AU2011202913B2 - Downhole swivel apparatus and method - Google Patents

Abstract

Abstract A swivel includes a mandrel having upper and lower end sections and connected to and rotatable with upper and lower drill or work string sections. The mandrel includes a longitudinal passage forming a continuation of a passage in the drill or work string sections. A sleeve having a 5 longitudinal sleeve passage is rotatably connected to the mandrel by a pair of longitudinally spaced bearings. A seal between upper and lower end portions of the mandrel and sleeve prevents leakage of fluid between the mandrel and sleeve. In one form of the invention the seal comprises a rope seal. In another form the sleeve is reciprocable between the upper and lower end sections of the mandrel. In an embodiment a pair of spaced apart packing units between 0 upper and lower end portions of the mandrel and sleeve prevent leakage of fluid between the mandrel and sleeve, and the sleeve restricts fluid flow between its interior and exterior sections.

Description

P/00/01 1 Regulation 3.2 AUSTRALIA Patents Act 1990 COMPLETE SPECIFICATION STANDARD PATENT Invention Title: Downhole swivel apparatus and method The following statement is a full description of this invention, including the best method of performing it known to us: TITLE "DOWNHOLE SWIVEL APPARATUS" BACKGROUND In deepwater drilling rigs, marine risers extending from a wellhead fixed on the ocean floor have 5 been used to circulate drilling fluid back to a structure or rig. The riser must be large enough in internal diameter to accommodate the largest bit and pipe that will be used in drilling a borehole. During the drilling process drilling fluid or mud fills the riser and wellbore. An example of a drilling rig and various drilling components is shown in Figure 1 of United States patent number 6,263,982 (which patent is incorporated herein by reference). A conventional slip 0 or telescopic joint SJ, comprising an outer barrel OB and an inner barrel IB with a pressure seal therebetween can be used to compensate for the relative vertical movement or heave between the floating rig and the fixed subsea riser R. A Diverter D can been connected between the top inner barrel LB of the slip joint SJ and the floating structure or rig S to control gas accumulations in the riser R or low pressure formation gas from venting to the rig floor F. A ball joint BJ between the diverter D and the 5 riser R can compensate for other relative movement (horizontal and rotational) or pitch and roll of the floating structure S and the riser R (which is fixed). The diverter D can use a diverter line DL to communicate drilling fluid or mud from the riser R to a choke manifold CM, shale shaker SS or other drilling fluid receiving device. Above the diverter D can be the flowline RF which can be configured to communicate with a mud pit MP. A conventional 20 flexible choke line CL can be configured to communicate with a choke manifold CM. The drilling fluid can flow from the choke manifold CM to a mud-gas buster or separator MB and a flare line (not shown). The drilling fluid can then be discharged to a shale shaker SS, and mud pits MP. In addition to a choke line CL and kill line KL, a booster line BL can be used. After drilling operations, when preparing the wellbore and riser for production, it is desirable to 25 remove the drilling fluid or mud. Removal of drilling fluid is typically done through displacement by a completion fluid. Because of its relatively high cost this drilling fluid is typically recovered for use in another drilling operation. Displacing the drilling fluid in multiple sections is desirable because the amount of drilling fluid to be removed during completion is typically greater than the storage space available at the drilling rig for either completion fluid and/or drilling fluid. 1A In deep water settings, after drilling is stopped the total volume of drilling fluid in the well bore and the riser can be in excess of 5,000 barrels. However, many rigs do not have the capacity for storing 5,000 plus barrels of completion fluid and/or drilling fluid when displacing in one step the total volume of drilling fluid in the well bore and riser. Accordingly, displacement is typically done in two or more 5 stages. Where the displacement process is performed in two or more stages, there is a risk that, during the time period between stages, the displacing fluid will intermix or interface with the drilling fluid thereby causing the drilling fluid to be unusable or require extensive and expensive reclamation efforts before being usable. 0 It is believed that rotating the drill string during the displacement process helps to better remove the drilling fluid along with down hole contaminants such as mud, debris, and/or other items. It is believed that reciprocating the drill string during the displacement process also helps to loosen and/or remove unwanted downhole items by creating a plunging effect. Reciprocation can also allow scrapers and/or brushes to better clean desired portions of the walls of the well bore and casing, 5 such as where perforations will be made for later production. During displacement there is a desire to allow the drilling fluid to be displaced in two or more sections. During displacement there is a desire to prevent intermixing of the drilling fluid with displacement fluid. 20 During displacement there is a desire to allow the drill string to rotate. During displacement there is a desire to allow the drill string to reciprocate longitudinally. While certain novel features of this invention shown and described below are pointed out in the annexed claims, the invention is not intended to be limited to the details specified, since a person of ordinary skill in the relevant art will understand that various omissions, modifications, substitutions and 25 changes in the forms and details of the device illustrated and in its operation may be made without departing in any way from the spirit of the present invention. No feature of the invention is critical or essential unless it is expressly stated as being "critical" or "essential." 2 Reference to any prior art in the specification is not, and should not be taken as, an acknowledgment or any form of suggestion that this prior art forms part of the common general knowledge in Australia or any other jurisdiction or that this prior art could reasonably be expected to be ascertained, understood and regarded as relevant by a person skilled in the art. 5 BRIEF SUMMARY One embodiment relates to an apparatus for deepwater rigs. In particular, one embodiment relates to an apparatus for removing or displacing working fluids in a well bore and riser. According to a first aspect, the present invention provides a swivel comprising: (a) a mandrel having upper and lower end sections and connected to and rotatable with upper 0 and lower drill or work string sections, the mandrel including a longitudinal passage forming a continuation of a passage in the drill or work string sections; (b) a sleeve having a longitudinal sleeve passage, the sleeve being rotatably connected to the mandrel by a pair of longitudinally spaced bearings; and (c) a seal between upper and lower end portions of the mandrel and sleeve, the seal preventing 5 leakage of the fluid between the mandrel and sleeve. In one form of the first aspect of the invention, the seal comprises a rope seal. In another form of the first aspect of the invention, the sleeve is reciprocable between the upper and lower end sections of the mandrel. In a second aspect, the invention provides a swivel insertable into a drill or work string 20 comprising: (a) a mandrel having upper and lower end sections and connected to and rotatable with upper and lower drill or work string sections, the mandrel including a longitudinal passage formed a continuation of a passage in the drill or work string sections; (b) a sleeve having a longitudinal sleeve passage, the sleeve being rotatably connected to the 25 mandrel by a pair of longitudinally spaced bearings; 3 (c) a pair of spaced part packing units between upper and lower end portions of the mandrel and sleeve, the packing units preventing leakage of fluid between the mandrel of sleeve, the packing units each comprising a rope seal; (d) the sleeve restricting fluid flow between its interior and exterior sections. 5 One embodiment provides an apparatus having a swivel which can operably and/or detachably connect to an annular blowout preventer thereby separating the drilling fluid or mud into upper and lower sections and allowing the drilling fluid to be displaced in two stages. In one embodiment a swivel can be used having a sleeve that is rotatably and sealably connected to a mandrel. The swivel can be incorporated into a drill or well string. 0 In one embodiment the sleeve can be fluidly sealed from the mandrel. In one embodiment the sleeve can be fluidly sealed with respect to the outside environment. In one embodiment the sealing system between the sleeve and the mandrel is designed to resist fluid infiltration from the exterior of the sleeve to the interior space between the sleeve and the mandrel. In one embodiment the sealing system between the sleeve and the mandrel has a higher pressure 5 rating for pressures tending to push fluid from the exterior of the sleeve to the interior space between the sleeve and the mandrel than pressures tending to push fluid from the interior space between the sleeve and the mandrel to the exterior of the sleeve. In one embodiment a swivel having a sleeve and mandrel is used having at least one catch or upset to restrict longitudinal movement of the sleeve relative to the annular blow out preventer. In one 20 embodiment a plurality of catches or upsets are used. In one 4 embodiment the plurality of catches are longitudinally spaced apart. In one embodiment means are provided (such as grooves, rings, and other fluid pathways) to prevent the sleeve from forming a complete seal with the horizontal surfaces of the annular blowout preventer while the sleeve does seal with the vertical surfaces of 5 the annular blowout preventer. One embodiment allows separation of the drilling fluid into upper and lower sections. One embodiment restricts intermixing between the drilling fluid and the displacement fluid during the displacement process. 10 One embodiment allows the riser and well bore to be separated into two volumetric sections (e.g., 2,500 barrels each) where the rigs can carry a sufficient amount of displacement fluid to remove each section without stopping during the displacement process. In one embodiment, fluid removal of the two volumetric sections in stages can be accomplished, but there is a break of an indefinite period of time between stages 15 (although this break may be of short duration). In one embodiment the drill or well string does not move in a longitudinal direction relative to the swivel during displacement of fluid during the removal process. In one embodiment the drill or well string is reciprocated longitudinally during displacement of fluid during the removal process. 20 In one embodiment the drill or well string is rotated during displacement of fluid during the removal process. In one embodiment the drill or well string is intermittently rotated during displacement of fluid during the removal process. In one embodiment the drill or well string is continuously rotated during 25 displacement of fluid during the removal process. In one embodiment the 'drill or well string is alternately rotated during displacement of fluid during the removal process. In one embodiment the direction of rotation of the drill or well string is changed during displacement of fluid during the removal process. 30 The drawings constitute a part of this specification and include exemplary embodiments to the invention, which may be embodied in various forms. -5- BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS For a further understanding of the nature, objects, and advantages of the present invention, reference should be had to the following detailed description, read in conjunction with the following drawings, wherein like reference numerals denote like 5 elements and wherein: Figure 1 is a schematic view showing a deep water drilling rig with riser and annular blowout preventer; Figure 2 is another schematic view of a deep water drilling rig showing a swivel detachably connected to an annular blowout preventer; 10 Figure 3 is a sectional view of a swivel; Figure 4 is a sectional view of the upper portion of the swivel in Figure 3; Figure 5 is a sectional view of the lower portion of the swivel in Figure 3; Figure 6 is a sectional side view of the swivel in Figure 3 taken along the lines B B; 15 Figure 7 is a sectional view of an alternative swivel; Figure 8 is a sectional view of the lower portion of the swivel in Figure 7; Figure 9 is a sectional view of the upper portion of the swivel in Figure 7; Figure 10 shows a mandrel for the swivel in Figure 7; Figure 11 is a sectional view of a sleeve for the swivel in Figure 7; 20 Figure 12 is a side view of the sleeve of Figure 11; Figure 13 is a sectional view of an alternative end cap for the swivel in Figure 7; Figure 14 is a side view of the end cap of Figure 13; Figure 14A is a sectional view of Figure 14; Figure 15 is a sectional view of a packing retainer nut for the swivel in Figure 7; 25 Figure 16 is a right side view of the packing retainer nut of Figure 15; Figure 17 is a left side view of the packing retainer nut of Figure 15; Figure 18 is a top view of a spacer ring; Figure 19 is a sectional view of the spacer ring of Figure 18 taken along the line 19-19; 30 Figure 20 is a top view of a male packing ring; Figure 21 is a sectional view of the male packing ring of Figure 20 taken along -6the line 21-21; Figure 22 is a top view of a spacer ring; Figure 23 is a sectional view of the spacer ring of Figure 22 taken along the line 22-22; 5 Figures 24A through 24C are schematic diagrams of an alternative swivel which has a stroke along the mandrel; Figures 25A through 25C show a swivel wherein the sleeve can slide along the mandrel. Figure 26 shows a mandrel which can be incorporated in the alternative swivel 10 of Figure 24. Figure 27 shows another alternative swivel. Figure 27A is an end view of the swivel of Figure 27. Figure 28 is a sectional view of the upper part of the swivel of Figure 27. Figure 29 shows a mandrel for the swivel of Figure 27. 15 Figure 30 shows a sleeve for the swivel of Figure 27. Figure 31shows an end view of the end cap for the swivel of Figure 27. Figure 32 is a sectional view of the end cap of Figure 31. Figure 33 shows an end view of a thrust hub for the swivel of Figure 27. Figure 34 is a sectional view of the thrust hub of Figure 33. 20 Figure 35 is an opposing end view of the thrust hub of Figure 33. Figure 36 shows an end view of a thrust ring. Figure 37 is a sectional view of the thrust ring of Figure 36. Figure 38 shows an end view of a bushing. Figure 39 is a sectional view of the busing of Figure 38. 25 Figure 39A is an enlarged view of the indicated area of Figure 39. Figure 40 is a rough cut of the bushing of Figure 38 showing various recessed areas. Figure 41 is an end view of the rough cut of Figure 40. Figure 42 shows a key which can be used in the swivel of Figure 27. 30 Figure 43 is a sectional view of the key of Figure 42. Figure 44 shows the lower portion of another alternative swivel. -7- Figure 45 shows an end view of the swivel of Figure 44. Figure 46 is a schematic diagram of another alternative swivel have upper and lower catches. Figure 47 is a perspective view of an another alternative swivel having modified 5 upper and lower catches. Figure 48 is a sectional view of the swivel of Figure 46. Figure 49 is an enlarged view of the upper portion of the section view of Figure 48. Figure 50 is a top view of a spacer ring for the swivel of Figure 46. 10 Figure 51 is a top perspective view of a retainer cap. Figure 52 shows the swivel of Figure 46 inside a blowout preventer. Figure 53 is a perspective view of a blowout preventer. Figure 54 is a perspective view of another alternative swivel having modified upper and lower catches. 15 Figure 55 is a sectional perspective view of the swivel of Figure 54. Figure 56 is a sectional perspective view of the sleeve from the swivel of Figure 54. Figure 57 is a perspective view of the mandrel from the swivel of Figure 54. Figure 58 is an end view of the part of the catch from the sleeve of Figure 56. 20 Figure 59 is a sectional perspective view of a retainer cap. Figure 60 is a perspective view of an end cap connected to a bearing. Figure 61 is a sectional view of the end cap and bearing of Figure 60. Figure 62 is a rear perspective view of the end cap of Figure 60. Figures 63 through 63C are views of the swivel of Figure 54 where the sleeve is 25 moved up with respect to the mandrel. Figures 64Athrough 64C are views of the swivel of Figure 54 where the sleeve is centered with respect to the mandrel. Figures 65Athrough 65C are views of the swivel of Figure 54 where the sleeve is moved down with respect to the mandrel. 30 Figure 66 is a perspective view of the swivel of Figure 54 where the mandrel and sleeve are pulled up with respect to the annular blow out preventer. -8- Figure 67 is a perspective view of the swivel of Figure 54 where the mandrel and sleeve are centered longitudinally with respect to the annular blow out preventer. Figure 68 is a perspective view of the swivel of Figure 54 where the mandrel and sleeve are pushed down with respect to the annular blow out preventer. 5 Figures 69 through 69 C are views of the swivel of Figure 54 where the mandrel and sleeve are pulled up with respect to the annular blow out preventer. Figure 70 is a schematic diagram illustrating the swivel of 54 seating on a well head. DETAILED DESCRIPTION 10 Detailed descriptions of one or more preferred embodiments are provided herein. It is to be understood, however, that the present invention may be embodied in various forms. Therefore, specific details disclosed herein are not to be interpreted as limiting, but rather as a basis for the claims and as a representative basis for teaching one skilled in the art to employ the present invention in any appropriate system, structure or manner. 15 Figure 1 is a schematic view showing rig 10 connected to riser 80 and having annular blowout preventer 70. Figure 2 is a schematic view showing rig 10 with swivel 100 separating upper drill string 85 and lower drill string 86. Swivel 100 is shown detachably connected to annular blowout preventer 70 through annular packing unit seal 71. With such construction drill string 85,86 can be rotated while annular blowout 20 preventer 70 is sealed around swivel 100 thereby separating a fluid into upper and lower longitudinal sections. Figures 3 through 6 show one embodiment of swivel 100. Figure 3 is a schematic view of swivel 100. Figure 4 is a sectional view of the upper portion of swivel 100 identified by bracket 101 in Figure 3. Figure 5 is a sectional view of the lower portion 25 of swivel 100 identified by bracket 102 in Figure 3. Figure 6 is a sectional side view of swivel 100 taken along the lines B-B of Figure 3. Swivel 100 can be comprised of mandrel 110 and sleeve 300. Sleeve 300 can be rotatably and sealably connected to mandrel 110. Accordingly, when mandrel 110 is rotated, sleeve 300 can remain stationary to an observer insofar as rotation is concerned. 30 Mandrel 110 can comprise upper end 120 and lower end 130. Central longitudinal passage 160 can extend from upper end 120 through lower end 130. Lower -9end 130 can include a pin connection 150 or any other conventional connection. Upper end 120 can include box connection 140 or any other conventional connection. Mandrel 110 can in effect become a part of drill string 85,86 as shown in Figure 2. Sleeve 300 can fit over mandrel 110 and be rotatably and sealably connected to 5 mandrel 110. Sleeve 300 can be rotatably connected to mandrel 110 by a plurality of bearings 230,240,250,260. The upper portion of sleeve 300 can be rotatably connected by upper bearings 230,240. The lower portion of sleeve 300 can be rotatably connected by lower bearings 250,260. Upper lubrication port 311 can be used to provide lubrication to upper bearings 230,240. Lower lubrication port 312 can be used to provide 10 lubrication to lower bearings 250,260. Mandrel 110 can include shoulder 170 to support bearings 230,240,250,260. Sleeve 300 can include protruding section 320 to support bearings 230,240,250,260. Upper bearings 230,240 are held in place by upper end cap 302. Lower bearings 250,260 are held in place by lower end cap 304. Upper end cap 302 and lower end cap 304 can 15 be connected to sleeve 300 respectively by plurality of fasteners 306,307, such as bolts. Upperbearings 230,240 can be positioned between tip 308 of upper end cap 302 and upper surface of shoulder 190 of sleeve 300 along with upper surface of shoulder 171 of mandrel 110. Lower bearings 250,260 can be positioned between tip 309 of lower end cap 304 and lower surface of shoulder 200 of sleeve 300 along with lower surface 20 of shoulder 172 of mandrel 110. Upper end cap 302 and lower end cap 304 can be connected to sleeve 300 respectively by plurality of fasteners 306,307, such as bolts. As shown in Figure 4, a spacer ring 303 canbeused to position lower end cap 304 in relation to mandrel 300. The spacer ring 303 can include a plurality of holes to allow fasteners 306 to pass through. 25 As shown in Figure 5, a spacer ring 305 can be used to position upper end cap 302 in relation to mandrel 300. The spacer ring 305 can include a plurality of holes to allow fasteners 307 to pass through (holes not shown). Alternatively, upper and lower end caps 302,304 can be threaded into sleeve 300. Upper end cap 302 can include mechanical seal 341 to prevent dirt and debris 30 from coming between upper end cap 302 and mandrel 110. Lower end cap 304 can include mechanical seal 461 to prevent dirt and debris from coming between lower end -10cap 304 and mandrel 110. Sleeve 300 can be seal ably connected to mandrel 110 by upper and lower packing units 330,450. Upper packing unit 330 can comprise male packing ring 410, plurality of seals 420, female packing ring 430, spacer ring 390, and packing retainer nut 340. 5 Packing retainer nut 340 can be threadably connected to upper end cap 302 at threaded connection 342. Tightening packing retainer nut 340 squeezes plurality of seals 420 between upper end cap 302 and retainer nut 340 thereby increasing sealing between sleeve 300 (through upper end cap 302) and swivel mandrel 110. Set screw 360 can be used to lock packing retainer nut 340 in place and prevent retainer nut 340 from 10 loosening during operation. Set screw 360 can be threaded into bore 361 and lock into upper end cap 302. O-ring 345 can be used to seal upper end cap 302 to sleeve 300. A back up ring 345A can be used with o-ring 345 to prevent extrusion of o-ring 345. Lower packing unit 450 can comprise male packing ring 530, plurality of seals 540, female packing ring 520, spacer ring 510, and packing retainer nut 460. Packing 15 retainernut 460 can be threadably connected to lower end cap 304 at threaded connection 343. Tightening packing retainer nut 460 squeezes plurality of seals 540 between lower end cap 304 and nut 460 thereby increasing sealing between sleeve 300 (through lower end cap 304) and swivel mandrel 110. Packing retainer nut 460 can be locked in place by set screw 470. Set screw 470 can be used to lock packing retainer nut 460 in place and 20 prevent retainer nut 460 from loosening during operation. Set screw 470 can be threaded into bore 471 and lock into lower end cap 304. O-ring 346 can be used to seal lower end cap 304 to sleeve 300. A back up ring 346A can be used with o-ring 346 to prevent extrusion of o-ring 346. Check valves 322,324 can be used to provide pressure relief from interior space 25 310. Figures 7 through 23 show a sectional view of an alternative swivel 100. Alternative swivel 100 can comprise mandrel 110 and sleeve 300. In this alternative embodiment a plurality of ninety degree locks 600 and set screws 610 can be used to prevent plurality of bolts 306 from loosening during use. Similarly, a plurality of locks 30 620 and set screws 630 can be used to prevent plurality of bolts 307 from loosening during use. -11- Figures 7 through 9 also show a different construction of packing units 330,450. Packing unit 330 can comprise male packing ring 410, plurality of seals 420, spacer ring 390, and packing retainer nut 340. Packing unit 450 can comprise male packing ring 530, plurality of seals 540, spacer ring 510, and packing retainer nut 460. Plurality of seals 5 420 can comprise first seal 421, female packing ring 422, and a plurality of rope seals 423. Similarly, plurality of seals 540 can comprise first seal 541, female packing ring 542, and a plurality of rope seals 543. First seals 421,541 can be a Chevron type seal such as CDI model number 0370650-VS-850 HNBR having a 3/8 inch section height. Plurality of rope seals 423,543 can be Garlock 7/16 inch (or 3/8 inch) section 8913 Rope 10 Seals by 22 13/16 inch long. Rope seals 421,541 have surprisinglybeen found to extend the live of first seals 421,541. This is thought to be by secretion of lubricants, such as graphite, during use. Figures 11 through 23 show the construction of the individual components of alternative swivel 100 shown assembled in Figures 7 through 9. Figure 10 shows a 15 mandrel 110. Figure 11 is a sectional view of sleeve 300. Figure 12 is a side view of sleeve 300. Sleeve 300 can include upper and lower lubrication ports 311,312. Ports 311,312 can be used to lubricate the bearings located under the ports when alternative swivel 100 is out of service. When in service it is preferred that lubrication ports 311,312 be closed 20 through threadable pipe plugs (or some pressure relieving type connection). This will prevent fluid migration through ports 311,312 when swivel 100 is exposed to high pressures (e.g., 5,000 pounds per square inch)(34.48 megapascals) such as when in deep water service. It is preferred that the heads of pipe plugs placed in lubrication ports 311,312 will be flush with the surface of sleeve 300. Flush mounting will minimize the 25 risk of having sleeve 300 catch or scratch something when in use. Upper o-ring 345 can be used to seal upper end cap 302 to sleeve 300. Back-up ring 347 can be used to increase the pressure rating of o-ring 345 (e.g., from 1,500 to 5,000 pound per square inch)(10.34 to 34.48 megapascals). Lower o-ring 346 can be used to seal lower end cap 304 to sleeve 300. Back-up ring 348 can be used to increase 30 the pressure rating of o-ring 346 (e.g., from 1,500 to 5,000 pound per square inch)(10.34 to 34.48 megapascals). Back up rings 347,348 increase pressure ratings by resisting -12extrusion of o-rings 345,346. Preferred constructions for o-rings 345,346 can be Parbak "0" ring 2-371 (75 Durometer V1 164 Viton) and Parkbak 371 (90 Durometer V0709 Viton). A preferred construction for back up rings 347,348 can be Parker "Parbak" 371 Teflon or Viton. 5 Figure 13 is a sectional view of alternative end caps 302,304. Both alternative end caps 302,304 are of similar construction. Figure 14 is a side view of the end caps 302,304 of Figure 13. Figure 14A is a sectional view of end caps 302, 304 taken along the line A of Figure 14. Figure 15 is a right side view of packing retainer nuts 340, 460. Figure 17 is a left side view of packing retainer nuts 340,460. Packing retainer nuts 10 340,460 can be of similar construction. Figure 18 is a top view of a spacer ring. This figure shows the construction of spacer rings 303,305. As shown spacer rings 303,305 can include a plurality of holes for fasteners 306,307. Figure 19 is a sectional view of the spacer ring 303,305 of Figure 18 taken along the line 19-19. Height 303A determines the space maintained between 15 endcaps 302,304 and sleeve 300. Spacer rings 303,305 can have the same or different heights 303A. Figure 20 is a top view of a male packing ring 410,530. Figure 21 is a sectional view of the male packing ring 410,530 of Figure 20 taken along the line 21-21. Male packing ring 410,530 can be machined from SAE 660 BRONZE or SAE 954 Aluminum 20 Bronze. Tip 412 preferably is machined at 45 degrees from a verticle with a flat head. Figure 22 is a top view of a spacer ring 390,510. Figure 23 is a sectional view of the spacer ring 390,510 taken along the line 22-22. Spacer ring 390,510 can comprise tip section 394 which has a smaller diameter than base section 392. Tip section 392 can be used to hold plurality of seals 420,540 (see Figure 8). Tip 394 is preferred in sealing 25 systems where female packing ring 400,520 is not used (e.g., the rope seal embodiment). Mandrel 110; sleeve 300; end caps 302,304; rings 303,305; packing retainer nuts 340,460 are preferably rough machined from 4340 NQT steel (1 30Y) forging having 285/321 BHN/125,000 minimum yield strength and 17 percent elongation. Regarding impact strength it is preferred that the average impact value will not be less than 31 FT 30 LBS withno tested value being less than24 FT-LBS when tested at -4 degrees Fahrenheit (tested as per ASTM E23). It is preferred that the tensile strength be tested using ASTM -13- A388 2% offset method or ASTM A370 2% offset method. It is preferred that a saver sub be placed on pin connection 150 of mandrel 110. The saver sub can protect the threads for pin connection 150. For example, if the threads on the saver sub are damaged only the saver sub need be replaced and not the entire 5 mandrel 110. To reduce friction between mandrel 110 and sleeve 300 and packing units 330, 450 and increase the life expectancy of packing units 330, 450, packing support areas 210,220 can be coated and/or sprayed welded with a materials of various compositions, such as hard chrome, nickel/chrome or nickel/aluminum (95 percent nickel and 5 percent 10 aluminum). A material which can be used for coating by spray welding is the chrome alloy TAFA 95MX Ultrahard Wire (Armacor M) manufactured by TAFA Technologies, Inc., 146 Pembroke Road, Concord New Hampshire. TAFA 95 MX is an alloy of the following composition: Chromium 30 percent; Boron 6 percent; Manganese 3 percent; Silicon 3 percent; and Iron balance. The TAFA 95 MX can be combined with a chrome 15 steel. Another material which can be used for coating by spray welding is TAFA BONDARC WIRE - 75B manufactured by TAFA Technologies, Inc. TAFA BONDARC WIRE - 75B is an alloy containing the following elements: Nickel 94 percent; Aluminum 4.6 percent; Titanium 0.6 percent; Iron 0.4 percent; Manganese 0.3 percent; Cobalt 0.2 percent; Molybdenum 0.1 percent; Copper 0.1 percent; and Chromium 0.1 20 percent. Another material which can be used for coating by spray welding is the nickel chrome alloy TAFALOY NICKEL-CHROME-MOLY WIRE-71T manufactured by TAFA Technologies, Inc. TAFALOY NICKEL-CHROME-MOLY WIRE-71T is an alloy containing the following elements: Nickel 61.2 percent; Chromium 22 percent; Iron 3 percent; Molybdenum 9 percent; Tantalum 3 percent; and Cobalt 1 percent. Various 25 combinations ofthe above alloys can also be used for the coating/spray welding. Packing support areas 210, 220 can also be coated by a plating method, such as electroplating or chrome plating. The surface of support areas 210, 220 can be ground/polished/finished to a desired finish to reduce friction and wear between support areas 210, 220 and packing units 330, 450. 30 Mandrel 110 can take substantially all of the structural load from drill string 85,86. The overall length of mandrel 110 is preferably 97 % inches. Mandrel 110 can -14be machined from a single continuous piece of 4340 heat treated steel bar stock (alternatively, can be from a rolled forging). NC50 is preferably the API Tool Joint Designation for the box connection 70 and pin connection 80. Such tool joint designation is equivalent to and interchangeable with 4 /2 inch IF (Internally Flush), 5 5 inch XH (Extra Hole) and 5 2 inch DSL (Double Stream Line) connections. Sleeve 300 is preferably 61 3/4 inches. End caps 302,304 are preferably about 8 inches. Spacer rings 303,305 can have a height 303A of 1 1/4 inches, however, this height is to be determined at construction. Various systems can be used to prevent plurality of fasteners 306,307 from 10 becoming loose or unfastened during use of swivel 100. One method is to use a specified torquing procedure. A second method is to use a thread adhesive on fasteners 306,307. Another is to use a plurality of snap rings or set screws above the heads of fasteners 306,307. Figures 7 through 9 show another method using a plurality of locks 600,620 and set screws 610,630 where locks 600,620 respectively connect to fasteners 306,307 15 and set screws 610,630 prevent locks 600,620 from backing out. Locks 600,620 can include hexagonal cross sections, such as an allen wrench tool, Additionally, a pair of covers can be threadably connected to end caps 302,304 and prevent fasteners 306,307 from backing out during use of swivel 100. Figures 24 through 27 show another alternative swivel. In this embodiment the 20 length of swivel 100' can be configured to allow sleeve 300' to reciprocate (e.g., slide up and down) on mandrel 110'. Figures 24A through 24C are schematic diagrams of a alternative swivel 100'which has a stroke along mandrel 110'. Figures 25A through 25C show swivel 100' wherein sleeve 300' can slide along mandrel 110'. Figure 26 shows mandrel 110' which can be incorporated in swivel 100'. Swivel can be made up of 25 mandrel 110' to fit in line of a drill work string 85,86 and sleeve 300' with a seal and bearing system (not shown but which can be similar to the seal and bearing system for swivel 100) to allow for the work string 85,86 to be rotated and reciprocated while swivel 100' and annular seal unit 71 separate the fluid column in riser 80 from the fluid column in wellbore 40. This can be achieved by locating swivel 100' in the annular blow out 30 preventer 70 where annular seal unit 71 can close around sleeve 300' forming a seal between sleeve 300' and annular seal unit 71, and the sealing system between sleeve 300' -15and mandrel 110' of swivel 100' forming a seal between sleeve 300' and mandrel 110', thus separating the two fluid columns (above and below annular seal unit 71) allowing. the fluid columns to be displaced individually. Swivel 100' can include a hard chromed sealing area on the o.d. of mandrel 110' throughout the travel length (or stroke length) to 5 assist in maintaining a seal between mandrel 110' and sleeve 300' seal area during rotation and/or reciprocation activities or procedures. Sleeve 300' can include a bearing system (not shown). The bearing system can include annular bearings, tapered bearings, or ball bearings. Alternatively, the bearing system can include teflon bearing sleeves or bronze bearing sleeves, allowing for low friction levels during rotating and/or 10 reciprocating procedures. In one embodimentjoints ofpipe 750,770 canbeplaced respectivelyon upper and lower sections 140', 130' of mandrel 110'. Joints of pipe 750 can include larger diameter sections than diameter 715 of mandrel 110'(see Figure 25A). Having larger diameters can prevent sleeve 300 from sliding off of mandrel 110'. Joints 750,780 can be 15 considered saver subs for the ends of mandrel 110' which take wear and handling away from mandrel 110'. Joints 750,780 are preferably of shorter length than a regular 20 or 40 foot joint of pipe, however, can be of the same lengths. In one embodiment joints of pipe include saver portions 760,770 which engage sleeve 300 at the end of mandrel 10' (see Figure 25B). Saver portions 760,770 can be shaped to cooperate with end caps 20 302,304. Saver portions can be of a different material such as polymers, teflon, rubber, or other material which is softer than steel or iron. As shown in Figure 25A, the stroke of swivel 100'can be the difference between height H 700 ofmandrel 110'and length L 710 ofsleeve 300. In one embodiment height H 700 can be about thirty feet (915 centimeters) and length L 710 can be about six feet 25 (183 centimeters). Preferably height H 700 is between two and twenty times that of length L 710. Alternatively, between two and fifteen times, two and ten times, two and eight times, two and six times, two and five times, two and four times, two and three times, and two and two and one half times. Also alternatively, between 1.5 and fifteen times, 1.5 and ten times, 1.5 and eight times, 1.5 and six times, 1.5 and five times, 1.5 30 and four times, 1.5 and three times, 1.5 and two times, 1.5 and two and one half times, and 1.5 and two times. -16- Figures 27 through 43 show an alternative swivel 100", which can comprise mandrel 110 and sleeve 300. As shown in Figure 28, sleeve 300 (see Figure 30) can be rotatably and sealably connected to mandrel 110 (see Figure 29). Similar to other embodiments, mandrel 110 can comprise upper end 120 and lower end 130. Central 5 longitudinal passage 160 can extend from upper end 120 through lower end 130. Lower end 130 can include a pin connection 150 or any other conventional connection. Upper end 120 can include box connection 140 or any other conventional connection. In this embodiment, sleeve 300 can be rotatably connected to mandrel 110 by a plurality of bushings 1300, preferably located on opposed longitudinal ends of mandrel 110. 10 Figure 28 shows a sectional view of the upper end of swivel 100". The lower end of swivel 100" is preferably constructed similar to that as shown in Figure 28 (but in mirror image). Sleeve 300 can be rotatably connected to mandrel 110 by one or more bushings 1300, preferably located on opposed longitudinal ends ofmandrel 110. Sleeve 300 can be sealably connected to mandrel 110 through one or more packing units 1100, 15 preferably located on opposed longitudinal ends of mandrel 110. The upper portion of sleeve 300 can be sealably connected to mandrel 110 by packing unit 1100. Packing unit 1100 can comprise male packing ring 1190, plurality of seals 1200, female packing ring 1180, spacer ring 1150, and packing retainer nut 1110. Packing retainer nut 1110 can be threadably connected to end cap 1000 through 20 threads 1050,1120. Tightening packing retainer nut 1110 squeezes spacer ring 1150 and plurality of seals 1200 between end cap 1000 and nut 1110 thereby increasing sealing between sleeve 300 (through end cap 1000) and swivel mandre 1110. Tip 1112 ofretainer nut 1110 can be used as a setting for proper tightening ofnut 1110 in end cap 1000. That is, as shown in Figure 28 nut 1110 can be tightened until tip 1112 is level 25 with second level 1012 of end cap 1000. Set screw 1130 can be used to lock packing retainer nut 1110 in place and prevent retainer nut 1110 from loosening during operation. Set screw 1130 can be threaded into bore 1140 and lock into end cap 1000. 0-ring 345 canbe used to seal upper end cap 302 to sleeve 300. Back up ring 347 can be used to increase the pressure rating of the seal between end cap 1000 and sleeve 300. 30 Spacer ring 1150, having base 1160 and tip 1170, can be of similar construction to spacer ring 390 shown in Figures 22 and 23. Tip 1170 is preferably located adjacent to -17female packing ring 1180. Plurality of seals 1200 can comprise first seal 1210, second seal 1220, third seal 1230, fourth seal 1240, and fifth seal 1250. First and third seals 1210,1230 can be Chevron type seals "VS" packingring (0370650-VS-85OHNBR) being highly saturated 5 nitrile. Second and fourth seals 1220,1240 can be Garlock 3/8 inch section 8913 rope seals having 22 13/16 inch LG. Fifth seal 1250 is preferably a Chevron type seal "VS" packingring being bronze filled teflon. Fifth seal1250 is preferably of a harder material than other seals (e.g., bronze or metal filled) so that it can seal at higher pressures relative to other softer or more flexible seals. 10 Figure 29 shows one possible construction of mandrel 110 for alternative swivel 100". Mandrel 110 can have upper end 120 and lower end 130. Mandrel 110 can have first surface 1600, second surface 1610, and third surface 1620 of increasing diameters. The change in diameters between second surface 1610 and third surface 1620 creates shoulders 1630 which restrict the maximum amount of relative longitudinal movement 15 (e.g., arrows 1550,1552 in Figure 28) between mandrel 110 and sleeve 300. Preferably, this relative movement will be about 1 and 1/4 inches (3.175 centimeters). Additionally, movement can vary between about 1/8 and 5 inches (0.3175 and 12.7 centimeters), between about 1/4 and 4 inches (0.635 and 10.16 centimeters), between about /2 and 3 inches (1.27 and 7.62 centimeters), between about 1 and 2 inches (2.54 20 and 5.08 centimeters). Similar to other described embodiments, to reduce friction between mandrel 110 and sleeve 300 and packing units 1100 along with increasing life expectancy of packing units 1100, packing support areas 1612,1614 can be treated, coated, and/or sprayed welded with a materials of various compositions, such as hard chrome, nickel/chrome 25 or nickel/aluminum (95 percent nickel and 5 percent aluminum). It is preferred that coating/spray welding does not enter a key recess 1650. First surface 1600 of mandrel 110 is shown being of a smaller relative diameter than second surface 1610. Looking at Figure 28, such construction can be used to facilitate insertion of packing unit 1100 on mandrel 110. If first 1600 and second 1610 30 surfaces were the same diameter then packing unit 1100 would be required to frictionally slide across the entire length of first surface 1600 and at least part of second -18surface 1610 to its final resting longitudinal location. Where first surface 1600 includes irregularities (such as scratches, nicks, etc.) these irregularities could damage packing unit 1100. Preferably, packing unit 1100 tightly fits only second surface 1610, and as can be seen from Figure 28, second surface 1610 is protected from damage during 5 operation by sleeve 300 and end cap 1000. Also seen from Figures 28 and 29, a substantial portion of first surface 1600 is not protected during use. Accordingly, the surface packing units 1100 will slide relative to during use (e.g., 1612 and 1614) are protected (by sleeve 300 during use) from damage such as scratching, nicks, dents, etc. Figure 30 shows one possible construction of'sleeve 300. Sleeve 300 can include 10 first inner diameter 1700, second inner diameter 1710, third inner diameter 1720, and fourth inner diameter 1730 - - each respectively of increasing diameter. Alternatively first inner diameter 1700 can be the same as second inner diameter 1710 (although having a smaller first inner diameter 1700 can provide increased strength for sleeve 300). Where a smaller first inner diameter 1700 is used, the longitudinal length of 15 second inner diameter is preferably long enough to facilitate installation of the components shown in Figures 28 on alternating ends of sleeve 300. That is, second inner diameter 1710 is large enough to slide a sufficient longitudinal amount over the top of key 1660. Sleeve 300 can have a uniform outer diameter 1760. At least a portion of the 20 surface of sleeve 300 can be designed to increase its frictional coefficient, such as by knurling, etching, rings, ribbing, etc. This can increase the gripping power of annular seal71 (ofblow-out preventer 70) against sleeve 300 where there exists high differential pressures above and below blow-out preventer 70 which tend to force sleeve 300 in a longitudinal direction. 25 One possible construction of bushing 1300 is shown in Figures 38 through 41. Bushing 1300 can be ofmetal or composite construction - - either coated with a friction reducing material and/or comprising a plurality of lubrication enhancing inserts 1382. Alternatively, bushing 1300 can rely on lubrication provided by different metals moving relative to one another. Bushings with lubrication enhancing inserts can be 30 conventionally obtained from Lubron Bearings Systems located in Huntington Beach, California. Bushing 1300 is preferably comprised of ASTM B271-C95500 cast nickel -19aluminum bronze. Lubrication enhancing inserts preferably comprise PTFE teflon epoxy composite dry blend lubricant (Lubron model number LUBRON AQ30 yield pressure 15,000 psi) and/or teflon and/or nylon. Different inserts (e.g., 1382A, 1382B, 1382C, etc.) can be of similar and/or different construction. For example one surface 5 of bushing 1300 can have inserts (e.g., 1382A) of one construction/composition while a second surface of bushing 1300 can have inserts (e.g., 1382B) of a different construction/composition. Additionally, inserts (e.g., 1382A, 1382B,etc.) on one surface can be of varying construction/composition. Circular inserts are shown, however, other shaped inserts can be used. Bushing 1300 allows for the overall outer diameter of sleeve 10 300 to be minimized relative to using roller or ball bearings between sleeve 300 and mandrel 110. Bushing 1300 also increases the maximum allowable thrust loading between mandrel 110 and sleeve 300 (relative to roller/ball bearings) while relative rotation between mandrel 110 and sleeve 300 occurs. Bushing 1300 can comprise outer surface 1310, inner surface 1320, upper surface 1330, and lower surface 1340. In Figure 15 39 bushing 1300 is shown with a plurality of inserts 1382 on lower surface 1340 and inner surface 1320. Inserts 1382 can be limited to the surfaces of bushing 1300 which see movement during relative rotation and/or longitudinal movement between mandrel 110 and sleeve 300. Figures 40 and 41 are rough outs ofbushing 1300, showing various recessed areas 1380 for inserts 1382. The finished bushing 1300 typically will have 20 more recessed areas 1380 than shown in Figures 40 and 41. Bushing 1300 is shown having outer surface 1310 being adjacent to fourth inner diameter 1730 of sleeve 300. Such construction facilitates centering sleeve 300 relative to mandrel 110, increases life expectancy of packing units 1000, and restricts relative movement in the directions of arrows 1554,1556 (shown in Figure 28). However, outer surface 1310 of bushing 1300 25 can be spaced apart from fourth inner diameter 1730 of sleeve 300. Bushing 1300 can be supported between end cap 1000 and hub 1400 (see Figure 28). More specifically, bushing 1300 can be supported between base 1020 (of end cap 1000) and upper surface 1500 (of ring 1490). Relative rotation between end cap 1000 and bushing 1300 can be prevented by having a plurality of tips 1010 (of end cap 1000) 30 operatively connected to a plurality of recesses 1390 (of bushing 1300). Base 1020 (of end cap 1006) supports upper surface 1330 (of bushing 1300). Lower surface 1340 of -20bushing 1300 is supported by upper surface 1500 (of ring 1490). Ring 1490 (Figures 37 and 38) can be operatively connected to hub 1400 (Figures 33 through 35) by a one or more dowels 1480 (see Figure 28). Preferablyring 1490 and hub 1400 would be a single piece of material, however, machining concerns 5 may make two pieces more practical. Hub 1400 can be operably connected to mandrel 110 by one or more keys 1660 (see Figures 28,29,41, and 42). Keys 1660 can sit in recesses 1650 of mandrel 110. Fasteners 1670 can be used to affix a key 1660 to mandrel 110. Preferably, two keys 1660 are used to connect each hub 1400 to mandrel 110 (providing a total of four keys 1660). Each key 1660 can slide in a groove 1430 of 10 hub 1400 allowing relative longitudinal movement between hub 1400 and mandrel 110. When mandrel 110 (of swivel 100") rotates hub 1400 (and ring 1490) rotates. When sleeve 300 rotates, end cap 1000 and bushing 1300 rotate. Based on this relative movement, lower surface 1340 (of bushing 1300) will move relative to upper surface 1500 (of ring 1490). Additionally, inner surface 1320 (of bushing 1300) will move 15 relative to second surface 1610 (of mandrel). This is one reason for inserts 1382 being placed on bushing's 1300 inner surface 1320 and lower surface 1340. Also assisting in lubricating surfaces which move relative to one another, one or more radial openings 1350 can be radially spaced apart around each bushing 1300. Through openings 1350 a lubricant can be injected which can travel to inner surface 1320 along with lower 20 surface 1340. The lubricant can be grease, oil, teflon, graphite, or other lubricant. The lubricant can be injected through a lubrication port (e.g., upper lubrication port 311). Perimeter pathway 1360 can assist in circumferentially distributing the injected lubricant around bushing 1300, and enable the lubricant to pass through the various openings 1350. Preferably no sharp surfaces/corners exist on outer surface 1310 of bushing 1300 25 which can damage o-ring 345 when (during assembly and disassembly of swivel 100") bushing 1300 passes by o-ring 345. Similarly preferable, no sharp surfaces/corners exist on first outer diameter 1070 of end cap 1000. Alternatively, outer surface 1310 can be constructed such that it does not touch o-ring 345 when being inserted into sleeve 300. In some situations a longitudinal thrust load canbe placed on mandrel 110 and/or 30 sleeve 300 causing mandrel 110 to move (relative to sleeve 300) in the direction of arrow 1552 and/or sleeve 300 to move (relative to mandrel 110) in the direction arrow -21- 1550. In such a case, assuming that mandrel 110 remains longitudinally static, sleeve 300, end cap 1000, ring 1490, and bearing 1300 will move in the direction of arrow 1550 until lower surface 1420 (ofhub 1400) is stopped by shoulder 1630 ofmandrel 110 (see Figure 28). During this motion hub 1400 will slide over one or more keys 1660 5 (through one or more grooves 1430). In such a manner a certain amount of longitudinal movement between sleeve 300 and mandrel 110 can be absorbed before a thrust load is generated by thrust hub 1400 contacting shoulder 1630. One example where absorption of longitudinal movement may be required where sleeve 300 is being held by annular seal unit 71 (see Figures 2 and 24), but where differential pressures existing between 10 fluid above annular seal unit 71 and below annular seal unit 71 cause deflection of annular seal unit 71. In such a case, longitudinal deflection of annular seal unit 71 can be absorbed by relative motion between sleeve 300 andmandre 1110 before a thrust load is placed on thrust hub 1400 and bearing 1300 (see Figure 28). Figures 44 and 45 show another alternative embodiment. Figure 44 shows the 15 lower portion of alternative swivel 100"' (upper portion can be substantially similar, but a mirror image). Figure 45 shows an end view of swivel 100"'. Swivel 100"' incorporates mandrel 110'(Figure 26) and sleeve 300'. Rotation between mandrel 110' and sleeve 300' is facilitated by bearing 1300. Additionally, relative longitudinal movement between mandrel 110' and sleeve 300'(in the directions of arrows 1550,1552) 20 is also facilitated by bearing 1300. End cap 1000' can be interconnected with bearing 1300 so that bearing 1300 will rotated with (and not relative to) sleeve 300'. Sleeve 300' can be sealed with respect to mandrel 110' through a plurality of seals 1200. Plurality of seals 1200 can be substantially the same as those in other embodiments. Additionally, the opposing end of swivel 100"' can be substantially similar to the end 25 shown in Figure 44. Swivel 100"' can be a reciprocating swivel and have movements as shown in Figures 24 through 27. In deep water settings, after drilling is stopped the total volume of drilling fluid 22 in the well bore 40 and the riser 80 can be in excess of 5,000 barrels. This drilling fluid 22 must be removed to ready the well for completion. Because of its relatively 30 high cost this drilling fluid 22 is typically recovered foruse in another drilling operation. Removal of drilling fluid 22 is typically done through displacement by a completion -22fluid 96 or displacement fluid 94. However, many rigs 10 do not have the capacity to store and supply 5,000 plus barrels of completion fluid 10 (and/or drilling fluid 22) and thereby displace "in one step" the total volume of drilling fluid 22 in the well bore 40 and riser 80. Accordingly, displacement is done in two or more stages. However, where 5 displacement process is performed in two or more stages, there is a high risk that, during the time period between the stages, the displacing fluid 94 and/or completion fluid 96 will intermix or interface with the drilling fluid 22 thereby causing the drilling fluid 22 to be unusable or require extensive and expensive reclamation efforts before being used again. Additionally, it has been found that, during displacement of the drilling fluid 10 22, rotation of the drill string 85,86 causes a rotation of the drilling fluid 22 in the riser 80 and well bore 40 and obtains a better overall recovery of the drilling fluid 22 and/or completion ofthe well. Additionally, during displacement there maybe a need to move in a vertical direction (e.g., reciprocate) and/or rotate the drill string 85,86 while performing displacement operations. In one embodiment the riser 80 and well bore 40 15 can be separated into two volumetric sections 90,92 (e.g., 2,500 barrels each) where the rig 10 can carry a sufficient amount of displacement fluid 94 and/or completion fluid 96 to remove each section without stopping during the displacement process. In one embodiment, fluid removal of the two volumetric sections 90,92 in stages can be accomplished, but there is a break of an indefinite period of time between stages 20 (although this break may be of short duration). In one embodiment a method and apparatus 100,100',100",100"' is provided which can be detachably connected to an annular blowout preventer 70 thereby separating the drilling fluid 22 or mud into upper and lower sections 90,92 and allowing the fluid 22 to be removed in two stages while the drill string 85,86 is being rotated. In 25 one embodiment the drill string 85,86 is not rotated, or rotated only intermittently. The swivel can be incorporated into a drill or well string 85,86 and enabling string sections both above and below the sleeve to be rotated in relation to the sleeve 300. Separating the drilling fluid 22 into upper and lower sections 90,92 prevents mixing displacement fluid 94, completion fluid 96 with the separated sections 90,92 during stages. 30 In one embodiment the drill or well string 85,86 does not move in a longitudinal direction relative to sleeve 300. In one embodiment drill or well string 85,86 does not -23move in a longitudinal direction relative to mandrel 110. In one embodiment drill or well string 85,86 does move in a longitudinal direction relative to sleeve 300. In one embodiment the drill or well string 85,86 moves in a longitudinal direction relative to the blow-out preventer 70. In one embodiment sleeve 300 does not rotate relative to 5 blow-out preventer 70, but does rotate relative to mandrel 110. In one embodiment blow-outpreventer 70is operatively connected to sleeve 300 while mandrel 110 and drill or well string 85,86 is reciprocated in a longitudinal direction relative to sleeve 300 and blow-out preventer 70. In one embodiment blow-out preventer 70 is operatively connected to sleeve 300 while mandrel 110 and drill or well 10 string 85,86 is reciprocated in a longitudinal direction relative to sleeve 300 and blow out preventer 70 and while mandrel 110 and drill or well string 85,86 are rotated relative to blow-out preventer 70. In any of these embodiments reciprocation in a longitudinal direction can be continuous, intermittent, and/or of varying speeds and/or amplitudes. In any of these embodiments rotation can be reciprocating, continuous, intermittent, 15 and/or of varying amplitudes and/or speeds. In one embodiment any of the swivels can also be used for reverse displacement in which the fluid is pumped in through the choke/kill lines down the annular of wellbore 40 and back up drill workstring 85,86. This process would help to remove debris that falls to the bottom of wellbore 40 that are difficult to remove using forward 20 displacement (where the fluid is pumped down the workstring 85,86 displacing up through the annular to the choke/kill lines. In an alternative embodiment (schematicallyillustratedby Figure 46) adds upper and lower catches 326,328 (or upsets) on sleeve 300. Upper and lower catches 326,326 restrict relative longitudinal movement of sleeve 300 with respect to blow out preventer 25 70 where high differential pressures exist above and or below blow-out preventer 70 tending to force sleeve 300 in a longitudinal direction. Upper and lower catches 326,328 can be integral with or attachable to sleeve 300. In one embodiment catches 326,328 can be threadably connected to sleeve 300. In one embodiment one or both catches 326,328 can be welded or otherwise connected to sleeve 300. In one embodiment one 30 or both catches 326,328 can be heat or shrink fitted onto sleeve 300. In one embodiment upper and lower catches 326,328 are of similar construction and of a disk like shape. -24- In one embodiment upper and lower catches 326,328 have perimeters which are curved or rounded to resist cutting/tearing of annular seal unit 71 if by chance annular seal unit 71 closes on either upper or lower catch 326,328. In one embodiment upper and lower catches 326,328 have are constructed to avoid any sharp corners to minimize any stress 5 enhances (e.g., such as that caused by sharp corners) and also resist cutting/tearing of other items. In one embodiment the largest distance from either catch 326,328 is less than the size of the opening in the housing for blow-out preventer 70 so that sleeve 300 can pass completely through preventer 70. In one embodiment the upper surface of upper catch 326 and the lower surface of lower catch 328 have frustoconical shapes 10 which can act as centering devices for sleeve 300 if for some reason sleeve 300 is not centered longitudinally when passing through blow-out preventer 70. In one embodiment upper catch 326 is actually larger than the size of the opening in the housing for blow-out preventer 70 which will allow sleeve to make metal to metal contact with the housing for blow-out preventer 70. 15 In one embodiment the largest distance from either catch 326,328 is less than the size of the opening in the housing for blow-outpreventer 70, but large enough to contact the supporting structure for annular seal unit 71 thereby allowing metal to metal contact either between upper catch 326 and the upper portion of supporting structure for seal unit 71 or allowing metal to metal contact between lower catch 328 and the lower 20 portion of supporting structure for seal unit 71. This allows either catch to limit the extent of longitudinal movement of sleeve 300 without relying on frictional resistance between sleeve 300 and annular seal unit 71. Preferably, contact is made with the supporting structure of annular seal unit 71 to avoid tearing/damaging seal unit 71 itself. In one embodiment non-symmetrical upper and lower catches 326,328 can be 25 used. For example a plurality of radially extending prongs can be used. As another example a single prong can be used. Additionally, channels, ridges, prongs or other upsets can be used. The catches or upsets to not have to be symmetrical. Whatever the configuration upper and lower catches 326,328 should be analyzed to confirm that they have sufficient strength to counteract longitudinal forces expected to be encountered 30 during use. Figures 47 through 53 illustrate another alternative embodiment for a swivel -25- 2100 having upper and lower catches 2326,2328 on sleeve 2300. Figure 48 is a sectional view of swivel 2100. Figure 49 is an enlarged view of upper end 2120 of swivel 2100. Figure 50 is a top view of a spacerring 2303,2305 for swivel 2100. Figure 51 is a top perspective view of a retainer cap 2400. Figure 52 shows swivel 2100 inside 5 a blowout preventer 70. Figure 53 is a perspective outside view of a blowout preventer 70. The construction of swivel 2100 can be substantially similar to the construction of swivel 100" shown in Figures 27 through 43 and accompanying text - - excepting the modifications fbr upper and lower catches 2326,2328 along with retainer caps 2400 for 10 end caps 2302,2304 and spacer rings 2303,2305. In this embodiment the upper and lower catches 2326,2328 can be shaped to act as centering devices for sleeve 2300 if for some reason sleeve 2300 is not centered longitudinally when passing through blow-out preventer 70. Upper and lower catches 2326,2328 can be constructed substantially similar to each other, but in mirror images. 15 Retainer caps 2400 (Figure 51) for end caps 2302,2304 can be designed to prevent the plurality ofbolts 2306 from falling out of end caps 2302,2304. Retainer cap 2400 for end cap 2302 can be of substantially similar construction to the retainer cap 2400 for end cap 2304. The design shown in this embodiment for retainer cap 2400 (see Figures 47,48, 49, and 51) uses tip 2420 which will restrict longitudinal movement of 20 any of the plurality of bolts 2306 holding end cap 2302 into sleeve 2300. Retainer cap 2400 can be attached to end cap 2302 (and sleeve 2300) through a plurality of bolts 2450. End cap 2302 can be connected to sleeve 2300 through a plurality of bolts 2306. Plurality of bolts 2450 can connect retainer cap 2400 to upper spacer ring 2303 (such as through threaded area 2460). In turn upper spacer ring 2303 can be connected to end cap 25 2302 through plurality of bolts 2306. Using such configuration will allow retainer cap 2400, upper spacer ring 2303, and upper end cap 2302 to be a single unit. Accordingly, if the plurality of bolts 2306 connecting upper end cap 2302 to sleeve 2300 were to fail, all bolts of plurality of bolts 1306 would be contained by retainer cap 2400. In such a situation end cap 2302 and retainer cap 2400 could only slide on mandrel 2100 until 30 blocked by a upset, such as by the next joint of pipe. Similarly, lower end cap 2304 would be a unit with retainer 2400 and spacer ring 2305. Accordingly, no bolts 2306 -26would fall down hole. Plurality of bolts 2450 are not expected to fail as they see no transient mechanical loads during operation (the transient mechanical loads are seen by plurality of bolts 2306 (connecting upper end cap 2302) and plurality of bolts 2307 (connecting lower end cap 2304). 5 Upper and lower catches 2326,2326 can restrict longitudinal movement ofsleeve 2300 where high differential pressures exist above and/or below blow-out preventer 70 tending to force sleeve 2300 in a longitudinal direction. Upper and lower catches 2326,2328 can be integral with or attachable to sleeve 2300. In this embodiment upper and lower catches 2326,2328 can include edges which are angled or rounded to resist 10 cutting/tearing of annular seal unit 71 if by chance annular seal unit 71 closes on either upper or lower catches 2326,2328. Upper catch 2326 can include base 2331, first transition area 2329, and second transition area 2330. Second transition area 2330 can shaped to fit with retainer cap 2400. Retainer cap 2400 can itself include upper surface 2410 which acts as a transition 15 area (See figure 49). Furthermore, upper surface 2410 can be shaped to match an angle of transition for upper end cap 2302. In such a way no sharp corners can be found and upper and lower catches 2326,2328, and they can act as centering devices when being moved downhole and through blow out preventer 70. Radiused area 2332 can be included to reduce or minimize and stress enhancers 20 between catch 2328 and sleeve 2300. Other methods of stress reduction can be used. Figures 54 through 70 illustrate another alternative embodiment for aswivel 300 having upper and lower catches 3326,3328 on sleeve 3300. Figure 54 is a perspective view of swivel 3100. Figure 55 is a sectional perspective view of swivel 3100 exposing mandrel 3110 and showing upper and lower shoulders 3170,3180 along with upper and 25 lower hubs 3190,3200. Upper and lower arrows 3102,3104 schematically indicate that mandrel 3110 and sleeve 3300 can have experience differential longitudinal movement with respect to each other. As will be described in more detail below this differential longitudinal movement is limited by upper and lower hubs 3190,3200 contacting upper and lower shoulders 3170,3180. In apreferred embodiment the differential longitudinal 30 movement is about 11/4 inches (3.175 centimeters). Figure 56 is a sectional perspective view of sleeve 3300. Figure 57 is a perspective view of mandrel 3110 and showing -27upper and lower shoulders 3170,3180 along with upper and lower hubs 3190,3200. Figure 59 is a sectional perspective view of a retainer cap 3400. Retainer cap 3400 can comprise base 3430 and tip 3420. Plurality of openings 3450 for bolts can be provided. Figures 60 through 62 show upper end cap 3302, packing system 3620, and bearing 5 3322. End cap 3302 can interlock with bearing 3322 through a plurality of tips (e.g., 3308, 3309, etc.). Packing system 3620 can be used to seal mandrel 3110 to sleeve 3300. Packing system 3620 can be locked into place by packing retainer nut 3600 and spacer ring 3610. Lower end cap 3304 can be constructed substantially similar to upper end cap 3302. 10 The construction of swivel 3100 can be substantially similar to the construction of swivel 100" shown in Figures 27 through 43 and accompanying text -- excepting the modifications for upper and lower catches 3326,3328 along with retainer caps 3400 for end caps 3302,3304. In this embodiment the upper and lower catches 3326,3328 can be shaped to act 15 as centering devices for swivel 3100 if for some reason swivel 3100 is not centered longitudinally when passing through blow-out preventer 70. Upper and lower catches 3326,3328 can be constructed substantially similar to each other, but in mirror images. Retainer caps 3400 (Figure 59) for end caps 3302,3304 can be designed to prevent the plurality of bolts 3306 from falling out of end caps 3302,3304. Retainer cap 20 3400 for end cap 3302 can be of substantially similar construction to the retainer cap 400 for end cap 3304. The design shown in this embodiment for retainer cap 3400 (see Figures 54-56,59, 63-65, and 69) uses tip 3420 (Figure 63B) which will restrict longitudinal movement of any of the plurality of bolts 3306 holding end cap 3302 into sleeve 3300, where one or more ofthe plurality ofbolts comes loose. Retainer cap 3400 25 can be attached to end cap 3302 (and sleeve 3300) through a plurality of bolts 3452. End cap 3302 can be connected to sleeve 3300 through a plurality of bolts 3306. Plurality of bolts 3452 can connect retainer cap 3400 to upper spacer ring 3303 (such as through threaded area 3460). In turn upper spacer ring 3303 can be connected to end cap 3302 through plurality of bolts 3306. Using such configuration will allow retainer cap 30 3400, upper spacer ring 3303, and upper end cap 3302 to be a single unit. Accordingly, if the plurality of bolts 3306 connecting upper end cap 3302 to sleeve 3300 were to fail, -28all bolts of plurality of bolts 3306 would be contained by retainer cap 3400. In such a situation end cap 3302 and retainer cap 3400 could only slide on mandrel 3100 until blocked by a upset, such as by the next joint of pipe. Similarly, lower end cap 3304 would be a unit with retainer 3400 and spacer ring 3305. Accordingly, no bolts 3306 5 would fall down hole. Plurality of bolts 3452 are not expected to fail as they see no transient mechanical loads during operation (the transient mechanical loads are seen by plurality of bolts 3306 (connecting upper end cap 3302) and plurality of bolts 3307 (connecting lower end cap 3304). Upper and lower catches 3326,3326 can restrict longitudinal movement of sleeve 10 3300 where high differential pressures exist above and/or below blow-out preventer 70 tending to force sleeve 3300 in a longitudinal direction. Upper and lower catches 3326,3328 can be integral with or attachable to sleeve 3300. In this embodiment upper and lower catches 3326,3328 can include edges which are angled or rounded to resist cutting/tearing of annular seal unit 71 if by chance annular seal unit 71 closes on either 15 upper or lower catches 3326,3328. Differential longitudinal movement in swivel 3100 between mandrel 3110 and sleeve 3300 is schematically illustrated in Figures 63 through 65C. Figures 63 through 63C are sectional views of swivel 3100 where sleeve 3300 is moved longitudinally upward with respect to mandrel 3110. Arrows 3700,3710 indicate this differential 20 longitudinal movement. Figure 63B shows gap 3702 between upper hub 3190 and upper shoulder 3170. Figure 63C shows lower hub 3200 being in contact with lower shoulder 3180. Figures 64Athrough 64C are sectional views of swivel 3100 where sleeve 3300 is longitudinally centered with respect to mandrel 3110. Figure 64B shows gap 3712 between upper hub 3190 and upper shoulder 3170. Figure 64C shows gap 3714 between 25 lower hub 3200 and lower shoulder 3180. Figures 65Athrough 65C are views of swivel 3100 where sleeve 3300 is moved longitudinally downward with respect to mandrel 3300. Arrows 3720,3730 indicate this differential longitudinal movement. Figure 65B shows upper hub 3190 being in contact with upper shoulder 3170. Figure 65C shows gap 3722 between lower hub 3200 and lower shoulder 3180. 30 Figures 66 through 68 schematically illustrate longitudinal movement of swivel 3100 relative to annular seal unit 71. Figure 66 is a perspective view of swivel 3100 -29where mandrel 3110 and sleeve 3300 are pulled up with respect to seal unit 71. Figure 67 is a perspective view of swivel 3100 where mandrel 3110 and sleeve 3300 are centered longitudinally with respect to seal unit 71. Figure 68 is a perspective view of swivel 3100 where mandrel 3110 and sleeve 3300 are pushed down with respect to seal 5 unit 71. The amount of differential longitudinal movement between sleeve 3300 and seal unit 71 is the difference between the distance 3760 between end catches (Figure 54) and the height 72 of annular seal unit 71. In Figure 66 distance 3770 shows this difference. In Figure 67, distances 3780 plus 3790 show this difference. In Figure 68 distance 3800 show this difference. 10 Figures 69 through 69 C are sectional views of swivel 3100 where sleeve 3300 is pulled up with respect to seal unit 71. In Figures 69A and 69C lower catch 3328 is in contact with seal unit 71 and upper catch 3326 is spaced apart from seal unit 71 by distance 3770. Plurality of arrows 3840 indicate fluid pressure above seal unit 71. Plurality of arrows 3850 indicate fluid pressure below seal unit 71. To reduce any a 15 differential force on sleeve 3300 when contacting seal unit 71, lower catch 3328 can be prevented from sealing with respect to seal unit 71. One embodiment includes a groove and valley design for the bases of upper and lower catches 3326,3328, which design is shown in Figures 54-56, 58, and 63-69. Such groove design is best shown in Figures 58 and 69A. 20 Plurality of arrows 3850 in Figures 69A and 69C schematically illustrate fluid migrating between seal unit 71 and lower catch 3328. Fluid cannot migrate past seal unit 71 as it seals with sleeve 3300. Figure 58 is a partial end view of the catches 3326,3328 showing a ridge and valley system. The upper half of the catch is not shown in Figure 58. Shown are first and second ridges 3331,3333. Between these two ridges 25 is first groove 3332. On the opposite side of second ridge 3333 as first groove 3332 is second groove 3334. A plurality of radial ports (e.g., 3336,3338, etc.) can be used to allow fluid to migrate to first and second grooves 3332,3334. Arrow 3342 schematically indicates a fluid migrating into a radial port. Arrows 3344,3346 schematically indicate the fluid continuing to migrate into first and second grooves 3332,3334. Inthismanner, 30 where a seal is made between either catch 3326,3328 and seal unit 71, the amount ofnet increase in thrust load seenby sleeve 3300 is reduced by the areas of grooves 3332,3334. -30- Figure 70 is a schematic diagram illustrating swivel 3100 resting on well head 88. It is preferred that swivel 3100 be prevented from passing through wellhead 88. Here, this preference is accomplished by making the diameter oflower catch 3328 larger than the smallest opening in wellhead 88. Additionally, it is preferred that where swivel 5 3100 and wellhead 88 make contact any damage be reduced. Here, reduction of damage from contact is accomplished by making swivel conform to the shape of the smallest opening in wellhead 88. As shown the angle of first transitional area 3360 matches the angle 88' of the smallest opening in wellhead 88. In another embodiment, a contacting surface can be provided, such as hard rubber, polymer, etc. 10 The following is a list of reference numerals: LIST FOR REFERENCE NUMERALS (Part No.) (Description) 15 Reference Numeral Description 10 rig 20 drilling fluid line 22 drilling fluid 30 rotary table 20 40 well bore 50 drill pipe 60 drill string or work string 70 annular blowout preventer 71 annular seal unit 25 80 riser 85 upper drill string. 86 lower drill string 87 ground surface 88 well head 30 90 upper volumetric section 92 lower volumetric section -31- 94 displacement fluid 96 completion fluid 100 swivel 101 upper section 5 102 lower section 110 swivel mandrel 120 upper end 130 lower end 140 box connection 10 150 pin connection 160 central longitudinal passage 170 shoulder 171 upper surface of shoulder 172 lower surface of shoulder 15 180 outer surface of shoulder 190 upper surface of shoulder 200 lower surface of shoulder 210 upper packing support area 220 lower packing support area 20 230 bearing 240 bearing 250 bearing 260 bearing 300 swivel sleeve 25 302 upper end cap 303 spacer ring 303A height 304 lower end cap 305 spacer ring 30 306 bolts 307 bolts -32- 308 tip 309 tip 310 interior section 311 upper lubrication port 5 312 lower lubrication port 320 protruding section 322 check valve 324 check valve 326 upper catch 10 328 lower catch 330 packing unit 332 support area 340 packing retainer nut 341 mechanical seal 15 345 o-ring 346 o-ring 347 back-up ring 348 back-up ring 350 bore for set screw 20 360 set screw for packing retainer nut 361 bore 370 threaded area 380 set screw for receiving area 390 spacer ring 25 392 base 394 tip 400 female packing ring 410 male packing ring 412 tip 30 420 plurality of seals 450 packing unit -33- 452 support area 460 packing retainer nut 461 mechanical seal 470 bore for set screw 5 480 set screw for packing retainer nut 490 threaded area 500 set screw for receiving area 510 spacer ring 520 female packing ring 10 530 male packing ring 540 plurality of seals 600 lock 610 set screw 620 lock 15 630 set screw 700 H or height of mandrel 715 W or outer diameter of mandrel 710 L or length of sleeve 750 joint of pipe 20 760 saver portion 770 joint of pipe 780 saver portion 1000 end cap 1010 tip 25 1012 second level 1020 base 1030 surface 1040 surface 1050 threads 30 1060 mechanical seal 1070 first outer diameter -34- 1100 packing unit 1110 packing retainer nut 1112 tip 1120 threaded area 5 1130 set screw for packing retainer nut 1140 bore for set screw 1150 spacer ring 1160 base 1170 tip 10 1180 female packing ring 1190 male packing ring 1200 plurality of seals 1210 first seal 1220 second seal 15 1230 third seal 1240 fourth seal 1250 fifth seal 1300 bearing 1310 outer surface 20 1320 inner surface 1330 upper surface 1332 recessed area 1340 lower surface 1350 opening 25 1360 pathway 1380 recessed area 1382 inserts 1390 opening 1392 base 30 1400 hub 1410 upper surface -35- 1420 lower surface 1430 groove 1440 inner diameter 1450 first outer diameter 5 1460 second outer diameter 1470 transition area 1480 dowel 1482 opening for dowel 1490 ring 10 1492 opening for dowel 1500 upper surface 1510 lower surface 1520 inner diameter 1530 outer diameter 15 1550 arrow 1552 arrow 1554 arrow 1556 arrow 1600 first surface of mandrel 20 1610 second surface of mandrel 1612 area for plurality of seals 1614 area for plurality of seals 1620 third surface of mandrel 1630 shoulder 25 1640 transition 1650 recess for key 1660 key 1662 curved end 1665 opening 30 1670 fastener for key 1700 first inner diameter of sleeve -36- 1710 second inner diameter of sleeve 1720 third inner diameter of sleeve 1730 fourth inner diameter of sleeve 1740 transition 5 1750 shoulder 1760 outer diameter 2100 swivel 2110 swivel mandrel 2120 upper end 10 2130 lower end 2140 box connection 2150 pin connection 2160 central longitudinal passage 2170 shoulder 15 2171 upper surface of shoulder 2172 lower surface of shoulder 2180 outer surface of shoulder 2190 upper surface of shoulder 2200 lower surface of shoulder 20 2210 upper packing support area 2220 lower packing support area 2300 swivel sleeve 2302 upper end cap 2303 spacer ring 25 2304 lower end cap 2305 spacer ring 2306 bolts 2307 bolts 2308 tip 30 2309 tip 2310 interior section -37- 2311 upper lubrication port 2312 lower lubrication port 2320 protruding section 2322 check valve 5 2324 check valve 2326 upper catch 2328 lower catch 2329 first transition section 2330 second transition section 10 2331 base 2332 radiused area 2400 retainer cap 2410 upper surface of retainer cap 2420 tip of retainer cap 15 2430 base of retainer cap 2450 bolts 2451 recessed area 2460 threaded area 2465 threaded area 20 2470 plurality of bolt holes 2480 plurality of bolt holes 3100 swivel 3102 arrow 3104 arrow 25 3110 swivel mandrel 3120 upper end 3130 lower end 3140 box connection 3150 pin connection 30 3160 central longitudinal passage 3170 upper shoulder of mandrel -38- 3180 lower shoulder of mandrel 3190 upper hub 3192 key 3194 ring 5 3200 lower hub 3202 key 3204 ring 3300 swivel sleeve 3302 upper end cap 10 3303 spacer ring 3304 lower end cap 3305 spacer ring 3306 bolts 3307 bolts 15 3308 tip 3309 tip 3310 interior section 3311 upper lubrication port 3312 lower lubrication port 20 3320 protruding section 3322 upper bearing 3324 lower bearing 3326 upper catch 3328 lower catch 25 3330 base 3331 first ridge 3332 first groove 3333 second ridge 3334 second groove 30 3336 first radial port 3338 second radial port -39- 3340 radiused area 3350 peripheral valley 3360 first transitional area 3370 angle of first transitional area 5 3340 radiused area 3400 retainer cap 3410 upper surface of retainer cap 3420 tip of retainer cap 3430 base of retainer cap 10 3450 plurality of openings for bolts 3451 recessed area 3452 plurality of bolts 3460 threaded area 3465 threaded area 15 3470 plurality of bolt holes 3480 plurality of bolt holes 3600 packing retainer nut 3610 spacer ring 3620 packing system 20 3700 arrow 3702 gap 3710 arrow 3712 gap 3714 gap 25 3720 arrow 3722 gap 3730 arrow 3740 arrow 3750 arrow 30 3760 distance between catches 3770 difference between catches and height of -40seal unit 3780 upper gap 3790 lower gap 3840 fluid pressure arrow 5 3850 fluid pressure arrow BJ ball joint BL booster line CM choke manifold CL diverter line 10 CM choke manifold 1) diverter DL diverter line F rig floor lB inner barrel 15 KL kill line MP mud pit MB mud gas buster or separator OB outer barrel R riser 20 RF flow line S floating structure or rig SJ slip or telescoping joint SS shale shaker W wellhead 25 All measurements disclosed herein are at standard temperature and pressure, at sea level on Earth, unless indicated otherwise. All materials used or intended to be used in a human being are biocompatible, unless indicated otherwise. It will be understood that each of the elements described above, or two or more together may also find a useful application in other types of methods differing from the 30 type described above. Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily -41adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention set forth in the appended claims. The foregoing embodiments are presented by way of example only; the scope of the present invention is to be limited 5 only by the following claims. -42-

Claims (20)

1. 1. A swivel comprising: (a) a mandrel having upper and lower end sections and connected to and rotatable with upper and lower drill or work string sections, the mandrel including a longitudinal passage 5 forming a continuation of a passage in the drill or work string sections; (b) a sleeve having a longitudinal sleeve passage, the sleeve being rotatably connected to the mandrel by a pair of longitudinally spaced bearings; (c) a seal between upper and lower end portions of the mandrel and sleeve, the seal preventing leakage of fluid between the mandrel and sleeve, the seal comprising a rope seal and 0 a non-rope seal.

2. The swivel of claim 1, wherein the seal further comprises a pair of spaced apart packing units; the sleeve further comprises a protruding section in the longitudinal sleeve passage, each of the packing units being located on opposite sides of the protruding section.

3. The swivel of claim 1 or 2, wherein the sleeve further comprises a plurality of lubrication 5 ports, the lubrication ports being positioned to lubricate at least two of the spaced bearings.

4. A swivel insertable into a drill or work string comprising: (a) a mandrel having upper and lower end sections and connected to and rotatable with upper and lower drill or work string sections, the mandrel including a longitudinal passage forming a continuation of a passage in the drill or work string sections; 20 (b) a sleeve having a longitudinal sleeve passage, the sleeve being rotatably connected to the mandrel by a pair of longitudinally spaced bearings; (c) a pair of spaced apart packing units between upper and lower end portions of the mandrel and sleeve, the packing units preventing leakage of fluid between the mandrel and sleeve, the packing units each comprising a rope seal and a non-rope seal; and 25 (d) the packing units restricting fluid flow between its interior and exterior sections.

5. The swivel of claim 4, wherein each packing unit further comprises a female packing end 43 and a male packing end.

6. The swivel of claim 5, wherein a chevron type seal is placed between the female and male packing ends.

7. The swivel of claim 4, further comprising a pair of packing retainer nuts threadably 5 engaging the sleeve, each packing retainer nut engaging one of the packing units.

8. The swivel of claim 4, wherein the sleeve further comprises a protruding section, the protruding section engaging each of the packing units.

9. The swivel of claim 4, wherein the sleeve includes at least one catch, the catch tending to restrict longitudinal movement of the sleeve relative to a blow out preventer when the swivel t0 detachably connected to the blowout preventer.

10. The swivel of claim 9, wherein the sleeve includes two catches which are spaced apart and which both tend to restrict longitudinal movement relative to the blow out preventer.

11. The swivel of claim 10, wherein each catch is radially symmetric relative to the sleeve.

12. The swivel of claim 11, wherein each catch includes at least one portion which is 15 frustoconical.

13. The swivel of claim 10, wherein the catches and sleeve are fabricated from a single piece of stock material.

14. The swivel of claim 9, wherein the catch includes a contacting surface, the contacting surface having at least one opening or groove for allowing fluid flow across at least part of the 20 surface.

15. A swivel insertable into a drill or work string comprising: (a) a mandrel having upper and lower end sections and connected to and rotatable with upper and lower drill or work string sections, the mandrel including a longitudinal passage forming a continuation of a passage in the drill or work string sections; 25 (b) a sleeve having a longitudinal sleeve passage, the sleeve being rotatably connected to the mandrel by a pair of longitudinally spaced bearings; 44 (c) a pair of spaced apart packing units between upper and lower end portions of the mandrel and sleeve, the packing units preventing leakage of fluid between the mandrel and sleeve, the packing units each comprising a plurality of rope seals and at least one non-rope seal; and 5 (d) the sleeve comprising an inlet port positioned between the spaced bearings.

16. The swivel of claim 15, further including a coated section located in the vicinity of at least one of the packing units.

17. The swivel of any of claims 1-16, wherein the sleeve is reciprocable between the upper and lower sections of the mandrel. .0

18. The swivel of any of claims 1-16, wherein the non-rope seal comprises teflon.

19. The swivel of any of claims 1-16, wherein the non-rope seal comprises metal filled teflon.

20. The swivel of any of claims 1-16, wherein the non-rope seal comprises bronze filled teflon. 45