REMOVABLE COIL IN PIPE SECTIONS OF A DOWNHOLE TUBULAR

Technical Field

[0001] Some embodiments relate to connections between sections of drill pipe. More particularly, some embodiments relate to a coil in ends of sections of drill pipe for electromagnetic induction.

Background

[0002] Drill pipe for downhole operations may be comprised of a series of pipe sections that are coupled together by threaded connections. The pipe sections may have a threaded male "pin" connection at one end and a threaded female "box" connection at the opposing end. Some drill pipe is wired for communication, power, etc.

Brief Description of the Drawings

[0003] Embodiments of the invention may be best understood by referring to the following description and accompanying drawings which illustrate such embodiments. The numbering scheme for the Figures included herein are such that the leading number for a given reference number in a Figure is associated with the number of the Figure. For example, a tubular 100 can be located in

Figure 1. In the drawings:

[0004] Figure 1 illustrates a tubular for downhole operations, according to some embodiments of the invention.

[0005] Figure 2 illustrates a pin end of a drill pipe section to mate to a box end of a different drill pipe section, according to some embodiments of the invention.

[0006] Figure 3 illustrates a more detailed diagram of the box end having a removable adapter that houses a coil, according to some embodiments of the invention.

[0007] Figure 4 illustrates a cross section of the removable adapter for a box end of a drill pipe section, according to some embodiments of the invention. [0008] Figure 5 illustrates an outer face of a removable adapter having more than one coil, according to some embodiments of the invention. [0009] Figure 7 illustrates a drilling well during Measurement While

Drilling (MWD)/ Logging While Drilling (LWD) operations that includes drill pipe sections, according to some embodiments of the invention.

Detailed Descrption

[0010] Methods, apparatus and systems for a removable coil in pipe sections of a downhole tubular are described. In the following description, numerous specific details are set forth. However, it is understood that embodiments of the invention may be practiced without these specific details, hi other instances, well-known circuits, structures and techniques have not been shown in detail in order not to obscure the understanding of this description. [0011] This description of the embodiments is divided into three sections.

The first section describes a downhole tubular with removable coil. The second section describes a MWD operating environment. The third section provides some general comments.

[0012] As described in more detail below, some embodiments include a removable adapter on the ends of the drill pipe sections, hi some embodiments, the removable adapter may include an inductive coil that is used for electromagnetic induction across two drill pipe sections. For example, the inductive coils may be used for data communication in a wired drill pipe. A removable adapter allows the coil to be removed. The end of the drill pipe section may be then recut, resurfaced, etc. and the removable adapter reconnected to the

end of the drill pipe section. Accordingly, some embodiments allow a coil to be reused after the end of the drill pipe section is recut, resurfaced, etc.

Downhole Tubular with Removable Coil

[0013] A tubular having a coil for electromagnetic radiation between sections of the tubular is now described. In particular, Figure 1 illustrates a tubular for downhole operations, according to some embodiments of the invention. In some embodiments, the tubular 100 is used in Measurement While Drilling (MWD) operations, Logging While Drilling (LWD) operations, wireline operations, slickline operations, etc. An example MWD operating environment is described in more detail below. In some embodiments, the tubular 100 is a wired tubular. The wire in the tubular 100 may be used for electromagnetic communications between the surface and downhole.

[0014] The tubular 100 comprises a drill pipe section 102 and a drill pipe section 104. The drill pipe section 102 includes a box end 106. The box end 106 may be connected to a pin end of separate drill pipe section (illustrated in more detail below). The box end includes an outward face 110. In some embodiments, the box end 106 is a threaded connection. Internal to the box end 106 and below the outward face 110, there is an internal shoulder 112. A removable adapter 108 is positioned on the internal shoulder 112. As further described below, in some embodiments, the removable adapter 108 houses one or more coils used for electromagnetic transmission between the box end 106 of the drill pipe connection 102 and a pin end of separate drill pipe section.

[0015] Figure 2 illustrates a pin end of a drill pipe section to mate to a box end of a different drill pipe section, according to some embodiments of the invention. A drill pipe section 202 includes a box end 206. A drill pipe section 222 includes a pin end 226 that may be connected to the box end 206. In some embodiments, a pin end may be at an opposing end from the box end 206 of the drill pipe section 202. Similarly, a box end may be at an opposing end from the

pin end 226. Both the box end and the pin end include a throughbore 201 that are aligned.

[0016] The box end 206 of the drill pipe section 202 may include internal threads 210 that extend radially between an outward face 210 and an internal shoulder 212. The pin end 226 of the drill pipe section 222 may include external threads 230 that extend radially between an outward face 228 and an external shoulder 232. In some embodiments, the internal threads 210 and the external threads 230 are tapered.

[0017] In some embodiments, the box end 206 includes a removable adapter 208 positioned over the internal shoulder 212. In some embodiments, the pin end 226 includes a removable adapter 228 positioned over the outward face 224. The removable adapter 208 and the removable adapter 228 may include one or more coils for electromagnetic transmission between the box end 206 and the pin end 226. In some embodiments, the one or more coils are used for electromagnetic induction for communications, power, etc. across the junction formed between the removable adapter 208 and the removable adapter 228 after the drill pipe sections 202 and 222 are mated together. While illustrated such that a box end and a pin end include the removable adapters, in some embodiments, less than all of the ends of the drill pipe sections may include such adapters. For example, only some or all of the box ends may include such removable adapters. Alternatively or in addition, only some or all of the pin ends may include such removable adapters.

[0018] During operations, the drill pipe sections may need to be repaired or serviced. In particular, the length of the drill pipe section may need to be adjusted. For example, the faces of the ends of the drill pipe sections may be damaged. Therefore, the faces may need to be recut or refaced. In some embodiments, the drill pipe sections may include a cut back section that could be \ - \ V2 inches in length to allow the sections to be cut and remain operational. In some situations, the drill pipe sections may need to be lengthened (using for

example a stub welding operation). To illustrate, with reference to the box end 202, the face 210 may need to be refaced. IfV ₄ of an inch of the face 210 is removed, VA of an inch of the inner shoulder 212 needs to be removed in order to maintain the proper tolerance after the drill pipe sections are reconnected. In contrast to conventional configurations, some embodiments provide a removable adapter (as described above) that houses the coil on the inner shoulder. Accordingly, the removable adapter along with the coil may be removed, prior to adjusting the length of the inner shoulder. Similarly, the length of the pin end 222 may need to be adjusted. Thus, the external shoulder 232 and the outward face 224 may be lengthened or shortened. The removable adapter 228 may be removed from the outward face 224 prior to such operations. Because of the removable adapter, the coil may be removed and replaced without approximately no damage to the coil. The end of the pipe can, thus, be reassembled such that the coil is operational thereafter.

[0019] A more detailed description of the removable adapter is now set forth. Figure 3 illustrates a more detailed diagram of the box end having a removable adapter that houses a coil, according to some embodiments of the invention. Figure 3 illustrates a box end 300 that is part of a drill pipe section. The box end 300 includes a housing 302 for internal threads. The housing 302 extends axially from an outer face 312 to an inner shoulder 309. A removable adapter 304 is positioned on the inner shoulder 309. A coil 308 is embedded in the removable adapter 304. In some embodiments, one to any number of coils may be embedded in the removable adapter 304. A description of some embodiments have a number of coils is set forth below. In some embodiments, the coil 308 is an induction coil that is used for electromagnetic induction between two drill pipe sections. The coil 308 may be used for data communication, power transmission, etc. The coil 308 is coupled to a wire 308. The wire 308 may be coupled to electronics, power supply, etc (not shown) that are in the drill pipe section. The wire 308 may be coupled to another coil at the opposing end of the

drill pipe section. Accordingly, a series of wired drill pipe sections, in accordance with some embodiments, may be used for surface/downhole communications. [0020] The box end 300 also includes an orifice 306 that may be sealed during operation. The orifice 306 allows access to the wire 308, which runs there through. Accordingly, a maintenance operator of the drill pipe sections may cut the wire 308 at the orifice 306. The removable adapter 304 may then be removed from the box end 300. After maintenance on the drill pipe section 300, the removable adapter 304 may be repositioned on the inner shoulder 309. The wire

308 can then be reconnected at the orifice 306. A more detailed description of the disconnecting and reconnecting of the removable adapter 304 is set forth below. [0021] Figure 4 illustrates a cross section of the removable adapter for a box end of a drill pipe section, according to some embodiments of the invention. The removable adapter 400 includes a cavity 404 that is around the circumference of an outer face 406. A coil 402 is embedded in the cavity 404. The coil is coupled to a wire 408. The wire 408 is run along the axis of the drill pipe section. The wire 408 may be coupled to electronics, a power supply, another coil, etc. in the drill pipe section, as described above. The removable adapter 400 also includes a number of openings 410A-410N. In some embodiments, the openings 410A-410N are threaded. Accordingly, the removable adapter 400 may be secured to the end of the drill pipe section using screws threaded therein. Alternatively or in addition, a bottom (opposite from the outer face 406) of the removable adapter 400 may be threaded. Accordingly, the removable adapter 400 may be secured by threading the removable adapter 400 onto the inner shoulder

309 (shown in Figure 3) that may include threads thereon. Alternatively or in addition, the removable adapter 400 may be secured to the end of the drill pipe section using a J-slot mechanism, or other retaining schemes. While Figure 4 illustrates a removable adapter for a box end, a similar removable adapter may be used on a pin end. With reference to Figure 2, a removable adapter may be secured over the outer face 224 of the pin end 22.

[0022] In some embodiments, a removable adapter may include more than one coil therein. Figure 5 illustrates an outer face of a removable adapter having more than one coil, according to some embodiments of the invention. The removable adapter 500 includes an outer face 502. A first coil 504 is positioned circumferentially around the outer face 502 having a circumferential length of A. A second coil 506 is positioned circumferentially around the outer face 502 having a circumferential length of B, wherein A is greater than B. The face of the opposing removable adapter after two drill pipe sections are mated may have the same number and positions of coils thereon.

[0023] While illustrated with two coils, the face of the removable adapter may have any number of coils thereon. In some embodiments, the coils 502 and 504 may be induction coils for data communication, power, etc. (as described above). For example, a first coil may be for data communication, while a second coil may be for power transmission. In some embodiments, two different coils could both provide data communication for greater bandwidth or redundancy, while one or more coils may be used for power transmission. [0024] Figure 5 illustrates the incorporation of multiple coils on the face of an end of a drill pipe section. Some embodiments can include multiple coils at different depths on an end of a drill pipe section. For example, Figure 6 illustrates a cross section of the removable adapter having multiple coils at different depths for a box end of a drill pipe section, according to some embodiments of the invention.

[0025] The removable adapter 600 includes a cavity 604 that is around the circumference of an outer face 606. A first coil 602 is embedded in the cavity 604. A second coil 603 is below the first coil 602 and at a different depth relative to the outer face 606. In some embodiments, the second coil 603 has approximately a same circumference as the circumference of the first coil 602. In some embodiments, the second coil 603 is not part of the removable adapter 600.

Accordingly, the removable adapter 600 along with the first coil 602 can be removed while the second coil 602 remains in the end of the drill pipe section. [0026] The second coil 603 is coupled to a wire 608. The wire 608 is run along the axis of the drill pipe section. The wire 608 may be coupled to electronics, a power supply, another coil, etc. in the drill pipe section, as described above. The removable adapter 400 also includes a number of openings 610A- 610N. In some embodiments, the openings 610A-610N are threaded. Accordingly, the removable adapter 600 may be secured to the end of the drill pipe section using screws threaded therein. Alternatively or in addition, a bottom (opposite from the outer face 606) of the removable adapter 600 may be threaded. Accordingly, the removable adapter 600 may be secured by threading the removable adapter 600 onto the inner shoulder 309 (shown in Figure 3) that may include threads thereon. Alternatively or in addition, the removable adapter 600 may be secured to the end of the drill pipe section using a J-slot mechanism. While Figure 6 illustrates a removable adapter for a box end, a similar removable adapter may be used on a pin end. With reference to Figure 2, a removable adapter may be secured over the outer face 224 of the pin end 22. Accordingly, as described, the configuration illustrated in Figure 6 may allow for the removal of the first coil without having to cut the wire that is coupled to the electronics, power, etc. The first coil and the second coil may be inductively coupled. While Figure 6 illustrates two coils at different depths, some embodiments may have a greater number of such coils at different depths.

[0027] Various embodiments described herein may be combined. For example, some embodiments may include multiple coils on the face that are inductively coupled to multiple coils at a lower depth in the end of the drill pipe section. Moreover, while described such that a coil is within a removable adapter, embodiments are not so limited. In particular, some embodiments may independent of a removable adapter. In particular, the coil may be secured to one of the faces (e.g., the inner shoulder of the box end, as described above) without a

removable adapter. The coil may be removed and reconnected to the face such that the coil remains operational after the reconnection. For example, the face may include a rigid outer diameter body and a split taper locking ring on a supporting inner diameter. The coil may be positioned between the outer and inner diameter that that the coil is essentially non-damaged during removal. In some embodiments, a spring may be positioned below the coil and a button element may secure the coil within the cavity. Accordingly, if the drill pipe is cut, the button element may be tightened to increase the tension of the spring and thus shortening the length of the end of the pipe.

[0028] Some embodiments are described such that the removable adapter is for housing a coil for inductive radiation. However, embodiments are not so limited. For example, a removable adapter may be used for various hard connections for downhole operations. An example of such a hard connection is described in U.S. Patent Application titled "Connector including Isolative Conductive Paths" to Michael D. Finke, et al., Serial No. 11/175,018, filed July 5, 2005, which is hereby incorporated by reference.

MWD Operating Environment

[0029] A system operating environment, according to some embodiments, is now described. Figure 7 illustrates a drilling well during Measurement While Drilling (MWD)/ Logging While Drilling (LWD) operations that includes cutouts for antennas for electromagnetic wave resistivity, according to some embodiments of the invention.

[0030] It can be seen how a system 764 may also form a portion of a drilling rig 702 located at a surface 704 of a well 706. The drilling rig 702 may provide support for a drill string 708. The drill string 708 may operate to penetrate a rotary table 710 for drilling a borehole 712 through subsurface formations 714. The drill string 708 may include a Kelly 716, a drill pipe 718,

and a bottom hole assembly 720, perhaps located at the lower portion of the drill pipe 718.

[0031] The bottom hole assembly 720 may include drill collars 722, a downhole tool 724, and a drill bit 726. The drill bit 726 may operate to create a borehole 712 by penetrating the surface 704 and subsurface formations 714. The downhole tool 724 may comprise any of a number of different types of tools including MWD (measurement while drilling) tools, LWD (logging while drilling) tools, and others. In some embodiments, the drill pipe 718 is a wired drill pipe for communications between the surface of the Earth to the downhole tool 724. In some embodiments, the drill pipe 718 is comprised of a number of drill pipe sections (as described above).

[0032] During drilling operations, the drill string 708 (perhaps including the Kelly 716, the drill pipe 718, and the bottom hole assembly 720) may be rotated by the rotary table 710. In addition to, or alternatively, the bottom hole assembly 720 may also be rotated by a motor (e.g., a mud motor) that is located downhole. The drill collars 722 may be used to add weight to the drill bit 726. The drill collars 722 also may stiffen the bottom hole assembly 720 to allow the bottom hole assembly 720 to transfer the added weight to the drill bit 726, and in turn, assist the drill bit 726 in penetrating the surface 704 and subsurface formations 714.

[0033] During drilling operations, a mud pump 732 may pump drilling fluid (sometimes known by those of skill in the art as "drilling mud") from a mud pit 734 through a hose 736 into the drill pipe 718 and down to the drill bit 726. The drilling fluid can flow out from the drill bit 726 and be returned to the surface 704 through an annular area 740 between the drill pipe 718 and the sides of the borehole 712. The drilling fluid may then be returned to the mud pit 734, where such fluid is filtered, hi some embodiments, the drilling fluid can be used to cool the drill bit 726, as well as to provide lubrication for the drill bit 726 during

drilling operations. Additionally, the drilling fluid may be used to remove subsurface formation 714 cuttings created by operating the drill bit 726. [0034] The different components of Figure 7 may all be characterized as

"modules" herein. Such modules may include hardware circuitry, and/or a processor and/or memory circuits, software program modules and objects, and/or firmware, and combinations thereof, as desired by the architect of the systems shown in Figure 7, and as appropriate for particular implementations of various embodiments. For example, in some embodiments, such modules may be included in an apparatus and/or system operation simulation package, such as a software electrical signal simulation package, a power usage and distribution simulation package, a power/heat dissipation simulation package, and/or a combination of software and hardware used to simulate the operation of various potential embodiments.

[0035] It should also be understood that the apparatus and systems of various embodiments can be used in applications other than for drilling and logging operations, and thus, various embodiments are not to be so limited. The illustrations of the systems of Figure 7 are intended to provide a general understanding of the structure of various embodiments, and they are not intended to serve as a complete description of all the elements and features of apparatus and systems that might make use of the structures described herein. [0036] Applications that may include the novel apparatus and systems of various embodiments include electronic circuitry used in high-speed computers, communication and signal processing circuitry, modems, processor modules, embedded processors, data switches, and application-specific modules, including multilayer, multi-chip modules. Such apparatus and systems may further be included as sub-components within a variety of electronic systems, such as televisions, personal computers, workstations, vehicles, and conducting cables for a variety of electrical devices, among others. Some embodiments include a number of methods.

General

[0037] In the description, numerous specific details such as logic implementations, opcodes, means to specify operands, resource partitioning/sharing/duplication implementations, types and interrelationships of system components, and logic partitioning/integration choices are set forth in order to provide a more thorough understanding of the present invention. It will be appreciated, however, by one skilled in the art that embodiments of the invention may be practiced without such specific details. In other instances, control structures, gate level circuits and full software instruction sequences have not been shown in detail in order not to obscure the embodiments of the invention. Those of ordinary skill in the art, with the included descriptions will be able to implement appropriate functionality without undue experimentation. [0038] References in the specification to "one embodiment", "an embodiment", "an example embodiment", etc., indicate that the embodiment described may include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one skilled in the art to affect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described.

[0039] In view of the wide variety of permutations to the embodiments described herein, this detailed description is intended to be illustrative only, and should not be taken as limiting the scope of the invention. What is claimed as the invention, therefore, is all such modifications as may come within the scope and spirit of me following claims and equivalents thereto. Therefore, the specification and drawings are to be regarded in an illustrative rather than a restrictive sense.