DK176349B1 - Coiled tubing and connector connection for oil field, has two rows of pockets and dimples, where one row of dimples provides snug fit, and other row of dimples introduces small amount of slop with respect to respective pockets - Google Patents

Abstract

The connection has a connector (12) with a connection section having a terminal end (32), and two rows of pockets formed in the connection section. A tubing section is positioned over the connection section of the connector, and two rows of dimples (34, 35) are positioned within the respective one of the rows of pockets, where the row of dimples (34) provides a snug fit, and row of dimples (35) introduces a small amount of slop with respect to the respective pockets. An independent claim is also included for connecting coiled tubing to a connector.

Description

DK 176349 B1

Field of the Invention The present invention relates generally to coiled tubing and more specifically to coupling coiled tubing with a coupling means.

Background 10 It is often necessary to provide a coupling with coiled tubing. The need arises when a borehole tool needs to be attached to the end of a string of coiled tubing. It also occurs when the amount of coiled tubing needed to perform the task cannot be on a single wheel as a continuous length tube. It could be a result of the lifting capacity of the handling equipment or the volume capacity of the working wheel. Further examples of conditions in an oil field where a coupling is required include situations where a leak or damaged area must be repaired in an existing continuous length of coiled tubing or a length of coiled tubing (such as a speed string) is taken from a well .

20

One method of coupling a coiled tube fitting is to deform the coiled tube into pre-formed pockets on the outside diameter of the fitting. By coupling the fitting to the coiled tube in accordance with this method, a strong, secure coupling is provided which can withstand both tensile stresses and torsional loads. A fitting that can be used for this application must provide a tensile strength corresponding to the strength of the coiled tube. In the case of a roll-up fitting, the fitting must also be able to bend around the wheel with the roll-up pipe and the injector swan neck in operation. This bending and straightening sequence causes 30 low cycle fatigue in the coiled tube and the fitting.

2 DK 176349 Bl

Problems encountered when using dents (GB: dimple) to connect coiled tubing to a fitting include, but are not limited to evaluating the tensile strength of the fitting and providing a fixed coupling that does not limit bending of the roller around the wheel or the swan neck when two sections of coiled tubing are joined together. For fittings attached to the end of a string of coiled tubing, a tensile test can be performed on the fittings with the injector.

This confirms the integrity of the coupling for the applied load, but the material often lends itself and could compromise the coupling. With the test it is not possible to determine where the limit of the coupling for when it is subtracted from each other lies. When two sections of coiled tubing are connected to each other using dents, it is not possible to carry out a tensile test which confirms the strength of the coupling.

For the moment, the size and depth of the dummy is not controlled. Bumps are generally formed using a hydraulic press head, which presses a spherical end pin into the surface of the rolled tube, causes the rolled tube material to yield and form a pre-formed bump on the outside diameter of the fitting (GB: OD). The force used to shape the bump is controlled by adjusting the hydraulic pressure applied to the press head. This pressure is usually set high enough to ensure that all pipe strengths and thicknesses can be completely supplied with dents with a predetermined force per minute. tap. As coiled tubes are delivered in different tensile strengths and with different wall thicknesses, the amount of deformation and yield can vary when making dents with a standard force per unit weight. tap. Testing has shown that bumps that are too low or too deep result in a coupling which, when subjected to tensile and bending loads, can break significantly before couplings made with the preferred bulb depth. Therefore, it is important to know if a dent is designed correctly.

If the pre-formed bulge in the fitting body is slightly larger than the bolt pin, the bolt will fill the cavity sufficiently to provide a secure coupling. If all the bumps in the rolled tube end tightly inside the pre-formed pockets in the fitting, a tensile load will not be absorbed uniformly, which means that some of the bumps are overloaded as shown in FIG. 1. In FIG.

1, there is shown a known coupling between fitting and coiled tube, where some of the bumps 5 are overloaded. The fitting 12 is connected to the reeled tube 14 via dents 18 formed in the reeled tube 14 and paired with pockets 16 (see Fig. 2) pre-formed in the fitting 12. The reeled tube 14 is overloaded near the dents 18 at the shaded areas 20.

Another disadvantage of the known bulge connections is shown in FIG. 2. When the pre-formed pocket 16 in the fitting 12 has considerably greater radius and volume, as shown in FIG. 2, its respective bulge 18 will not completely fill the pocket cavity 22 and the coupling is loose, allowing the fitting 12 to move slightly relative to the coiled tube 14. This provides a space 24 between the coupling shoulder 26 and the coiled tube 14. The gap 24 can cause problems when the coupling unit passes through the pipeline trigger. For a traditional, retractable fitting, both of these conditions - overload and gap - can cause problems that lead to diminished efficiency.

20

Therefore, there is a desire to provide an improved curved tube coupling for a coiled tube and a method for providing a coiled tube coupled to coiled tube with such integrity that the disadvantages arising from the known systems and methods are addressed. In addition, there is a desire to provide a method for confirming the strength of a coupling, while providing flexibility in the coupling to improve the performance of low cycle fatigue during bending. There is yet another desire to provide a secondary barrier without compromising the effectiveness of the primary gasket.

30 DK 176349 B1 4

BRIEF DESCRIPTION OF THE INVENTION In view of the foregoing and from other considerations, the present invention relates to coiled tubes and more specifically coiled tubes coupled with fittings.

5

Accordingly, couplings are provided between coiled tubes and fittings as well as methods for coupling coiled tubes with fittings. According to one embodiment, a coupling between coiled tubing and a fitting comprises a plurality of bumps formed with a tube, each bulb being within a respective pocket provided in a fitting for forming at least two rows of bulb / pocket couplings, the fitting of the bulges inside the pockets of the rows graduate from dense to loose throughout the extent of the coupling. The coupling may further comprise a gasket element provided between the coiled tube and the fitting located between at least two of the rows of the provided bump / pocket couplings.

15

An embodiment of a method for coupling the coiled tubing to a fitting comprises the following steps: placing a portion of the coiled tubing over a coupling section of a fitting, forming bumps in the coiled tubing so that each dent is within a respective pocket configured in the coupling section, thereby providing bulge / pocket couplings between the coiled tube and the fitting, to control the depth at which each of the bulges penetrates into the respective pocket so that the connection between the coiled tube and the fitting increases from closer to looser. to the extent of the coupling section. It is desired to provide at least two rows of bump / pocket couplings, the fit of the bump / pocket couplings in the same row being substantially the same. It may further be desired to provide a gasket between the coiled tube and the fitting located between at least two of the rows of bump / pocket couplings.

In the foregoing, the features and technical advantages of the present invention have been outlined to facilitate understanding of the following detailed description of the invention. Further features and advantages of the invention will be described hereinafter, which are the subject of the invention.

Brief description of the drawing 5

The foregoing and other features and aspects of the present invention will be best understood with reference to the following detailed description of a specific embodiment of the invention when read in conjunction with the accompanying drawings, in which:

Figure 1 illustrates a known bulge coupling and shows the overloaded areas of the coiled tube near the bulges;

Figure 2 illustrates a further disadvantage of known bulge couplings; 15

Figure 3 shows in cross-section a fitting for rolled tube;

Figure 4 is a cross-sectional view of one embodiment of a bulb coupling of a reel fit between two sections of reeled pipe of the present invention; 20

Figure 5 illustrates the load that arises in a bulb coupling according to the present invention in relation to the one in Figs. 2, known coupling.

Figure 6 is a perspective view of a known bulb coupling of a reelable fitting and reel tube;

Figure 7 is a perspective view of one embodiment of a graduated fitting bulb coupling in accordance with the present invention.

Figure 8 shows in perspective an embodiment of a bending tool with a press head for providing dents according to the present invention; and

Figure 9 shows an embodiment of a fitting according to the present invention with a twisted gasket.

DK 176349 B1 6

Detailed Description 5

Reference is now made to the drawing, where depicted elements are not necessarily displayed in correct aspect ratios, and where like or similar elements are denoted by the same reference numerals throughout all depictions.

The present invention provides graduated-fitting bend couplings between fittings and coiled tubes as well as methods for confirming the strength of a coupling, while providing coupling flexibility to improve low-cycle fatigue bending performance. Another barrier which does not compromise the effectiveness of the primary pack is also disclosed.

In general, the present invention provides a secure coupling by measuring the depth of the bumps formed in the coiled tube when coupling a fitting and a section of coiled tube. Furthermore, by controlling the depth of the bulb 20 in the coiled tube and the diameter and depth of the pre-formed pockets in the fitting, it becomes possible to control and graduate the fit between the coiled tube and the fitting. The present invention encompasses graduated fitting bulge couplings and methods in which dents fit tightly into one set of pockets, providing secure coupling, and the dents in a next set of fits loosely in another set of pockets, thereby reducing the ability of the coiled tube to bending around the wheel and swan neck is enhanced by the clutch. With the graduated fit bulb connections of the present invention, the low cycle fatigue life of the coiled tube and the fitting is provided. Another gasket can also be incorporated with the dummy pattern by cutting an o-ring groove in a twisted pattern between two rows of dents.

DK 176349 Pg 7

Fig. 3 is a cross-sectional view of an end fitting indicated by 12a. The end fitting 12 comprises a first connecting section 28a for coupling with the coiled tube and a tool end 30 adapted for coupling with a tool or other device not shown. The first coupling section 28a extends from the fitting shoulder 5 26 to a fitting end 32a. At least two rows of pockets 16 are provided on the first coupling section 28a. The first row 34a comprises pockets 16a which are spaced circumferentially around the first section 28 and which are near the shoulder 26 relative to the further rows of pockets.

The second row 35a comprises a series of pockets 16b spaced along the circumference of the first section 28a between the first row 34a and the fitting end 32a. The fitting 12 may comprise additional rows of pockets which are sequentially numbered in the direction towards the fitting end 32a. Each pocket 16 forms a cavity 22 having a depth 16D and a radius 16R. For each row, the pockets 16 have substantially the same depth 16D and radius 16R. As will be more readily understood by reading the following description, the depth 16D and / or radius 16R may vary between subsequent rows of pockets 16 to make it easier to achieve a graduated fit bulge coupling. However, it should be noted that the bulge coupling with graduated fit can be obtained by sorting the bumps for the respective rows 34 of the pockets 20 16.

FIG. 4 is a cross-sectional view of one embodiment of a graduated fitting bulb coupling 10 of the present invention. The FIG. 4 shows a reel fitting, indicated by 12b, coupled to a first reeled pipe section 14a and a second reeled pipe section 14b. In contrast to the one shown in FIG. 3, the retractable fitting 12b comprises a first coupling section 28a and a second coupling section 28b. The first coupling section 28a is arranged to be coupled to the first coiled tube section 14a and the second coupling section 28b is arranged to be coupled to the second coiled tube section 14b. The second coupling section 28b is essentially a mirror image of the first coupling section 28a, comprising at least two rows of pockets 16a and 35b respectively 16a and 16b. It should also be noted that each coupling section 28 may comprise a primary gasket 36 located between the fitting 12 and the coiled tube 14 and the fitting end 32a and the last row of bumps and pockets (row 35 of Figure 4).

5

How, in FIG. 4 will now be described with reference to the first coupling section 28a, it being understood that it is essentially the same process performed for the second coupling section 28b. The first coupling section 28a is positioned within the first coiled tube section 14a so that the coiled tube 14a substantially abuts the shoulder 26. Thereafter, a bump 18, e.g. with a buoy tool 42 as described in FIG. 8, in the reeled tube 14 so that it resides in a respective pocket 16. For example, in a first row 34a, a bump 18a is formed in the reeled tube 14a for each pocket 15a. Each bump 18 forms a bead with a depth 18D and a radius 18R.

In order to obtain the graduated bulb coupling 10, the first row 34a has pockets 16a and the dents 18a have a fit different from the fit of the second row 35a of dents 16b and pockets 18b. In the illustrated embodiments 20, the bumps 18a fit relatively tightly within the pockets 16a to form a tight or tight fitting first row 34a. The bump / pocket couplings in the second row 35a have a looser fit than the corresponding in the first row 34a, in other words, the diameter 18D and / or radius 18R of the second row 35a will diverge more from their respective pocket diameters 16D and / or 25 radius. 16R than the corresponding in the first row 34a. It should be noted that the bulge / pocket couplings need not be graduated for another fit between two adjacent rows, but that modulation or progressively looser fit of the bulge / pocket couplings must be designed throughout the coupling section 28. For example, a further (not shown) row of bucket / pocket couplers may be placed between rows 34a and 35a shown in FIG. 4, since this additional row is offset relative to the first row 34a and has the same bulge / pocket fit as correspondingly in the first row 34a.

The bumps 18a in the first row 34a fit snugly from side to side in their respective first row 34a pockets 16a, thereby providing a fixed coupling between pipe section 14a and the fitting 12b, which has essentially no axial slack (slack). . The bulbs 18b in the second row 35a loosely fit into their respective pockets 16b relative to the couplings in the first row 34a.

The looser fit of the second row 35a allows some movement of the coiled tube 14a relative to a fitting 12b in the region of the second row 35b. By graduating the bulge / pocket fit along the coupling section 28, the bulges 16 in each row will be loaded more uniformly than in the known bulge couplings.

15 Referring now to FIG. 5, where load is shown on a graduated bulb coupling 10 of the present invention. In FIG. 5 it is shown that the load in the region 20 near the bumps 18 is distributed and is lower than in the case of FIG. 2, known bulge coupling.

20 Referring now to FIG. 6 and 7, wherein FIG. 6 shows a known bulge coupling and FIG. 7 shows a graduated fitting bulb coupling 10 according to the present invention. The figures of FIG. 6 and 7, reference numerals used are similarly used for comparison purposes.

25 In FIG. 6 shows a roll-up fitting 12, which is connected to first and second sections of coiled tubes 14a and 14b. Each section of roughened pipe 14 is coupled to the fitting 12 by three rows 34, 35, 37 bumps 18 and pockets 16. Each of the rows 34, 35, 37 has essentially the same loose fit between their respective bumps 18 and pockets 16. When the rollable fitting 12b bends around wheel 30 or swan neck (not shown, but well known), the stretching side 38 inherent in the reeled tube 14 will attempt to pull away from the fitting 12b and the compression pressure 12 on the fitting 12b. When the bulge 18 to the pocket 16 fit is loose, as will be seen in FIG. 6, the coiled tube 14 can rotate relative to the fitting 12, thereby opening a gap 24 between the coiled tube 14 and the shoulder 26 along the tension side 38. In addition, the load from the compression side 40 causes the lip of the fitting 12b to yield and get the bell shape.

In FIG. 7, a graduated bulb coupling 10 is used. In this embodiment, the bulb / pocket coupling in the first row 34 is dense, the bulb / pocket fitting of the second row 35 is looser than the first row 34, and the bulb / pocket-10 coupling in the third row 37 is looser than the second row 35. The graduated fitting coupling 10 restricts or prevents rotation of the coiled tube 14 relative to the fitting member 12b, while allowing mutual movement between the coiled tube 14 relative to the fitting 12b throughout. the extent of the fitting 12b. Thus, the gap 24 between the retractable tube 14 and the shoulder 26 is significantly reduced, not to say removed, relative to the known couplings as shown in FIG. 6. Furthermore, the high compression load on the shoulder 26 on the compression side 40 is significantly reduced.

By controlling the fit of the bump 18 in the pre-formed pockets 16 of the fitting 12, the efficiency of the coupling between the coiled tube 14 and the fitting 12 can be improved. In addition, a graduated or progressive fit, where the first row 34 of bumps provides a tight fit and the subsequent rows of bumps introduce some slack, distributes the strain loads and bending loads, improving the coupling efficiency.

The fit of the bump 18 in the pocket 16 can be controlled by controlling the depth 18D of the bump 18. Measuring the bumps 18 formed in the rolled-up tube 14 confirm that the fit meets the requirements. When the bumps are performed to the recommended depth, the clutch 30 will perform as it should.

DK 176349 B1 11 Knowing the strength of a bump based on its measured depth, a weak point can be formed in the coiled tubing string. A weak point would provide a coupling in the string that would break at a predetermined location and at a predetermined force. It is particularly advantageous when the coiled tubing gets stuck in the well and has to be disconnected from the tool string down the borehole. By controlling the depth or number of dents of equivalent depth, the strength of each coupling can be controlled and predicted.

In FIG. 8, a buoy tool 42 is shown which uses piston force to produce bumps having a desired depth 18D and hence radius 18R. The bulging tool 42 is arranged to control its stroke and thus the bulge depth 18D. Piston force is maintained at the recommended level, which ensures that bulge 18 is made in the reeled tube, but the stroke is controlled to ensure that the bulge depth 18D is within the specifications. A controlled bolt-forming depth can also be obtained by counting screw turns or by limiting the depth with a bolt-type bolt-forming bracket.

In FIG. 9 shows an embodiment of a fitting 12 according to the present invention having a secondary gasket or barrier 48. The fitting 12 comprises three rows 34, 35, 37 of pockets 16. The primary gasket is on the fitting 12 between the fitting end 32 and the last row 37 of pockets 16. A twisted groove 44 is formed in the fitting 12 between at least two rows of dents 18 (GB text: 16). In this embodiment, a twisted groove 44 is formed between the first row 34 and the second row 35, the first row 25 34 being intended to be a closely matched row and the second row 35 being intended to be a row of looser fit than the first row 34. A gasket material 46, such as an O-ring, is located within the groove 44 to provide another barrier or gasket 48 relative to the coiled tube by coupling.

30 DK 176349 B1 12

This provides a robust gasket in a very stable coupling area. The location of the twisted gasket 45 also allows the primary gasket 36 to be positioned close to the last row 37 of bumps 18, which improves the effectiveness of the gasket in a bent state.

5

From the foregoing detailed description of specific embodiments of the invention, it will be apparent that a system for coupling coiled tubes by dents and a novel method are described. Although specific embodiments of the invention are described in some degree of detail herein, this has been done solely for the purpose of describing various features and aspects of the invention, and is not intended to limit the scope of the invention. It is contemplated that various substitutions, modifications and / or modifications, including but not limited to the implementation variants proposed herein, may be made in relation to the embodiments described, without departing from the spirit and scope of the invention as disclosed herein. the following related requirements.

Claims (8)

A coupling between a fitting (12) and coiled tube, comprising: - a fitting having a coupling section (28) with a fitting end (32); 5. a first row of pockets (34) formed in the coupling section; a second row of pockets (35) formed in the coupling section disposed between the first row of pockets and the fitting end; - a pipe section (14) disposed about the coupling section of the fitting; - a first row of bumps (18A) in the pipe section, each of said first row of bumps being in a respective pocket of said first row of pockets; and - a second row of bumps (18B) in the pipe section, each of the second row of bumps being in a respective pocket of the second row of pockets, characterized in that the second row of bumps have a loose fit in their respective second row of pockets in relation for the fit of the first row of dents in their respective first row of pockets. A coupling according to claim 1, wherein the fitting further comprises a shoulder (26), 20 and wherein the first and second series of bumps are between the shoulder and the fitting end, and the pipe section does not extend further past the shoulder. A coupling according to claims 1-2, further comprising a primary gasket (36) 25 disposed between the fitting end and the last one among the rows of dents. A coupling according to claims 1-3, further comprising a secondary gasket (48) formed between the first and second series of dents. A coupling according to claim 4, wherein the secondary gasket has a twist design. 2 DK 176349 Bl A method of coupling a coiled tube to a fitting (12), the method comprising the steps of: placing a piece of coiled tube about the coupling section (28) of a fitting; 5. forming bumps (18A, 18B) in coiled tubes such that each bump is in a respective pocket (34,35) formed in the coupling section, thereby providing bool / pocket couplings between the coiled tube and the fitting; and - controlling the depth (18D) at which each of the bulges penetrates into the respective pocket, so that the connection between the coiled tube and the fitting increases from closer to looser throughout the extent of the coupling section. The method of claim 6, wherein at least two rows of butt / pocket couplings (18A / 34, 18B / 35) are formed, and each of the butt / pocket couplings in the same one of the at least two rows has essentially the same fit as the other bulge / pocket couplings in the same row. The method of claim 6, wherein at least two rows of bulge / pocket couplings are formed and further comprising a step comprising providing a gasket (48) between two rows among the at least two rows of bulge / pocket. couplings.