System and method for splicing a non-spoolable tool anywhere along a coiled tubing string

Abstract

A system and method for splicing a non-spoolable tool anywhere along a coiled tubing string. A removable tubing section may be connected along a coiled tubing string by two spoolable connectors. The coiled tubing string may be unspooled from a reel until the removable tubing section and connectors are positioned within a work window. The removable tubing section may be disconnected from the tubing string through the work window and a tool may be connected to the coiled tubing string via the two connectors. The tool may then be positioned within a wellbore by insertion of the coiled tubing string. The tool may aid in the insertion of the coiled tubing string into the wellbore. A portion of the wellhead may be disconnected and raised to expose the connectors to permit the removal of the removable tubing section and the connection of a non-spoolable tool.

Claims

1. A method for splicing a tool along a coiled tubing string, the method comprising: connecting an upper connector to an upper coiled tubing string and an upper portion of a removable coiled tubing section; connecting a lower connector to a lower coiled tubing string and a lower portion of the removable coiled tubing section to form a coiled tubing string comprising the upper coiled tubing string, removable coiled tubing section, and lower coiled tubing string; passing the lower connector, removable coiled tubing section, and upper connector through a coiled tubing injector head; disconnecting the coiled tubing injector head after passing the lower connector, removable coiled tubing section, and upper connector through the coiled tubing injector head; raising the disconnected coiled tubing injector head to expose the upper and lower connectors; disconnecting the removable coiled tubing section from the exposed upper connector and the exposed lower connector; removing the disconnected removable coiled tubing section from the coiled tubing string; and connecting a tool to the upper connector and the lower connector after removing the disconnected removable coiled tubing section from the coiled tubing string, wherein connecting the upper and lower connectors to the removable coiled tubing section further comprises dimple connections, and disconnecting the removable coiled tubing section further comprises machining out the dimple connections.

2. The method of claim 1 further comprising: securing the position of the coiled tubing string within a blow out preventer (BOP); and sealing against an exterior of the coiled tubing string within the BOP, wherein the securing and sealing are performed prior to disconnecting the removable coiled tubing section.

3. The method of claim 1, wherein connecting the tool to the upper connector and the lower connector further comprises connecting the tool with dimple connections.

4. The method of claim 1, wherein the tool is a rotary tool or a water hammer pulse tool.

5. The method of claim 1, wherein the tool is a circulating sub or a gas lift sub.

6. The method of claim 1 further comprising passing the lower connector, removable coiled tubing section, and upper connector through a lubricator.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a side view of a connector that may be used to connect a tool along a coiled tubing string;

(2) FIG. 2 is a cross-sectional view of an upper connector connected to a coiled tubing string on the upper end and connected to short removable tubing section on the lower end;

(3) FIG. 3 is a cross-sectional view of a lower connector connected to a coiled tubing string on the lower end and connected to short removable tubing section on the upper end;

(4) FIG. 4 is a cutaway top view of a water hammer pulse tool that may be connected along a coiled tubing string;

(5) FIG. 5 shows an example of a rotary tool that may be connected along a coiled tubing string;

(6) FIG. 6 shows an example of a hydraulic style work window through which a tool may be inserted to be spliced onto a coiled tubing string;

(7) FIG. 7 shows coiled tubing from a reel passing through a coiled tubing injector head and into a wellhead;

(8) FIG. 8 shows coiled tubing passing through a coiled tubing injector head being suspended from a crane;

(9) FIG. 9 is a flow chart for one embodiment of a method for splicing a tool along a coiled tubing string;

(10) FIG. 10 is a flow chart for one embodiment of a method for splicing a tool along a coiled tubing string; and

(11) FIG. 11 shows a coiled tubing string with two removable tubing sections connected along the coiled tubing string.

(12) While the disclosure is susceptible to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and will be described in detail herein. However, it should be understood that the disclosure is not intended to be limited to the particular forms disclosed. Rather, the intention is to cover all modifications, equivalents and alternatives falling within the scope of the invention as defined by the appended claims.

DETAILED DESCRIPTION

(13) It may be desired to attach a rigid tool to a position somewhere along the length of coiled tubing string that may not be able to be spooled onto a coiled tubing reel. One embodiment of the present disclosure is the method of connecting a tool anywhere along a coiled tubing string using connectors that are flexible and may be spooled onto a coiled tubing reel. The connectors may be positioned anywhere along the coiled tubing string where it may be desired to attach a downhole tool after the specified position of the coiled tubing string has been spooled off of the reel. The connectors may be used to connect a tool that aids in the insertion of the coiled tubing into a wellbore such as a water pulse hammer tool. The connectors may be used to connect various tools, and not just a water pulse hammer tool, to the coiled tubing string as would be appreciated by one of ordinary skill in the art having the benefit of this disclosure. For example, the connectors may be used to connect a rotary tool or a downhole tractor or any other tool dimensioned to fit within the wellbore to a desired location along a coiled tubing string. The connectors may also be used to connect a circulating sub or gas lift sub anywhere along a coiled tubing string.

(14) FIG. 1 is shows one embodiment of a connector 8 that may be used to connect a tool along the coiled tubing string 6 (Shown in FIG. 7). The connector 8 includes entry sections 10 that are used to connect the connector 8 to coiled tubing 6. The entry sections 10 are located at the ends of the body 14 of the connector 8. The connector 8 includes shoulders 18 and an annular void between the shoulders 18. An elastomer backfill 12 and centralizers 16 fills the annular void between the shoulders 18. The outer diameter of the body 14 of the connector 8 is less than that of the outer diameter of the coiled tubing 6. The elastomer backfill 12 and centralizers 16 help to centralize the connector 8 as it passes through the stuffing box 230 (shown in FIG. 8) and blow out preventer 250 (shown in FIG. 8). A plurality of connectors 8 may be used to selectively connect a removable tubing section 106 (shown in FIGS. 2-3) and selectively connect a tool after removing the removable tubing section 106 as will be described in detail herein.

(15) FIG. 2 shows an upper connector 8a connected on a first end to an upper coiled tubing string 6a and connected on a second end to a removable tubing section 106. The removable tubing section 106 may be connected to a lower coiled tubing string 6b via a lower connector 8b as shown in FIG. 3. The lower tubing string 6b, lower connector 8b, removable tubing section 106, upper connector 8a, and upper tubing sting 6a may be connected together to form a coiled tubing string 6 that may be spooled onto a reel 200 (shown in FIG. 7). After unspooling the portion of the coiled tubing string 6 that includes the connectors 8a and 8b and the removable tubing section 106, the removable tubing section 106 may be disconnected from the connectors 8a and 8b and a tool may be connected to the connectors 8a and 8b as described herein. Multiple removable sections of tubing 106 may be positioned along the tubing string 106 to permit the connection of multiple tools along the tubing string 106 as would be appreciated by one of ordinary skill in the art having the benefit of this disclosure. The removable section of tubing 106 may be of a predetermined length required to permit the connection of a tool to the tubing string 6. For example, the removable section of tubing 106 may be less than 10 feet long. The removable section of tubing 106 may only be 2 to 3 feet long. The length of the removable section of tubing 106 may be varied depending on the application as would be appreciated by one of ordinary skill in the art having the benefit of this disclosure. The removable section of tubing 106 may be a section of coiled tubing or can be any section of tubing that has substantially the same diameter and wall thickness as the coiled tubing string 6. The strength and elongation of the removable section of tubing 106 may also be comparable, but not necessarily identical, as the strength and elongation of the coiled tubing string 6.

(16) As discussed above, the removable section of tubing 106 may be removed to permit the connection of a tool to the coiled tubing string 6. Various types of downhole tools may be connected to the tubing string 6. For example, the tools may be, but is not limited to, a water pulse hammer tool, a rotary tool, a tractor, a circulating sub, or a gas lift sub. The tools may be connected to the tubing string 6 by an upper connecting tube and a lower connecting tube. The lower end of the upper connecting tube may be connected to an upper portion of the tool. For example, the lower end of the upper connecting tube may include a threaded profile permitting the upper connecting tube to be threaded into a corresponding threaded opening in the tool. The upper end of the upper connecting tube may include a tube profile and may be connected to the coiled tubing string 6 by a crimping tool to create a dimple connection, as is well known in the art. The upper end of the lower connecting tube may be connected to a lower portion of the tool. For example, the upper end of the lower connecting tube may include a threaded profile permitting the lower connecting tube to be threaded into a corresponding threaded opening in the tool. The lower end of the lower connecting tube may include a tube profile and may be connected to the coiled tubing string 6 by a crimping tool to create a dimple connection, as is well known in the art. Various other mechanisms may be used to connect the tool to the coiled tubing string 6 as would be recognized by one of ordinary skill in the art having the benefit of this disclosure.

(17) FIG. 4 shows one example of a water hammer pulse tool 100 that may be connected to the coiled tubing string 6 after removal of a removable tubing section 106. The water hammer pulse tool 100 may aid in the insertion of the coiled tubing string 6 into a wellbore. FIG. 5 shows one example of a rotary tool 110 that may be connected to the coiled tubing string 6 after removal of a removable tubing section 106.

(18) FIG. 6 shows a hydraulic actuated work window 270 that may be used to access the coiled tubing string 106 to remove the removable tubing section 106 and install a tool along the coiled tubing string 6. The coiled tubing string 6 including spoolable connectors 8 that connect a removable tubing section 106 along the coiled tubing string 6 may be stored on a reel as shown in FIG. 7. The coiled tubing string 6 is unreeled over a gooseneck 210 and through a coiled tubing injector head 220 as shown in FIG. 6 and FIG. 7. The coiled tubing string 6 continues to travel through a stuffing box 230, lubricator 240, and blow out preventer (BOP) 250 into the wellbore. One of ordinary skill in the art will recognize that that the figures may not be drawn to scale. For example, the lubricator 240 of FIG. 7 may be at least twice the length of the BOP 250 to accommodate a tool.

(19) The coiled tubing string 6 may continue to travel off of the reel 200 until the removable tubing section 106 and connectors 8 are located within a work window 270 positioned above the BOP 250. Upon the removable tubing section 106 reaching the work window 270, slip rams of the BOP 250 may be actuated to secure the coiled tubing string 6 in place and seal rams of the BOP 250 may be actuated to create a seal on the exterior of the coiled tubing string 6. The work window 270 may then be opened to access the upper and lower connectors 8a and 8b securing the removable tubing section 106 along the coiled tubing string 6. The removable tubing section 106 may then be disconnected from the connectors 8a and 8b. For example, dimples connecting the removable tubing section 106 to the connectors 8a and 8b may be machined out permitting the removable of the removable tubing section 106. A tool may be then inserted through the work window 270 and connected to the coiled tubing string 6 via the upper and lower connectors 8a and 8b. For example, a crimping tool may connect the connecting tubes to the connectors 8a and 8b via a dimple connection. The work window 270 may then be closed, the BOP 250 may release the coiled tubing string 6, and the coiled tubing string 6 may be run into the wellbore with the tool, such as a water hammer pulse tool 100, positioned along the coiled tubing string 6.

(20) Various other methods may be used to access the removable tubing section 106 and install a tool along the coiled tubing string 6. For example, after the connectors 8a and 8b have passed through the injector 220, stuffing box 230, and lubricator 240, the slip rams and seal rams BOP 250 may be actuated to retain and seal the coiled tubing string 6. The injector 220, stuffing box 230, and lubricator 240 may then be disconnected and raised with a hook 260 of a crane to expose the connectors 8a and 8b and the removable tubing section 106. The removable tubing section 106 may then be removed and a tool, such as a rotary tool 110, may then be connected to the coiled tubing string 106 via the connectors 8a and 8b. The injector 220, stuffing box 230, and lubricator 240 may then be lowered into position and reconnected. The rams of the BOP 250 may then be deactivated releasing the coiled tubing string 6, which may then be used to run the tool into the wellbore.

(21) FIG. 9 shows one embodiment of a method 300 for splicing a tool along a coiled tubing string. The method 300 includes the step 305 of unspooling the coiled tubing string from a reel, the coiled tubing string comprising a lower coiled tubing string connected to a lower connector, an upper coiled tubing string connected to an upper connector, and a removable tubing section connected between the lower and upper connectors. The method 300 includes the step 310 of disconnecting an upper end of the removable tubing section from the upper connector and the step 315 of disconnecting a lower end of the removable tubing section from the lower connector. The method 300 includes the step 320 of connecting an upper portion of the tool to the upper connector and the step 325 of connecting a lower portion of the tool to the lower connector. The steps 310 and 315 of disconnecting the removable tubing section may further comprise machining out dimples from the removable tubing section. The steps 320 and 325 of connecting the tool may further comprise crimping the upper portion of the tool with a portion of the upper connector and crimping the lower portion of the tool with a portion of the lower connector.

(22) FIG. 10 shows one embodiment of a method 350 for splicing a tool along a coiled tubing string. The method 350 includes the step 352 of connecting an upper connector to an upper coiled tubing string and an upper portion of a removable coiled tubing section and the step 354 of connecting a lower connector to a lower coiled tubing string and a lower portion of the removable coiled tubing section to form a coiled tubing string comprising the upper coiled tubing string, removable coiled tubing section, and lower coiled tubing string. The method 350 includes the step 356 of passing the lower connector, removable coiled tubing section, and upper connector through a coiled tubing injector head and the step 364 disconnecting the removable coiled tubing section from the upper connector and the lower connector. The method 350 includes the step 366 of removing the removable coiled tubing section from the coiled tubing string and the step 368 of connecting a tool to the upper connector and the lower connector. After connecting the tool, the method 350 may include the step 370 of positioning the tool within the wellbore.

(23) The method 350 may include a step 358 of closing rams of a BOP. The closure of the rams may secure the position of the coiled tubing string within the BOP and create a seal against an exterior of the coiled tubing string within the BOP. Step 358 may be performed prior to step 366 the removal of the removable coiled tubing section. The method 350 may include the step 360 of positioning the connectors and removable tubing section within a work window. Alternatively, the method 350 may include the step 362 of disconnecting an injector head and lubricator and raising these components to expose the connectors and removable tubing section.

(24) FIG. 11 shows a coiled tubing string 6 having two removable sections of tubing 106a and 106b connected along the tubing string 6. A first connector 8a connects on end of an upper portion 6a of the coiled tubing string 6 to an end of a first removable section of tubing 106a. A second connector 8b connects the first removable tubing section 106a to a middle portion 6c of the tubing string 6. A third connector 8c connects an end of the middle portion 6c of the tubing string 6 to an end of a second removable section of tubing 106b and a fourth connector 8d connects the other end of the second removable section of tubing 106b to a lower portion 6b of the tubing string 6. The upper tubing string 6a, first connector 8a, first removable section of tubing 106a, second connector 8b, middle tubing string 6c, third connector 8c, second section of removable tubing 106b, fourth connector 8d, and lower tubing string 6b may be connected together to form a coiled tubing string 6 that may be spooled onto a reel 200 (shown in FIG. 7).

(25) After unspooling the portion of the coiled tubing string 6 that includes the connectors 8c and 8d and the second removable tubing section 106b, the second removable tubing section 106b may be disconnected from the connectors 8c and 8d and a tool may be connected to the connectors 8c and 8d as described herein. Likewise, after unspooling the portion of the coiled tubing string 6 that includes the connectors 8a and 8b and the first removable tubing section 106a, the first removable tubing section 106a may be disconnected from the connectors 8a and 8b and a tool may be connected to the connectors 8a and 8b as described herein. Multiple removable sections of tubing 106 may be positioned along the tubing string 106 to permit the connection of multiple tools along the tubing string 106 as would be appreciated by one of ordinary skill in the art having the benefit of this disclosure.

(26) The removable sections of tubing 106 may be of a predetermined length required to permit the connection of a tool to the tubing string 6. For example, the removable section of tubing 106 may be less than 10 feet long. The removable section of tubing 106 may only be 2 to 3 feet long. The length of the removable section of tubing 106 may be varied depending on the application as would be appreciated by one of ordinary skill in the art having the benefit of this disclosure. The removable section of tubing 106 may be a section of coiled tubing or can be any section of tubing that has substantially the same diameter and wall thickness as the coiled tubing string 6. The strength and elongation of the removable section of tubing 106 may also be comparable, but not necessarily identical, as the strength and elongation of the coiled tubing string 6.

(27) Although this invention has been described in terms of certain preferred embodiments, other embodiments that are apparent to those of ordinary skill in the art, including embodiments that do not provide all of the features and advantages set forth herein, are also within the scope of this invention. Accordingly, the scope of the present invention is defined only by reference to the appended claims and equivalents thereof.