US20090250228A1

US20090250228A1 - Well packers and control line management

Info

Publication number: US20090250228A1
Application number: US12/062,087
Authority: US
Inventors: Ives Loretz; Nitin Vaidya
Original assignee: Schlumberger Technology Corp
Current assignee: Schlumberger Technology Corp
Priority date: 2008-04-03
Filing date: 2008-04-03
Publication date: 2009-10-08

Abstract

An example of a wellbore tool assembly includes a mandrel having an outer surface and a longitudinal bore; a tubular, swellable seal member having opposing ends and an inner surface defining a bore between the opposing ends, the seal member encircling a portion of the mandrel; an operable downhole element carried with the mandrel; and a control line connected to the operable downhole element, the control line extending from the downhole element between the outer surface of the mandrel and the inner surface of the seal member to the other side of the seal member from the downhole element.

Description

TECHNICAL FIELD

The present invention relates in general to wellbore packers and more specifically to extending a conduit, control line or the like past a well packer that is set in a wellbore.

BACKGROUND

It is often necessary to utilize a packer to provide an annular seal in a wellbore. It is also often necessary to provide a physical link to across the annular seal to an operable downhole tool or device. For example, it is often necessary to transmit electrical signals, optical signals, hydraulic pressure, and electrical energy across the annular seal.

SUMMARY

In view of the foregoing and other considerations, the present invention relates to extending a control line across a packer that set and forming an annular seal. Accordingly, examples of devices, systems, and methods for extending the control line across the annular seal provided by the packer are provided.
An example of a packer for providing an annular seal when set in a wellbore or tubular includes a tubular mandrel having an outer surface; a seal member having an inner surface defining a bore, the seal member encircling a portion of the mandrel; and a control line positioned between the inner surface of the seal member and the outer surface of the mandrel and extending across the length of the seal member.
An example of a wellbore tool assembly includes a mandrel having an outer surface and a longitudinal bore; a tubular, swellable seal member having opposing ends and an inner surface defining a bore between the opposing ends, the seal member encircling a portion of the mandrel; an operable downhole element carried with the mandrel; and a control line connected to the operable downhole element, the control line extending from the downhole element between the outer surface of the mandrel and the inner surface of the seal member to the other side of the seal member from the downhole element.
An example of a method for extending a control line across a packer set in a wellbore includes the steps positioning a control line along an outer surface of a tubular mandrel; encircling a portion of the tubular mandrel and the control line with a seal member, the control line passing between the outer surface of the tubular mandrel and an inner surface of the seal member; and activating the seal member in a wellbore to form a seal between the outer surface of the tubular mandrel and a sidewall of the wellbore.
The foregoing has outlined some of the features and technical advantages of the present invention in order that the detailed description of the invention that follows may be better understood. Additional features and advantages of the invention will be described hereinafter which form the subject of the claims of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

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, wherein:

FIG. 1 is a cross-section, elevation view of an example of a swell packer of the present invention;

FIG. 2 is a cross-section view of an example of a swell packer of the present invention along the line I-I of FIG. 1;

FIG. 3 is a cross-section view of an example of a tool assembly of the present invention including a swell packer and a downhole element;

FIG. 4 is a schematic illustration an example of a packer of the present invention set in a wellbore; and

FIG. 5 is a cross-section view along the line II-II of FIG. 4.

DETAILED DESCRIPTION

Refer now to the drawings wherein depicted elements are not necessarily shown to scale and wherein like or similar elements are designated by the same reference numeral through the several views.
As used herein, the terms “up” and “down”; “upper” and “lower”; and other like terms indicating relative positions to a given point or element are utilized to more clearly describe some elements. Commonly, these terms relate to a reference point as the surface from which drilling operations are initiated as being the top point and the total depth of the well being the lowest point.
Wellbore packers are utilized to form annular seals between the mandrel that carries the seal member of the packer and a sidewall of a bore in which the packer is positioned. The outer sidewall may be an outer tubular or the earthen formation in which the wellbore is formed.
Common types of packers include inflatable packers, mechanical expandable packers, and swell packers. Inflatable packers typically carry a bladder that may be pressurized to expand outwardly to form the annular seal. Mechanical expandable packers have a flexible material expanding against the outer casing or wall of the formation when compressed in the axial direction of the well. Swell packers comprise a sealing material that increases in volume and expands radially outward when a particular fluid contacts the sealing material in the well. For example the sealing material may swell in response to exposure to a hydrocarbon fluid or to exposure to water in the well. The sealing material may be constructed of a rubber compound or other suitable swellable material.
FIG. 1 is a cross-section, elevation view of an example of a swell packer of the present invention generally noted by the numeral 10. Swell packer 10 includes a mandrel 12, swellable seal member 14, and a control line 16. The illustrated example provides anchors 18 positioned on opposing sides of seal member 14. Swell packer 10 is particularly adapted for providing an annular seal in a wellbore.
Mandrel 12 may be a tubular member, such as a sub, or the like dedicated as the base member of packer 10. For example, in a pre-fabricated example mandrel 12 may be a sub. Mandrel 10 may have opposing ends that are adapted for connecting with other tools and or tubular joints. In some installations, mandrel 12 may be a tubular joint that is connected in a work string or that is to be connected into a work string. For example, it may be desired to provide a packer 10 at a well site by disposing seal member 14 over a control line 16 and tubular joint as further described below.
Seal member 14 is a substantially tubular member having a bore 20 extending between opposing ends 22, 24. Seal member 14 is formed of a material that swells when exposed to a particular fluid or condition. For example, seal member 14 may swell in volume in response to a hydrocarbon, water, or other activating fluid or chemical. Seal material 14 may be formed of a rubber compound or other material. Seal member 14 encircles mandrel 12 and is constructed as a unitary member. Member 14 may be constructed of concentric layers and the layers may have different modulus of elasticity and or different swellability from one another.
Various mechanisms and means may be utilized to connect seal member 14 to mandrel 12. In FIG. 1, mechanisms 18 are positioned on opposing sides of member 14 to hold member 14 at a desired location on mandrel 12. Mechanism 18 is defined generally herein as an anchor and may include various elements including end-rings that hold member 14 in a desired position and/or limit extrusion of member 14 when it is set in the wellbore, for example from differential pressure. Non-mechanical means, such as adhesives or bonding methods, of holding member 14 in position may also be utilized.
Mechanism 18 may comprise a radially swellable member. The radially swellable mechanism 18 may have a higher modulus of elasticity and therefore be stiffer than seal member 14. As such, mechanism 18 may act to prevent or mitigate the extrusion of seal member 14 when it is set in the wellbore. Swellable anchor mechanism 18 may include multiple disc members each of which is swellable and that may have different swellabilities and Young's modulus. Control line 16 may be passed between an inner surface of mechanism 18 and the outer surface of mandrel 12.
Control line 16, as described further below, is positioned between seal member 14 and mandrel 12 to provide communication between elements on opposing sides of packer 10. “Control line” is defined herein to include various mechanisms that may be utilized to communicate signals, or data, or energy across packer 10. Examples of control line 16 include without limitation: cables of any type, including conductors and fiber optics; and conduits, such as tubing and the like for passing a pressurized fluid such as hydraulic fluid. Control line 16 may be provided to transmit data, electronic signals, pressurized fluid, and/or electrical power. For example, it may be desired to transmit an actuating signal from above packer 10 to a control valve on the other side of packer 10 or to transmit data from a sensor positioned below packer 10 to the surface.
FIG. 2 is a cross-section view of packer 10 along the line I-I of FIG. 1. Packer 10 is illustrated in the un-set or unactivated position prior to seal member 14 being activated to swell. Seal member 14 is positioned about mandrel 12 and a gap 28 is formed between a portion of the inner surface 26 of seal member 14 and the outer surface 30 of mandrel 12. Control line 16 is disposed in and through gap 28 such that it extends past opposing ends 22, 24 (FIG. 1) of seal member 14. In this example control line 16 a is an electrical cable for providing electrical power and control line 16 b is hydraulic line.
In the illustrated examples, control lines 16 are positioned between inner surface 26 of seal member 14 and outer surface 30 of mandrel 12. Control lines 16 are not positioned within a groove, slit or other passage formed in or through inner surface 26 of seal member 14. Gap 28 is not formed by removing any material from seal member 14 but exists by separating seal member 14 from mandrel 12. It is envisioned that forming a groove, slit or the like in seal member 14 may weaken the member or otherwise increase the incidence of failure in the wellbore.
Referring to FIGS. 1 and 2, packer 10 may be pre-fabricated for connecting within a work string at the well site or other location. By pre-fabricated it is meant that packer 10 is prepared for connecting within a tubular string at a well site, or other location, at a later time. Terminal ends 32 may be blank, for splicing, or include a suitable connector, for connecting with additional tools and/or the work string control line.
In other examples, control line 16 may be installed at the well site. For example, a control line 16 may be run along the outer surface of mandrel 12 which may be a tubular joint. Mandrel 12 and control line 16 may be inserted through bore 20 of seal member 14. When seal member 14 is properly positioned it may be cemented in place and/or secured with anchor member 18. For example, in FIG. 2 a portion of inner surface 26 of member 14 is cemented with an adhesive to outer surface 30 of mandrel 12 at section 34.
FIG. 3 is a cross-section view of an example of a tool assembly generally denoted by the numeral 40. Tool assembly 40 includes a packer 10 interconnected with an operable downhole element 42. Control line 16 is shown extending across packer 10 and operationally connected to downhole element 42. In this example, control line 16 is shown extending beyond downhole element 42 for connecting to a subsequent downhole element that is not shown. Downhole element 42 is referred to herein as operable for purposes of describing that it is a device that utilizes control line 16 for at least a portion of its operational purpose.
Downhole element 42 may be any device, tool, or sensor to which control line 16 is connected and is referred to herein as a valve for purposes of description. Packer 10 includes mandrel 12 and valve 42 includes a mandrel 12 a which form a continuous longitudinal bore 44. In FIG. 3, mandrel 12 and mandrel 12 a are illustrated as separate members interconnected at seam 46. However, it should be recognized that mandrel 12 and mandrel 12 a may be sections or portion of a continuous tubular joint.
Tool assembly 40 may be prefabricated for later installation in a work string, for example at a well site. One advantage of preassembled tool assembly 40 is the elimination of the requirement to splice or otherwise connect control line 16 between packer 10 and downhole element 42 at the well site. Elimination of this step can reduce rig costs and mitigate one source of failure of a control system. Another advantage is that control line 16 is held close to tubular 12 and is thus protected during shipping, handling, and well installation operations.
Refer now to FIG. 4, wherein an example of packer 10 is illustrated positioned and set in a wellbore 36. Packer 10 is conveyed into and positioned at a selected position within wellbore 36 on a tubular string. Seal member 14 is set by contact with an activating agent that causes seal member 14 to swell. When activated, seal member 14 expands radially outward from mandrel 12 and into sealing contact with a sidewall 38. In this example sidewall 38 may be an earthen formation, casing, or any other tubular such as sand screen base pipe, liners and the like. It is noted that packer 10 may be utilized as an open-hole packer or a cased-hole packer. It is envisioned that packer 10 promotes annular sealing in open-hole applications while facilitating the passing of control lines across the set packer.
FIG. 5 is a cross-section view along the line II-II of FIG. 4. FIG. 5 illustrates seal member 14 in the set position. When seal member 14 is activated it swells such that inner surface 26 closes against control line 16 and mandrel 12 closing gap 28 (FIG. 2). A slight gap is shown around control line 16 in FIG. 4 for purposes of illustration. However, it is envisioned that seal member 14 will seal or substantially seal about control line 16 and mandrel 12.
From the foregoing detailed description of specific embodiments of the invention, it should be apparent that novel devices, systems, and methods for running a control line across a packer that is set in a wellbore have been disclosed. Although specific embodiments of the invention have been disclosed herein in some detail, this has been done solely for the purposes of describing various features and aspects of the invention, and is not intended to be limiting with respect to the scope of the invention. It is contemplated that various substitutions, alterations, and/or modifications, including but not limited to those implementation variations which may have been suggested herein, may be made to the disclosed embodiments without departing from the spirit and scope of the invention as defined by the appended claims which follow.

Claims

1. A packer for providing an annular seal when set in a wellbore or tubular, the packer comprising:

a tubular mandrel having an outer surface;

a seal member having an inner surface defining a bore, the seal member encircling a portion of the mandrel; and

a control line positioned between the inner surface of the seal member and the outer surface of the mandrel and extending across the length of the seal member.

2. The packer of claim 1, wherein the control line is not positioned in a slot cut into the inner surface of the seal member.

3. The packer of claim 1, wherein the packer includes an anchor mechanism positioned at each end of the seal member to position the seal member on the mandrel.

4. The packer of claim 3, wherein the anchor mechanism includes a radially swellable material.

5. The packer of claim 2, wherein the packer includes an anchor mechanism positioned at each end of the seal member to position the seal member on the mandrel.

6. The packer of claim 5, wherein the anchor mechanism includes a radially swellable material.

7. The packer of claim 1, wherein the seal member is constructed of a swellable material that expands radially from the mandrel upon contact with an activating agent.

8. The packer of claim 7, wherein the seal member is a unitary member.

9. The packer of claim 8, wherein the control line is not positioned in a slot cut into the inner surface of the seal member.

10. The packer of claim 9, further including an anchor mechanism positioned at each of the seal member, the anchor mechanism constructed of a radially swellable member.

11. The packer of claim 10, wherein the anchor mechanism has as a modulus of elasticity greater than that of the seal member.

12. The packer of claim 7, wherein the control line is not positioned in a slot cut into the inner surface of the seal member.

13. The packer of claim 12, wherein the seal member is a unitary member.

14. A wellbore tool assembly, the assembly comprising:

a mandrel having an outer surface and a longitudinal bore;

a tubular, swellable seal member having opposing ends and an inner surface defining a bore between the opposing ends, the seal member encircling a portion of the mandrel;

an operable downhole element carried with the mandrel; and

a control line connected to the operable downhole element, the control line extending from the downhole element between the outer surface of the mandrel and the inner surface of the seal member to the other side of the seal member from the downhole element.

15. The assembly of claim 14, wherein the control line is not positioned in a slot cut into the inner surface of the seal member.

16. The assembly of claim 14, wherein the downhole element is connected to a tubular that is connected to the mandrel carrying the seal member.

17. The assembly of claim 16, wherein the control line is not positioned in a slot cut into the inner surface of the seal member.

18. A method for extending a control line across a packer set in a wellbore, the method comprising the steps of:

positioning a control line along an outer surface of a tubular mandrel;

encircling a portion of the tubular mandrel and the control line with a seal member, the control line passing between the outer surface of the tubular mandrel and an inner surface of the seal member; and

activating the seal member in a wellbore to form a seal between the outer surface of the tubular mandrel and a sidewall of the wellbore.

19. The method of claim 18, wherein the control line is not positioned in a slot cut into the inner surface of the seal member.

20. The method of claim 18, wherein the step of activating includes contacting the seal member with an activating agent causing the seal member to expand radially between the sidewall and the outer surface of the mandrel and substantially sealing about the control line.