Patent Publication Number: US-2023151700-A1

Title: Downhole swivel apparatus and method

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This is a continuation of U.S. patent application Ser. No. 17/240,073, filed Apr. 26, 2021 (issuing as U.S. Pat. No. 11,506,000 on Nov. 22, 2022), which is a continuation of U.S. patent application Ser. No. 16/983,488, filed Aug. 3, 2020 (now U.S. Pat. No. 10,988,989), which is a continuation of U.S. patent application Ser. No. 16/416,439, filed May 20, 2019 (now U.S. Pat. No. 10,294,732), which is a continuation of U.S. patent application Ser. No. 15/829,953, filed Dec. 3, 2017 (now U.S. Pat. No. 10,294,732), which is a continuation of U.S. patent application Ser. No. 15/162,665, filed May 24, 2016 (now U.S. Pat. No. 9,834,996), which is a continuation of U.S. patent application Ser. No. 14/595,713, filed Jan. 13, 2015 (now U.S. Pat. No. 9,347,283), which is a continuation of U.S. patent application Ser. No. 14/276,459, filed May 13, 2014 (now U.S. Pat. No. 8,931,560), which is a continuation of U.S. patent application Ser. No. 13/686,139, filed Nov. 27, 2012 (now U.S. Pat. No. 8,720,577), which is a continuation of U.S. patent application Ser. No. 11/943,012, filed Nov. 20, 2007 (now U.S. Pat. No. 8,316,945), which was a continuation of U.S. patent application Ser. No. 11/284,425, filed Nov. 18, 2005 (now U.S. Pat. No. 7,296,628), which is a non-provisional and claims the benefit of each of the following provisional patent applications: (a) U.S. Provisional Patent Application Ser. No. 60/631,681, filed Nov. 30, 2004; (b) U.S. Provisional Patent Application Ser. No. 60/648,549, filed Jan. 31, 2005; (c) U.S. Provisional Patent Application Ser. No. 60/671,876, filed Apr. 15, 2005; and (d) U.S. Provisional Patent Application Ser. No. 60/700,082, filed Jul. 18, 2005. 
     Each of the above referenced patents/patent applications are incorporated herein by reference in their entirety, and priority to/of each is hereby claimed. 
    
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not applicable 
     REFERENCE TO A “MICROFICHE APPENDIX” 
     Not applicable 
     BACKGROUND 
     In deepwater drilling rigs, marine risers extending from a wellhead fixed on the ocean floor have 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 FIG. 1 of U.S. Pat. No. 6,263,982 (which patent is incorporated herein by reference). A conventional slip 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 IB 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 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 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 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. 
     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 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. 
     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, such as where perforations will be made for later production. 
     During displacement there is a need to allow the drilling fluid to be displaced in two or more sections. 
     During displacement there is a need to prevent intermixing of the drilling fluid with displacement fluid. 
     During displacement there is a need to allow the drill string to rotate. 
     During displacement there is a need 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 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.” 
     BRIEF SUMMARY 
     The method and apparatus of the present invention solves the problems confronted in the art in a simple and straightforward manner. 
     One embodiment relates to a method and apparatus for deepwater rigs. In particular, one embodiment relates to a method and apparatus for removing or displacing working fluids in a well bore and riser. 
     One embodiment provides a method and 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. 
     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 a the sealing system between the sleeve and the mandrel has a higher pressure 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 embodiment a plurality of catches or upsets are used. In one 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 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. 
     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 (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. 
     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 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. 
     The drawings constitute a part of this specification and include exemplary embodiments to the invention, which may be embodied in various forms. 
    
    
     
       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 elements and wherein: 
         FIG.  1    is a schematic view showing a deep water drilling rig with riser and annular blowout preventer; 
         FIG.  2    is another schematic view of a deep water drilling rig showing a swivel detachably connected to an annular blowout preventer; 
         FIG.  3    is a sectional view of a swivel; 
         FIG.  4    is a sectional view of the upper portion of the swivel in  FIG.  3   ; 
         FIG.  5    is a sectional view of the lower portion of the swivel in  FIG.  3   ; 
         FIG.  6    is a sectional side view of the swivel in  FIG.  3    taken along the lines B-B; 
         FIG.  7    is a sectional view of an alternative swivel; 
         FIG.  8    is a sectional view of the lower portion of the swivel in  FIG.  7   ; 
         FIG.  9    is a sectional view of the upper portion of the swivel in  FIG.  7   ; 
         FIG.  10    shows a mandrel for the swivel in  FIG.  7   ; 
         FIG.  11    is a sectional view of a sleeve for the swivel in  FIG.  7   ; 
         FIG.  12    is a side view of the sleeve of  FIG.  11   ; 
         FIG.  13    is a sectional view of an alternative end cap for the swivel in  FIG.  7   ; 
         FIG.  14    is a side view of the end cap of  FIG.  13   ; 
         FIG.  14 A  is a sectional view of  FIG.  14   ; 
         FIG.  15    is a sectional view of a packing retainer nut for the swivel in  FIG.  7   ; 
         FIG.  16    is a right side view of the packing retainer nut of  FIG.  15   ; 
         FIG.  17    is a left side view of the packing retainer nut of  FIG.  15   ; 
         FIG.  18    is a top view of a spacer ring; 
         FIG.  19    is a sectional view of the spacer ring of  FIG.  18    taken along the line  19 - 19 ; 
         FIG.  20    is a top view of a male packing ring; 
         FIG.  21    is a sectional view of the male packing ring of  FIG.  20    taken along the line  21 - 21 ; 
         FIG.  22    is a top view of a spacer ring; 
         FIG.  23    is a sectional view of the spacer ring of  FIG.  22    taken along the line  22 - 22 ; 
         FIGS.  24 A through  24 C  are schematic diagrams of an alternative swivel which has a stroke along the mandrel; 
         FIGS.  25 A through  25 C  show a swivel wherein the sleeve can slide along the mandrel. 
         FIG.  26    shows a mandrel which can be incorporated in the alternative swivel of  FIG.  24   . 
         FIG.  27    shows another alternative swivel. 
         FIG.  27 A  is an end view of the swivel of  FIG.  27   . 
         FIG.  28    is a sectional view of the upper part of the swivel of  FIG.  27   . 
         FIG.  29    shows a mandrel for the swivel of  FIG.  27   . 
         FIG.  30    shows a sleeve for the swivel of  FIG.  27   . 
         FIG.  31    shows an end view of the end cap for the swivel of  FIG.  27   . 
         FIG.  32    is a sectional view of the end cap of  FIG.  31   . 
         FIG.  33    shows an end view of a thrust hub for the swivel of  FIG.  27   . 
         FIG.  34    is a sectional view of the thrust hub of  FIG.  33   . 
         FIG.  35    is an opposing end view of the thrust hub of  FIG.  33   . 
         FIG.  36    shows an end view of a thrust ring. 
         FIG.  37    is a sectional view of the thrust ring of  FIG.  36   . 
         FIG.  38    shows an end view of a bushing. 
         FIG.  39    is a sectional view of the busing of  FIG.  38   . 
         FIG.  39 A  is an enlarged view of the indicated area of  FIG.  39   . 
         FIG.  40    is a rough cut of the bushing of  FIG.  38    showing various recessed areas. 
         FIG.  41    is an end view of the rough cut of  FIG.  40   . 
         FIG.  42    shows a key which can be used in the swivel of  FIG.  27   . 
         FIG.  43    is a sectional view of the key of  FIG.  42   . 
         FIG.  44    shows the lower portion of another alternative swivel. 
         FIG.  45    shows an end view of the swivel of  FIG.  44   . 
         FIG.  46    is a schematic diagram of another alternative swivel have upper and lower catches. 
         FIG.  47    is a perspective view of an another alternative swivel having modified upper and lower catches. 
         FIG.  48    is a sectional view of the swivel of  FIG.  46   . 
         FIG.  49    is an enlarged view of the upper portion of the section view of  FIG.  48   . 
         FIG.  50    is a top view of a spacer ring for the swivel of  FIG.  46   . 
         FIG.  51    is a top perspective view of a retainer cap. 
         FIG.  52    shows the swivel of  FIG.  46    inside a blowout preventer. 
         FIG.  53    is a perspective view of a blowout preventer. 
         FIG.  54    is a perspective view of another alternative swivel having modified upper and lower catches. 
         FIG.  55    is a sectional perspective view of the swivel of  FIG.  54   . 
         FIG.  56    is a sectional perspective view of the sleeve from the swivel of  FIG.  54   . 
         FIG.  57    is a perspective view of the mandrel from the swivel of  FIG.  54   . 
         FIG.  58    is an end view of the part of the catch from the sleeve of  FIG.  56   . 
         FIG.  59    is a sectional perspective view of a retainer cap. 
         FIG.  60    is a perspective view of an end cap connected to a bearing. 
         FIG.  61    is a sectional view of the end cap and bearing of  FIG.  60   . 
         FIG.  62    is a rear perspective view of the end cap of  FIG.  60   . 
         FIGS.  63  through  63 C  are views of the swivel of  FIG.  54    where the sleeve is moved up with respect to the mandrel. 
         FIGS.  64 A through  64 C  are views of the swivel of  FIG.  54    where the sleeve is centered with respect to the mandrel. 
         FIGS.  65 A through  65 C  are views of the swivel of  FIG.  54    where the sleeve is moved down with respect to the mandrel. 
         FIG.  66    is a perspective view of the swivel of  FIG.  54    where the mandrel and sleeve are pulled up with respect to the annular blow out preventer. 
         FIG.  67    is a perspective view of the swivel of  FIG.  54    where the mandrel and sleeve are centered longitudinally with respect to the annular blow out preventer. 
         FIG.  68    is a perspective view of the swivel of  FIG.  54    where the mandrel and sleeve are pushed down with respect to the annular blow out preventer. 
         FIGS.  69  through  69    C are views of the swivel of  FIG.  54    where the mandrel and sleeve are pulled up with respect to the annular blow out preventer. 
         FIG.  70    is a schematic diagram illustrating the swivel of  54  seating on a well head. 
     
    
    
     DETAILED DESCRIPTION 
     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. 
       FIG.  1    is a schematic view showing rig  10  connected to riser  80  and having annular blowout preventer  70 .  FIG.  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 preventer  70  is sealed around swivel  100  thereby separating a fluid into upper and lower longitudinal sections. 
       FIGS.  3  through  6    show one embodiment of swivel  100 .  FIG.  3    is a schematic view of swivel  100 .  FIG.  4    is a sectional view of the upper portion of swivel  100  identified by bracket  101  in  FIG.  3   .  FIG.  5    is a sectional view of the lower portion of swivel  100  identified by bracket  102  in  FIG.  3   .  FIG.  6    is a sectional side view of swivel  100  taken along the lines B-B of  FIG.  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. 
     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 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. Mandrel  110  can in effect become a part of drill string  85 , 86  as shown in  FIG.  2   . 
     Sleeve  300  can fit over mandrel  110  and be rotatably and sealably connected to 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 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 be connected to sleeve  300  respectively by plurality of fasteners  306 , 307 , such as bolts. 
     Upper bearings  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 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  FIG.  4   , a spacer ring  303  can be used 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. As shown in  FIG.  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 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 cap  304  and mandrel  110 . 
     Sleeve  300  can be sealably 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 . 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 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  345 A 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 retainer nut  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 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  346 A 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  310 . 
       FIGS.  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  620  and set screws  630  can be used to prevent plurality of bolts  307  from loosening during use. 
       FIGS.  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  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 ⅜ inch section height. Plurality of rope seals  423 , 543  can be Garlock 7/16 inch (or ⅜ inch) section 8913 Rope Seals by 22 13/16 inch long. Rope seals  421 , 541  have surprisingly been found to extend the live of first seals  421 , 541 . This is thought to be by secretion of lubricants, such as graphite, during use. 
       FIGS.  11  through  23    show the construction of the individual components of alternative swivel  100  shown assembled in  FIGS.  7  through  9   .  FIG.  10    shows a mandrel  110 .  FIG.  11    is a sectional view of sleeve  300 .  FIG.  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 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) 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 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). 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 the pressure rating of o-ring  346  (e.g., from 1,500 to 5,000 pound per square inch). Back up rings  347 , 348  increase pressure ratings by resisting extrusion of o-rings  345 , 346 . Preferred constructions for o-rings  345 , 346  can be Parbak “0” ring 2-371 (75 Durometer V1164 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. 
       FIG.  13    is a sectional view of alternative end caps  302 , 304 . Both alternative end caps  302 , 304  are of similar construction.  FIG.  14    is a side view of the end caps  302 , 304  of  FIG.  13   .  FIG.  14 A  is a sectional view of end caps  302 ,  304  taken along the line A of  FIG.  14   .  FIG.  15    is a right side view of packing retainer nuts  340 ,  460 .  FIG.  17    is a left side view of packing retainer nuts  340 , 460 . Packing retainer nuts  340 , 460  can be of similar construction. 
       FIG.  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 .  FIG.  19    is a sectional view of the spacer ring  303 , 305  of  FIG.  18    taken along the line  19 - 19 . Height  303 A determines the space maintained between endcaps  302 , 304  and sleeve  300 . Spacer rings  303 , 305  can have the same or different heights  303 A. 
       FIG.  20    is a top view of a male packing ring  410 , 530 .  FIG.  21    is a sectional view of the male packing ring  410 , 530  of  FIG.  20    taken along the line  21 - 21 . Male packing ring  410 , 530  can be machined from SAE 660 BRONZE or SAE 954 Aluminum Bronze. Tip  412  preferably is machined at 45 degrees from a verticle with a flat head. 
       FIG.  22    is a top view of a spacer ring  390 , 510 .  FIG.  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  FIG.  8   ). Tip  394  is preferred in sealing 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 (130Y) 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-LBS with no tested value being less than 24 FT-LBS when tested at −4 degrees Fahrenheit (tested as per ASTM E23). It is preferred that the tensile strength be tested using ASTM 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 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 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 N.H. TAFA 95 MX is an alloy of the following composition: Chromium 30 percent; Boron 6 percent; Manganese 3 percent; Silicon 3 percent; and lion balance. The TAFA 95 MX can be combined with a chrome 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 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 combinations of the 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 . 
     Mandrel  110  can take substantially all of the structural load from drill string  85 , 86 . The overall length of mandrel  110  is preferably 97½ inches. Mandrel  110  can be 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 4½ inch IF (Internally Flush), 5 inch XH (Extra Hole) and 5½ inch DSL (Double Stream Line) connections. 
     Sleeve  300  is preferably 61¾ inches. End caps  302 , 304  are preferably about 8 inches. Spacer rings  303 , 305  can have a height  303 A of 1¼ inches, however, this height is to be determined at construction. 
     Various systems can be used to prevent plurality of fasteners  306 , 307  from 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 .  FIGS.  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  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 . 
       FIGS.  24  through  27    show another alternative swivel. In this embodiment the length of swivel  100 ′ can be configured to allow sleeve  300 ′ to reciprocate (e.g., slide up and down) on mandrel  110 ′.  FIGS.  24 A through  24 C  are schematic diagrams of a alternative swivel  100 ′ which has a stroke along mandrel  110 ′.  FIGS.  25 A through  25 C  show swivel  100 ′ wherein sleeve  300 ′ can slide along mandrel  110 ′.  FIG.  26    shows mandrel  110 ′ which can be incorporated in swivel  100 ′. Swivel can be made up of 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 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 ′ and 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 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 reciprocating procedures. 
     In one embodiment joints of pipe  750 , 770  can be placed respectively on 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  FIG.  25 A ). Having larger diameters can prevent sleeve  300  from sliding off of mandrel  110 ′. Joints  750 , 780  can be 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  FIG.  25 B ). Saver portions  760 , 770  can be shaped to cooperate with end caps  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  FIG.  25 A , the stroke of swivel  100 ′ can be the difference between height H  700  of mandrel  110 ′ and length L  710  of sleeve  300 . In one embodiment height H  700  can be about thirty feet and length L  710  can be about six feet. 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 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. 
       FIGS.  27  through  43    show an alternative swivel  100 ″, which can comprise mandrel  110  and sleeve  300 . As shown in  FIG.  28   , sleeve  300  (see  FIG.  30   ) can be rotatably and sealably connected to mandrel  110  (see  FIG.  29   ). Similar to other embodiments, 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 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 . 
       FIG.  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  FIG.  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 of mandrel  110 . Sleeve  300  can be sealably connected to mandrel  110  through one or more packing units  1100 , 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 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 mandrel  110 . Tip  1112  of retainer nut  1110  can be used as a setting for proper tightening of nut  1110  in end cap  1000 . That is, as shown in  FIG.  28    nut  1110  can be tightened until tip  1112  is level 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 . 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 the seal between end cap  1000  and sleeve  300 . Spacer ring  1150 , having base  1160  and tip  1170 , can be of similar construction to spacer ring  390  shown in  FIGS.  22  and  23   . Tip  1170  is preferably located adjacent to female 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” packing ring (0370650-VS-850HNBR) being highly saturated nitrile. Second and fourth seals  1220 , 1240  can be Garlock ⅜ inch section 8913 rope seals having 22 13/16 inch LG. Fifth seal  1250  is preferably a Chevron type seal “VS” packing ring being bronze filled teflon. Fifth seal  1250  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. 
       FIG.  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 (e.g., arrows  1550 , 1552  in  FIG.  28   ) between mandrel  110  and sleeve  300 . Preferably, this relative movement will be about 1 and ¼ inches. Additionally, movement can vary between about ⅛ and 5 inches, between about ¼ and 4 inches, between about ½ and 3 inches, between about 1 and 2 inches. 
     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 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  FIG.  28   , such construction can be used to facilitate insertion of packing unit  1100  on mandrel  110 . If first  1600  and second  1610  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 surface  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  FIG.  28   , second surface  1610  is protected from damage during operation by sleeve  300  and end cap  1000 . Also seen from  FIGS.  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. 
       FIG.  30    shows one possible construction of sleeve  300 . Sleeve  300  can include 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 second inner diameter is preferably long enough to facilitate installation of the components shown in  FIG.  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 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 seal  71  (of blow-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. 
     One possible construction of bushing  1300  is shown in  FIGS.  38  through  41   . Bushing  1300  can be of metal 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 conventionally obtained from Lubron Bearings Systems located in Huntington Beach, Calif. Bushing  1300  is preferably comprised of ASTM B271-C95500 cast nickel aluminum 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.,  1382 A,  1382 B,  1382 C, etc.) can be of similar and/or different construction. For example one surface of bushing  1300  can have inserts (e.g.,  1382 A) of one construction/composition while a second surface of bushing  1300  can have inserts (e.g.,  1382 B) of a different construction/composition. Additionally, inserts (e.g.,  1382 A, 1382 B,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  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  FIG.  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 .  FIGS.  40  and  41    are rough outs of bushing  1300 , showing various recessed areas  1380  for inserts  1382 . The finished bushing  1300  typically will have more recessed areas  1380  than shown in  FIGS.  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  FIG.  28   ). However, outer surface  1310  of bushing  1300  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  FIG.  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 ) operatively connected to a plurality of recesses  1390  (of bushing  1300 ). Base  1020  (of end cap  1000 ) supports upper surface  1330  (of bushing  1300 ). Lower surface  1340  of bushing  1300  is supported by upper surface  1500  (of ring  1490 ). 
     Ring  1490  ( FIGS.  37  and  38   ) can be operatively connected to hub  1400  ( FIGS.  33  through  35   ) by a one or more dowels  1480  (see  FIG.  28   ). Preferably, ring  1490  and hub  1400  would be a single piece of material, however, machining concerns may make two pieces more practical. Hub  1400  can be operably connected to mandrel  110  by one or more keys  1660  (see  FIGS.  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 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 relative to second surface  1610  (of mandrel). This is one reason for inserts  1382  being placed on bushing&#39;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 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  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 can be placed on mandrel  110  and/or 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  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  (of hub  1400 ) is stopped by shoulder  1630  of mandrel  110  (see  FIG.  28   ). During this motion hub  1400  will slide over one or more keys  1660  (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  FIGS.  2  and  24   ), but where differential pressures existing between 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  and mandrel  110  before a thrust load is placed on thrust hub  1400  and bearing  1300  (see  FIG.  28   ). 
       FIGS.  44  and  45    show another alternative embodiment.  FIG.  44    shows the lower portion of alternative swivel  100 ″ (upper portion can be substantially similar, but a mirror image).  FIG.  45    shows an end view of swivel  100 ′″. Swivel  100 ′″ incorporates mandrel  110 ′ ( FIG.  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 ) 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 shown in  FIG.  44   . Swivel  100 ″ can be a reciprocating swivel and have movements as shown in  FIGS.  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 high cost this drilling fluid  22  is typically recovered for use in another drilling operation. Removal of drilling fluid  22  is typically done through displacement by a completion fluid  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 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  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 of the well. Additionally, during displacement there may be 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  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 (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 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. 
     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 move 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 blow-out preventer  70 , but does rotate relative to mandrel  110 . 
     In one embodiment blow-out preventer  70  is 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 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, 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 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 (schematically illustrated by  FIG.  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  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 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. 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 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 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 . 
     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 , 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 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 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 during use. 
       FIGS.  47  through  53    illustrate another alternative embodiment for a swivel  2100  having upper and lower catches  2326 , 2328  on sleeve  2300 .  FIG.  48    is a sectional view of swivel  2100 .  FIG.  49    is an enlarged view of upper end  2120  of swivel  2100 .  FIG.  50    is a top view of a spacer ring  2303 , 2305  for swivel  2100 .  FIG.  51    is a top perspective view of a retainer cap  2400 .  FIG.  52    shows swivel  2100  inside a blowout preventer  70 .  FIG.  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  FIGS.  27  through  43    and accompanying text—excepting the modifications for upper and lower catches  2326 , 2328  along with retainer caps  2400  for 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. 
     Retainer caps  2400  ( FIG.  51   ) for end caps  2302 , 2304  can be designed to prevent the plurality of bolts  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  FIGS.  47 , 48 ,  49 , and  51   ) uses tip  2420  which will restrict longitudinal movement of 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  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 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  would 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 ). 
     Upper and lower catches  2326 , 2326  can restrict longitudinal movement of sleeve  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 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 area (See  FIG.  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 between catch  2328  and sleeve  2300 . Other methods of stress reduction can be used. 
       FIGS.  54  through  70    illustrate another alternative embodiment for a swivel  300  having upper and lower catches  3326 , 3328  on sleeve  3300 .  FIG.  54    is a perspective view of swivel  3100 .  FIG.  55    is a sectional perspective view of swivel  3100  exposing mandrel  3110  and showing upper and lower shoulders  3170 , 3180  along with upper and 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 a preferred embodiment the differential longitudinal movement is about 1¼ inches.  FIG.  56    is a sectional perspective view of sleeve  3300 .  FIG.  57    is a perspective view of mandrel  3110  and showing upper and lower shoulders  3170 , 3180  along with upper and lower hubs  3190 , 3200 .  FIG.  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.  FIGS.  60  through  62    show upper end cap  3302 , packing system  3620 , and bearing  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 . 
     The construction of swivel  3100  can be substantially similar to the construction of swivel  100 ″ shown in  FIGS.  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 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  ( FIG.  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  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  FIGS.  54 - 56 , 59 ,  63 - 65 , and  69   ) uses tip  3420  ( FIG.  63 B ) which will restrict longitudinal movement of any of the plurality of bolts  3306  holding end cap  3302  into sleeve  3300 , where one or more of the plurality of bolts comes loose. Retainer cap  3400  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  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, all 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  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  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 upper or lower catches  3326 , 3328 . 
     Differential longitudinal movement in swivel  3100  between mandrel  3110  and sleeve  3300  is schematically illustrated in  FIGS.  63  through  65 C .  FIGS.  63  through  63 C  are sectional views of swivel  3100  where sleeve  3300  is moved longitudinally upward with respect to mandrel  3110 . Arrows  3700 , 3710  indicate this differential longitudinal movement.  FIG.  63 B  shows gap  3702  between upper hub  3190  and upper shoulder  3170 .  FIG.  63 C  shows lower hub  3200  being in contact with lower shoulder  3180 .  FIGS.  64 A through  64 C  are sectional views of swivel  3100  where sleeve  3300  is longitudinally centered with respect to mandrel  3110 .  FIG.  64 B  shows gap  3712  between upper hub  3190  and upper shoulder  3170 .  FIG.  64 C  shows gap  3714  between lower hub  3200  and lower shoulder  3180 .  FIGS.  65 A through  65 C  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.  FIG.  65 B  shows upper hub  3190  being in contact with upper shoulder  3170 .  FIG.  65 C  shows gap  3722  between lower hub  3200  and lower shoulder  3180 . 
       FIGS.  66  through  68    schematically illustrate longitudinal movement of swivel  3100  relative to annular seal unit  71 .  FIG.  66    is a perspective view of swivel  3100  where mandrel  3110  and sleeve  3300  are pulled up with respect to seal unit  71 .  FIG.  67    is a perspective view of swivel  3100  where mandrel  3110  and sleeve  3300  are centered longitudinally with respect to seal unit  71 .  FIG.  68    is a perspective view of swivel  3100  where mandrel  3110  and sleeve  3300  are pushed down with respect to seal 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 ( FIG.  54   ) and the height  72  of annular seal unit  71 . In  FIG.  66    distance  3770  shows this difference. In  FIG.  67   , distances  3780  plus  3790  show this difference. In  FIG.  68    distance  3800  show this difference. 
       FIGS.  69  through  69    C are sectional views of swivel  3100  where sleeve  3300  is pulled up with respect to seal unit  71 . In  FIGS.  69 A and  69 C  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 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  FIGS.  54 - 56 ,  58 , and  63 - 69   . Such groove design is best shown in  FIGS.  58  and  69 A . 
     Plurality of arrows  3850  in  FIGS.  69 A and  69 C  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 .  FIG.  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  FIG.  58   . Shown are first and second ridges  3331 , 3333 . Between these two ridges 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 . In this manner, where a seal is made between either catch  3326 , 3328  and seal unit  71 , the amount of net increase in thrust load seen by sleeve  3300  is reduced by the areas of grooves  3332 , 3334 .  FIG.  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 of lower catch  3328  larger than the smallest opening in wellhead  88 . Additionally, it is preferred that where swivel  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. 
     The following is a list of reference numerals: 
     
       
         
           
               
            
               
                   
               
               
                 LIST FOR REFERENCE NUMERALS 
               
            
           
           
               
               
               
            
               
                   
                 (Part No.) 
                 (Description) 
               
               
                   
                 Reference Numeral 
                 Description 
               
               
                   
                   
               
               
                   
                  10 
                 rig 
               
               
                   
                  20 
                 drilling fluid line 
               
               
                   
                  22 
                 drilling fluid 
               
               
                   
                  30 
                 rotary table 
               
               
                   
                  40 
                 well bore 
               
               
                   
                  50 
                 drill pipe 
               
               
                   
                  60 
                 drill string or work string 
               
               
                   
                  70 
                 annular blowout preventer 
               
               
                   
                  71 
                 annular seal unit 
               
               
                   
                  80 
                 riser 
               
               
                   
                  85 
                 upper drill string 
               
               
                   
                  86 
                 lower drill string 
               
               
                   
                  87 
                 ground surface 
               
               
                   
                  88 
                 well head 
               
               
                   
                  90 
                 upper volumetric section 
               
               
                   
                  92 
                 lower volumetric section 
               
               
                   
                  94 
                 displacement fluid 
               
               
                   
                  96 
                 completion fluid 
               
               
                   
                  100 
                 swivel 
               
               
                   
                  101 
                 upper section 
               
               
                   
                  102 
                 lower section 
               
               
                   
                  110 
                 swivel mandrel 
               
               
                   
                  120 
                 upper end 
               
               
                   
                  130 
                 lower end 
               
               
                   
                  140 
                 box connection 
               
               
                   
                  150 
                 pin connection 
               
               
                   
                  160 
                 central longitudinal passage 
               
               
                   
                  170 
                 shoulder 
               
               
                   
                  171 
                 upper surface of shoulder 
               
               
                   
                  172 
                 lower surface of shoulder 
               
               
                   
                  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 
               
               
                   
                  230 
                 bearing 
               
               
                   
                  240 
                 bearing 
               
               
                   
                  250 
                 bearing 
               
               
                   
                  260 
                 bearing 
               
               
                   
                  300 
                 swivel sleeve 
               
               
                   
                  302 
                 upper end cap 
               
               
                   
                  303 
                 spacer ring 
               
               
                   
                  303A 
                 height 
               
               
                   
                  304 
                 lower end cap 
               
               
                   
                  305 
                 spacer ring 
               
               
                   
                  306 
                 bolts 
               
               
                   
                  307 
                 bolts 
               
               
                   
                  308 
                 tip 
               
               
                   
                  309 
                 tip 
               
               
                   
                  310 
                 interior section 
               
               
                   
                  311 
                 upper lubrication port 
               
               
                   
                  312 
                 lower lubrication port 
               
               
                   
                  320 
                 protruding section 
               
               
                   
                  322 
                 check valve 
               
               
                   
                  324 
                 check valve 
               
               
                   
                  326 
                 upper catch 
               
               
                   
                  328 
                 lower catch 
               
               
                   
                  330 
                 packing unit 
               
               
                   
                  332 
                 support area 
               
               
                   
                  340 
                 packing retainer nut 
               
               
                   
                  341 
                 mechanical seal 
               
               
                   
                  345 
                 o-ring 
               
               
                   
                  346 
                 o-ring 
               
               
                   
                  347 
                 back-up ring 
               
               
                   
                  348 
                 back-up ring 
               
               
                   
                  350 
                 bore for set screw 
               
               
                   
                  360 
                 set screw for packing retainer nut 
               
               
                   
                  361 
                 bore 
               
               
                   
                  370 
                 threaded area 
               
               
                   
                  380 
                 set screw for receiving area 
               
               
                   
                  390 
                 spacer ring 
               
               
                   
                  392 
                 base 
               
               
                   
                  394 
                 tip 
               
               
                   
                  400 
                 female packing ring 
               
               
                   
                  410 
                 male packing ring 
               
               
                   
                  412 
                 tip 
               
               
                   
                  420 
                 plurality of seals 
               
               
                   
                  450 
                 packing unit 
               
               
                   
                  452 
                 support area 
               
               
                   
                  460 
                 packing retainer nut 
               
               
                   
                  461 
                 mechanical seal 
               
               
                   
                  470 
                 bore for set screw 
               
               
                   
                  480 
                 set screw for packing retainer nut 
               
               
                   
                  490 
                 threaded area 
               
               
                   
                  500 
                 set screw for receiving area 
               
               
                   
                  510 
                 spacer ring 
               
               
                   
                  520 
                 female packing ring 
               
               
                   
                  530 
                 male packing ring 
               
               
                   
                  540 
                 plurality of seals 
               
               
                   
                  600 
                 lock 
               
               
                   
                  610 
                 set screw 
               
               
                   
                  620 
                 lock 
               
               
                   
                  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 
               
               
                   
                  760 
                 saver portion 
               
               
                   
                  770 
                 joint of pipe 
               
               
                   
                  780 
                 saver portion 
               
               
                   
                 1000 
                 end cap 
               
               
                   
                 1010 
                 tip 
               
               
                   
                 1012 
                 second level 
               
               
                   
                 1020 
                 base 
               
               
                   
                 1030 
                 surface 
               
               
                   
                 1040 
                 surface 
               
               
                   
                 1050 
                 threads 
               
               
                   
                 1060 
                 mechanical seal 
               
               
                   
                 1070 
                 first outer diameter 
               
               
                   
                 1100 
                 packing unit 
               
               
                   
                 1110 
                 packing retainer nut 
               
               
                   
                 1112 
                 tip 
               
               
                   
                 1120 
                 threaded area 
               
               
                   
                 1130 
                 set screw for packing retainer nut 
               
               
                   
                 1140 
                 bore for set screw 
               
               
                   
                 1150 
                 spacer ring 
               
               
                   
                 1160 
                 base 
               
               
                   
                 1170 
                 tip 
               
               
                   
                 1180 
                 female packing ring 
               
               
                   
                 1190 
                 male packing ring 
               
               
                   
                 1200 
                 plurality of seals 
               
               
                   
                 1210 
                 first seal 
               
               
                   
                 1220 
                 second seal 
               
               
                   
                 1230 
                 third seal 
               
               
                   
                 1240 
                 fourth seal 
               
               
                   
                 1250 
                 fifth seal 
               
               
                   
                 1300 
                 bearing 
               
               
                   
                 1310 
                 outer surface 
               
               
                   
                 1320 
                 inner surface 
               
               
                   
                 1330 
                 upper surface 
               
               
                   
                 1332 
                 recessed area 
               
               
                   
                 1340 
                 lower surface 
               
               
                   
                 1350 
                 opening 
               
               
                   
                 1360 
                 pathway 
               
               
                   
                 1380 
                 recessed area 
               
               
                   
                 1382 
                 inserts 
               
               
                   
                 1390 
                 opening 
               
               
                   
                 1392 
                 base 
               
               
                   
                 1400 
                 hub 
               
               
                   
                 1410 
                 upper surface 
               
               
                   
                 1420 
                 lower surface 
               
               
                   
                 1430 
                 groove 
               
               
                   
                 1440 
                 inner diameter 
               
               
                   
                 1450 
                 first outer diameter 
               
               
                   
                 1460 
                 second outer diameter 
               
               
                   
                 1470 
                 transition area 
               
               
                   
                 1480 
                 dowel 
               
               
                   
                 1482 
                 opening for dowel 
               
               
                   
                 1490 
                 ring 
               
               
                   
                 1492 
                 opening for dowel 
               
               
                   
                 1500 
                 upper surface 
               
               
                   
                 1510 
                 lower surface 
               
               
                   
                 1520 
                 inner diameter 
               
               
                   
                 1530 
                 outer diameter 
               
               
                   
                 1550 
                 arrow 
               
               
                   
                 1552 
                 arrow 
               
               
                   
                 1554 
                 arrow 
               
               
                   
                 1556 
                 arrow 
               
               
                   
                 1600 
                 first surface of mandrel 
               
               
                   
                 1610 
                 second surface of mandrel 
               
               
                   
                 1612 
                 area for plurality of seals 
               
               
                   
                 1614 
                 area for plurality of seals 
               
               
                   
                 1620 
                 third surface of mandrel 
               
               
                   
                 1630 
                 shoulder 
               
               
                   
                 1640 
                 transition 
               
               
                   
                 1650 
                 recess for key 
               
               
                   
                 1660 
                 key 
               
               
                   
                 1662 
                 curved end 
               
               
                   
                 1665 
                 opening 
               
               
                   
                 1670 
                 fastener for key 
               
               
                   
                 1700 
                 first inner diameter of sleeve 
               
               
                   
                 1710 
                 second inner diameter of sleeve 
               
               
                   
                 1720 
                 third inner diameter of sleeve 
               
               
                   
                 1730 
                 fourth inner diameter of sleeve 
               
               
                   
                 1740 
                 transition 
               
               
                   
                 1750 
                 shoulder 
               
               
                   
                 1760 
                 outer diameter 
               
               
                   
                 2100 
                 swivel 
               
               
                   
                 2110 
                 swivel mandrel 
               
               
                   
                 2120 
                 upper end 
               
               
                   
                 2130 
                 lower end 
               
               
                   
                 2140 
                 box connection 
               
               
                   
                 2150 
                 pin connection 
               
               
                   
                 2160 
                 central longitudinal passage 
               
               
                   
                 2170 
                 shoulder 
               
               
                   
                 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 
               
               
                   
                 2210 
                 upper packing support area 
               
               
                   
                 2220 
                 lower packing support area 
               
               
                   
                 2300 
                 swivel sleeve 
               
               
                   
                 2302 
                 upper end cap 
               
               
                   
                 2303 
                 spacer ring 
               
               
                   
                 2304 
                 lower end cap 
               
               
                   
                 2305 
                 spacer ring 
               
               
                   
                 2306 
                 bolts 
               
               
                   
                 2307 
                 bolts 
               
               
                   
                 2308 
                 tip 
               
               
                   
                 2309 
                 tip 
               
               
                   
                 2310 
                 interior section 
               
               
                   
                 2311 
                 upper lubrication port 
               
               
                   
                 2312 
                 lower lubrication port 
               
               
                   
                 2320 
                 protruding section 
               
               
                   
                 2322 
                 check valve 
               
               
                   
                 2324 
                 check valve 
               
               
                   
                 2326 
                 upper catch 
               
               
                   
                 2328 
                 lower catch 
               
               
                   
                 2329 
                 first transition section 
               
               
                   
                 2330 
                 second transition section 
               
               
                   
                 2331 
                 base 
               
               
                   
                 2332 
                 radiused area 
               
               
                   
                 2400 
                 retainer cap 
               
               
                   
                 2410 
                 upper surface of retainer cap 
               
               
                   
                 2420 
                 tip of retainer cap 
               
               
                   
                 2430 
                 base of retainer cap 
               
               
                   
                 2450 
                 bolts 
               
               
                   
                 2451 
                 recessed area 
               
               
                   
                 2460 
                 threaded area 
               
               
                   
                 2465 
                 threaded area 
               
               
                   
                 2470 
                 plurality of bolt holes 
               
               
                   
                 2480 
                 plurality of bolt holes 
               
               
                   
                 3100 
                 swivel 
               
               
                   
                 3102 
                 arrow 
               
               
                   
                 3104 
                 arrow 
               
               
                   
                 3110 
                 swivel mandrel 
               
               
                   
                 3120 
                 upper end 
               
               
                   
                 3130 
                 lower end 
               
               
                   
                 3140 
                 box connection 
               
               
                   
                 3150 
                 pin connection 
               
               
                   
                 3160 
                 central longitudinal passage 
               
               
                   
                 3170 
                 upper shoulder of mandrel 
               
               
                   
                 3180 
                 lower shoulder of mandrel 
               
               
                   
                 3190 
                 upper hub 
               
               
                   
                 3192 
                 key 
               
               
                   
                 3194 
                 ring 
               
               
                   
                 3200 
                 lower hub 
               
               
                   
                 3202 
                 key 
               
               
                   
                 3204 
                 ring 
               
               
                   
                 3300 
                 swivel sleeve 
               
               
                   
                 3302 
                 upper end cap 
               
               
                   
                 3303 
                 spacer ring 
               
               
                   
                 3304 
                 lower end cap 
               
               
                   
                 3305 
                 spacer ring 
               
               
                   
                 3306 
                 bolts 
               
               
                   
                 3307 
                 bolts 
               
               
                   
                 3308 
                 tip 
               
               
                   
                 3309 
                 tip 
               
               
                   
                 3310 
                 interior section 
               
               
                   
                 3311 
                 upper lubrication port 
               
               
                   
                 3312 
                 lower lubrication port 
               
               
                   
                 3320 
                 protruding section 
               
               
                   
                 3322 
                 upper bearing 
               
               
                   
                 3324 
                 lower bearing 
               
               
                   
                 3326 
                 upper catch 
               
               
                   
                 3328 
                 lower catch 
               
               
                   
                 3330 
                 base 
               
               
                   
                 3331 
                 first ridge 
               
               
                   
                 3332 
                 first groove 
               
               
                   
                 3333 
                 second ridge 
               
               
                   
                 3334 
                 second groove 
               
               
                   
                 3336 
                 first radial port 
               
               
                   
                 3338 
                 second radial port 
               
               
                   
                 3340 
                 radiused area 
               
               
                   
                 3350 
                 peripheral valley 
               
               
                   
                 3360 
                 first transitional area 
               
               
                   
                 3370 
                 angle of first transitional area 
               
               
                   
                 3340 
                 radiused area 
               
               
                   
                 3400 
                 retainer cap 
               
               
                   
                 3410 
                 upper surface of retainer cap 
               
               
                   
                 3420 
                 tip of retainer cap 
               
               
                   
                 3430 
                 base of retainer cap 
               
               
                   
                 3450 
                 plurality of openings for bolts 
               
               
                   
                 3451 
                 recessed area 
               
               
                   
                 3452 
                 plurality of bolts 
               
               
                   
                 3460 
                 threaded area 
               
               
                   
                 3465 
                 threaded area 
               
               
                   
                 3470 
                 plurality of bolt holes 
               
               
                   
                 3480 
                 plurality of bolt holes 
               
               
                   
                 3600 
                 packing retainer nut 
               
               
                   
                 3610 
                 spacer ring 
               
               
                   
                 3620 
                 packing system 
               
               
                   
                 3700 
                 arrow 
               
               
                   
                 3702 
                 gap 
               
               
                   
                 3710 
                 arrow 
               
               
                   
                 3712 
                 gap 
               
               
                   
                 3714 
                 gap 
               
               
                   
                 3720 
                 arrow 
               
               
                   
                 3722 
                 gap 
               
               
                   
                 3730 
                 arrow 
               
               
                   
                 3740 
                 arrow 
               
               
                   
                 3750 
                 arrow 
               
               
                   
                 3760 
                 distance between catches 
               
               
                   
                 3770 
                 difference between catches 
               
               
                   
                   
                 and height of seal unit 
               
               
                   
                 3780 
                 upper gap 
               
               
                   
                 3790 
                 lower gap 
               
               
                   
                 3840 
                 fluid pressure arrow 
               
               
                   
                 3850 
                 fluid pressure arrow 
               
               
                   
                 BJ 
                 ball joint 
               
               
                   
                 BL 
                 booster line 
               
               
                   
                 CM 
                 choke manifold 
               
               
                   
                 CL 
                 diverter line 
               
               
                   
                 CM 
                 choke manifold 
               
               
                   
                 D 
                 diverter 
               
               
                   
                 DL 
                 diverter line 
               
               
                   
                 F 
                 rig floor 
               
               
                   
                 IB 
                 inner barrel 
               
               
                   
                 KL 
                 kill line 
               
               
                   
                 MP 
                 mud pit 
               
               
                   
                 MB 
                 mud gas buster or separator 
               
               
                   
                 OB 
                 outer barrel 
               
               
                   
                 R 
                 riser 
               
               
                   
                 RF 
                 flow line 
               
               
                   
                 S 
                 floating structure or rig 
               
               
                   
                 SJ 
                 slip or telescoping joint 
               
               
                   
                 SS 
                 shale shaker 
               
               
                   
                 W 
                 wellhead 
               
               
                   
                   
               
            
           
         
       
     
     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 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 adapt 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 only by the following claims.