Patent Application
20150101828
In coiled tubing operations, a coil connector is a downhole tool that provides a mechanical connection between coiled tubing and a bottom hole assembly or other equipment in a downhole tool string. In addition to providing a mechanical connection, the coil connector also provides a seal between an internal flow path of the bottom hole assembly and the surrounding annulus. However, coiled tubing experiences plastic deformation during running in and out of a well. For example, coiling and uncoiling of the coiled tubing as well as pumping fluids through the coiled tubing at high pressure can cause plastic deformation. Sometimes the coiled tubing becomes ballooned and ovalized which causes difficulty with respect to both installing the coil connector and achieving a pressure tight seal between the tubing and the coil connector.
In general, a methodology and system are provided for plastically deforming tubing, e.g. coiled tubing, to a desired size and shape. For example, the technique may be employed to reform a coiled tubing end in a manner which facilitates installation of a coil connector. A coiled tubing forming device is used in cooperation with a coiled tubing injector. The coiled tubing injector moves coiled tubing through a die of the coiled tubing forming device in a manner which deforms the coiled tubing to a desired shape and/or size.
However, many modifications are possible without materially departing from the teachings of this disclosure. Accordingly, such modifications are intended to be included within the scope of this disclosure as defined in the claims.
Certain embodiments of the disclosure will hereafter be described with reference to the accompanying drawings, wherein like reference numerals denote like elements. It should be understood, however, that the accompanying figures illustrate the various implementations described herein and are not meant to limit the scope of various technologies described herein, and:
a is an illustration of an embodiment of a die which may be employed in the tubing forming device, according to an embodiment of the disclosure;
b and 4c are schematic illustrations, respectively, of embodiments of dies which may be employed in the tubing forming device, according to an embodiment of the disclosure;
d is a schematic, cut-away, cross-sectional view of embodiments of segments of a die which may be employed in the tubing forming device, according to an embodiment of the disclosure; and
In the following description, numerous details are set forth to provide an understanding of some embodiments of the present disclosure. However, it will be understood by those of ordinary skill in the art that the system and/or methodology may be practiced without these details and that numerous variations or modifications from the described embodiments may be possible.
The present disclosure generally relates to a system and methodology which facilitate the deployment of tubing, such as coiled tubing. The system and methodology utilize a tubing forming device which can be used to reshape the tubing in a manner which facilitates connection of the tubing to adjacent components in a tubing string. Various types of tubing may be reformed in both well and non-well related applications. In well applications, the system and methodology work well in shaping coiled tubing to facilitate a variety of downhole, intervention operations and other types of well related operations which utilize coiled tubing. By way of example, the system may be used to plastically deform a coiled tubing end so as to reshape the end to a desired roundness and outside diameter. This allows the coiled tubing to be readily connected to the rest of a downhole tool string by a coil connector.
According to an embodiment, the system and methodology employ a tubing forming device used in cooperation with a coiled tubing injector. The coiled tubing injector moves coiled tubing through a forming die of the tubing forming device in a manner which deforms the coiled tubing to a desired shape and/or size. In this type of embodiment, the forming die may be selectively contracted in a radial direction to a desired diameter. As the coiled tubing, or other type of tubing, is forced through the die by the coiled tubing injector, the coiled tubing is deformed to the desired specifications. The deformation technique may be employed to reduce the diameter and to improve the roundness of an end of the coiled tubing, thus reforming the end for coupling and sealing with a coil connector. Effectively, the system uses the available power of the coiled tubing injector head to push or pull the tubing, e.g. coiled tubing, through the tubing forming device to resize and/or reshape the tubing.
In coiled tubing applications, the system and methodology may thus be used to reform coiled tubing back to, for example, an original outer diameter and tolerance as specified by a manufacturer. By way of example, the system utilizes axial motion of the tubing, e.g. coiled tubing, provided by a coiled tubing injector head or other tubing deployment device to pull or push the coiled tubing through the forming die. The forming die converts the axial force to a radial force which squeezes and plastically deforms the coiled tubing to the desired shape and size, e.g. to the desired outer diameter.
In some embodiments, the forming die is constructed as a variable diameter, segmented die. The segmented die works in cooperation with other components which collapse the segmented die to a desired diameter. For example, the segmented die may be part of a coiled tubing forming device having a die limit ring, an upper die, a lower housing, and a segmented forming die. However, other and/or additional components may be employed in the coiled tubing forming device. Additionally, the various components may have a variety of sizes, arrangements and configurations to form ends and/or other sections of the coiled tubing or other types of tubing.
Referring generally to
The coiled tubing injector head 30 moves the coiled tubing through a tubing forming device 34 which is used to deform the coiled tubing 26, e.g. an end of the coiled tubing, to a desired size and shape. For example, the tubing forming device 34 may be used to reform an end of the coiled tubing 26 to an original diameter and tolerance as specified by the coiled tubing manufacturer. In some applications, the coiled tubing 26 ultimately may be deployed down through the tubing forming device 34 after the desired tubing deformation. As illustrated, the coiled tubing 26 is deployed down through surface equipment 36 and into a wellbore 38. In some applications, surface equipment 36 may comprise a Christmas tree 40 and may be positioned at a surface 42, such as an earth surface or a seabed. Although coiled tubing 26 is illustrated, the tubing forming device 34 also may be utilized to deform other types of tubing in a variety of well applications and non-well applications.
As illustrated in
Referring generally to
The illustrated tubing forming device 34 also may comprise a die limit ring 58 which controls the final diameter of the coiled tubing 26 by limiting the longitudinal travel and, therefore, the radial contraction or squeeze of the forming die 50. As described in greater detail below, the forming die 50 may be constructed as a segmented die which performs the resizing of the coiled tubing 26 by squeezing the outside of the coiled tubing. However, forming die 50 may have other types of constructions which enable selective radial contraction and expansion of the die to appropriately squeeze the outside of the coiled tubing 26 when forming the coiled tubing to a desired size and shape.
The tubing forming device 34 further comprises a die 60, e.g. an upper die, which comprises a wedge-shaped portion 62. The wedge-shaped portion 62 has an inner surface 64 which is angled with respect to an axis 66 of the tubing forming device 34. The angled inner surface 64 engages and works in cooperation with a corresponding exterior surface 68 of forming die 50. The wedge-shape portion 62 forces the forming die 50 to contract radially as the forming die 50 is moved in a longitudinal direction along axis 66. The forming die 50 may be moved longitudinally along axis 66 by movement of coiled tubing 26 via coiled tubing injector head 30. In the example illustrated, coiled tubing injector head 30 is operated to pull coiled tubing 26 in an upward direction which moves forming die 50 upwardly toward die limit ring 58. In an embodiment, the angle (with respect to the axis 66) of the angled inner surface 64 of the wedge-shaped portion 62 and the angle of the exterior surface 68 of the forming die 50 may be selected with knowledge of the range of coefficients of friction expected between the die 50 and the coiled tubing 26. With this knowledge and a free body diagram, the angles of the surfaces 64 and 68 with respect to the axis 66 may be selected such that the forming die 50 will move along with the coiled tubing 26 (rather than slipping) when the device 34 is in operation. The wedging action between the die 50 and the coiled tubing 26 will increase the gripping force on the coiled tubing 26 as the coiled tubing 26 moves inward and will act to reduce the diameter of the coiled tubing. When the die limit ring 58 is encountered (discussed in more detail below), the die 50 is prevented from moving radially inwardly any further, limiting its clamping force on the coiled tubing 26 to a force required to reach the current diameter, and thus allowing the coiled tubing 26 to slide with respect to the die 50. The coiled tubing 26 may then be further pulled entirely out of the forming die 50 without harming the coiled tubing 26, which action may greatly simplify the use of the tubing forming device 34 by eliminating the need for precision motion. Coefficients of friction as discussed above are dependent on the surface condition of both the coiled tubing 26 and the die 50, lubrication, and types of gripping dies (due to lubrication movement). Expected coefficients of friction may range as high as 0.5 and as low as 0.05. The variation in use may be greatly reduced by specifying a particular lubricant and/or surface condition of the die 50 and/or the coiled tubing 26.
Die limit ring 58 comprises an abutment surface 70 which blocks further longitudinal travel of forming die 50. By controlling, e.g. limiting, the longitudinal travel of forming die 50, the desired degree of radial contraction of the forming die 50 also is controlled. In certain applications, the longitudinal position of die limit ring 58 may be adjustable to facilitate control over the radial contraction of forming die 50 and thus control over the degree of deformation of coiled tubing 26 as coiled tubing 26 is drawn through forming die 50.
The tubing forming device 34 further comprises a housing 72, e.g. a lower housing, which is designed to force the forming die 50 against the wedge-shape portion 62 of upper die 60 during initial installation of tubing forming device 34 onto coiled tubing 26. The lower housing 72 moves the forming die 50 into engagement with both coiled tubing 26 and wedge-shape portion 62 to provide the initial grip between the forming die 50 and the coiled tubing 26. By way of example, lower housing 72 may be removably engaged with upper die 60 via a threaded region 74. This structure allows rotation of lower housing 72 with respect to upper die 60 so that the lower housing 72 is able to advance longitudinally and thus drive forming die 50 in a longitudinal direction. The forming die 50 is moved in the longitudinal direction until the forming die 50 is squeezed radially inwardly against the coiled tubing 26 via inner surface 64 of wedge-shape portion 62.
Similarly, die limit ring 58 may be releasably engaged with upper die 60 via a threaded region 76. The die limit ring 58 may be rotated relative to upper die 60 to adjust the longitudinal position of abutment surface 70 and thus the limit of radial contraction with respect to forming die 50. However, other types of fastening systems (other than threaded regions 74 and 76) may be used to adjustably and/or releasably engage lower housing 72 and die limit ring 58 with upper die 60.
In the illustrated example, the tubing forming device 34 further comprises a mounting structure 78 which may be used to mount the tubing forming device 34 at a desired location in well system 20. For example, the mounting structure 78 may be used to position and mount the tubing forming device 34 against a bottom of the coiled tubing injector head 30.
In an operational example, the coiled tubing injector head 30 is used in cooperation with the tubing forming device 34 to reshape an outer diameter of the end 44 of coiled tubing 26. The coiled tubing injector head 30 and tubing forming device 34 may be operated to return the coiled tubing end 44 to an original diameter and roundness specified by the coiled tubing manufacturer. By reforming the coiled tubing end 44, coil connector 46 is easier to install on the coiled tubing 26 and the reformed end 44 improves the ability of the coil connector 46 to seal against the coiled tubing 26.
The expandable and contractible forming die 50 is designed to enable selective expansion of the die 50 to initially allow the tubing forming device 34 to be slid over the coiled tubing 26 (e.g. to receive the coiled tubing therethrough) for reshaping of the coiled tubing. As illustrated in
Subsequently, the coiled tubing injector head 30 is operated to slowly pull the coiled tubing 26 in an upward direction toward the coiled tubing injector head. Friction between the coiled tubing 26 and the forming die 50 causes the forming die 50 to be pulled farther into the upper die 60 along wedge-shape portion 62. This lineal movement of the forming die 50 causes further radial contraction of the forming die 50 until the coiled tubing is squeezed past its yield point, i.e. plastically deformed. The upward movement of coiled tubing 26 via coiled tubing injector head 30 is continued until the forming die 50 contacts abutment surface 70 of die limit ring 58, at which point the coiled tubing 26 has reached its desired size. The coiled tubing injector head 30 continues to pull the coiled tubing 26 until the end 44 of the coiled tubing 26 is reshaped and permanently reduced in diameter for engagement with coil connector 46.
The coiled tubing injector head 30 may be operated to pull the coiled tubing entirely through the tubing forming device 34 or to pull until a desired section of the coiled tubing 26 has been resized. In some applications, greater lengths of tubing, or tubing sections other than end 44, may be reshaped and/or resized. Additionally, the die limit ring 58 may be adjustable to enable selective variation of the final diameter of the coiled tubing 26. In some applications, the die limit ring 58 is adjustable, via threaded region 76, by rotating the die limit ring 58 with respect to die 60. After reshaping and/or resizing the desired length of coiled tubing 26, forming die 50 may be released by backing off, e.g. unscrewing, lower housing 72 from upper die 60. The device 34 may then be removed or it may remain in this loosened state while the coiled tubing 26 is deployed down through the tubing forming device 34.
Referring generally to
The segments 80 may be in the form of elongate bars or other suitable structures formed of a material which is stronger and harder than the material of coiled tubing 26. By way of example, the segments 80 may be formed from a hardened metal or a variety of other suitable alloys and/or composites. The construction of segmented die 50 allows the segmented die to expand and contract so that it can be expanded to fit over the coiled tubing 26 and then compressed to a smaller size. As described above, the radial compression of forming die 50 with the aid of wedge-shaped portion 62 enables the squeezing and plastic deformation of coiled tubing 26 when reshaping and/or resizing the coiled tubing. In an embodiment, the segments 80 may be formed having a radially interior surface 83 that is rounded or curved to correspond to the radially curved outer surface 27 of the coiled tubing 26, best seen in
Another embodiment of tubing forming device 34 is illustrated in
In this embodiment, the die limit ring 58 is again set to control deformation of the coiled tubing 26 to a desired size. The connection 74 between housing 72 and die 60 is then tightened until the forming die 50 touches the die limit ring 58, as illustrated in
Depending on a given application, the overall system 20 may be in the form of a well system or other type of system in which coiled tubing or other tubing is reshaped and/or resized. In well applications, the well system 20 may comprise many types of components combined with the tubing forming device. For example, a variety of coiled tubing injectors, tubing guides, coiled tubing reels, and other surface equipment may be used for many types of well applications. Additionally, the coiled tubing may be deployed through many types of surface equipment in various intervention operations or other well related operations in vertical and/or deviated wellbores.
The tubing forming device 34 also may have a variety of configurations created in many different sizes depending on the parameters of a given application. The tubing forming device may be mounted directly to the coiled tubing injector head or to other surface equipment. Additionally, the tubing forming device may utilize a variety of forming dies selectively expandable and contractible via various mechanisms. The components employed to selectively expand and contract the forming die also may have a variety of sizes and configurations and may be constructed from different types of materials depending on the environment and parameters of a given application.
Although a few embodiments of the disclosure have been described in detail above, those of ordinary skill in the art will readily appreciate that many modifications are possible without materially departing from the teachings of this disclosure. Accordingly, such modifications are intended to be included within the scope of this disclosure as defined in the claims.
