TOP DRIVE SERVICE LOOP CLAMP WITH TORSIONAL RELIEF

Abstract

A flange assembly for supporting a cable has a flange for supporting a cable therein. A flange body has one or more lugs disposed about a circumference of said flange body. A retention ring is dimensioned to fit over the flange body and retain the flange assembly by connecting with the lugs.

Claims

1. A flange assembly for supporting a cable comprising: a flange for supporting a cable therein; a flange body having one or more lugs disposed about a circumference of said flange body; and a retention ring dimensioned to fit over said flange body and retain said flange assembly by connecting with said lugs.

2. The flange assembly as claimed in claim 1, wherein said flange body has a plurality of lugs.

3. The flange assembly as claimed in claim 2, wherein said retention ring has a plurality of lug retention elements corresponding to said plurality of lugs.

4. The flange assembly as claimed in claim 3, wherein said flange body has a plurality of lugs.

5. The flange assembly as claimed in claim 4, wherein said lugs each have a first dimension spanning an arc of the circumference of the flange body and said lug retention elements each have a corresponding first dimension spanning an arc of the retention ring.

6. The flange assembly as claimed in claim 5, wherein first dimension spanning an arc of the circumference of the flange body of said lugs is smaller than corresponding first dimension spanning an arc of the retention ring of said lug retention elements.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The present invention can be best understood through the following description and accompanying drawings, wherein:

[0017] FIG. 1 is an image of a prior art of a top drive service loop;

[0018] FIG. 2 is an image of a prior art top drive service loop cable;

[0019] FIG. 3 is an image of a prior art top drive service loop cable;

[0020] FIGS. 4A and 4B are images of a prior art top drive service loop cable flange;

[0021] FIGS. 5A-5C are images of a top drive service loop cable in accordance with one embodiment;

[0022] FIGS. 6A and 6B are images of a top drive service loop cable flange in accordance with one embodiment;

[0023] FIG. 7 is an image of a flange body with lugs in accordance with one embodiment;

[0024] FIG. 8 is an image of a flange body with lugs in accordance with one embodiment;

[0025] FIG. 9 is an image of a flange body with lugs in accordance with one embodiment;

[0026] FIG. 10 is an image of a flange body retention ring with lug retention elements in accordance with one embodiment;

[0027] FIG. 11 is an image of a flange body retention ring with lug retention elements in accordance with one embodiment;

[0028] FIG. 12 is an image of a flange body retention ring with lug retention elements in accordance with one embodiment;

[0029] FIG. 13 is an image of a flange body with lugs in a flange body retention ring with lug retention elements in accordance with one embodiment; and

[0030] FIG. 14 is an image of a flange body with lugs in a support with lug retention elements in accordance with one embodiment.

DETAILED DESECRATION

[0031] Beginning with the structure of the top drive service loop cables, cables 12A-12C, FIGS. 5A-5C show the exemplary basic structure top drive service cables used with a flange configured in accordance with various embodiments of the present invention.

[0032] FIG. 5A illustrates an exemplary power cable 12A that includes an outer sheath 100, armoring 102, and a reinforcement layer 104 within jacket 106. Inside of jacket 106, power cable 12A has a shielding 110, encompassing the entirety of the conducting elements. For example, inside shielding 110, there are primary ground wires 112 and conductors 114 (777KCMIL 1/CKilo circular mils) forming the core of cable 12A.

[0033] As shown in FIG. 5B, the basic structure of control cable 12B, includes an outer sheath 200, armoring 202, and a reinforcement layer 204 within inner jacket 206. Inside of inner jacket 206, cable 12B has a core binder 208 having a group of insulated conductors 210 and a central filler 212.

[0034] As shown in FIG. 5C, the basic structure of auxiliary/instruments cable 12C, includes an outer sheath 300, armor 302, and a reinforcement layer 304 within inner jacket 306. Inside of inner jacket 306, cable 12C has a series of electrical conductors 308, filler 310 and a central set of twisted pair communication cables 312 all held within binder 314.

[0035] In one embodiment, the present arrangement employs a different material for its armor than the prior art which is usually the standard armor of bronze or tinned copper. In one arrangement armor 102, 202 and 302 is constructed from 316 type stainless steel (standard molybdenum-bearing grade, austenitic stainless steel). Stainless steel armor such as 102, 202 and 302 serve three purposes: First, it protects cables 12A-12C from external damage. Second, it is designed in such a way that it also independently supports the weight of cables 12A-12C, along with a generous safety factor, when properly secured. Third, it guards against Electromagnetic Interference (EMI) when primary shielding is not provided between adjacent cables, when properly grounded electrically.

[0036] In accordance with one embodiment, the cables 12A-12C work together with flange (described below) to create a durable cable which stands up to multiple flexations typically seen in dynamic applications such as on top drive service loops 11. Inner jackets 106, 206, 306 of each of cables 12A-12C is greater than or equal to the thickness specified for such cables according to standard IEEE 1580, and includes an aramid fiber reinforcement 104, 204, 304. According to this arrangement, when cables 12A-12C and their corresponding jackets 106, 206, 306 are properly secured to flanges 16, this reinforcement along with the thick jackets 106, 206, 306 allow the entire weight of cables 12A-12C to be supported by jackets 106, 206, 306, with a generous safety factor.

[0037] FIGS. 6A and 6B each illustrate a flange 16 (FIG. 6A showing compression of the grommet 405) in accordance with one embodiment of the invention. Flange 16 has a flange body 400, armor retainer 402, and grommet holder 404. Flange body 400, while varying in dimensions for different cables 12A-12C serves the basic function of enabling inner jackets 106, 206, 306 of cables 12A-12C to be supported by means of a polymer bonding agent added through fill port 401 (FIG. 6B), The polymer bonding agent is designed to bond chemically with cable jackets such as 106, 206, 306. Flange body 400 has a void which, when filled with the polymer bonding agent, geometrically prevents cable 12 from being pulled through flange body 400 since the cured polymer gets bonded to cable jackets such as 106, 206, 306.

[0038] Armor retainer 402 serves a dual purpose in each flange 16. First, armor retainer 402, works to secure stainless steel armors such as 102, 202, 302 so that the weight of cables 12A-12C may be supported by the stainless steel armor. Second, armor retainer 402 acts as an electrical ground path between stainless steel armor 102, 202, 302 and flange 16. Armor retainer 402 is secured to flange body 400 by means of socket head cap screws 403.

[0039] Grommet holder 404 of flange 16, when screwed on to flange body 400, compresses a rubber grommet 405 (FIG. 6B) which then creates a seal within the interior of flange body 400. This not only prevents the ingress of water into flange 16A-16C but also prevents the polymer bonding agent from escaping during the pouring and subsequent curing process.

[0040] In one arrangement, flange 16 for power cable 12A has one additional item, namely a shield terminator 406. Shield terminator 406 secures shielding 110 of power cable 12A, which is typically created from tinned copper braid, and allows for a second electrical path for EMI shielding.

[0041] Flange 16 may be advantageously made from a variety of materials depending on the application. High strength steel is typically used for land based applications (ASTM (American Society, for Testing and Materials) standards such asA675, GR 70, 4140 HT, etc.incorporated herein by reference), and stainless steel is predominantly used for applications where corrosion resistance is required (AISI (American Iron and Steel Institute) standards such as 316, AISI 304, etcincorporated herein by reference).

[0042] Once the polymer cures and sets up within flange 16 and also chemically bonds to the jackets such as 106, 206, 306 surrounding each of the individual conductors within cables 12A-12C, this additional support from the cured polymer is capable of independently supporting all cables 12A-12C within the entire cable assembly even if the stainless steel armor system were to fail.

[0043] Turning to the torsional relief aspect, flange body 400 is shown in FIG. 7 with a series of lugs 410 in accordance with one embodiment. It is noted that lugs 410 and the related features described hereinafter may be used on a flange 16 as shown in FIGS. 6A and 6B, or alternatively on other flanges used in top drive service loops. To the extent such features of lugs 410 are described in connection with flange 16 the structure of flange 16 is considered exemplary.

[0044] In accordance with one embodiment, as illustrated in FIG. 7, a flange body 400 maintains a series of lugs 410. In the illustrated instance the number of lugs 410 may be eight, each with an arc width of 20. In another embodiment as shown in FIG. 8, lugs 410 are of the same size (20), but they are only four lugs 410 present on the flange body 400. In another embodiment as shown in FIG. 9, flange body 400 also has four lugs 410, but they are larger, e.g. 80, covering a greater circumferential area.

[0045] The size/circumferential arc of lugs 410 may be a matter of design depending on the desired expected weight load of the top drive service loop cable, as well as the degree of torsional freedom desired, as described below.

[0046] To connect flange body 400 and lugs 410 to the support on the derrick or top drive service equipment, a metal retention ring 420 is used as shown in FIG. 10. The retention ring is constructed of a similar material as the flange body 400, such as 4140 HT steel.

[0047] Retention ring 420 has an outer ring 422 and a series of lug retention elements 424. Lug retention elements 424 have side walls 426 and a bottom lug retainer 428. In accordance with one embodiment, retention ring 420 includes a corresponding number of lug retention elements to match the number of lugs 410 in flange body 400. For example, retention ring 420 shown in FIG. 10 has eight lug retention elements 424 corresponding for example to the eight lugs 410 on flange body 400 shown in FIG. 7.

[0048] FIG. 11 shows retention ring 420 with four lug retention elements 424 corresponding for example to the four lugs 410 on flange body 400 shown in FIG. 8.

[0049] FIG. 12 shows retention ring 420 with four larger lug retention elements 424 corresponding for example to the four larger lugs 410 on flange body 400 shown in FIG. 9.

[0050] In each arrangement lugs 410 preferably have some rotational/torsional freedom as the two walls 426 of lug retention elements 424 are spaced farther apart than the arc size of the corresponding lugs 410. For example, if lugs 410 span an arc of 20 and lug retention elements 424 have walls 426 that span 30, then flange body 400 and lugs 410 would have 10 (+/5) of torsional freedom. If lug retention elements 424 have walls 426 than span 40, using the same 20 lugs 410 then flange body 400 and lugs 410 would have 20 (+/10) of torsional freedom. The amount of torsional freedom that is desired can be adjusted down to 0 of freedom (walls 426 spaced to the exact size of lugs 410) and up to 360 (+/180) is desired (ring 420 having one retention element 424 with no walls 426 and one large lug retainer 428). However, typically lugs 410 preferable have between 10 (+/5)40 (+/20) of freedom within lug retainers. The amount of torsional freedom may be a matter of design depending on the desired expected weight load of the top drive service loop cable, and torsional flexibility of the cable.

[0051] FIG. 13 shows flange 400 with lugs 410 and the retention ring 420 fitted thereover with lugs 410 contained within lug retention members 424. Retention ring 420 may then be bolted to the derrick or top drive support, preferably in the area between lug retention elements 424.

[0052] In another embodiment as shown in FIG. 14, instead of using a separate retention ring 420 fitted over lugs 410 and flange body 400, lug retention elements 424 may be directly formed in similar style into a support 500 such as the support on a derrick or top drive equipment. After lugs 410 are fitted into lug retention elements 424 with support 500, in one arrangement a cap 502 may be placed over flange body 400 and bolted to support 500, locking flange body 400 and lugs 410 into their respective lug retention elements 420. In another arrangement, retention elements 424 may be on the inside of support 500 (as shown in FIG. 14) and thus cap 502 is not needed as flange body 400 is larger than the opening in support 500.

[0053] Essentially, this arrangement has the same function as flange retention ring 420, but builds its feature of lug retention members 424 directly into a custom support 500 (whereas flange retention ring 420 shown in FIG. 13 can be used on existing/regular top drive service loop cable attachment supports).

[0054] Owing to the above arrangement as described, as the top drive moves within the derrick, and as the top drive service loop cable correspondingly moves, the connection to the derrick support and the top drive support allows for torsional movement of the flange/connection point. As such, unlike the prior art where such torsional strains are imparted to the flange and cable elements, in the present arrangement, lugs 410 move within lug retention elements 420 with a given amount of rotational freedom. This absorbs some or all of the torsional stress imparted into the cable by the movement of the top drive within the derrick, without imparting it to the cable or flange elements extending the life of the cable and connection.

[0055] While only certain features of the invention have been illustrated and described herein, many modifications, substitutions, changes or equivalents will now occur to those skilled in the art. It is therefore, to be understood that this application is intended to cover all such modifications and changes that fall within the true spirit of the invention.