1. Field of the Invention
The invention relates generally to devices and methods used to dispose tubewire into and remove it from radially surrounding tubing strings. In particular aspects, the invention relates to the insertion and removal of tubewire in situations wherein separate strings of coiled tubing are being connected.
2. Description of the Related Art
Coiled tubing has become a popular means for running a bottom hole assembly (“BHA”) or other tools into a subterranean wellbore. In most cases, it is desirable to be able to transmit electrical power down to the BHA or other tools as well as to permit control signals or sensed data to be transmitted between the surface and the downhole tools. Conventionally, this is done by disposing wireline into the coiled tubing. Wireline is a braided steel cable with layers of armor with conductors inside.
Use of wireline can be problematic. Wireline is prone to damage from acidic fluids in some instances. The slack in wireline must be adjusted over time, which requires time and money.
Tubewire is an alternative to wireline and has many advantages over wireline. Tubewire can be disposed inside coiled tubing to provide electrical power and a signal path from the surface to various downhole tools attached to the end of the coiled tubing. Tubewire is a tube that contains an insulated wire that is used to provide electrical power and/or data to the bottom hole assembly or to transmit data from the BHA to the surface. Tubewire is substantially inflexible relative to wireline. Tubewire is available commercially from manufacturers such as Draka Cableteq of North Dighton, Mass.
Tubewire can be disposed into coiled tubing at the surface. Systems and methods for injecting and retrieving tubewire into and out of coiled tubing are discussed in U.S. Pat. No. 7,845,419 by Naumann, which is incorporated herein by reference in its entirety. While the coiled tubing is spooled up on a reel at surface, the tubewire is placed into the coiled tubing by pumping fluid through the coiled tubing at high flow rates while an injector is used to feed the tubewire into the coiled tubing by applying a pushing force. According to the '419 patent, tubewire is pumped into the whip end (i.e., the end of the coiled tubing furthest away from the center of the reel) of the coiled tubing and toward the core end (i.e., the end of the coiled tubing nearest the center of the reel).
In many scenarios, such as off-shore situations, there are weight restrictions on equipment used to handle reels of coiled tubing, such as cranes. For this reason, a number of separate reels of coiled tubing are often used. These are moved one at a time by the crane or other handling equipment to a staging area for injection into the wellbore. The separate coiled tubing sections are joined together, then spooled up onto one reel and then injected into the wellbore from a single reel.
The present invention provides devices and methods that allow tubewire to be injected into and/or removed from coiled tubing in situations wherein there are two separate reels of coiled tubing which are to be connected together. This situation could occur on land or offshore. The invention describes devices and methods for disposing tubewire into (or removing the tubewire from) the core end of a section of coiled tubing on a reel. A conduit, such as a high pressure hose, as well as a tee and treating iron are affixed to the core end of the coiled tubing section to facilitate injection of tubewire into the core end. The procedures for disposing tubewire into, or retrieving tubewire from, coiled tubing section are preferably performed at surface, with the coiled tubing sections on either one reel or two. It is further noted that the devices, techniques and methods described herein could also be applied where there are three, four or even more separate sections of coiled tubing involved.
The devices and methods that permit injection of coiled tubing into the core end of a coiled tubing section lend themselves to particular use wherein there are separate reels of coiled tubing. The inventor has recognized that this technique permits the whip ends of the separate coiled tubing sections to be interconnected.
An exemplary method of disposing tubewire into coiled tubing is described wherein two separate reels of coiled tubing sections are provided. A high-pressure conduit is affixed to the core end of the coiled tubing of the first reel. Tubewire is pumped through the high-pressure hose and the coiled tubing of the first reel. Thereafter, the whip end of the coiled tubing of the first reel is interconnected with the whip end of the coiled tubing of the second reel with a coil-to-coil connector. The tubewire is then pumped through the coiled tubing of the second reel from the whip end of the coiled tubing to its core end. Once this is done, the interconnected coiled tubing sections can be spooled onto a single reel, allowing it to be injected into a wellbore.
An alternative method of disposing tubewire into coiled tubing on multiple reels is described. According to this method, separate coiled tubing sections are initially spooled upon separate first and second reels. Prior to injecting tubewire into the coiled tubing, the whip ends of the coiled tubing sections on each reel are joined together using a coil-to-coil connector or in other ways known in the art. Tubewire is then injected into the core end of the coiled tubing section on the first reel. The injected tubewire then passes through the connection of the coiled tubing sections and into the coiled tubing section of the second reel. The injected tubewire can then exit through the core end of the coiled tubing section of the second reel. Thereafter, the interconnected coiled tubing sections with tubewire within can be reeled onto a single reel.
A further method for disposing tubewire into two separate sections of coiled tubing is described. According to this method, the whip ends of the coiled tubing on each of the first and second reels are interconnected. Then the interconnected coiled tubing sections are spooled onto a single reel. Tubewire is injected either into the core end of interconnected coiled tubing sections and through both sections or into the whip end of interconnected coiled tubing sections and through both sections.
Another method for disposing tubewire into two separate section of coiled tubing is also described. In accordance with this method, first and second reels of coiled tubing are provided. A first section of tubewire is injected into the coiled tubing section on the first reel, and a second section of tubewire is injected into the coiled tubing section on the second reel. The tubewire on the first reel is then interconnected with the tubewire of the second reel. Thereafter, the two coiled tubing sections are interconnected. At this point, the interconnected coiled tubing sections are spooled onto a single reel.
Exemplary methods are described for removing tubewire from a coiled tubing string that is made up of multiple sections of coiled tubing. According to one method, the entire tubewire is pumped out of the coiled tubing in the conventional manner using the coiled tubing injector while the multiple sections of coiled tubing are still spooled on one reel. Once the tubewire is removed, the coil is then separated into separate sections and spooled onto separate reels for transport.
An alternative method for removing the tubewire from the coiled tubing is described. In accordance with this method, a portion of coiled tubing is spooled onto the second reel. When the coil-coil connection between coiled tubing sections emerges from the first reel, spooling is stopped. Tubewire is pumped out of the coiled tubing via the core end of the second reel until the end of the tubewire is located at the coil-coil connection point of the coiled tubing sections, at which point tubewire retrieval is stopped. The coil-coil connector is removed, thereby disconnecting the two sections of coiled tubing. Treating iron is then attached to the whip end of the second coil and the tubewire is fully retrieved from the second coil via the core end of the second coil.
For a thorough understanding of the present invention, reference is made to the following detailed description of the preferred embodiments, taken in conjunction with the accompanying drawings, wherein like reference numerals designate like or similar elements throughout the several figures of the drawings and wherein:
The term “tubewire”, as used herein, refers to a tube which may or may not encapsulate a conductor or other communication means, such as, for example, the tubewire manufactured by Draka Cableteq of North Dighton, Mass. Tubewire for example, might consist of a ⅛″ outer diameter by 0.023″ wall of stainless steel or Incoloy 825 tube containing 16-18 gauge stranded copper wire covered by Halar™ or Teflon™ insulator. In this example, the insulator is tight against the tube and the wire. In the alternative, the tubewire may encapsulate one or more fiber optic cables or a mixture of wire(s) and fiber optic cable(s). The tubewire may consist of multiple tubes and may be concentric or may be coated on the outside with plastic or rubber.
The tubewire injector 26 is hydraulically driven and controlled. However, it could be electrically driven and controlled or some combination of the two. Preferably, the injector 26 has a drive mechanism adapted to apply an axial pushing force to tubewire in order to inject the tubewire into the coiled tubing. Preferably, the injector can also apply an axial pulling force on the tubewire in order to retrieve the tubewire. Preferably, the tubewire injector 26 includes a drive mechanism that will drive the tubewire at a preselected speed or rate so that tension is maintained on the tubewire during injection and retrieval. The tubewire injector 26 can further include a control system to regulate injector forces, such as spool speed, drive mechanism speed and fluid pressure, at levels desirable for injection or removal of the tubewire.
A treating iron 28 is also affixed to the tee 24. A treating iron 28b is also affixed to the whip end 18. Tubewire 30 is shown being injected by the tubewire injector 26 into the core end 20 of the coiled tubing 12. Fluid is flowed through the treating iron 28 into the tee 24 in the direction of arrow 32, through the coil 12 and out the treating iron 28a. As tubewire 30 exits the injector 26, the fluid helps to pass the tubewire 30 through the tee 24, conduit 22 and coiled tubing 12. The tubewire 30 enters the core end 20 of the coiled tubing 12 and moves toward the whip end 18.
According to a first method of disposing tubewire 30 into the coiled tubing sections 12a, 12b, tubewire 30 is first pumped through the conduit 22 and the coiled tubing section 12a to the whip end 18a of the first reel 14a, in the manner depicted in
According to an alternative method of disposing tubewire 30 into the coiled tubing sections 12a, 12b, separate coiled tubing sections 12a, 12b are initially spooled upon separate first and second reels 14a, 14b, as depicted in
According to a further method of disposing tubewire into two separate coiled tubing sections, the whip ends 18a, 18b of the coiled tubing sections 12a, 12b on each of the first and second reels 14a, 14b are interconnected. Then the interconnected coiled tubing sections 12a, 12b are spooled onto a single reel. Tubewire 30 is injected into the new core end 20 or the new whip end 18 of the interconnected coiled tubing sections and through both coiled tubing sections 12a, 12b.
Another method for disposing tubewire 30 into two separate sections of coiled tubing 12a, 12b is illustrated by
Tubewire sections 30a, 30b and coiled tubing sections 12a, 12b, which are joined together using one of the previously described techniques, can be injected into a wellbore after having been coiled onto a single reel, as depicted in
In accordance with withdrawal of the coiled tubing 12 and tubewire 30 from the wellbore, a number of methods may be used to remove the joined tubewire sections 30a, 30b from within the coiled tubing sections 12a, 12b and return the coiled tubing sections 12a, 12b to their individual reels 14a, 14b.
According to a first method of removal, which is illustrated in
According to a second method for removing the tubewire 30 from the coiled tubing 12, in instances wherein the coiled tubing sections 12a, 12b and tubewire sections 30a, 30b are secured together using a connector 34 as depicted in
A further method may be used to remove tubewire 30 from coiled tubing 12 in instances wherein the tubewire 30 is comprised of one continuous piece of tubewire 30. However, it can also be used where there are interconnected sections of tubewire. Once the combined coiled tubing sections 12a, 12b are removed from the wellbore and fully spooled onto one reel 14a, a portion of coiled tubing 12 is spooled from the reel 14a and onto a second reel 14b prior to removing tubewire 30 from the coiled tubing 12. First, coiled tubing section 12b is spooled onto the second reel 14b from first reel 14a. When the connection point provided by connector 34 between the coiled tubing sections 12a, 12b emerges from the first reel 14a (see position illustrated by
Those of skill in the art will recognize that numerous modifications and changes may be made to the exemplary designs and embodiments described herein and that the invention is limited only by the claims that follow and any equivalents thereof.