WO2004076803A1

WO2004076803A1 - Protector for downhole control lines and related method

Info

Publication number: WO2004076803A1
Application number: PCT/GB2004/000431
Authority: WO
Inventors: Iain Baxter; Jeanine Alexander; Ewen A. Connell; David A. Blane
Original assignee: Schlumberger Surenco Sa; Schlumberger Oilfield Assistance Limited; Schlumberger Overseas Sa; Prad Research And Development N.V.; Schlumberger Holdings Limited; Schlumberger Services Limited; Schlumberger Technology Bv; Services Petroliers Schlumberger; Schlumberger Canada Limited
Priority date: 2003-02-28
Filing date: 2004-02-04
Publication date: 2004-09-10
Also published as: GB0304501D0; GB2398807A; GB2398807B

Abstract

An apparatus and method is provided for protecting control lines (4) used with tool strings in a downhole environment. A control line protector assembly (19) has a plurality of pieces, such as a guard section (5) and end sections (6A,6B) that are attachable to the guard section. To provide flexibility, the dimensions of the guard section (15) and/or end sections (6A,6B) can be adjusted to suit a particular tool string, such as tubing sections and a coupling mechanism for coupling the tubing sections.

Description

PROTECTOR FOR DOWNHOLE CONTROL LINES AND RELATED METHOD

BACKGROUND [01] Oil, gas, or water wells commonly employ the use of some form of control lines to communicate with or to provide power to downhole equipment. Examples of control lines used in a downhole environment include electrical lines, fluid pressure lines, fiber optic lines, and so forth. For example, downhole sensors may communicate measurements to surface equipment over electrical cables or fiber optic lines. Also, hydraulic power can be provided to control downhole components, such as to operate valves, set downhole packers, and so forth, using hydraulic lines or other lines for communicating fluid pressure. If unprotected, control lines may be easily damaged during deployment of tool strings into the well, or by other movement or operation of downhole components.

[02] Control lines, such as electrical cables, are especially susceptible to damage near the joints between tubing or pipe sections, because of the presence of extra components (such as a coupling mechanism) used for attaching the joints. Cable protectors are usually provided at such pipe or tubing couplings to provide protection for electrical cables.

[03] A cable protector for protecting electrical cables typically includes a body section, in which the electrical cables are accommodated, with the body section coupled to a clamp piece to enable fastening of the cable protector to a tubing or pipe section. However, a conventional cable protector is rather limited in the types of tubings or pipes that the cable protector can be used with. As the requirements of a well operator change, tubing or pipe sizes may also need to change. When that occurs, existing cable protectors may not be suitable for use with the different tubings or pipes. As a result, in anticipation of such changes, a well operator may have to keep various different types of cable protectors. This increases the number of components that must be kept by the well operator, which may increase the cost of well operation. SUMMARY [04] In general, according to one embodiment, a flexible protection mechanism is provided for protecting control lines used in a downhole environment. For example, a method of protecting a control line for use with a string having sections and a coupling to couple the sections includes providing a control line protector having plural segments, with the control line protector configurable to a number of different dimensions based on corresponding arrangements of at least one of the coupling and string sections. A dimension of at least one of the control line protector segments is tailored based on a given arrangement of at least one of the coupling and string sections. The control line protector segments are attached to each other to cover a portion of the control line.

[05] Other or alternative features will become more apparent from the following description, from the drawings, and from the claims.

BRIEF DESCRIPTION OF THE DRAWINGS [06] Fig. 1 illustrates a tool string positioned in a wellbore, according to one example.

[07] Fig. 2 is a perspective view of an assembly of tubing sections, a coupling, electrical control lines, and a cable protector assembly in accordance with an embodiment.

[08] Fig. 3 is a perspective view of a guard section of the cable protector assembly of Fig. 2.

[09] Fig. 4 shows a portion of the guard section of Fig. 3, which includes a vertical key element.

[010] Fig. 5 is a perspective view of an end section that is configured to mate with the guard section of Fig. 3.

[011] Fig. 6 is a different perspective view of the end section of Fig. 5, with a portion of the housing of the end section removed.

[012] Fig. 7 is a longitudinal sectional view of the assembly of Fig. 2. [013] Fig. 8 is a sectional view of a smaller portion of the assembly of Fig. 2.

[014] Fig. 9 is a perspective view of an assembly of tubing sections, a coupling, and a control line protector assembly according to another embodiment.

[015] Fig. 10 is a perspective view of a guard section of the control line protector assembly of Fig. 7.

[016] Fig. 11 illustrates a portion of the guard section of Fig. 10.

[017] Fig. 12 is a bottom perspective view of an end section configured to be mated with the guard section of Fig. 10.

[018] Fig. 13 is a different perspective view of the end section of Fig. 12.

DETAILED DESCRIPTION [019] In the following description, numerous details are set forth to provide an understanding of the present invention. However, it will be understood by those skilled in the art that the present invention may be practiced without these details and that numerous variations or modifications from the described embodiments are possible.

[020] Fig. 1 illustrates a tubing string 102, according to one example, positioned in a wellbore 100. The tubing string 102 has multiple tubing sections 2 that are coupled to each other by coupling mechanisms 3. One or more control lines 4 are routed along the outside of the tubing string 102, with the control lines 4 passing through the coupling mechanisms 3. Examples of the control lines 4 include hydraulic control lines, electrical cables, fiber optic lines, and the like. Control line protector assemblies 19 according to some embodiments are provided at each of the coupling mechanisms 3 to protect the one or more control lines 4.

[021] Although reference is made to a tubing string in the described embodiments, the control line protector assembly 19 according to some embodiments can be employed with other types of tool strings used in a well. A tubing string can have multiple tubing sections. More generally, a tool string can have multiple string sections.

[022] A portion of the tubing string 102 is shown in greater detail in Fig. 2 (cross- section shown in Fig. 7). The portion shown in Fig. 2 includes tubing sections 2, a coupling mechanism 3, and a control line protector assembly 19. In Fig. 2, the tubing sections 2 are shown as tubing section 2 A and tubing section 2B, with the two tubing sections 2 A and 2B coupled by the coupling mechanism 3. As used here, a "tubing" refers to any structure, cylindrical or otherwise, that is run into a wellbore in sections that are attached by a coupling mechanism. The "tubing" can be a solid structure, or it can be a hollow structure with a longitudinal bore.

[023] As also shown in Fig. 2, one or more control lines 4 (e.g., an electrical cable) are run along the outer surface of the tubing sections 2 A, 2B. The control lines 4 are especially vulnerable at the sections that run over the outer surface of the coupling mechanism 3. That is because the coupling mechanism 3 is raised above the outer surface of the tubing sections 2A, 2B. To protect the control lines from damage in the region proximate the coupling mechanism 3, the control line protector assembly 19 is mounted over the control lines 4, as shown.

[024] For improved flexibility in accordance with some embodiments, the control line protector assembly 19 has a number of sections or segments that are attached together. The dimensions of the sections or segments of the control line protector assembly 19 are adjustable by a manufacturer (such as by cropping, cutting, and the like) to adjust the control line protector assembly to fit with tubing sections and coupling mechanisms of various sizes. More generally, the sections or segments of the control line protector assembly 19 can be tailored to suit a given arrangement (e.g., size, length, and so forth) of at least one of the coupling mechanism 3 and the tubing sections 2 A, 2B.

[025] The tailoring of one or more segments of the control line protector assembly 19 can be performed. This enables a manufacturer to keep one type of control line protector assembly 19 for multiple possible arrangements of coupling mechanisms 3 and tubing sections 2 A, 2B. [026] The control line protector assembly 19 includes a guard section 5 that fits over a portion of the housing of the coupling mechanism 3. The guard section 5 is engaged with end sections 6 (illustrated as 6 A, 6B in Fig. 2) at the two ends of the guard section 5. The guard section 5 and end sections 6 are separate elements that can be lockingly engaged to enable fastening of the control line protector assembly 19 to the rest of the tool string. As described further below, profiles in the guard section 5 can be adjusted to modify the dimensions of the guard section 5 so that the control line protector assembly 19 can be fitted with components (e.g., the coupling mechanism 3, the pipe sections 2A, 2B, etc.) of varying sizes and configurations. In other embodiments, profiles of the end sections 6 can also be modified.

[027] In the embodiment shown in Fig. 2, the guard section 5 does not extend around the entire circumference, but rather it extends less than the entire circumference. This is best seen in Fig. 3, which shows the cable guard section 5 having a generally arcuate main body 202. Alternatively, the guard section 5 can be generally tubular in shape to completely enclose portions of the tubing sections 2 A, 2B and the coupling mechanism 3.

[028] Longitudinal side members 204 and 206 extend downwardly from the arcuate main body 202. In the implementation of Fig. 3, the arcuate main body 202 and the longitudinal side members 204, 206 are integrally connected. However, in other embodiments, the main body 204 and side members, 204, 206 are separate pieces that are connected to each other. The arcuate main body 202 and side members 204, 206 define an inner longitudinal groove 205 for receiving an outer surface of the coupling mechanism 3 and/or outer surfaces of the tubing sections 2A, 2B.

[029] The side members 204 and 206 are connected to outwardly protruding vertical key elements 17, with each key element having a vertical segment 208 that is spaced apart from the outer wall of a respective side member 204, 206. Each key element 17 also has a connector member 209 that connects the vertical segment 208 to the side member 204, 206. In one embodiment, the side member 204, 206, connector member 209, and vertical segment 208 are all integrally connected. In other embodiments, the different pieces can be separate elements that are bonded or attached together. [030] The guard section 5 has four discrete key elements 17, with one at each corner of the guard section 5. Each key element 17 extends some length LI along the longitudinal axis of the guard section 5.

[031] As best seen in Fig. 4, the upper portion of the vertical segment 208 of each key element 17 has a snap lock projection 18 that protrudes inwardly toward the outer wall of the respective member 204, 206. A gap 210 exists between the key element 17 and the outer wall of the side member 204, 206. This gap 210 enables insertion of each key element 17 into a corresponding structure of an end section 6.

[032] Each end section 6 is shown in greater detail in Figs. 5 and 6. As shown in Fig. 5, vertical slots 12 are provided on the two lateral sides of the end section 6 to receive respective key elements 17 on the two lateral sides of the guard section 5. Note that each of the vertical slots 12 is completely enclosed to provide an enclosed slot or duct. A rear perspective view of the end section 6 is shown in Fig. 6, with a portion of the housing of the end section 6 removed to illustrate the slots 12. Within each slot 12 is a snap lock ledge 13, which is designed to engage the snap lock projection 18 of a respective key element 17. Once the key element 17 is pushed upwardly into the slot 12, and the snap lock projection 18 engages the snap lock ledge 13, the end section 6 and the cable guard section 5 are engaged and locked with respect to each other in the manner shown in Fig. 1. Because the slot 12 is enclosed, the length LI of the key element 17 is adjusted (by cropping or cutting the key element 17) such that the length LI (Fig. 3) is equal to the width W (Fig. 5) of each slot 12.

[033] More generally, the key element 17 is referred to as a "first engagement member" and the slot 12 and snap lock ledge 13 are collectively referred to as a "second engagement member." In other embodiments, other types of first and second engagement members can be employed.

[034] The end section 6 also has a generally arcuate main body portion 220, with protruding members 222 and 224 extending in a first direction from the arcuate body portion 220. Locking and clamping segments 226 and 228 extend from the other side of the arcuate body portion 220 of the end section 6. The locking and clamping segments 226 and 228 define the slots 12 for receiving the key elements 17. The inner profiles of the arcuate body portion 220, protruding members 222, 224, and the locking and clamping segments 226, 228 are shaped to receive portions of the pipe sections 2A, 2B and coupling mechanism 3.

[035] The arcuate body portion 220 has a control line conduit structure 14, which defines plural grooves 232 through which the control lines 4 can extend. In one example implementation, one type of control line (e.g., an electrical cable) runs through a first one of the grooves 232, a second type of control line (e.g., a hydraulic line) runs through a second one of the grooves 232, and so forth. The control line conduit structure 14 is designed to slightly bend the control line 4 to provide support for the control lines 4. In one embodiment, as best shown in Fig. 8, the conduit structure 14 has a sloped inner surface 240 to bend the portions of the control lines 4 in the grooves 232. The sloped surface 240 is achieved by providing one end 234 with a larger inner diameter than a second end 236.

[036] Further, an outer groove 230 is provided in each of the locking and clamping segments 226 and 228. Holes 15 and 16, which extend generally in a longitudinal direction of the end section 16 extend through rear portions of locking and clamping segments 226 and 228, respectively. The holes 15 and 16 are provided to receive a hinge pin and barrel fastener assembly.

[037] As shown in Fig. 2, two collar clamps 7A, 7B are hingedly joined to respective end sections 6 A, 6B, with hinge pins (not shown) extending through the holes 15 and 16. The control line protector assembly 19 is clamped to the tubing sections 2 A, 2B with swing barrel 9 and bolt 10 arrangements. A swing barrel 9A and bolt 10A arrangement attaches the end section 6A to tubing section 2A, and a swing barrel 9B and bolt 10B arrangement attaches the end section 6B to tuning section 2B. When assembled, each of the barrel and bolt arrangements 9, 10 is locked in place by the use of a respective lock washer 11 A, 11B, which is designed to prevent the bolt from fully being backed out of the barrel. Effectively, the use of the lock washer ties the bolt and barrel into an integral assembly. [038] As further shown in Fig. 2, the control line protector assembly 19 covers portions of the control lines 4, which are routed through one of the conduits defined in the control line conduit structure 14 of the end section 6.

[039] Fig. 9 shows an alternative embodiment of a string that includes a different control line assembly 119 for protecting control lines (not shown in Fig. 9) extending along the outside of tubing sections 2 A, 2B. A guard section 105 and end sections 106 A, 106B (that are attached to the two end portions of the guard section 105) of the control line assembly 119 have different designs from the guard section 5 and end sections 6 A, 6B, respectively, of the control line assembly 19 described above.

[040] As shown in Fig. 10, the guard section 105 has continuous key elements 117 on the two lateral sides of the guard section 105 (unlike the discrete vertical key elements 17 of Fig. 3). The outer surface of each of the key elements 117 has a series of vertical ridges 122 that run along the longitudinal direction of the guard section 105. Also, each key element 117 defines a continuous snap lock projection 118 on its inner surface that extends the length of the guard section 105. The length of the guard section 105 (and of the key elements 117) is selected based on the expected size of the tubing sections 2 A, 2B and the expected range of length of the coupling mechanism 3.

[041] As shown in Figs. 12 and 13, the end section 106 defines open slots 112 (unlike the enclosed slots 12 of the first embodiment) to receive respective key elements 117. Because of the open slot 112 arrangement of the second embodiment, the key elements 117 do not need to be cut to fit into the slots 112 after cropping of the guard section 105. A first inner surface of each slot 112 contains vertical ridges 121 that are designed to be aligned with the ridges 122 of the guard section 105. The other inner surface of the slot 112 has a snap lock ledge 113 for locking engagement with the snap lock projection 118 of the vertical key element 117. As with the first embodiment, each end section 106 has a generally arcuate body portion 302, with locking and clamping segments 304, 306 extending from one side of the arcuate body portion 302. Holes 115 and 116 are formed through the locking and clamping segments 304, 306 to receive a hinge pin 108 and barrel fastener, respectively. [042] The body portion 302 also has a control line conduit structure 114 having plural grooves 306 through which control lines are routed.

[043] In operation, using the arrangement according to the first embodiment of the control line protector assembly 19, the guard section 5 is imtially prepared by cropping the overall length to suit the particular coupling mechanism 3. Next, the vertical key elements 17 may be cropped to suit the length of the slots 12 in the end sections 6 A, 6B. The guard section 5 and the end sections 6 A, 6B are then joined together by placing the end sections 6A, 6B over the top of the guard section 5 to lockingly engage the key element 17 inside the slots 12. Once the key elements 17 and slots 12 are lined up, the two are pressed together so that the snap lock ledge 13 and the snap lock projection 18 engage. The two collar clamps 7 are then made up to the assembly with hinge pins 8. The swing barrel and bolt arrangement 9, 10 is then installed in the collar clamp 7 and the lock washer 11 is engaged to the bolt 10.

[044] In the second embodiment, to make up the control line protector assembly 119, the guard section 105 is initially prepared by cropping the overall length to suit a given coupling mechanism 3. Unlike the first embodiment, however, the length of the key elements 117 does not need to be adjusted to fit into slots 112 of the end sections 106A, 106B. The two collar clamps 107 A, 107B are then made up to the assembly using hinge pins 108, with the barrel and bolt arrangement in the collar clamps 107 A, 107B. The lock washer is then made up.

[045] The various pieces of each control line protector assembly 19, 119 can be made of various materials, such as steel, plastic, or a composite material. Certain pieces can be made of steel, while other pieces made of plastic, or a combination thereof. Also, in addition to metal or plastic, other types of materials can also be used.

[046] The guard section 5, 105 can be manufactured by casting, molding, extruding, or by other means appropriate to the materials of the guard section. The guard section has a width and height selected to accommodate the expected range of control line sizes, coupling diameters, coupling lengths, tubing sections, and so forth. The end sections 6, 106 are manufactured by casting, molding, extruding, or by any other means appropriate to the material of the end sections.

[047] While the invention has been disclosed with respect to a limited number of embodiments, those skilled in the art will appreciate numerous modifications and variations therefrom. It is intended that the appended claims cover such modifications and variations as fall within the true spirit and scope of the invention.

Claims

What is claimed is:

1. A method of protecting a control line for use with a string having sections and a coupling to couple the sections, the method comprising: providing a control line protector having plural segments, the control line protector configurable to a number of different dimensions based on corresponding arrangements of at least one of the couplmg and string sections; tailoring a dimension of at least one of the control line protector segments based on a given arrangement of at least one of the coupling and string sections; and attaching the control line protector segments to each other to cover a portion of the control line.

2. The method of claim 1, further comprising selecting a size of at least one of the control line protector segments to fit an anticipated range of sizes of the string sections and coupling.

3. The method of claim 1 , further comprising tailoring a dimension of another one of the segments based on the arrangement of at least one of the coupling and string sections.

4. The method of claim 1 , further comprising wherein tailoring a dimension of the at least one of the segments comprises tailoring a length of the at least one of the segments.

5. The method of claim 4, wherein tailoring the length comprises cutting off a portion of the at least one of the segments.

6. The method of claim 1 , wherein providing the control line protector having plural segments comprises providing the control line protector having a body segment and at least one end segment lockingly engageable with the body segment, the method further comprising providing a key element in the body segment to couple the body segment to the at least one end segment.

7. The method of claim 6, wherein tailoring the dimension of at least one of the segments comprises cropping a length of the body segment.

8. The method of claim 7, wherein tailoring the dimension of at least one of the segments further comprises cropping a size of the key element to fit the key element into a corresponding portion of the end segment.

9. The method of claim 8, further comprising providing a first locking profile on the key element and a second locking profile in a slot of the end segment, the first locking profile to lockingly engage the second locking profile.

10. The method of claim 1 , further comprising engaging the plural segments using a snap lock mechanism.

11. The method of claim 1 , wherein the plural segments comprise a body segment and at least one end segment, the body segment having at least one key element to engage the body segment to the at least one end segment, the method further comprising providing ridges along an external surface of the key element.

12. A control line protector for protecting a control line that is part of a tool string having plural sections and a coupling to attach the tool string sections, the control line protector comprising: a body segment having a first engagement member; and an end segment having a second engagement member adapted to engage the first engagement member to attach the end segment to the body segment, the body segment configurable to a plurality of dimensions based on corresponding arrangements of at least one of the coupling and the plural tool string sections.

13. The control line protector of claim 12, wherein the body segment is configurable to the plurality of dimensions based on corresponding sizes of at least one of the coupling and the plural tool string sections.

14. The control line protector of claim 13, wherein the body segment and end segment each has a size selected based on an anticipated range of sizes of the coupling and tool string sections.

15. The control line protector of claim 12, wherein the end segment is attached to the body segment at one end of the body segment, the control line protector further comprising another end segment that is attached to another end of the body segment.

16. The control line protector of claim 12, wherein the body segment is configurable to a plurality of different lengths based on corresponding sizes of at least one of the coupling and the plural sections.

17. The control line protector of claim 16, wherein the first engagement member is configurable to one of plural different sizes to fit the first engagement member to the second engagement member.

18. The control line protector of claim 17, wherein the first engagement member comprises a key element, and wherein the second engagement member comprises an enclosed slot.

19. The control line protector of claim 18, further comprising ridges arranged along an outer surface of the key element.

20. The control line protector of claim 17, wherein the first engagement member comprises a key element, and wherein the second engagement member comprises an open slot.

21. The control line protector of claim 12, further comprising a snap lock mechanism to attach the body segment and the end segment.

22. An apparatus for use in a wellbore, comprising: a control line; and a contiol line protector according to claim 12 to protect the control line.

23. The apparatus of claim 22, further comprising a tubing string, the control line extending along an external surface of the tubing string.