High pressure D-tube with enhanced through tube access
A high pressure D-tube with enhanced through tube access for use in a well system. The well system includes the tube having an interior and a generally D-shaped exterior surface. An inner support structure spans the interior of the tube. The exterior surface may be formed on a single piece of material. The inner support structure may resist deformation of the tube due to pressure applied to the interior and/or exterior surface of the tube. The inner support structure may form at least a portion of the exterior surface of the tube.
The present invention relates generally to operations performed and equipment utilized in conjunction with subterranean wells and, in an embodiment described herein, more particularly provides a high pressure D-tube with enhanced through tube access.
Cross-sectional area in a wellbore is a limited commodity. The wellbore must accommodate equipment and tubing strings passing therethrough, and must provide sufficient flow area for efficient production or injection of fluids therethrough.
In general, where multiple tubing strings are used in a single wellbore, conventional circular cross-section tubing strings have merely been positioned side-by-side in the wellbore. Although this may be the easiest solution, it is also very inefficient in utilizing the available cross-sectional area in the wellbore.
Another solution is to manufacture the tubing strings so that each has a generally D-shaped cross-section. When positioned side-by-side in the wellbore, the two tubing strings together have a generally circular cross-section and occupy a substantial portion of the cross-sectional area of the wellbore, and are therefore able to utilize more of this area for fluid flow, access, etc. Such a tube system is found in the FlexRite™ System marketed by Sperry-Sun Drilling Services.
Although the D-shaped tubes used in the FlexRite™ System represent a significant advance in the art, they do have a few disadvantages. One disadvantage is that the D-shaped tubes are somewhat expensive to manufacture. Another disadvantage is that the D-shaped tubes can have a relatively low burst and collapse strength as compared to a circular tube having equivalent cross-sectional area and wall thickness. Another disadvantage is that the D-shaped tubes have interior corners in which equipment (well tools, wireline, coiled tubing, etc.) conveyed through the tubes can get stuck or bind.
Therefore, it may be seen that improvements are needed in D-shaped tube designs for use in subterranean wells. It is among the objects of the present invention to provide such improvements.
SUMMARYIn carrying out the principles of the present invention, a high pressure D-tube with enhanced through tube access is provided which solves at least one problem in the art. One example is described below in which an inner support structure increases the pressure bearing capabilities of a D-tube. Another example is described below in which an inner support structure provides for enhanced conveyance of tools and equipment through a D-tube.
In one aspect of the invention, a well system includes a tube having an interior and a generally D-shaped exterior surface. An inner support structure spans the interior of the tube.
In another aspect of the invention, the inner support structure may resist deformation of the tube due to external pressure applied to the tube.
In another aspect of the invention, the inner support structure may resist deformation of the tube due to interior pressure applied to the tube.
In another aspect of the invention, the D-shaped exterior surface may be formed on a single piece of material.
In another aspect of the invention, the tube and the inner support structure may be integrally formed from a single piece of material.
In another aspect of the invention, the inner support structure may include a plate.
In another aspect of the invention, the inner support structure may include a tubular structure.
In another aspect of the invention, the inner support structure may include a series of individual support structures distributed longitudinally within the tube.
In another aspect of the invention, the inner support structure may form at least a portion of the exterior surface of the tube.
In another aspect of the invention, the tube may include multiple open-sided sections which are attached to the inner support structure to thereby form the generally D-shaped exterior surface.
These and other features, advantages, benefits and objects of the present invention will become apparent to one of ordinary skill in the art upon careful consideration of the detailed description of representative embodiments of the invention hereinbelow and the accompanying drawings, in which similar elements are indicated in the various figures using the same reference numbers.
BRIEF DESCRIPTION OF THE DRAWINGS
It is to be understood that the various embodiments of the present invention described herein may be utilized in various orientations, such as inclined, inverted, horizontal, vertical, etc., and in various configurations, without departing from the principles of the present invention. The embodiments are described merely as examples of useful applications of the principles of the invention, which is not limited to any specific details of these embodiments.
In the following description of the representative embodiments of the invention, directional terms, such as “above”, “below”, “upper”, “lower”, etc., are used for convenience in referring to the accompanying drawings. In general, “above”, “upper”, “upward” and similar terms refer to a direction toward the earth's surface along a wellbore, and “below”, “lower”, “downward” and similar terms refer to a direction away from the earth's surface along the wellbore.
Representatively illustrated in
The tubes 12, 14 are run into the wellbore 16 together and are secured to each other at an upper end thereof by a Y-connector 18. Note that each of the tubes 12, 14 could be made up of multiple individual tubes connected to each other in series longitudinally.
A deflector 20 positioned in the wellbore 16 deflects the longer tube 14 from the parent wellbore into a branch wellbore 22 as the tubes are conveyed into the well. The deflector 20 is positioned in the parent wellbore 16 and secured therein by an anchoring device 24, which may be a packer, a latch and inflatable seals, etc.
The tube 14 may have equipment, such as well screens, etc. attached at a lower end thereof. A connector 26 adapts the tube 14 to the generally cylindrical shaped equipment attached therebelow.
The tube 12 is not deflected into the branch wellbore 22, but instead is directed into the deflector 20. Seals 28 in the deflector 20 sealingly engage the tube 12.
With the tube 14 extending into the branch wellbore 22 and the tube 12 received within the deflector 20, an anchoring device 30, such as a liner hanger, is set in the parent wellbore 16. The anchoring device 30 secures the tubes 12, 14 in position and permits commingled flow via the tubes to the parent wellbore above the anchoring device.
Referring additionally now to
As depicted in
An inner support structure 36 spans an interior 38 of the tubular member 34. As illustrated in
The support structure 36 resists deformation of the tubular member 34 due to both external pressure applied to the exterior surface 32, and due to internal pressure applied to the interior 38 of the tubular member. Thus, the support structure 36 enhances both the collapse resistance and burst resistance of the tube 14.
In addition, the support structure 36 divides the interior 38 of the tubular member 34 into separate passages 40, 42. These separate passages 40, 42 may be advantageous in situations where, for example, it is desired to produce fluid (such as hydrocarbons) through one passage while injecting fluid (such as steam, water, treatment chemicals through the other passage, or it is desired to use one passage for access (e.g., for wireline tools, coiled tubing, etc.) and the other passage for fluid flow, etc.
Of course, the separate passages 40, 42 may be used for many other purposes in keeping with the principles of the invention. Furthermore, more than two passages may be provided, for example, by installing multiple support structures 36 in the tubular member 34 and thereby dividing the interior 38 into as many passages as desired.
By using the tubular member 34 as a single piece of material on which the exterior surface 32 is formed, manufacturing costs are decreased to produce the D-shaped exterior. However, it may be difficult in some circumstances to attach the support structure 36 to the interior 38 of the tubular member 34, for example, when it is desired to use the support structure for pressure isolation between the passages 40, 42 and the support structure is to be welded along its entire length to the interior of the tubular member.
In
The sections 44, 46 could be formed by any method, such as pressing, roll forming, etc. For example, the sections 44, 46 could be formed by cutting the tubular member 34 in half longitudinally.
Note that, in the embodiment depicted in
Referring additionally now to
Referring additionally now to
The passage 50 may be pressure isolated from either or both of the other passages 40, 42 in the tube 14c, or the passage 50 could be in fluid communication with either or both of the passages 40, 42. One advantage of the cylindrical shape of the passage 50 is that it provides a smooth interior for conveying tools, equipment, wireline, coiled tubing, etc. therethrough, without any corners in which such equipment could get caught or bind.
Of course, shapes other than cylindrical may be used for the tubular structure 48. For example, the tubular structure 48 could have an oval or elliptical cross-sectional shape, or any other shape, in keeping with the principles of the invention.
As depicted in
Referring additionally now to
To accommodate the increased wall thickness of the tubular structure 48a without decreasing the cross-sectional area of the passage 50, outer surfaces 52, 54 of the tubular structure may be formed so that they conform to the interior of the tubular member 34. This reduces the wall thickness of the tubular structure 48a at these areas, but the tubular member 34 outwardly overlies these areas, and the full wall thickness portions of the tubular structure can still resist deformation of the tubular member due to external and internal pressure applied thereto.
Referring additionally now to
Referring additionally now to
One advantage of this tube 14e configuration is that the passage 50 can have an increased cross-sectional area. Another advantage is that the steps of machining the tubular structure 48b to conform to the interior 38 of the tubular member 34, and attaching the tubular structure to the tubular member are eliminated.
Referring additionally now to
This alternate construction of the tube 14f is similar in this respect to the tube 14a shown in
Note that, in the embodiment depicted in
Referring additionally now to
Referring additionally now to
These slots 64 allow the tubular structure 48e to more easily flex, thereby allowing the tube 14 to more easily flex when it is deflected from the parent wellbore 16 into the branch wellbore 22 as depicted in
The alternate configuration of the tubular structure 48e may be used in place of the tubular structure 48 of
Referring additionally now to
Referring additionally now to
In this alternate configuration tube 14h, increased flexibility is provided by having a series of multiple tubular structures 48g distributed longitudinally within the tubular member 34. The tubular structures 48g overlap each other (e.g., each tubular member has a male end and a female end), so that the passage 50 is continuous through the multiple tubular structures. Alternatively, the tubular structures 48g could be individual longitudinally spaced apart rings which do not overlap each other.
One way of attaching the individual tubular structures 48g to the tubular member 34 would be to provide a series of slots 66 through the tubular member, and weld the tubular structures to the tubular member in the slots. Of course, other methods of attaching the tubular structures 48g to the tubular member 34 could be used (such as adhesive bonding, mechanical fasteners, etc.) in keeping with the principles of the invention.
Referring additionally now to
The tubular structures 48g may be used in place of the tubular structure 48 of
Of course, a person skilled in the art would, upon a careful consideration of the above description of representative embodiments of the invention, readily appreciate that many modifications, additions, substitutions, deletions, and other changes may be made to these specific embodiments, and such changes are within the scope of the principles of the present invention. Accordingly, the foregoing detailed description is to be clearly understood as being given by way of illustration and example only, the spirit and scope of the present invention being limited solely by the appended claims and their equivalents.
Claims
1. A well system, comprising:
- a tube having an interior and a generally D-shaped exterior surface; and
- an inner support structure spanning the interior of the tube.
2. The well system of claim 1, wherein the inner support structure resists deformation of the tube due to exterior pressure applied to the tube.
3. The well system of claim 1, wherein the inner support structure resists deformation of the tube due to interior pressure applied to the tube.
4. The well system of claim 1, wherein the D-shaped exterior surface is formed on a single piece of material.
5. The well system of claim 1, wherein the tube and the inner support structure are integrally formed from a single piece of material.
6. The well system of claim 1, wherein the inner support structure comprises a plate.
7. The well system of claim 1, wherein the inner support structure comprises a tubular structure.
8. The well system of claim 1, wherein the inner support structure comprises a series of individual support structures distributed longitudinally within the tube.
9. The well system of claim 1, wherein the inner support structure forms at least a portion of the exterior surface of the tube.
10. The well system of claim 1, wherein the tube comprises multiple open-sided sections which are attached to the inner support structure to thereby form the generally D-shaped exterior surface.
11. A well system, comprising:
- a tube having an interior and a generally D-shaped exterior surface, the exterior surface being formed on a single piece of material; and
- an inner support structure within the interior of the tube, the support structure resisting deformation of the tube due to pressure applied to the exterior surface.
12. The well system of claim 11, wherein the tube and the inner support structure are integrally formed from a single piece of material.
13. The well system of claim 11, wherein the inner support structure comprises a plate.
14. The well system of claim 11, wherein the inner support structure comprises a tubular structure.
15. The well system of claim 11, wherein the inner support structure comprises a series of individual support structures distributed longitudinally within the tube.
16. The well system of claim 11, wherein the inner support structure resists deformation of the tube due to interior pressure applied to the tube.
17. A well system, comprising:
- a tube having an interior and a generally D-shaped exterior surface; and
- an inner support structure resisting deformation of the tube due to pressure applied to the exterior surface, and the inner support structure forming at least a portion of the exterior surface of the tube.
18. The well system of claim 17, wherein the tube comprises multiple open-sided sections which are attached to the inner support structure to thereby form the generally D-shaped exterior surface.
19. The well system of claim 17, wherein the inner support structure comprises a plate.
20. The well system of claim 17, wherein the inner support structure comprises a tubular structure.
21. The well system of claim 17, wherein the inner support structure resists deformation of the tube due to pressure applied to the interior of the tube.
Type: Application
Filed: Oct 21, 2005
Publication Date: Apr 26, 2007
Inventors: David Steele (Irving, TX), Frode Berge (Royneberg)
Application Number: 11/256,388
International Classification: E21B 23/03 (20060101);