WO2001073331A2

WO2001073331A2 - Coiled tubing connector

Info

Publication number: WO2001073331A2
Application number: PCT/US2001/008172
Authority: WO
Inventors: Haoshi Song; James W. Estep
Original assignee: Halliburton Energy Services, Inc.
Priority date: 2000-03-24
Filing date: 2001-03-14
Publication date: 2001-10-04
Also published as: AU2001249199A1; NO20024543L; EP1303720A2; MXPA02009349A; NO20024543D0; EP1303720A4; WO2001073331A3; CA2403960A1; JP2003531320A; CN1527901A; BR0109506A

Abstract

A coiled tubing connector includes a male (20) and female housing (40). A rotating ring (27) having threads (31) is disposed on the male housing. When the male housing is joined to the female housing, the threads of the rotating ring threadingly engage threads (41) disposed on the internal circumference of the female housing. The male housing also includes splines (28) which align with grooves (48) on the female housing. Situated on both the male and female housing are electrical contacts (50, 60) which themselves engage when the housings are joined. The electrical contacts are connected to wires embedded in the composite tubing (12, 14) so that electrical power or data signals from one length of composite tubing can pass through the connector to another length of coiled tubing. The ends of the composite tubing are affixed to both the male and female housings through a compression fitting.

Description

COILED TUBING CONNECTOR

STATEMENTREGARDINGFEDERALLY SPONSORED RESEARCHORDEVELOPMENT

Not Applicable.

FIELD OF THE INVENTION

The present invention relates generally to devices used to connect lengths of coiled tubing and more particularly to devices used to connect lengths of composite coiled tubing. Another feature of the present invention relates to providing a mechanical connection of sufficient strength so that forces of tension, compression, and torque can be transferred from one length of tubing to the other through the connector. Further the connection between lengths of tubing is hydraulic ally sealed so as to separate fluids conducted inside the tubing and the connector from any fluids on the outside of the tubing and connector. The connector also permits the fluids inside a length of tubing to flow through the connector on to the sequential length of tubing. The connector of the present invention also provides a mechanism that permits the lengths of tubing to be connected without imparting any rotation on either length of tubing. Additionally, the invention relates to connectors that will also allow an electrical connection from the joining of electrical wires, or other types of signaling cables, embedded within each multi-conductor pair of tubing to be joined. The electrical connection provides seals and insulation that insulates both wire-to-wire and wire-to-fluid.

BACKGROUND OF THE INVENTION Coiled tubing, as currently deployed in the oilfield industry, generally includes small diameter cylindrical tubing having a relatively thin wall made of metal or composite material. Coiled tubing is typically much more flexible and of lighter weight than conventional drill pipe. These characteristics of coiled tubing have led to its use in various well operations. For example, coiled tubing is routinely utilized to inject gas or other fluids into the well bore, inflate or activate bridges and packers, transport well logging tools downhole, perform remedial cementing and clean-out operations in the well bore, and to deliver or retrieve drilling tools downhole. The flexible, lightweight nature of coiled tubing makes it particularly useful in deviated well bores.

Typically, coiled tubing is introduced into the oil or gas well bore through wellhead control equipment. A conventional handling system for coiled tubing can include a reel assembly, a gooseneck, and a tubing injector head. The reel assembly includes a rotating reel for storing coiled tubing, a cradle for supporting the reel, a drive motor, and a rotary coupling. During operation, the tubing injector head draws coiled tubing stored on the reel and injects the coiled tubing into a wellhead. The drive motor rotates the reel to pay out the coiled tubing and the gooseneck directs the coil tubing into the injector head. A rotary coupling provides an interface between the reel assembly and a fluid line from a pump. Fluids are often pumped through the coiled tubing during operations. Such arrangements and equipment for coiled tubing are well known in the art.

While prior art coiled tubing handling systems are satisfactory for coiled tubing made of metal such as steel, these systems do not accommodate the relatively long spans or drill string lengths achievable with coiled tubing made of composites. Such extended spans of composite coiled tubing strings are possible because composite coiled tubing is significantly lighter than steel coiled tubing. In fact, composite coiled tubing can be manufactured to have neutral buoyancy in drilling mud. With composite coiled tubing effectively floating in the drilling mud, downhole tools, such as tractors, need only overcome frictional forces in order to tow the composite coiled tubing through a well bore. This characteristic of composites markedly increases the operational reach of composite coiled tubing. Thus, composite coiled tubing may well allow well completions to depths of 20,000 feet or more, depths previously not easily achieved by other methods. Moreover, composite coiled tubing is highly resistant to fatigue failure caused by

"bending events," a mode of failure that is often a concern with steel coiled tubing. At least three bending events may occur before newly manufactured coiled tubing enters a well bore: unbending when the coiled tubing is first unspooled from the reel, bending when travelling over a gooseneck, and unbending upon entry into an injector. Such accumulation of bending events can seriously undermine the integrity of steel coiled tubing and pose a threat to personnel and rig operations. Accordingly, steel coiled tubing is usually retired from service after only a few trips into a well bore. However, composite coiled tubing is largely unaffected by such bending events and can remain in service for a much longer period of time. Hence, systems utilizing composite coiled tubing can be safely and cost-effectively used to drill and explore deeper and longer wells than previously possible with conventional drilling systems. Moreover, completed but unproductive wells may be reworked to improve hydrocarbon recovery. Thus, composite coiled tubing systems can allow drilling operations into formations that have been inaccessible in the past and thereby further maximize recovery of fossil fuels.

However, these dramatic improvements in drilling operations cannot be realized without handling systems that can efficiently and cost-effectively deploy extended lengths of composite coiled tubing. Prior art coiled tubing handling systems do not readily accommodate the reel change-outs needed when injecting thousands of feet of coiled tubing downhole. Prior art coiled tubing handling systems require a work stoppage to change out an empty reel for a full reel. Because such a procedure is inefficient, there is a need for a coiled tubing handling system that more efficiently changes out successive reels of coiled tubing. Composite coiled tubing offers the potential to exceed the performance limitations of isotropic metals, thereby increasing the service life of the pipe and extending operational parameters. Composite coiled tubing is constructed as a continuous tube fabricated generally from non-metallic materials to provide high body strength and wear resistance. This tubing can be tailored to exhibit unique characteristics which optimally address burst and collapse pressures, pull and compression loads, as well as high strains imposed by bending. This enabling capability expands the performance parameters beyond the physical limitations of steel or alternative isotropic material tubulars. In addition, the fibers and resins used in composite coiled tubing construction make the tube impervious to corrosion and resistant to chemicals used in treatment of oil and gas wells. High performance composite structures are generally constructed as a buildup of laminant layers with the fibers in each layer oriented in a particular direction or directions. These fibers are normally locked into a preferred orientation by a surrounding matrix material. The matrix material, normally much weaker than the fibers, serves the role of transferring load into the fibers. Fibers having a high potential for application in constructing composite pipe include glass, carbon, and aramid. Epoxy or thermoplastic resins are good candidates for the matrix material.

In current practice coiled tubing is often used in conjunction with a bottom hole assembly connected to the end of the tubing string. The bottom hole assembly may include a variety of downhole tools and devices including sensors, orientation devices, motors, hydraulic rams, and steering tools. If the tubing is supporting a bottom hole assembly for drilling, the bottom hole assembly will include a drill bit and other drilling equipment. Sensors and monitoring equipment of other kinds may be located upstream of the drill bit. One consequence of the variety of equipment used in conjunction with coiled tubing string is the need for some means to conduct electrical power and signals from one end of the string to the other. In this way power and signals from the control/operating point on the surface can be sent to the bottom hole assembly at the opposite end of the string, and likewise signals from the bottom hole assembly can be transmitted to the surface. Thus composite coiled tubing may be manufactured with conductors embedded in the wall of the tubing itself. The conductors may be electrical wires, optical transmitting cables, or other forms of cabling that permit the transmission of energy or data. Electrical conductors within the coiled tubing can be connected to the bottom hole assembly at one end of the string; and at the opposite end of the string, the conductors can be connected to meters, gauges, control equipment, computers, and the like.

The transmission of signals through composite coiled tubing does present one problem, however. When two or more lengths of tubing must be joined to provide the required overall length for the particular well operation, a connector must be provided to pass the energy or data between adjoining lengths of coiled tubing. Such a connection must first provide a robust electrical contact between the two lengths of wire to be joined so that an uninteirupted signal may pass even in the presence of the shaking and jarring that occur during a well operation. In addition the connection must provide insulation. The connected conductors must not only be insulated from the fluids and other matter in the surrounding well environment but in addition the connected conductors must be properly insulated from the other conductors within the composite tubing. Materials that are present in the well environment can be highly corrosive and destructive of electrical conductors. A common shortcoming of the existing methods for connecting composite coiled tubing is that they do not adequately meet the need for a robust and well insulated electrical connection of the electrical conductors in the joined sets of tubing. Notwithstanding the foregoing described prior art, there remains a need for a coiled tubing connector that combines the features of a strong mechanical connection, sealing the fluids within the coiled tubing from the outside environment, and providing a robust electrical connection. These and other features and advantages are found in the present invention.

SUMMARY OF THE INVENTION The present invention overcomes the aforementioned deficiencies of the prior art by providing a connector that comprises female and male housings which join together to create the coiled tubing connection. A rotating ring on the male housing includes threads that engage corresponding threads on the female housing. Spindles on the male housing also align with corresponding flutes on the female housing. The female and male housings each attach to end portions of coiled tubing through a clamp or threaded connection.

A first advantage of the connector of the present invention is that it provides a robust connection to join successive lengths of composite coiled tubing. In this way forces of compression, tension and torque can be passed along the length of composite drill string.

Another advantage of the connector of the present invention is that it provides a hydraulic seal to separate the fluids passing through the interior of the coiled tubing from fluids and materials passing externally of the coiled tubing. The connector also allows fluids to pass uninterrupted from one length of tubing to the succeeding length of tubing. Composite tubing may not hold a perfectly round cross-section. The fact that composite tubing is flexible allows it to bend to an out-of-round cross-section. The connector of the present invention assures that the coiled tubing will be strongly bound and sealed to the connector in spite of the tubing's tendency to be out-of-round. The connector achieves this advantage by providing hydraulic seals. A further advantage of the present invention is that the connector may be assembled without imparting rotational forces on either length of coiled tubing.

A further advantage of the present invention is that it provides for a strong, well protected contact between matched pairs of electrical conductors in adjoining lengths of composite tubing. This contact is achieved through matching sets of ring contacts. The ring contact attached to the male end has a spring back located underneath the mating surface of the ring contact. Thus when the male contact ring engages the female contact ring, the spring back firmly engages the contacts.

Another advantage of the electrical contact achieved through the present connector is the insulation it provides from the surrounding well environment as well as between the neighboring electrical signals from adjacent conductors.

Another advantage of the connector is that many of the parts in the sub-assembly of the connector are the same for both the male and female pieces of the connector. Thus, there is no need for additional designs, drawings, or inventory. The same part may be used for construction of either the male or female housing. Thus, the present invention comprises a combination of features and advantages that enable it to overcome various problems of prior art coiled tubing connectors. The various characteristics described above, as well as other features, objects, and advantages, will be readily apparent to those skilled in the art upon reading the following detailed description of the preferred embodiments of the invention, and by referring to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS For a detailed description of a preferred embodiment of the present invention, reference will now be made to the accompanying drawings, which form a part of the specification, and wherein:

Figure 1 is a cross-sectional view of a connector connecting two lengths of composite tubing;

Figure 2 is a cross sectional view of the male housing of the connector; Figure 3 is a cross-sectional view of the female housing of the connector;

Figure 4 is a cross-sectional view of the clamping sub-assembly of the connector; Figure 5 is a cross-sectional view of the female end piece of the connector; Figure 6 is a cross-sectional view of the male end piece of the connector; Figure 7 is a cross-sectional view of a split ring wedge. DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention is susceptible to embodiments of different forms. There are shown in the drawings, and herein will be described in detail, specific embodiments of the present invention with the understanding that the present disclosure is to be considered an exemplification of the principles of the invention, and is not intended to limit the invention to that illustrated and described herein.

The coiled tubing connector of the present invention includes a female and a male housing which join together to create the coiled tubing connection, A rotating ring on the male housing includes threads that engage corresponding threads on the female housing. Splines on the male housing also align with corresponding grooves on the female housing. The female and male housings each attach to end portions of coiled tubing through a clamp connection. Passageways or conduits within the female and male housings also allow electrical conductors embedded within each piece of coiled tubing to pass to ring contacts. Ring contacts on both the female and male housings also align when the housings are connected so as to allow electrical energy or signals to pass from one length of coiled tubing to the next.

Referring initially to Figure 1, there is shown one preferred embodiment of a connector 10 for connecting adjacent lengths 12, 14 of composite coiled tubing. The connector 10 comprises a male housing 20 and female housing 40. Referring now to Figure 2, the male housing 20 is generally in the form of a hollow cylinder. Moving generally from right to left in Figure 2, several features of the male housing are shown. Splines 28 are machined on or affixed onto an exterior edge of said male housing. An inner electrical contact 50 is also positioned on male housing 20. Inner electrical contact 50 is generally cylindrical in shape and includes both electrical contacts or rings 51 and wiper seals 52. Inner electrical contact 50 generally rests on the outer radius of male housing 20. Contact rings 51 are composed of any electrical conductor, and wiper seals 52 are composed of an electrical insulator.

Still referring to Figure 2, rotating ring 27 is positioned on male housing 20. Rotating ring 27 rotates freely around the barrel of male housing 20; however rotating ring 27 does not slide axially along the length of male housing 20. Rotating ring 27 is prevented from sliding along the length of male housing 20 by a lock ring 30 and may be prevented by conventional mechanical devices such as splines or stops. Rotating ring 27 also includes threads 31 on its exterior surface. Another feature of male housing 20 and rotating ring 27 is the presence of seals 29.

In the preferred embodiment of this invention, seals 29 are positioned on the surfaces of the male housing 20 and the rotating ring 27, respectively. However, the seals could also be positioned on female housing 40. The seals themselves are composed of an elastomeric material that will allow a compression seal to form against the hydraulic pressures encountered in the well. As shown, seals 29 may be positioned into grooves, recesses or rings positioned on the male housing 20 and rotating ring 27.

Referring now to Figure 3, female housing 40 is shown. Like male housing 20, the female housing 40 is also generally cylindrical in form. Female housing 40 includes slots or grooves 48 and receiving threads 41. Female housing 40 also has sealing surfaces 49 and outer electrical contact 60, both positioned on the internal diameter of female housing 40.

Outer electrical contact 60 is generally cylindrical in shape and includes outer electrical plates or rings 61. In a preferred embodiment, the outer electrical contact 60 contains an outer electrical ring 61 for each conductor on the inner electrical contact 50. Contact rings 61 may be composed of any conducting material. Outer electrical rings 61 are not separated by wiper seals but by a plastic insulator, not shown. Outer electrical contact 60 is positioned on the inner radius of female housing 40. Electrical rings 61 are connected to conductors embedded in composite tubing 14 that is joined to female housing 40. Both male housing 20 and female housing 40 share many common features. For ease of discussion, these common features are identified below together.

Referring again to Figures 2 and 3 there is shown a passage 71 and conforming seal 72. The conforming seals 72 are composed of an elastomeric material that will allow a compression seal to form under hydraulic pressure.

Both male and female housings include axial passageways 73. These passageways are hollows or grooves, approximately of the diameter or clearance of an electrical wire. The passageways may take any of several shapes depending on the ultimate shape of the connector 10 and the chosen method of manufacture. In a preferred embodiment, the male housing 20, female housing 40, and rotating ring

27 have a plurality of apertures 32, 34, and 42 drilled into each member.

Both male housing 20 and female housing 40 include an outer conical housing 43 and inner skirt 44. Encircling inner skirt 44 on both male and female housings is split ring wedge 45. In a preferred embodiment, the outer diameter of split ring wedge 45 is straight and the inner diameter is tapered. The conical housing 43 has a straight outer diameter and a tapered inner diameter. The inner skirt 44 has a straight inner diameter and a tapered outer diameter. The split ring wedge 45 itself is manufactured from a material that shows strength at high stress and yet is relatively flexible. Beryllium copper has been used as a suitable material. The other components of both the female and male housing 40, 20 are constructed of any high strength material, such as steel, and preferably of a material that will resist corrosion.

Referring still to Figure 2 and 3 there is shown a transition 53, 54 in the internal diameter of male and female housings 20, 40.

In a preferred embodiment the inner electrical contact 50 and outer electrical contact 60 each have four contact plates or rings 51, 61. This number is selected as it corresponds to the number of conductors disposed in the typical coiled tubing 12, 14 in use. A different number of contact rings may be used. Both inner electrical contact 50 and outer electrical contact 60 may contain wiper seals such as seals 52. Wiper seals, formed of an elastomeric insulating material, create ridge-like separations between electrical contacts 51, 61. In a preferred embodiment wiper seals are only present on inner electrical contact 50 and not on outer electrical contact 60.

Also shown on Figures 2 and 3 are caps 36, 46 positioned on the male and female housings. These caps are not part of the assembled connector; however, they are attached to each housing during manufacturing to allow for handling and to prevent foreign matter from entering and possibly damaging the housings. In a preferred embodiment, the structure of both the male and the female housings 20, 40 may consist of separate parts that assemble into the final housing.

Referring now to Figure 4, a clamping sub-assembly 80 includes pieces of both the male and female housing and may be converted into either a male housing or a female housing by the assembly of additional parts. A skirt or liner support 81 is shown as a separate piece of the clamping sub-assembly 80. The liner support 81 is joined to the body of the clamping sub-assembly 80 through a suitable fastener such as a threaded connection or a pressed fitting. oining the clamping sub-assembly 80 to the liner support 81 are metal and plastic seals 82, 83, which themselves contain o-ring elastomeric seals 84. Figure 4 also shows a stop clamping ring 85 forming a separate part of the clamping sub-assembly 80. The stop clamping ring 85 forms an underlying structure upon which the outer conical housing 43, inner skirt 44, and split ring 45 are mounted.

Referring again to Figure 3, the clamping sub-assembly 80 further includes a plug 86 and adapter 87. Figure 3 also shows the clamping sub-assembly 80 further converted to the final female housing 40 through the addition of a female retainer sleeve 88 and female end piece 89. Figures 5 and 6 provide a detailed views of female retainer sleeve 88 and female end piece 89. Similarly, Figure 2 shows the clamping sub-assembly 80 converted into the male housing 20 through the addition of male end-piece 90 and rotating ring 27. The assembly of male housing 20 and female housing 40 creates the complete connector 10. Assembly of the male and female housings 20, 40 begins by aligning splines 28 located on the male housing 20 with the grooves 48 located on female housing 40. The female housing 40 is constructed with an inner diameter at one end, and the male housing is constructed with a reciprocal outer diameter, so that said male housing 20 may sealingly engage the female housing 40 in assembly.

When male housing 20 is connected to female housing 40, the threads 31 of rotating ring 27 engage the receiving threads 41 of female housing 40. Rotating ring 27 is then rotated so that threads 31 threadingly lock into receiving threads 41. Because rotating ring 27 freely rotates around the barrel 33 of male housing 20, the male housing 20 and female housing 40 do not themselves rotate upon the rotation of rotating ring 27. In this way, the male housing 20 may be firmly connected to the female housing 40 without imparting any twisting or torsional forces on the lengths of composite coiled tubing 12, 14 that are connected to male and female housings 20, 40. The plurality of apertures 31, 34 and 42 drilled into male housing 20, female housing 40, and rotating ring 27 assist in the connection of male housing 20 to female housing 40. Apertures 32, 34, and 42 in housing 20, ring 27 and housing 40, respectively, include projections from a connection tool (not shown) used to join the lengths 12, 14 of composite coiled tubing at the job site. The engagement allows the connection tool to engage, grasp or manipulate male housing 20, female housing 40, and rotating ring 27. During the assembly step, male housing 20 and female housing 40 are held stationary through use of apertures 32 and 42. At the same time the rotating ring 27 is rotated, through use of apertures 34, so as to join male housing 20 to female housing 40 as described above. Although apertures 32, 34, 42 have been described for engaging a connection tool, it will be apparent that other methods may be used. For example the apertures 32, 34, 42 may have various shapes. Likewise, instead of apertures, flats may be machined onto these members so as to allow wrenching tools to apply forces at these flats. In addition, chains or frictional tools may be applied to non-machined, smooth surfaces on male housing 20, female housing 40, and rotating ring 27 to apply the necessary gripping forces.

Seals 29 present on male housing 20 and rotating ring 27 are compressed onto corresponding sealing surfaces -49 on female housing 40 when male housing 20 is joined to female housing 40. In this manner the assembled connector 10 provides a fluid-tight seal that isolates fluids in the interior of the coiled tubing 12, 14 from the fluids around the outside of the coiled tubing 12, 14. Seals 29, 37 are placed on male housing 20 and rotating ring 27 for ease of manufacturing and could be equally positioned on female housing 40.

Attachment of the coiled tubing 12, 14 to the connector 10 is similar for both the male and female housings 10, 40. Referring again to Figures 2 and 3, there is shown lengths 12, 14 of composite tubing joined to male housing 20 and female housing 40. Male and female housing 20, 40 include an outer conical housing 43 and inner skirt 44. Encircling inner skirt 44 is split ring wedge 45. As can be seen, the end of composite tubing 14 is fitted around split ring wedge 45 and inside the inner radius of outer conical housing 43. As the outer conical housing 43 is drawn against the inner skirt 44, composite tubing 14 is compressively clamped in place against ring wedge 45. Additionally, split ring wedge 45 will be drawn tightly against the composite tubing 14 as the outer conical housing 43 is compressed against inner skirt 44.

In practice it may be advantageous to affix male housing 20 and female housing 40 to the ends of the composite coiled tubing at the factory, job site, or other work site. In that way lengths of coiled tubing that are preassembled with connector ends may then be shipped to the job site. At the job site the male and female portions of the connector may then be joined as needed.

Frictional forces hold the conical housing 43, inner skirt 44, and composite tubing together. In practice clamping forces are achieved such that the strength of the tubing-to- housing bond exceeds the strength of the coiled tubing itself.

When assembling the conical housing 43, inner skirt 44, and split ring wedge 45 to the composite tubing, it is beneficial to cut a taper 56 on the end of the composite tubing 12, 14. The tapers on the conical housing 43, inner skirt 44, split ring wedge 45, and the composite tubing 12, 14 are preferably of approximately the same degree in order to achieve a firm connection. A preferred degree of taper is approximately 1 V_ degrees.

Referring now to Figure 7, there is shown a preferred split ring wedge 45 that is generally cylindrical in shape. The wall thickness of split ring wedge 45 tapers from one end to the other. Further the degree of taper is such that when positioned around inner skirt 44, the inner surface 47 of split ring wedge 45 will bear at all points of surface 47 against inner skirt 44. The outer surface 49 of split ring wedge 45 will also press at all points against composite tubing 14 so as to clamp composite tubing 14 against the inner bearing surface of outer conical housing 43. Split ring wedge 45 does not form a continuous cylinder shape, however. A split 46 runs along the length of split ring wedge 45. The split 46 allows split ring wedge 45 to compress as outer conical housing 43 compresses against inner skirt 44. An identical method is used to join the composite tubing to the male housing 20 as that just described with respect to the joining the composite tubing to the female housing 40. Thus, the composite tubing is likewise joined to the male housing 20 through a friction joint including an outer conical housing 36, an inner skirt 37, and a split ring wedge 38. As previously stated, when the coiled tubing lengths 12, 14 are connected to female and male housings 40, 20, it is advantageous to taper the end of the coiled tubing that is to be connected. When forming the taper on the end of the coiled tubing, it is also preferred to strip out a working length of the embedded conductors. The conductors are first passed through axial passageways 73, shaped into the female and male housings 40, 20, that allow the conductor to pass from the end of the coiled tubing to the inner electrical contact 50 and outer electrical contact 60.

In a preferred embodiment, the conductors from the composite tubing 12, 14 are not connected directly to the inner electrical contact 50 or the outer electrical contact 60. Rather the contact plates or rings 51, 61 of both the inner electrical contact 50 and outer electrical contact 60 are manufactured with separate conductor leads (not shown). These leads are themselves drawn through passageways 73 in male and female housings 20, 40. During assembly the conductors originating from the coiled tubing are connected or soldered to the lead conductors originating from the contact plates 51, 61. This conductor-to-conductor connection is then covered by a pressure boot (not shown). A pressure boot is essentially an elastomeric seal that keeps out fluids from the conductor-to-conductor contact by pressure means. Pressure boots are known in the industry.

Inner electrical contact 50 and outer electrical contact 60 are positioned on male and female housings 20, 40, respectively, so that when male housing 20 is joined to female housing 40 to form connector 10, the electrical rings 51 of inner electrical contact 50 match up and make electrical contact with outer electrical rings 61 disposed on outer electrical contact 60. Either or both inner electrical contact 50 and outer electrical contact 60 may have a spring back or biasing members that act to hold inner electrical contact 50 and outer electrical contact 60 in firm contact with each other.

Each contact ring 51, 61 is mounted radially and is positioned to mate with a corresponding ring 51, 61. There is an advantage to having the rings 51, 61 mounted in a radial position in that the electrical contact does not then depend on the relative radial positions of male and female housings 20, 40. Rather, it is the relative axial position of both male and female housings 20, 40 that assures the proper alignment and contact between each contact ring 51, 61. Thus, the inner and outer contacts 51, 61 are positioned to align when in the axial position that is achieved when male and female housings 20, 40 are completely connected. There is no need to position the housings 20, 40 in a particular radial position in order to achieve an electrical contact. The wiper seals 52 found on the inner electrical contact 50 serve a function during assembly. The dimensions of the male and female housing diameters are such that during their assembly into the connector 10, wiper seals 52 are partially compressed. Further, assembly of male and female housings 20, 40 drag the partially compressed wiper seals 52 across the electrical contacts rings 61 of outer electrical contact 60. This dragging action serves to wipe the contact rings 61 clean of any contaminating material, thus assuring a clean mating surface for inner and outer electrical contacts 50, 60.

In operation, once male housing 20 is firmly joined to female housing 40, the assembled connector 10 passes forces of tension and compression up and down the coiled tubing string. In this way successive lengths 12, 14 of coiled tubing may be drawn into the well or extracted from the well. When splines 28 are engaged with grooves 48, torsional forces in one length of tubing are passed to the connected length of another tubing. Additionally, the alignment of splines 28 and grooves 48 allows for a precise rotational alignment of male housing 20 and female housing 40. .

The assembled connector 10 also provides a sealed passage for the fluids that are conducted in the coiled tubing. During assembly, seals 29 sealingly engage with receiving surfaces 49. Thus the fluids can pass up and down successive lengths 12, 14 of coiled tubing, through the connector 10, without contacting the materials on the exterior of the coiled tubing.

Referring again to Figure 1, transitions 53, 54 in the internal diameter of male housing 20 and female housing 40 respectively of the connector 10 direct the fluid as the fluid passes from one length of the coiled tubing and into the connector 10. The fluid encounters a gradual tapered decrease in the internal diameter of the connector 10 as it enters and as the fluid passes out of the connector 10 to another length of the coiled tubing, the internal diameter gradually increases. Thus the taper assists with fluid flow. The gradual taper in the connector 10 reduces turbulence in the flowing fluid. The reduced fluid turbulence serves the added benefit of reducing harm or damage to the interior of the connector 10.

Referring again to Figures 2 and 4, inner sldrt 81 extends for some distance along the inner diameter of the coiled tubing. The purpose of the extended length of the inner sldrt 81 is to provide a support on which the coiled tubing can rest. The support will prevent the coiled tubing from over flexing and breaking, at the point where the coiled tubing is attached to female housing 40. The length of the inner skirt 44 is preferably from between 1 to 20 times the diameter of the coiled tubing. Referring again to Figures 2, 3, and 4, there is shown a passage 71 and conforming seal 72. Passage 71 allows fluid communication between the interior of composite tubing 12, 14 and conforming seal 72. Conforming seal 72 is made of a deformable material such as rubber or an elastomer. Thus, when fluid in the interior of the coiled tubing flows into passage 71, pressure in the fluid will fill conforming seal 72. In this manner conforming seal 72 acts to seal coiled tubing against the male and female housings 20, 40.

Electrical signals are transmitted through the conductors embedded in coiled tubing 12, 14. These conductors pass through passageways 73 in male housing 20 until they make electrical contact with electrical contact rings 51 of inner electrical contact 50. At this point, the electrical signals, or electrical energy if the cables are energy-carrying conductors, pass from inner electrical contact 50 to outer electrical contact 60. The signals are further transmitted through the female housing 40 through the passageways 73 in the female housing 40 and on into the cables of the coiled tubing 14 that is attached to the female housing 40. Wiper seals 52 also serve to isolate and insulate the contact rings 61 from the fluids and other materials that are either outside the composite tubing 12, 14, or being conducted inside the composite tubing 12, 14. Thus wiper seals 52 protect the contact rings 51, 61 from chemical corrosion and physical decay. By insulating the metal plates or rings 51, 61, wiper seals 52 also assure that an uninterrupted contact is maintained between the conducting conductors of the upper and lower lengths 12, 14 of the coiled tubing. Finally wiper seals 52 also act to insulate individual electrical rings 51, 61 from each other. Thus no signal interference or power loss occurs as a result of crossed or fouled connections among the electrical plates.

While a preferred embodiment of the invention has been shown and described, modifications thereof can be made by one skilled in the art without departing from the spirit or teaching of this invention. The embodiments described herein are exemplary only and are not limiting. Many variations and modifications of the system and apparatus are possible and are within the scope of the invention. Accordingly, the scope of protection is not limited to the embodiments described herein, but is only limited by the claims that follow, the scope of which shall include all equivalents of the subject matter of the claims.

Claims

CLAIMS We claim:

1. A connector for joining lengths of composite coiled tubing comprising: a male housing that may be affixed to one end of a first length of composite coiled tubing and shaped so as to permit fluids from the composite coiled tubing to pass through said male housing; a female housing that may be affixed to one end of a second length of composite coiled tubing, shaped so as to permit fluids from the composite coiled tubing to pass through said female housing, and also formed to sealingly engage said male housing; a rotating ring, rotatably mounted on said male housing, firmly held in lateral position on said male housing, and formed to sealingly engage said female housing; a first threading radially disposed on said rotating ring; a second threading radially disposed on said female housing and formed so that rotating said rotating ring engages said first threading with said second threading, thereby sealingly engaging said male housing and said female housing; and sealing members radially disposed on said male housing and said rotating ring, that sealingly engage said male housing and said female housing.

2. The connector as recited in claim 1 further comprising: at least one spline disposed on said male housing; at least one groove disposed on said female housing and formed to tightly engage said spline.

3. The connector as recited in claim 1 further comprising: a plurality of splines disposed on said male housing; a plurality of grooves disposed on said female housing and formed to tightly engage said splines when said male housing and said female housing are sealingly engaged.

4. The connector as recited in claim 1 wherein said male housing, said female housing, and said rotating ring are formed so as to allow tools to manipulate said male housing, said female housing, and said rotating ring.

5. The connector as recited in claim 1 wherein said male housing, said female housing, and said rotating ring are formed with voids that permit manipulation of said male housing, said female housing and said rotating ring by work tools.

6. The connector as recited in claim 1 further comprising seals, radially disposed on said male housing and said rotating ring, and formed so as to sealingly engage said male housing and rotating ring with said female housing.

7. The connector as recited in claim 1 wherein said female housing is formed with annular spaces that sealingly engage said seals.

8. A connector according to claim 1 further comprising an inner skirt on both male housing and said female housing wherein said inner sldrt extends along the interior of the composite coiled tubing for a length of between one to twenty times the interior diameter of the coiled tubing.

9. A connector according to claim 1 wherein said male housing and said female housing both have inner diameters that taper.

10. A connector for joining lengths of composite coiled tubing comprising a male and female housing wherein said male and female housing each further comprise: a split ring fitting inside the inner diameter of one end of a length of coiled tubing; an inner skirt formed to fit securely in the inner diameter of said split ring; and a conical housing formed to fit over the end of coiled tubing that compresses said end of coiled tubing against said split ring and against inner sldrt.

11. The female housing as recited in claim 10 wherein said split ring has a tapered inner diameter and a straight outer diameter, wherein said inner sldrt has a tapered outer diameter and a constant inner diameter; and wherein said conical housing has a straight outer diameter and a tapered inner diameter.

12. The female housing according to claim 10 wherein the taper of said split ring, said inner skirt, and said conical housing is about one and a half degrees.

13. A connector for establishing an electrical connection between a first and second section of composite coiled tubing having a embedded wiring comprising: a male housing affixed to the first section of composite coiled tubing and having conduits formed to allow the wires embedded in the composite coiled tubing to pass through said conduits; a female housing affixed to the second section of composite coiled tubing and having conduits formed to allow the wires of the composite coiled tubing to pass through said conduits; a first electrical contact ring disposed on said male housing, said first electrical contact ring comprising at least one contact plate circumferentially embedded in said first electrical contact ring and further comprising a plurality of wiper seals, and said first electrical contact ring also having a conduit to allow wire from the first composite coiled tubing to connect to said contact plate; and a second electrical contact ring disposed on said female housing, said second electrical contact ring comprising at least one matching plate circumferentially embedded in said second electrical contact ring, and said electrical contact ring also having a conduit to allow wire from the second composite coiled tubing to connect to said matching plate, and said electrical contact positioned so that said contact plate of said first electrical contact ring firmly engages said matching plate of said second electrical contact ring when said male housing is joined to said female housing.

14. A connector according to claim 13 wherein said first electrical contact ring disposed on said male housing comprises four contact plates and wherein said second electrical contact ring disposed on said female housing comprises four matching plates.

15. A connector according to claim 13 further comprising biasing means to bias said contact plates against said matching plates when said male housing is joined to said female housing.

16. A connector for establishing an electrical connection between a first and second section of composite coiled tubing having embedded electrical wiring comprising: a male housing affixed to the first section of composite coiled tubing; a ring disposed on said male housing with a circumferentially embedded contact in said ring; said contact having an exposed surface; said ring having a conductor for receiving the wire from the first section of composite coiled tubing; and a female housing affixed to the second section of composite coiled tubing.

17. A connector for joining lengths of composite coiled tubing comprising: a male housing that may be affixed to one end of a first length of composite coiled tubing; said mail housing having a hollow shape so as to permit fluids in the composite coiled tubing to pass through said male housing; a female housing that may be affixed to one end of a second length of composite coiled tubing; said female housing having a hollow shape so as to permit fluids in the composite coiled tubing to pass through said female housing; said female housing also formed to sealingly engage said male housing, also having receiving threads to locate on an inner circumference of said female housing; a rotating ring, rotatably mounted on said male housing, having engaging threads located on said rotating ring; said engaging threads placed so as to engage said receiving threads on said female housing, whereby rotating said rotating ring sealingly engages said male housing to said female housing; first electrical contact disposed on said male housing comprising a plurality of contact rings and wiper seals, said contact rings having wire leads that may be joined to wires embedded in length of composite coiled tubing that may be affixed to said male housing; a second electrical contact disposed on the inner circumference of said female housing comprising a plurality of contact rings, said contact rings having wire leads that may be joined to wires embedded in a length of composite coiled tubing that may be affixed to said female housing; and biasing means located under said contact rings located on said male housing, said biasing means acting to firmly engage said contact rings of said first electrical contact against said contact rings of said second electrical contact when said mail housing is joined to said female housing.

18. A connector for mechanically joining and hydraulically sealing a first and second section of composite coiled tubing comprising: a male housing having a hollow shape so as to permit fluids in the composite coiled tubing to pass through said male housing; means for affixing said male housing to one and a first length of composite coiled tubing; a female housing having a hollow shape so as to permit fluids in the composite coiled tubing to pass through said female housing; means for affixing said female housing to one end of a second length of composite coiled tubing; a rotating ring rotatably mounted on said male housing and being sealing means disposed on said rotating ring; a first thread means disposed on said.rotating ring; and a second thread means disposed on said female housing so that rotating said rotating ring engages said first thread means with said second threads means, thereby sealingly engaging said male housing to said female housing.