripping a broad range of pipe diameters. The size of the outlet of the bell guide must necessarily be larger than the largest diameter of pipe that can be gripped by the elevator assembly. If the outlet of the bell guide is too small to pass the largest pipe diameter that may be gripped by the elevator assembly, then the bell guide may need to be replaced in order to make-up and run a large diameter pipe string. Depending on its capacity, an elevator assembly may weigh up to 15,000 pounds or more, and the bell guide alone may weigh hundreds of pounds. Replacing the bell guide may be difficult and time consuming. Similarly, a bell guide sized to accommodate a large-diameter pipe string may not be useful for running a smaller diameter pipe string. If the outlet at the proximal end of the bell guide is too large, then a smaller diameter pipe string may not be sufficiently aligned by the bell guide with the bore of the gripping zone in the tapered bowl of the elevator assembly as it exits the bell guide, and the proximal end of the pipe string may enter the elevator assembly and hit the bottom of one or more slips as the elevator assembly is lowered over the proximal end of the pipe string.
A bottom guide is another tool that may cooperate with a bell guide and a elevator assembly to position the end of the pipe string to enter the elevator assembly. The bottom guide may be coupled between the outlet of a bell guide and the bore in the bottom of the tapered bowl to receive the end of the pipe string as it passes the bell guide and to further direct it to the bore of the tapered bowl. In one embodiment disclosed in the parent application from which this application depends, a bottom guide may comprise a plurality of replaceable inserts to cooperate with a bell guide and to provide a second convergent structure to position the proximal end of a pipe string within the gripping zone of the elevator assembly. A bottom guide has the same limitation as a bell guide when used with elevator assemblies with tapered bowls having a non-stepped profile. That is, the bottom guide may require adjustment or retro-fitting when the pipe diameter being run into the borehole is changed.
A spider, like an elevator assembly, may also include a tapered bowl having a smooth, non-stepped profile that enables the spider to grip and support a broader range of pipe diameters. Unlike a elevator assembly, a spider does not typically receive the end of a pipe string (except on the very first pipe segment used to begin the string), but it may receive and pass internally threaded pipe sleeves of the kind used to form conventional threaded pipe connections. Each internally threaded sleeve comprises a downwardly disposed shoulder that may be, depending on the diameter and grade of the pipe string being formed, up to 0.30 inches or more in thickness. Misalignment of a pipe connection as it passes through the tapered bowl of the spider may result from the same material imperfections, winds and thermal expansion or contraction, that affect alignment between the bore of the gripping zone of a elevator assembly and the proximal end of the pipe string. A misaligned pipe connection may cause the sleeve to hang on the top of one or more slips or other structures of the spider as the lengthened pipe string is lowered into the borehole using the draw works. Given the large weight of a pipe string, hanging a sleeve shoulder on a spider slip as the pipe string is lowered through the spider may damage the spider, the pipe connection, or both.
A gripping assembly capable of gripping and supporting a broad range of pipe string diameters without alignment problems would provide a significant advantage because it could be used to make-up and run tapered pipe strings, or pipe strings having a generally telescoping configuration, into a borehole with less rig downtime. But misalignment problems caused by material imperfections in pipe, the derrick and other rig structures, and winds and thermal expansion or contraction, make it difficult to achieve the full benefit of using gripping assemblies with tapered bowls having non-stepped profiles. While some tools exist to center the proximal end of a pipe string or a pipe connection, these conventional tools limit the range of diameters of pipe that may be run, thereby defeating the advantage provided by the use of a gripping assembly having a tapered bowl with a non-stepped profile.
What is needed is an adjustable guide that can be coupled to an elevator assembly to position the proximal end of a pipe string relative to the bore of the elevator assembly, and that can be used to position pipe strings within a range of pipe string diameters. What is needed is an adjustable guide that can be coupled to a spider to position a pipe connection relative to the bore of the spider, and that can be used to position pipe connections within a range of pipe connection diameters. What is needed is an adjustable guide that may be used to radially position the proximal end of a pipe string as the elevator assembly is lowered over the proximal end of the pipe string, and that can be used to position pipe strings having a range of diameters. What is needed is an adjustable guide that may be used to radially position a pipe connection within a pipe string as the pipe string is lowered through the spider, and that can be used to position pipe connections having a range of diameters.
This invention satisfies some or all of the above needs, and others. One embodiment provides a method of forming a tapered pipe string having at least one outer diameter transition along its length without replacing the gripping assemblies. One embodiment includes the steps of using a spider and a elevator assembly, each having smooth, non-stepped tapered bowls for receiving and cooperating with a set of slips, to make-up and run a first portion of a pipe string having a first diameter, connecting a pipe segment having a second diameter larger than the first to the proximal end of the first portion of the pipe string, and using the same spider and elevator assembly to make-up additional pipe segments having the second diameter to lengthen the pipe string. The resulting tapered pipe string may be used to strategically position thicker-walled pipe at critical intervals of the borehole, while using less expensive standard pipe at less critical intervals of the borehole to minimize the overall cost of the completed well.
The forming of a tapered pipe string using the method described above may be hindered if the proximal ends of smaller diameter segments of the tapered pipe string do not sufficiently align with the bore of the elevator assembly, or if threaded connections of the smaller diameter portion of the tapered pipe string do not sufficiently align with the bore of the spider. In these events, the proximal end of the pipe string or the internally threaded sleeve of the threaded pipe connections may hang on or otherwise land on slips or other portions of the elevator assembly or spider due to misalignment. This problem may be abated using another embodiment of the method that comprises the steps of securing an adjustable pipe guide to the bottom of the elevator assembly, and adjusting the adjustable pipe guide to steer the proximal end of a pipe string into the bore of the elevator assembly as the elevator assembly is being lowered over the proximal end of the pipe string. The adjustable guide may be securable to the bottom of the elevator assembly, or the portion disposed toward the spider, in a generally aligned position with a bore of its tapered bowl. The additional steps pertaining to the installation and use of the adjustable guide facilitates the unobstructed entry of the proximal end of the pipe string into the bore in the bottom of the tapered bowl as the elevator assembly is lowered over the proximal end of the pipe string.
An adjustable pipe guide apparatus that may be used in the steps of the alternate embodiment of the method may comprise a set of generally angularly distributed guide inserts, each guide insert being radially positionable within or on a guide insert retainer. The guide inserts each may have a retracted position and at least one deployed position to engage and position the proximal end of a pipe string into general alignment with the bore of the tapered bowl of the elevator assembly.
Another embodiment of the method comprises the steps of securing an adjustable pipe guide to the top portion of a spider to center a pipe connection within a pipe string to generally coincide with the bore of the spider. The steps may include securing the adjustable pipe guide to the top portion of the spider, or the portion of the spider disposed toward the elevator assembly, and deploying the adjustable guide to generally center a pipe connection of a pipe string within the bore of the spider to facilitate unhindered movement of the pipe connection through the disengaged spider as the pipe string is lowered into a borehole. The adjustable pipe guide apparatus that may be used in the steps of this embodiment of the method may comprise a plurality of generally angularly distributed guide inserts, each guide insert radially positionable within or on a guide insert retainer. The guide inserts each may have a retracted position and at least one deployed position to engage and generally center a pipe connection of a pipe string into general alignment with the bore of the tapered bowl of the spider.
Another embodiment of the apparatus comprises an adjustable guide wherein the guide inserts are each movable within a groove, a furrow, passage, gutter or channel in a guide insert retainer. The guide inserts may be rollably, slidably or pivotably movable relative to the guide insert retainer. The guide inserts may each be coupled to and radially positionable relative to the guide insert retainer by a drive member to provide controlled radial positioning of the guide inserts between a retracted position and the at least one deployed position. The drive member may comprise a threaded shaft, a pneumatic cylinder, a hydraulic cylinder, a rack and pinion gear, or some other mechanical drive device to provide controlled deployment and/or retraction of each guide insert. The drive member may be pneumatically, hydraulically, or electrically powered, and the drive member may be remotely controlled using wired or wireless control.
For example, but not by way of limitation, a drive member used to controllably and radially position a guide insert may comprise an externally threaded and rotatable shaft that is threadably received within an internally threaded hole in the guide insert. In this embodiment, the threaded shaft is controllably rotatable about its axis to so that rotation of the threaded shaft in a first direction deploys the guide insert radially towards its at least one deployed position, and rotation of the threaded shaft in the second, opposite direction retracts the guide insert radially towards a retracted position. It should be understood that the controlled rotation of the threaded shaft may be manual, such as by use of a crank, a hand tool with a bit or a hand-held drill, or the controlled rotation may be powered using a motor. In one embodiment, an adjustable guide may comprise guide inserts that are radially positionable using a small servo-motor coupled to the threaded shaft for imparting controlled rotation to the shaft to deploy and retract the guide insert. The servo-motor used to position a guide insert may be pneumatically, hydraulically or electrically powered, and a single motor may be mechanically coupled to one, two or more adjacent threaded shafts to achieve simultaneous guide insert deployment or retraction.
An adjustable guide having one or more powered servo-motors to deploy and retract guide inserts may be remotely controlled using wired or wireless systems. A portable power source, such as a battery, may be disposed onboard the adjustable guide to power the servo-motor(s) and other control circuitry or devices related to the adjustable guide. Remotely controlling the adjustable guide may provide enhanced flexibility and enable the user to engage and “push” the proximal end of a pipe string or a pipe connection toward a desired position instead of relying only on the radial component of the force imparted by contact between the pipe string and one or more guide inserts to position the pipe string. For example, but not by way of limitation, an adjustable guide coupled to the bottom of an elevator assembly may be “opened” by fully retracting the guide inserts to capture the proximal end of a pipe string that is misaligned with the centerline of the elevator assembly and, once the proximal end of the pipe string is disposed within the radially interior space formed between the guide inserts, the adjustable guide may be remotely actuated to deploy the guide inserts and thereby reduce the size of the radially interior space. In this manner, the adjustable guide may be used to push the proximal end of the pipe string toward the center bore of the elevator assembly. It should be noted that with an adjustable guide on an elevator assembly, as opposed to a spider, there may be lateral displacement of the pipe string combined with lateral displacement of the elevator assembly in the opposite direction to reduce misalignment between the proximal end of the pipe string and the bore of the tapered bowl of the pipe string.
In one embodiment, the guide inserts may each comprise at least one generally sloped surface to engage and impart a positioning force to a pipe end or to the sleeve of a pipe connection. The sloped surface of a guide insert may be sloped at, for example, a 45 degree angle relative to vertical to impart a force to the pipe string that has a generally lateral component to position a pipe end or a pipe connection. The sloped surfaces of the guide inserts may together form portions of a variable and generally frustoconical guide to steer a pipe end or a pipe connection generally towards alignment with the bore of the tapered bowl of an elevator assembly or a spider.
In an embodiment, a guide insert retainer may comprise two or more guide insert retainer portions that cooperate to position the guide inserts in a generally angularly distributed arrangement that is generally aligned with the bore of the tapered bowl of the elevator assembly or the spider. Each guide insert retainer portion may comprise one or more grooves, tracks or channels therein to slidably receive a corresponding tongue, rail or key on the at least one guide insert. The guide insert retainer portion may be movably secured to the elevator assembly or spider, and movable between a deployed position, to position the guide inserts in a generally angularly distributed arrangement aligned with the bore of the tapered bowl, and a removed position, to remove the guide inserts away from the bore and out of an angularly distributed arrangement. In another embodiment, two or more guide insert retainer portions may be actuatable to move between the removed position and the deployed position by a retainer drive member, such as a cylinder. In yet another embodiment, two or more guide insert retainer portions may be hingedly movable between the deployed position and the removed position.
In another embodiment, the guide insert retainer may comprise a bell guide. That is, the guide insert retainer may comprise a generally frustoconical and rigid interior guide surface that can be used when the guide inserts are in the retracted position to engage and position the proximal end of a pipe string or a pipe connection generally into alignment with the bore of the tapered bowl of an elevator assembly or a spider, respectively. Each guide insert may be movable within a channel terminating at an aperture in the bell guide between a generally retracted position and at least one deployed position. The guide inserts may each comprise a generally sloped surface that may be positioned to be generally flush with the interior surface of the bell guide when the guide inserts are in the retracted position, and the guide inserts may each be deployable from that retracted position to radially position the sloped surfaces within the interior of the bell guide to provide an adjustable guide.
The embodiments of the adjustable guide disclosed herein may be especially useful to form and install a tapered pipe string in a borehole without damaging the elevator assembly or the spider due to misalignment and without additional rig downtime to change out the elevator assembly or the spider.
So that the manner in which the above recited features of the present invention can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings. However, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.
Embodiments of the adjustable guide is useful to position the proximal end of a pipe string, or a pipe connection within a pipe string, relative to an elevator assembly, or relative to a spider, respectively that may have a smooth, non-stepped tapered bowl. The adjustable guide may be used to make-up and run a pipe string into a drilled borehole, particularly a tapered pipe string having at least one outer diameter transition along its length.
The elevator assembly 10 shown in
The slips 17 of the elevator assembly 10 are movable between an engaged position and a disengaged position (shown in
Referring again to
The omission of the pipe string 88 (see
It should be understood by those skilled in the art that the guide inserts of the adjustable guide may comprise a steering surface, which is a portion of the guide insert that may be positioned to actively engage and displace a pipe end and/or a pipe connection. It should be understood that the sloped steering surface of each guide insert is generally disposed on the guide insert in an orientation that facilitates engagement with a pipe end and/or a pipe connection that may be received in and/or through the adjustable guide.
The guide inserts 30 of the embodiment of the adjustable guide 10a shown in
It should be further understood that, where an actuator is used to position a guide insert 30 by, for example, but not by way of limitation, powered rotation of a threaded shaft on which the guide insert is threadably received, then a controller may be used to position the guide insert 30 at a predetermined or memorized position. For example, but not by way of limitation, a controller may be coupled to a sensor that senses the rotation of the threaded shaft, and that records the number of times the threaded shaft rotates during displacement of the guide insert. The sensor may be disposed within a common case with the actuator, or the sensor may be electronically, mechanically or optically coupled to the actuator or to the threaded shaft. The sensor may be used to disable the actuator upon rotation of the threaded shaft a predetermined number of times or, alternately, the sensor may be used to disable the actuator after the rotation of the actuator moves the guide insert or other member into a sensed proximity with the sensor. In this way, the guide insert may be pre-positioned, using the controller and the actuator, to receive and center a pipe end of a known diameter.
In another embodiment, an actuator may be coupled to one or more guide inserts to position the guide insert between the retracted position and one or more deployed positions, and vice-versa. An actuator can be fluid powered, electric powered, mechanically powered, etc. For example, but not by way of limitation, a fluidically powered rotary motor may be disposed within a plurality of cases 95, each of which is coupled to the adjustable guide 10a to rotate a socket 42 at the end of the threaded shaft (not shown in FIGS. 4A-4C—see
It should be understood that the guide inserts 30 of the embodiment of the adjustable guide 10a shown in
The embodiment of the adjustable guide 60a shown in
It should be further understood that the sloped surfaces 80A may also comprise a curvature, in addition to the curvature in the circumferential direction, if any, along the pipe contacting face of each guide insert and in a direction generally along the axis of the bore of the adjustable guide, or along the axis of the bore of pipe gripping apparatus to which the adjustable guide is coupled. In one embodiment, the curvature in the axial direction may be skewed off of parallel to the axis of the bore to “funnel” the pipe end or the pipe connection contacted by the adjustable guide toward the center of the bore. In one embodiment, the curvature of the face of the sloped surface may provide an axially concave shape to the guide insert along the sloped surface, and in another embodiment, the curvature of the face of the sloped surface may provide an axially convex shape to the guide insert along the sloped surface. It should be appreciated by those skilled in the art that the aggregation of the sloped surfaces of a set of movable guide inserts, each having a radially inwardly disposed sloped surface with a curvature that is convex in the axial direction, and the set generally surrounding the bore of the adjustable guide, may resemble an inverted vortex, and the aggregation of the sloped surfaces of a set of movable guide inserts, each having a radially inwardly disposed sloped surface with a curvature that is concave in the axial direction, may resemble an inverted bowl.
It should be understood that the movable guide inserts may be prepositioned to form a guide of a desired size and shape and to engage and steer a pipe end or a pipe connection toward the center of a bore of a pipe gripping apparatus, as described above. Alternately, where a pipe string or a pipe connection is in contact with one or more sloped surfaces 80A of one or more movable guide inserts 80, manual or powered rotation of the one or more sockets 92 and the related one or more threaded shafts may controllably position the contacting guide inserts 80 and the pipe string or pipe connection that contacts the sloped surfaces 80A of the guide inserts 80.
It should be understood that the guide inserts may be secured to the guide insert retainer in a number of ways to ensure controllable positioning to form a guide. For example, but not by way of limitation, the guide inserts may each be pivotally coupled to the retainer so that the size of the steering guide formed by deployment of the guide inserts may be controlled by angularly pivoting the guide inserts into a deployed position rather than by displacement of the guide inserts while generally maintaining the same orientation of the guide inserts relative to the retainer.
It should be understood that an “elevator assembly,” as used herein, means a vertically movable spider, a casing running tool (CRT) or any other pipe gripping assembly that can be manipulated to raise or lower a pipe string that is supported within the elevator assembly. It should be further understood that “pipe gripping apparatus,” as used herein, means an apparatus that can support a pipe string, and specifically includes an elevator assembly and also includes a spider.
The terms “comprising,” “including,” and “having,” as used in the claims and specification herein, shall be considered as indicating an open group that may include other elements not specified. The terms “a,” “an,” and the singular forms of words shall be taken to include the plural form of the same words, such that the terms mean that one or more of something is provided. The term “one” or “single” may be used to indicate that one and only one of something is intended. Similarly, other specific integer values, such as “two,” may be used when a specific number of things is intended. The terms “preferably,” “preferred,” “prefer,” “optionally,” “may,” and similar terms are used to indicate that an item, condition or step being referred to is an optional (not required) feature of the invention.
While the foregoing is directed to embodiments of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.
This application is a continuation of U.S. patent application Ser. No. 12/126,072 filed on May 23, 2008, which is a continuation-in-part application depending from and claiming benefit of priority to U.S. patent application Ser. No. 11/846,169 filed on Aug. 28, 2007.
| Number | Date | Country | |
|---|---|---|---|
| Parent | 12126072 | May 2008 | US |
| Child | 12618705 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 11846169 | Aug 2007 | US |
| Child | 12126072 | US |
