COILED TUBING HAVING A CAPILLARY WINDOW AND METHOD FOR MAKING SAME
A coiled tubing assembly includes coiled tubing having a side wall that defines an opening and an insert covering the opening and affixed to the coiled tubing. The coiled tubing has a longitudinal axis. The insert defines a capillary window therethrough. The opening and the insert include ends that are non-perpendicular to the longitudinal axis. A method of making a coiled tubing assembly includes providing coiled tubing defining a side wall opening and pulling a capillary tube into the interior of the coiled tubing through the side wall opening. The method further includes attaching the capillary tube to a capillary window of an insert for covering the side wall opening and affixing the insert to the coiled tubing.
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This application claims priority from U.S. Provisional Application 61/246,815, filed on Sep. 29, 2009, which is incorporated herein by reference.
BACKGROUND OF THE INVENTION1. Field of the Invention
The present invention relates to coiled tubing used in oilfield operations.
2. Description of Related Art
Information concerning, for example, the temperatures and pressures exhibited within a wellbore is used to predict the production interval of the well. Knowledge of the production interval is used to enhance the recovery rate of a well and, in turn, make the well more economical to operate. Tools exist to retrieve such information relating to conventional wells that exhibit temperatures below about 204° C. (400° F.). In wells that exhibit higher temperatures, such as steam assisted gravity drainage (SAGD) wells, cyclic steam wells, and the like, design of such tools becomes difficult, as elastomer materials often cannot withstand such high temperatures.
Other downhole devices have been constructed to measure characteristics, such as temperature and pressure, within a wellbore. For example, one such conventional device employs a coiled tubing in which a plurality of capillary tubes is disposed. Some of the plurality of capillary tubes have temperature sensors disposed therein, while others of the plurality of capillary tubes are used to measure pressure. In high temperature applications, however, such coiled tubing devices are susceptible to failure due to fatigue.
There are devices for measuring characteristics, such as pressure and temperature, in a downhole environment that are well known in the art, however, considerable shortcomings remain.
BRIEF SUMMARY OF THE INVENTIONIn one aspect, the present invention provides a coiled tubing assembly. The coiled tubing assembly includes a coiled tubing having a side wall that defines an opening and an insert covering the opening and affixed to the coiled tubing. The coiled tubing has a longitudinal axis. The insert defines a capillary window therethrough. The opening and the insert include ends that are non-perpendicular to the longitudinal axis.
In another aspect, the present invention provides a method of making a coiled tubing assembly. The method includes providing a coiled tubing defining a side wall opening and pulling a capillary tube into an interior of the coiled tubing through the side wall opening. The method further includes attaching the capillary tube to a capillary window of an insert for covering the side wall opening and affixing the insert to the coiled tubing.
The present invention provides significant advantages, including increasing fatigue life of coiled tubing assemblies over conventional coiled tubing assemblies. Additional objectives, features and advantages will be apparent in the written description which follows.
The novel features characteristic of the invention are set forth in the appended claims. However, the invention itself, as well as a preferred mode of use, and further objectives and advantages thereof, will best be understood by reference to the following detailed description when read in conjunction with the accompanying drawings, in which the leftmost significant digit(s) in the reference numerals denote(s) the first figure in which the respective reference numerals appear, wherein:
While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof have been shown by way of example in the drawings and are herein described in detail. It should be understood, however, that the description herein of specific embodiments is not intended to limit the invention to the particular forms disclosed, but on the contrary, 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 OF THE INVENTIONIllustrative embodiments of the invention are described below. In the interest of clarity, not all features of an actual implementation are described in this specification. It will be appreciated that in the development of any such actual embodiment, numerous implementation-specific decisions must be made to achieve the developer's specific goals, such as compliance with system-related and business-related constraints, which will vary from one implementation to another. Moreover, it will be appreciated that such a development effort might be complex and time consuming, but would nevertheless be a routine undertaking for those of ordinary skill in the art having the benefit of this disclosure.
The present invention relates to a coiled tubing assembly comprising a coiled tubing having an opening in which an insert is affixed. The insert defines a capillary window in which a capillary tube is affixed. The capillary tube is used in the measurement of various downhole conditions, such as temperature, pressure, or the like.
In the embodiment illustrated in
Referring in particular to
Referring again to
Referring again to
Similarly, as shown in
As discussed herein, opening 105 of coiled tubing 107 and insert 103 incorporate particular features that inhibit fatigue-related failure of such coiled tubing assemblies. Generally, fatigue cracks tend to propagate radially in coiled tubing, i.e., generally circumferentially about the coiled tubing perpendicular to a longitudinal axis of the coiled tubing, such as longitudinal axis 205 of coiled tubing 107. Weldments reduce fatigue life and tend to fail along heat affected zones adjacent weldments where the material of the coiled tubing is more brittle. Thus, axial weldments, i.e., weldments that are generally parallel to a longitudinal axis of the coiled tubing, such as longitudinal axis 205 of coiled tubing 107, perform better than radial weldments. As shown in at least
It should be noted that the present invention is not limited to the particular shape of insert 103 depicted in the drawings. For example, an insert for the present coiled tubing assembly may exhibit shapes such as those depicted in
Coiled tubing assembly 101 may include one insert and corresponding capillary tube, such as insert 103 and capillary tube 1301, or coiled tubing assembly 101 may include many inserts and corresponding capillary tubes. While there are many ways to assemble coiled tubing assembly 101,
Referring to
In one embodiment, as depicted in
The particular embodiments disclosed above are illustrative only, as the invention may be modified and practiced in different but equivalent manners apparent to those skilled in the art having the benefit of the teachings herein. Therefore, no limitations are intended to the details of construction or design herein shown, other than as described in the claims below.
Claims
1. A coiled tubing assembly, comprising:
- a coiled tubing having a side wall that defines an opening, the coiled tubing having a longitudinal axis; and
- an insert covering the opening and affixed to the coiled tubing, the insert defining a capillary window therethrough;
- wherein the opening and the insert include ends that are non-perpendicular to the longitudinal axis.
2. The coiled tubing assembly of claim 1, wherein the opening and the insert include ends that exhibit angles with respect the longitudinal axis within a range of about 15 degrees to about 70 degrees.
3. The coiled tubing assembly of claim 1, wherein the opening includes a side and a transition extending between the side of the opening and the end of the opening and the insert includes a side and a transition extending between the side of the insert and the end of the insert, the transitions exhibiting radii that are greater than about 3 millimeters.
4. The coiled tubing assembly of claim 1, wherein the opening and the insert include ends that exhibit angles with respect the longitudinal axis of about 30 degrees.
5. The coiled tubing assembly of claim 1, further comprising a capillary tube extending from the capillary window, such that an environment external to the coiled tubing assembly may be communicated to the capillary tube via the capillary window.
6. The coiled tubing assembly of claim 1, wherein the insert includes a fitting that defines the capillary window.
7. The coiled tubing assembly of claim 6, wherein the insert tapers from a greater thickness proximate the fitting to a thinner thickness proximate the ends of the insert.
8. The coiled tubing assembly of claim 1, wherein the insert is affixed to the coiled tubing by one or more weldments.
9. The coiled tubing assembly of claim 1, wherein the ends of the opening and the insert are semi-circular.
10. The coiled tubing assembly of claim 1, wherein the ends of the opening and the insert are angular shapes having central apexes.
11. A method of making a coiled tubing assembly, comprising:
- providing a coiled tubing defining a side wall opening;
- pulling a capillary tube into an interior of the coiled tubing through the side wall opening;
- attaching the capillary tube to a capillary window of an insert for covering the side wall opening; and
- affixing the insert to the coiled tubing.
12. The method of claim 11, wherein pulling the capillary tube into the interior of the coiled tubing is accomplished by:
- providing a primary pulling tool disposed within the interior of the coiled tubing;
- attaching a secondary pulling cable between the primary pulling tool and a secondary pulling tool;
- attaching the capillary tube to the secondary pulling tool; and
- advancing the primary pulling tool within the interior of the coiled tubing away from the side wall opening.
13. The method of claim 12, wherein the primary pulling tool is affixed to a primary pulling cable for advancing the primary pulling tool within the interior of the coiled tubing.
14. The method of claim 12, wherein attaching the secondary pulling cable between the primary pulling tool and the secondary pulling tool is accomplished by:
- attaching a first end of the secondary pulling cable to the primary pulling tool;
- disposing the secondary pulling cable through a first bore in the secondary pulling tool, the bore extending into a body of the secondary pulling tool between and through a first end of the body and a side surface of the body; and
- advancing one or more fasteners into contact with the secondary pulling cable to retain the secondary pulling cable within the first bore.
15. The method of claim 12, wherein attaching the capillary tube to the secondary pulling tool is accomplished by:
- disposing the capillary tube into a second bore in the secondary pulling tool, the bore extending into a body of the secondary pulling tool from a second end of the body and terminating within the body; and
- advancing one or more fasteners into contact with the capillary tube to retain the capillary tube within the second bore.
16. The method of claim 12, further comprising:
- advancing the primary pulling tool along the interior of the coiled tubing until the secondary pulling cable is adjacent a second side wall opening;
- attaching a second secondary pulling tool to the secondary pulling cable; and
- attaching a second capillary tube to the second secondary pulling tool.
17. The method of claim 11, further comprising disposing a capillary tube guide adjacent the side wall opening prior to pulling the capillary tube into the interior of the coiled tubing, such that the capillary tube contacts the capillary tube guide rather than an edge of the side wall opening as the capillary tube is pulled into the interior of the coiled tubing.
18. The method of claim 17, wherein the capillary tube guide comprises:
- a base;
- a first leg extending from the base;
- a second leg extending from the base, the first leg, the second leg, and the base defining a groove for receiving the capillary tube; and
- a protrusion extending from the first leg, the second leg, and the base configured to be received in the side wall opening.
19. The method of claim 11, wherein the side wall opening and the insert include ends that are non-perpendicular to a longitudinal axis of the coiled tubing.
20. The method of claim 11, wherein the side wall opening and the insert include ends that exhibit angles with respect a longitudinal axis of the coiled tubing within a range of about 15 degrees to about 70 degrees.
Type: Application
Filed: Feb 24, 2010
Publication Date: Mar 31, 2011
Applicant: SCHLUMBERGER TECHNOLOGY CORPORATION (Sugar Land, TX)
Inventors: Mitchel Stretch (Calgary), Nathan Kathol (Chestermere), Vi Nguy (Calgary)
Application Number: 12/711,811
International Classification: F16L 9/00 (20060101); B23P 11/00 (20060101);