Patent Abstract:
Coiled tubing with a secured conduit and a method for manufacturing same. A slickline held by a retainer is introduced to the coiled tubing manufacturing process by attaching the retainer and slickline to a metal plate, prior to the metal plate being welded into a tubular. The slickline is unaffected by the welding and heat treatment process or processes. To install the conduit into the coiled tubing, the coiled tubing is unrolled from the reel, the conduit is attached to an end of the slickline and the other end of the slickline pulled to fish the conduit through the coiled tubing, resulting in conduit held within the retainer inside the coiled tubing. In embodiments where a slickline is not used, the conduit can be pumped into the retainer or dropped therein by gravity when the coiled tubing is hung in a wellbore. Alternatively, a heat resistant conduit may be secured within the coiled tubing by attachment directly to the coiled tubing or held therein by a retainer.

Full Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a divisional application of U.S. patent application Ser. No. 12/113,069, filed Apr. 30, 2008 claiming priority of U.S. Patent Application No. 60/914,830, filed Apr. 30, 2007, the entirety of which is incorporated herein by reference. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates generally to coiled tubing. More particularly, the present invention relates to coiled tubing with a conduit secured within the coiled tubing. 
     BACKGROUND OF THE INVENTION 
     Coiled tubing (CT) (also referred to as endless tubing or continuous tubing) is frequently used for down hole well completions, operations, servicing, etc. 
     Coiled tubing is typically manufactured from flat plate which is formed into a tubular, longitudinally (or otherwise) welded, heat treated, pressure tested, and rolled into a coil. Heat treating may include annealing. 
     Some down hole operations benefit from being able to convey electrical power from surface to the bottom hole assembly (BHA) or to communicate signals from surface to the BHA or from the BHA to surface. Wireline is frequently used for these electrical power (may also be referred to as electric line) or communication signals. Examples include directional control or measurement tools, pressure/temperature and other sensors, packers etc. 
     Wireline can be loosely inserted into finished coiled tubing, for example, by uncoiling the coiled tubing and then pumping a steel cable through the coiled tubing using a cup and then using the steel cable to pull (fish) the wireline through the coiled tubing and recoiling the coiled tubing, by uncoiling the coiled tubing into a well bore and using gravity to drop the wireline into the CT (U.S. Pat. No. 6,148,925 to Moore), or by pumping the wireline into the coiled tubing with the coiled tubing on the reel (U.S. Pat. No. 5,699,996 and U.S. Pat. No. 5,429,194). 
     Wireline can instead be inserted into coiled tubing during the manufacturing process, for example, by using a spring guide to position the electrical conductor to the side opposite the welding operation and providing cooling to reduce the heat damage to the electrical conductor (U.S. Pat. No. 5,122,209 to Moore et al.), or by using a cable placement tube which conducts coolant along the electrical conductor to prevent heat degradation (the cable placement tube extending past the welding operation and the subsequent heat treating operation) (U.S. Pat. No. 5,121,872 to Legget). 
     The unrestrained wireline in coiled tubing has a number of problems, including, when the coiled tubing with wireline combination is roiled onto a reel or unrolled from the reel, the difference in radius of the unrestrained wireline results in slack and length problems, during operations, fluid flow past the unrestrained wireline results in slack problems, birdcaging, and in deviated or horizontal wells, the difference in radius results in slack and length problems. 
     It is, therefore, desirable to provide coiled tubing with wireline secured within. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to obviate or mitigate at least one disadvantage of previous methods and apparatus for providing and using coiled tubing with wireline. 
     The present invention provides coiled tubing with wireline secured within. Due to the common requirement that coiled tubing be heat treated, the wireline may be installed directly where it is heat resistant or is installed in a configuration that it can withstand the heat exposure during heat treatment of the coiled tubing, or may be installed indirectly (with slickline installed first to be replaced with wireline) where the wireline is not heat resistant or is not installed in a configuration where it would normally withstand the heat exposure during heat treatment. The wireline may be attached or otherwise secured to the coiled tubing by adhesive or other bond, or may be attached by retention in a retainer or a chamber. 
     In one aspect the present invention provides a method of providing coiled tubing from a strip of metal flat plate including attaching a retainer to the flat plate, installing a slickline into the retainer, forming the flat plate into a slit tubular having a longitudinal joint, and welding the longitudinal joint to form coiled tubing. 
     In one embodiment the retainer is attached and the slickline installed substantially continuously. In one embodiment the retainer is attached and the slickline installed substantially simultaneously. In one embodiment the slickline is frictionally retained within the retainer. In one embodiment, the coiled tubing is subsequently heat treated, for example annealing. 
     In a further aspect the present invention provides a method of providing coiled tubing with a retained conduit including providing coiled tubing with a slickline retainer having a retainer affixed to the inside of the coiled tubing for releasably retaining the slickline in the welded tubular, and fishing a conduit through the coiled tubing using the slickline. 
     In one embodiment an end of the conduit is attached to an end of the slickline and the slickline pulled from the coiled tubing leaving the conduit within the retainer in the coiled tubing. The conduit is preferably selected from the group of wireline, electric line, fiber optic line, or tubing. In one embodiment, the coiled tubing is unrolled from a reel before fishing, and rolled onto a reel after fishing. 
     In a further aspect, the present invention provides a method of performing a down hole operation including providing coiled tubing with slickline axially movably retained within a retainer, fishing conduit through the coiled tubing using the slickline, connecting a bottom hole assembly to the coiled tubing and conduit, and performing the down hole operation. 
     The conduit is preferably selected from the group of wireline, electric line, fiber optic line, or tubing. 
     In a further aspect the present invention provides coiled tubing with a retainer affixed to the inside of the coiled tubing for releasably retaining slickline in the coiled tubing. 
     In one embodiment, the slickline is adapted to be pulled from the coiled tubing to fish a conduit retained within the retainer. The conduit is preferably selected from the group of wireline, electric line, fiber optic line, or tubing. 
     In a further aspect, the present invention provides a method of providing coiled tubing from a strip of metal flat plate including attaching a heat resistant wireline to the flat plate, forming the flat plate into a slit tubular having a longitudinal joint, and welding the longitudinal joint to form coiled tubing. 
     In one embodiment, the method further includes heat treating the coiled tubing at a heat treating temperature for a heat treating time, the heat resistant wireline adapted to withstand heat treating the coiled tubing. 
     In a further aspect, the present invention provides a method of providing coiled tubing from a strip of metal flat plate including attaching a retainer to the flat plate, installing a heat resistant wireline into the retainer, forming the flat plate into a slit tubular having a longitudinal joint, and welding the longitudinal joint to form. 
     In one embodiment, the method further includes heat treating the coiled tubing at a heat treating temperature for a heat treating time, the heat resistant wireline adapted to withstand heat treating the coiled tubing. 
     Other aspects and features of the present invention will become apparent to those ordinarily skilled in the art upon review of the following description of specific embodiments of the invention in conjunction with the accompanying figures. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Embodiments of the present invention will now be described, by way of example only with reference to the attached Figures, wherein: 
         FIGS. 1A to 1E  are simplified schematics depicting the steps in a prior art method of making longitudinally welded coiled tubing, more particularly, 
         FIG. 1A  illustrates a strip of a flat metal plate for forming a coiled tubing, 
         FIG. 1B  illustrates a slit tubular formed from the plate of  FIG. 1A , the slit tubular having a longitudinal joint, 
         FIG. 1C  illustrates sealing the longitudinal joint in the tubular of  FIG. 1B , 
         FIG. 1D  illustrates subjecting the tubular of  FIG. 1C  to heat treatment, and 
         FIG. 1E  illustrates the tubular of  FIG. 1D  undergoing non-destructive examination; 
         FIGS. 2A to 2E  are simplified schematics depicting a method of making coiled tubing in accordance with the present invention, more particularly, 
         FIG. 2A  illustrates a strip of a flat metal plate, 
         FIG. 2A.5  illustrates attachment of a retainer to the plate of  FIG. 2A , 
         FIG. 2B  illustrates a slit tubular formed from the plate of  FIG. 2A.5 , the slit tubular having a longitudinal joint, 
         FIG. 2C  illustrates sealing the longitudinal joint in the tubular of  FIG. 2B , 
         FIG. 2D  illustrates subjecting the tubular of  FIG. 2C  to heat treatment, and 
         FIG. 2E  illustrates the tubular of  FIG. 2D  undergoing non-destructive examination; 
         FIGS. 3A to 3C  depict two manufacturing configurations of the present invention, more particularly, 
         FIG. 3A  shows a manufacturing configuration where rolls of the flat plate, slickline and the retainer are joined prior to forming the slit tubular, 
         FIG. 3B  shows a manufacturing configuration where rolls of the flat plate and the retainer are joined prior to forming the slit tubular and the wireline is installed after the heat treatment, and 
         FIG. 3C  shows a manufacturing configuration where rolls of the flat plate and the wireline are joined prior to forming the slit tubular; 
         FIGS. 4A to 4G  are simplified depictions of a number of alternate embodiments of the present invention, more particularly, 
         FIG. 4A  shows an embodiment where the retainer is welded to the flat metal plate and the retainer extends along a select portion of the slickline or wireline, 
         FIG. 4B  shows an embodiment where the retainer is sealingly attached to the flat metal plate by spot welding for forming a pressure chamber, 
         FIG. 4C  shows an embodiment where the retainer is sealingly attached to the flat metal plate by continuous welding for forming a pressure chamber, 
         FIG. 4D  shows an embodiment where an airspace is provided between the slickline or wireline and the flat plate, the figure also identifies a curved portion of the retainer, 
         FIG. 4E  shows an embodiment where an airspace is provided between the slickline or wireline and the flat plate, the figure also identifies the sealed pressure chamber being formed by the retainer, 
         FIG. 4F  shows an embodiment where wireline is connected or secured to the flat plate without the retainer, and 
         FIG. 4G  shows an embodiment where a plurality of runs of slickline or wireline is provided; 
         FIGS. 5A-5F  are simplified depictions of a method of installing a conduit into a coiled tubing in accordance with the present invention, more particularly, 
         FIG. 5A  illustrates a coiled tubing comprising a slickline retained in a retainer, 
         FIG. 5B  illustrates the coiled tubing of  FIG. 5A  in an uncoiled position, 
         FIG. 5C  illustrates attachment of a conduit to one end of the slickline, 
         FIG. 5D  illustrates pulling of the slickline from the coiled tubing for leaving the conduit of  FIG. 5C  within the retainer in the coiled tubing, 
         FIG. 5E  illustrates completion of the step shown in  FIG. 5D  leaving the conduit within the retainer in the coiled tubing, and 
         FIG. 5F  illustrates the coiled tubing comprising the slickline retained in the retainer; 
         FIG. 6  is a semi-transparent isometric view of coiled tubing with retainer of the present invention; 
         FIG. 7  is a magnified semi-transparent isometric view of the coiled tubing with retainer of  FIG. 6 ; 
         FIG. 8  is a magnified semi-transparent isometric view of the coiled tubing with retainer of  FIG. 6 ; 
         FIG. 9  is a magnified semi-transparent isometric view of the coiled tubing with retainer of  FIG. 6 ; 
         FIG. 10  is an isometric view of a retainer of the present invention; 
         FIG. 11A  is a magnified isometric view of the retainer of  FIG. 10 ; 
         FIG. 11B  is an isometric view of the retainer of  FIG. 10  wherein the cavity is a sealed cavity; and 
         FIG. 12  is a cross-section view of the retainer of  FIG. 10 . 
     
    
    
     DETAILED DESCRIPTION 
     Generally, the present invention provides a method and system for providing coiled tubing or other tubular with secured wireline. 
     Referring to  FIGS. 1A to 1E , the typical (simplified) steps in manufacturing coiled tubing include forming flat plate  10  (e.g. skelp) ( FIG. 1A ) into a slit tubular  20  forming a longitudinal joint  30  ( FIG. 1B ), sealing the longitudinal joint  30  ( FIG. 1C ), for example by application of a weld  40  to form a tubular  50 . In other words, steps in manufacturing include forming the flat plate into a slit tubular having a longitudinal joint and welding the longitudinal joint to form coiled tubing. The tubular  50  may be, for example, conventional jointed tubing or coiled tubing. The tubular  50  may then be passed through heat treatment  60  ( FIG. 1D ), for example annealing or other treatment. The tubular  50  may undergo non-destructive examination and/or testing  70  ( FIG. 1E ). In the case of coiled tubing, the length of the tubular  50  is then coiled onto a reel. 
     Referring to  FIGS. 2A to 2E , a retainer  12  is attached to the flat plate  10  ( FIG. 2A ) prior to application of the weld  40  to the longitudinal joint  30 . As depicted in  FIG. 2A.5 , the retainer  12  is preferably attached while the flat plate  10  is flat or substantially flat prior to forming, but one skilled in the art would recognize that the plate may be at least partially formed into the slit tubular  20  prior to the attachment of the retainer  12 . 
     The retainer  12  is adapted to retain a wire rope or cable or metallic wire or other flexible member, preferably the retainer  12  is adapted to retain a small diameter steel member known as slick wireline or slickline  14 . Alternatively, the retainer  12  is adapted to retain a heat resistant wireline  130 . 
     Referring to  FIGS. 3A to 3C , representative manufacturing configurations are depicted. In  FIG. 3A , rolls of flat plate  10 , slickline  14 , and retainer  12  (either as flat plate pre-formed into a shaped retainer) may be joined (for example welding) prior to forming the slit tubular  20 . The slickline is replaced with the conduit  22  such as wireline  26  after heat treatment  60 . 
     In  FIG. 3B , rolls of flat plate  10  and retainer  12  (either as flat plate pre-formed into a shaped retainer) may be joined (for example welding) prior to forming the slit tubular  20 . In this configuration, the wireline  26  may be installed into the retainer  12  after heat treatment  60 . 
     In  FIG. 3C , rolls of flat plate  10  and heat resistant wireline  130  are joined. Optionally, retainer  12  (either as flat plate or pre-formed into a shaped retainer) may also be joined (for example welding) prior to forming the slit tubular  20 . 
     The manufacturing of tubulars such as joints of conventional tubing or lengths of coiled tubing is preferably a continuous, or semi-continuous process, and preferably the slickline  14  or heat resistant wireline  130 , and optionally retainer  12  are introduced into that process at a velocity that is substantially equal to the velocity of the flat plate  10 . The retainer  12  may be preformed into a desired shape, or may be formed from flat plate proximate to or as the flat plate  10  is formed into the slit tubular  20 . 
     Referring to  FIGS. 4A to 4G , embodiments of the present invention are depicted. In one alternate embodiment heat resistant wireline  130  is retained within the retainer  12  rather than the slickline  14 . The heat resistant wireline  130  may be adapted to withstand the heat treatment  60 , which may be a relatively high temperature but only for a short period of time. In a further alternate embodiment and as shown in  FIG. 4F , the heat resistant wireline  130  is connected or secured to the flat plate  10  without a retainer  12 , for example by bonding, adhesive, glue or otherwise. The heat treatment  60  may form the bond, for example by thermally activated or cured adhesive or soldering. 
     In one embodiment and as shown in  FIGS. 4D and 4E , the heat resistant wireline  130  may be designed, by material selection, by insulation (air space  62 , ceramic etc.) to withstand the heat treatment  60 . The heat treatment  60  may include annealing at a suitable temperature and duration (for example 1200 degree F.-1400 degree F. for a duration of seconds). The air space  62  provides insulation between the heat resistant wireline  130  (or wireline  26 ) so that the heat treatment  60 , for example annealing by induction heating, treats the tubular  50 , but does not damage the wireline  26  or heat resistant wireline  130 . 
     As can be seen in  FIGS. 4F and 4G , the heat resistant conduit  130  is connected or secured to the flat plate  10  at a connection between the conduit  130  and the flat plate  10 . The connection can be continuous, or semi-continuous such as spot welding. 
     The retainer  12  is preferably attached to the flat plate  12  by welding but may be otherwise connected, for example by adhesive or integrally formed within the flat plate  12 . The retainer  12  may extend along select portions of the slickline  14  or may extend substantially continuously along the slickline  14 , forming a track or race  16 . The retainer  12  may be spot welded ( FIGS. 4A ,  4 B,  4 D,  4 E,  4 F and  4 G) with gaps between adjacent welds), tack welded, etc. to the flat plate  10  along the length of the retainer  12 , having a gap between welds to increase flexibility of the retainer  12  relative to the coiled tubing, or the retainer  12  may be fully welded or continuously welded to the flat plate  10  along the length of the retainer  12  ( FIGS. 4A ,  4 C,  4 D,  4 E,  4 F and  4 G). The retainer  12  may be made of a material similar or substantially the same as the flat plate  10  thus providing sufficient ductility without the need for gaps between welds. 
     In certain configurations, the retainer  12  may be continuously welded to the flat plate  10  along the length of the retainer thus forming a sealed pressure chamber  28  (for example, see  FIGS. 4C and 4E ). The slickline  14  or heat resistant wireline  130  may be installed within the pressure chamber  28  during forming of the slit tubular  20  prior to heat treatment  60 , or may be installed subsequently. 
     The slickline  14  is preferably retained by the geometry of the retainer  12 , such that the retainer  12  retains the slickline once the retainer  12  is attached to the flat plate  10 , the retainer  12  forming the track or race  16  for the slickline. Preferably, the slickline  14  Is inserted into the retainer  12  prior to the retainer  12  being attached to the plate. The slickline  14  is axially movable within the retainer  12  to provide for pulling the slickline  14  axially from the retainer  12  (see below) but the slickline  14  may be geometrically or otherwise movably retained within retainer  12 . 
     With the retainer  12  attached (and retaining the slickline  14 ) the coiled tubing is formed into the slit tubular  20 , and the weld  40  applied to seal the longitudinal joint  30  to form the tubular  50 . The tubular  50  may be, for example, conventional jointed tubing or coiled tubing. The tubular  50  may then be passed through heat treatment  60 , for example annealing or other treatment. The tubular  50  may undergo non-destructive examination and/or testing  70 . In the case of coiled tubing, the length of the tubular  50  is then coiled onto a reel. The flexible member (e.g. slickline  14 ) is substantially unaffected by the welding step and heat treatment step or steps etc. 
     The retainer  12  may optionally form a chamber  28  which may be a sealed (pressure retaining) chamber  28 . In which case the chamber  28  is empty (no slickline nor heat resistant wireline is installed during milling of the tubular  50 ), but wireline may be installed after, for example by pumping the wireline through the cavity or chamber  28  or by hanging the tubular  50  in a well and dropping the wireline into the chamber  28  by gravity. 
     The retainer  12  may optionally be made of or include non-metallic materials, such as fiberglass, plastic, or ceramic, and may be attached to the flat plate by appropriate means, such as adhesive, glue, fusion, solder, welding etc. 
     Referring to  FIGS. 5A to 5F , in embodiments where the slickline  14  is first installed and then replaced with the conduit  22 , the tubular  50  ( FIG. 5A , in this case coiled tubing) having the retainer  12  and the slickline  14  retained in the retainer  12  is uncoiled ( FIG. 5B ). A conduit  22  is attached to one end of the slickline  14  at attachment  24  ( FIG. 5C ), and the other end of the slickline  14  pulled to fish the conduit  22  through the retainer  12  such that the slickline  14  is removed from the retainer  12  and replaced with the conduit  22  ( FIGS. 5D and 5E ). The coiled tubing is then coiled back onto a reel ( FIG. 5F ). Alternatively, for shorter lengths, the coiled tubing does not have to be uncoiled and the conduit  22  (preferably wireline  26 ) may be pulled into the coiled tubing on the coil. 
     While the preferred conduit  22  is wireline or electricline (either for delivery of electrical power to the bottom hole assembly (BHA) or sending/receiving data or control signals to/from the BHA or a combination of power, control, or data), one skilled in the art recognizes that other conduits may be used, for example, single or multiple-conductor coax, single or multiple-conductor cable (for example mono cable, two or three conductor cable or seven strand conductor known as ‘hepta cable’ etc.), fiber optic, small diameter tubing for fluid conveyance, etc. The wireline may be armored or not, and may be single wrapped or dual wrapped. The wireline may preferably be in the typical size range of between about 7/32″ and about ¾″ but other sizes may be used. 
     Referring to  FIGS. 6-9 , a conduit  22  in the form of a wireline  26  or heat resistant wireline  130  (two conductor wireline as just one example) is shown in the retainer  12  within the tubular  50 . In the case of regular wireline  26 , the wireline  26  may be installed by first installing the slickline  14  and fishing the wireline  26  into the retainer  12  after the heat treatment  60 . In the case of heat resistant wireline  130 , the heat resistant wireline may be installed directly in the retainer  12  prior to the heat treatment  60 . 
     Referring to  FIGS. 10-12 , the retainer  12  has a fixed portion  80  and a free portion  90 , the fixed portion  80  attached to the flat plate  10  and the free portion  90  extending from the fixed portion  80  to remain unattached. The free portion  90  may include a curved portion  100 , the curved portion  100  adapted to frictionally retain the slickline  14  within the retainer  12 . 
     The fixed portion  80  and/or the free portion  90  may include slots  110  along the length of the retainer  12  to increase flexibility. As depicted, the slots  110  may be formed into both the free portion  90  and the fixed portion  80 , provided there remains a connection/bridge  120  (see  FIG. 9 ) between adjacent sections. While shown between the fixed region and the free region, the connection/bridge may instead be in the fixed region or the free region. The free portion  90  may form a cavity  92  which may be sealed for retaining pressure ( FIG. 11B ) or may not be a sealed cavity ( FIG. 11A ). 
     In another embodiment, the retainer  12  has two fixed portions  80  with a free portion  90  in-between, forming a double retainer. Alternately, a plurality of runs of slickline  14  or heat resistant wireline  130  may be provided (See  FIG. 4G ). 
     While depicted as a continuous retainer  12  forming the track or race  16 , one ordinarily skilled in the art recognizes that the fixed portion  80  and/or the free portion  90  could have substantial gaps between adjacent retainers  12 . While the retainer  12  is depicted as having slots  110  in the fixed portion  80  and the free portion  90 , the retainer may be substantially continuous to provide for the pressure chamber  28  for example by sealingly attaching the retainer  12  to the flat plate  10 . 
     In the preceding description, for purposes of explanation, numerous details are set forth in order to provide a thorough understanding of the embodiments of the invention. However, it will be apparent to one skilled in the art that these specific details are not required in order to practice the invention. 
     The above-described embodiments of the invention are intended to be examples only. Alterations, modifications and variations can be effected to the particular embodiments by those of skill in the art without departing from the scope of the invention, which is defined solely by the claims appended hereto.

Technology Classification (CPC): 2