Patent Publication Number: US-9834997-B2

Title: Tool connection release system

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     Not applicable. 
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not applicable. 
     BACKGROUND 
     This disclosure relates to a tool connection release system for one or more pieces of equipment that may be positioned in a borehole, a well, subsea, or other environment that allows the disconnection of various connections (e.g., electrical, hydraulic, optical, and/or multi-connector) in a high pressure environment. More particularly, this disclosure relates to systems for hydraulically disconnecting a tool independent of the environmental pressure. The systems may also include a secondary release mechanism. 
     Traditionally, if a tool package suspended from an armored or coiled tubing umbilical is to be recovered, the tool is released to allow heavy lift capable equipment using a retrieval string to be deployed to recover the tool. For hydraulic release of the tool, a piston would have to overcome the external pressure in the well, which can be as high as 24,000 psi or more. This high pressure then may lead the line pressure to be higher than the external pressure to allow actuation of the piston. Shear pins have also been conventionally used as a disconnection means, but shear pins are delicate and typically highly loaded, and can suffer fracture due to fatigue or localized corrosion from stress corrosion cracking. 
     BRIEF SUMMARY OF THE DISCLOSURE 
     In an embodiment, a tool connection release system includes a housing having a first portion and a second portion, a piston disposed at least partially within the housing first portion and at least partially within the housing second portion, a first fluid chamber including a first pressurized fluid acting against the piston, a fluid source coupled to the first fluid chamber, and a second fluid chamber including a second pressurized fluid acting against the piston to oppose the first pressurized fluid and pressure-balance the piston. Moreover, addition of a fluid from the fluid source to the pressure-balanced piston causes the piston to move and the first housing portion to separate from the second housing portion. 
     In an embodiment, a tool connection release system includes a housing having a first portion and a second portion, the first portion being coupled to a cable, a piston having a first end axially disposed at least partially within the housing first portion, and a plurality of threads at a second end. In addition, the release system includes a release nut disposed within the housing second portion and having a plurality of threads at an interior portion of a first end, a recess at an exterior portion of the first end, a second end, and a plurality of circumferentially disposed slots that pass through the plurality of threads and the recess in the first end, the second end being attached to a portion of the housing second end. Further, the threaded exterior portion of the piston is configured to releasably engage the threaded interior portion of the release nut and the plurality of circumferentially disposed slots is configured to allow the release nut first end to move radially outward and disengage the threaded exterior portion of the piston from the threaded interior portion of the release nut such that the piston and the housing first portion can be separated from the release nut and the housing second portion. 
     In an embodiment, a tool connection release system includes a plug connector having a first end and a second end, the first end coupled to a cable, and an outer portion of the second end having at least one axial protrusion. The release system further includes an actuation cylinder housing having a first end coupled to the plug connector, a second end, and a plurality of circumferentially spaced galleries, and a piston having a first end, a second end, and a plurality of threads at an exterior portion of the second end, the piston being axially disposed at least partially within the activation cylinder housing and forming a first cavity therein. In addition, the release system includes a piston cap that is disposed around the piston and forms a second cavity therein, threadably engages the second end of the actuation cylinder, and is configured to retain the first end of the piston within the actuation cylinder, and a motor head having a first end and a second end, an inner portion of the first end having at least one axial recess configured to engage the protrusion on the outer portion of the plug connector second end. Moreover, the release system includes a release nut having a plurality of threads at an interior portion of a first end, a recess at an exterior portion of the first end, a second end, and a biasing member disposed in the recess, and a protection sleeve disposed about the release nut and a portion of the piston cap, the sleeve forming a third cavity with the release nut. Furthermore, the piston is configured to axially slide around an outer portion of the motor head and the plurality of threads on the exterior portion of the piston second end is configured to releasably engage the threads on the interior portion of the release nut first end upon addition of a pressurized fluid. 
     Embodiments described herein comprise a combination of features and advantages intended to address various shortcomings associated with certain prior devices, systems, and methods. The foregoing has outlined rather broadly the features and technical advantages of the disclosure such that the detailed description of the disclosure that follows may be better understood. The various characteristics described above, as well as other features, will be readily apparent to those skilled in the art upon reading the following detailed description, and by referring to the accompanying drawings. It should be appreciated by those skilled in the art that the conception and the specific embodiments disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the disclosure. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the disclosure as set forth in the appended claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For a detailed description of the various embodiments, reference will now be made to the accompanying drawings in which: 
         FIG. 1  is a schematic exploded and partial cross-sectional view of a tool release system with a plug connector and motor head in accordance with the principles described herein; 
         FIG. 2  is a cross-sectional side view of the release system of  FIG. 1 ; 
         FIG. 3  is a cross-sectional side view of the release system of  FIG. 2  in a disconnected state; 
         FIG. 4  is an isometric view of the plug connector of the release system of  FIG. 2 ; 
         FIG. 5  is a front view of the plug connector of  FIG. 4 ; 
         FIG. 6  is a cross-sectional side view of the actuation cylinder housing of the release system of  FIG. 2 ; 
         FIG. 7  is an isometric view of the actuation cylinder housing of  FIG. 6 ; 
         FIG. 8  is a cross-sectional front view of the actuation cylinder housing of  FIG. 6 ; 
         FIG. 9  is a cross-sectional side view of the piston of the release system of  FIG. 2 ; 
         FIG. 10  is a cross-sectional side view of the piston cap of the release system of  FIG. 2 ; 
         FIG. 11  is a cross-sectional side view of the motor head of the release system of  FIG. 2 ; 
         FIG. 12  is a cross-sectional side view of the release nut of the release system of  FIG. 2 ; 
         FIG. 13  is a cross-sectional side view of the protection sleeve of the release system of  FIG. 2 ; 
         FIG. 14  is a cross-sectional side view of the release system of  FIG. 2  in a connected state; and 
         FIG. 15  is a cross-sectional side view of the release system of  FIG. 2  in a disconnected state. 
     
    
    
     DETAILED DESCRIPTION 
     The following discussion is directed to various exemplary embodiments. However, one skilled in the art will understand that the examples disclosed herein have broad application, and that the discussion of any embodiment is meant only to be exemplary of that embodiment, and not intended to suggest that the scope of the disclosures, including the claims, is limited to that embodiment. 
     Certain terms are used throughout the following description and claim to refer to particular system components. This document does not intend to distinguish between components that differ in name but not function. Moreover, the drawing figures are not necessarily to scale. Certain features of the disclosure may be shown exaggerated in scale or in somewhat schematic form, and some details of conventional elements may not be shown in the interest of clarity and conciseness. 
     In the following discussion and in the claims, the terms “including” and “comprising” are used in an open-ended fashion, and thus should be interpreted to mean “including, but not limited to . . . ” Also, the term “couple” or “couples” is intended to mean either an indirect or direct connection. Thus, if a first device couples to a second device, that connection may be through a direct connection, or through an indirect connection via other devices, components, and connections. In addition, as used herein, the terms “axial” and “axially” generally mean along or parallel to a central axis (e.g., central axis of a body or a port), while the terms “radial” and “radially” generally mean perpendicular to the central axis. For instance, an axial distance refers to a distance measured along or parallel to the central axis, and a radial distance means a distance measured perpendicular to the central axis. Still further, reference to “up” or “down” may be made for purposes of description with “up,” “upper,” “upward,” or “above” meaning generally toward or closer to the surface of the earth, and with “down,” “lower,” “downward,” or “below” meaning generally away or further from the surface of the earth. 
     The present disclosure relates to a hydraulic tool connection release system that functions independent of environmental pressure and provides a consistent release pressure. The system may also include a secondary release means. 
     Referring now to  FIG. 1 , the tool connection release system or release system  100  allows the disconnection of various connections (e.g., electrical, hydraulic, optical, and/or multi-connector) to a service tool in a high pressure environment. The release system  100  comprises a central axis  105  and a first or upper end  200  that releasably connects to a second or lower end  300 . The upper end  200  includes a plug connector  210  configured to connect to a cable  150 , shown in the top portion of  FIG. 1 . The remaining components of the upper end  200 , described in further detail below, are shown in the middle portion of  FIG. 1 ; and the components of the lower end  300  are shown in the bottom portion of  FIG. 1 . 
     Referring now to  FIGS. 1 and 2 , the plug connector  210  of the first or upper end  200  of the release system  100  is coupled to an actuation cylinder housing  230 , a piston  260  disposed in a portion of the cylinder housing  230 , and a piston cap  280  configured to engage the cylinder housing  230  and retain at least a portion of the piston  260  within the cylinder housing  230 . The plug connector  210  of the upper end  200  is configured to connect to a cable  150  that extends upward to the surface. The cable may be connected to the plug connector  210  by any manner known in the art. See, for example, U.S. Patent Application Publication No. 2013/0312996, which is incorporated in its entirety by reference herein. The cable may be any type of cable standard in the art including, but not limited to, an armored or coiled tubing umbilical, which may contain high voltage (HV) power feed cables for pumps or heaters as well as instrumentation and at least one hydraulic line for actuation of the release system. 
     Referring now to  FIGS. 1, 2, 4, and 5 , the plug connector  210  comprises a first annular end  210   a  opposite a second annular end  210   b  and a generally cylindrical inner surface  215 . For clarity, the various electrical, hydraulic, and optical connections are removed, but would generally be located within the cylindrical inner surface  215 . 
     Referring now to  FIGS. 4 and 5 , the plug connector  210  further comprises a first cylindrical outer surface  220  extending axially from the first end  210   a  ( FIG. 1 ) to an outer angular shoulder  221  that extends axially toward plug connector second end  210   b  and radially inward to a second cylindrical outer surface  222 . Second cylindrical outer surface  222  extends axially to a flange  223  having a plurality of circumferentially spaced through holes  223   a . A third cylindrical outer surface  224  extends axially from the flange  223  to a first downward-facing shoulder  225 . The third cylindrical outer surface  224  includes two grooves  224   a , each configured to receive a seal. The seal may be any type of seal known in the art including, but not limited to an O-ring, metal C-seals, and labyrinth seals with back-up rings. A fourth cylindrical outer surface  226  extends axially between the first downward-facing shoulder  225  and a second downward-facing shoulder  227 . The fourth cylindrical outer surface  226  has a plurality of protruding keys  226   a  that extend axially between the first downward-facing shoulder  225  and a groove  226   b  disposed on the fourth cylindrical outer surface  226  proximate a fifth cylindrical outer surface  228 . In the present embodiment, the fourth cylindrical surface  226  has three keys  226   a ; in other embodiments, surface  226  may have as few as one key or four or more keys. 
     Referring now to  FIGS. 2, 3, 6, and 7 , the actuation cylinder housing  230  is tubular and has a first end  230   a  opposite a second end  230   b , a cylindrical outer surface  232 , and a generally cylindrical inner surface  233 . The inner surface  233  comprises a first cylindrical surface  234  that extends axially from the housing first end  230   a  to a first downward-facing shoulder  235 . A second inner cylindrical surface  236  extends axially from the first shoulder  235  to a second downward-facing shoulder  237 . The diameter of the first cylindrical surface  234  is smaller than the diameter of the second cylindrical surface  236 . The second cylindrical surface  236  includes a groove  236   a  disposed proximate the second downward-facing shoulder  237 . A third cylindrical surface  238  extends axially from the second shoulder  237  to a graduated downward-facing shoulder  239 , and a threaded cylindrical surface  240  extends from the shoulder  239  to the second end  230   b.    
     Referring to  FIGS. 6 and 7 , the housing  230  further comprises a first cylindrical chamber  241  that extends between the housing first end  230   a  and a first elongate channel  243 . The first cylindrical chamber  241  has a cover  245  covering the opening of the chamber at housing first end  230   a , and an inlet port  247  radially disposed proximate the housing first end  230   a  and in fluid communication with a control line or hydraulic fluid source (not shown). The first cylindrical chamber  241  and the first elongate channel  243  together form a first fluid chamber  248 . The cover  245  may be secured to the housing first end  230   a  in any manner known in the art including, but not limited to, welded, threaded, or any other suitable mechanical fastener that is configured to seal with housing  230 . The first elongate channel  243  extends axially from the first chamber  241  through to the graduated downward-facing shoulder  239 . The first chamber  241  and the first elongate channel  243  are in fluid communication, and the first elongate channel  243  is in fluid communication with the housing inner surface  233  at shoulder  239 . 
     The housing  230  also comprises a second cylindrical chamber  242  that extends between the housing first end  230   a  and a second elongate channel  244 . The second cylindrical chamber  242 , like the first cylindrical chamber  241 , has a cover  245  covering the opening of the chamber at housing first end  230   a . The second cylindrical chamber  242  also contains a sealed opening  246  having an outer diameter substantially similar to the inner diameter of the second cylindrical chamber  242  to form a seal. The second elongate channel  244  extends axially from the second chamber  242  to an opening  237   a  disposed at the second shoulder  237 . The second chamber  242  and the second elongate channel  244  are in fluid communication after the sealed opening  246  is opened. The sealed opening  246  may be any type of sealed opening or barrier capable of opening under a predetermined pressure known in the art including, but not limited to, a burst disc. The sealed opening  246  may also be referred to as a burst disc  246  that opens or ruptures at a predetermined pressure. Until the burst disc  246  bursts, the second cylindrical chamber  242  is at 1 atm and the second elongate channel  244  is in fluid communication with the housing third cylindrical surface  238  via the opening  237   a  at shoulder  237 . The second elongate channel  244  and the opening  237   a  form a second fluid chamber  258 . 
     Referring now to  FIGS. 7 and 8 , the housing first end  230   a  further includes a plurality of threaded bores  250  spaced circumferentially about the central axis  105  between the outer surface  232  and the first cylindrical surface  234 . The threaded bores  250  are configured to accept threaded fasteners or bolts  251 . However, a portion of the bolts  251  threadably engage a plug  253 , each plug being coupled to and disposed in a cylindrical overflow cavity  255  disposed circumferentially between the outer surface  232  and the first cylindrical surface  234  and extending from the first end  230   a  toward first downward-facing shoulder  235 . Each plug  253  may be coupled to each cavity  255  in any manner known in the art including, but not limited to, welded, threaded, or any other suitable mechanical fastener configured to seal with housing  230 . In the present embodiment, there are ten cavities  255  disposed about the second cylindrical chamber  242  (five on either side) with no cavities  255  disposed about the first cylindrical chamber  241  for the remaining bolts or fasteners, as shown in  FIGS. 6 and 7 . Though, in the embodiment as shown, plugs  253  are disposed in each cavity  255 , a bolt  251  need not be threadably engaged in each plug  253 . 
     Referring still to  FIGS. 7 and 8 , furthermore, each cavity  255  is in fluid communication with one another and with the second chamber  242  through connecting galleries  257  disposed between and connecting each adjacent cavity  255  and chamber  242  proximate upper end  230   a  of the housing  230 . Each plug  253  includes axial channels  253   a  that allow fluid communication between the portion of the cavity  255  surrounding the plug  253  and the portion of the cavity below the plug  253 . Thus, each cavity  255  is in fluid communication with the other cavities  255 , the second chamber  242 , second elongate channel  244  once the burst disc  246  is breached, and the opening  237   a  at shoulder  237   
     Referring now to  FIG. 9 , the piston  260  is tubular and has a first or upper end  260   a  opposite a second or lower end  260   b , a generally cylindrical outer surface  262 , and a cylindrical inner surface  263 . The outer surface  262  comprises a first cylindrical surface  264  that extends axially from the housing first end  260   a  to a downward-facing shoulder  265 . A second cylindrical surface  266  extends axially from the shoulder  265  to a threaded portion  268 , and the threaded portion  268  extends from the second cylindrical surface  266  to the piston second side  260   b . The first cylindrical surface  264  includes a first and a second annular protrusion or ring  264   a ,  264   b , respectively, spaced apart to form an annular groove  261  therebetween and disposed approximately midway between the piston first end  260   a  and the shoulder  265 . A sealing element  269  may be disposed in the annular groove  261 , and may be any type of seal known in the art including, but not limited to, an O-seal, T-seal with back up rings, polymeric spring energized lip seals, metallic lip seals, and C-rings. The diameter of the first cylindrical surface  264  is greater than the diameter of the second cylindrical surface  266 . 
     Referring now to  FIGS. 3 and 10 , the piston cap  280  is tubular and has a first or upper end  280   a  opposite a second or lower end  280   b , a generally cylindrical outer surface  282 , and a generally cylindrical inner surface  283 . The outer surface  282  comprises a threaded portion  284  that extends axially from the piston cap first end  280   a  to an upward-facing shoulder  285 . An annular protrusion or ring  286  extends axially from the upward-facing shoulder  285  to a cylindrical surface  287 , and the cylindrical surface  287  extends from the protrusion  286  to the piston cap second end  260   b . The cylindrical surface  287  includes an annular indention or groove  287   a  spaced approximately midway between the protrusion  286  and the piston cap second end  280   b . The indention  287   a  is configured to receive a seal. The seal may be any type of seal known in the art including, but not limited to an O-ring, O-seal, T-seal with back up rings, polymeric spring energized lip seals, metallic lip seals, and C-rings. 
     The piston cap  280  further comprises a first cylindrical surface  288  that extends between the piston cap first end  280   a  and a downward-facing shoulder  289 . The first cylindrical surface  288  has an annular groove or indentation  288   a  disposed approximately midway between the piston cap first end  280   a  and the shoulder  289 . The indention  288   a  is configured to house a seal. The seal may be any type of seal known in the art including, but not limited to an O-ring, O-seal, T-seal with back up rings, polymeric spring energized lip seals, metallic lip seals, and C-rings. 
     Referring now to  FIGS. 2 and 3 , the second or lower end  300  of the release system  100  comprises a motor head  310 , a release nut  340  disposed about a portion of the motor head  310 , and a protection sleeve  370  disposed about and coupled to the release nut  340 . The motor head  310  of the lower end  300  is configured to connect to a service tool (not shown). The service tool may be any type of service tool standard in the art including, but not limited to, an electric submersible pump. 
     Referring now to  FIGS. 2, 3, and 11 , the motor head  310  comprises a first annular end  310   a  opposite a second annular end  310   b , a generally cylindrical outer surface  312 , and a generally cylindrical inner surface  313 . For clarity, the various electrical, hydraulic, and optical connections are removed, but would generally be located within the cylindrical inner surface  313 . 
     The generally cylindrical outer surface  312  of motor head  310  comprises a first cylindrical outer surface  314  extending axially from the first end  310   a  to an outer upward-facing shoulder  319 . The first cylindrical outer surface  314  includes a first elongate annular indentation  314   a  disposed proximate motor head first end  310   a  and a second elongate annular indentation  314   b  disposed approximately midway between motor head first end  310   a  and shoulder  319 . A second cylindrical outer surface  320  extends axially from the shoulder  319  to a third indentation  321 ; the third indentation is configured to receive a retention member  339 . The retention member  339  may be any type of retention member known in the art including, but not limited to, a snap ring. A third cylindrical outer surface  322  extends axially from the third indentation  321  to the motor head second end  310   b . The third cylindrical outer surface  322  includes a groove  322   a  configured to receive a seal. The seal may be any type of seal known in the art including, but not limited to an O-ring, O-seal, T-seal with back up rings, polymeric spring energized lip seals, metallic lip seals, and C-rings. 
     The generally cylindrical inner surface  313  of motor head  310  comprises a first cylindrical inner surface  325  extending axially from the first end  310   a  to a first upward-facing shoulder  326 . A second cylindrical inner surface  328  having a reduced diameter extends from the first shoulder  326  to a second upward-facing shoulder  329 . A third cylindrical inner surface  330  having a reduced diameter extends from the second shoulder  329  to the motor head second end  310   b . In the present embodiment, the first cylindrical inner surface  325  has three axial cutouts or slots  325   a ; in other embodiments, surface  325  may have as few as one cutout or slot, or four or more cutouts or slots. 
     Referring now to  FIGS. 2, 3, and 12 , the release nut  340  is tubular and has a first or upper end  340   a  opposite a second or lower end  340   b , a generally cylindrical outer surface  342 , and a generally cylindrical inner surface  343 . The generally cylindrical outer surface  342  of the release nut  340  comprises a first cylindrical outer surface  344  extending axially from the first end  340   a  to an outer angular shoulder  347  that extends axially toward release nut second end  340   b  and radially inward to a second cylindrical outer surface  348 . The first cylindrical outer surface  344  includes an elongate annular indentation or recess  344   a  disposed proximate release nut first end  340   a . The recess  344   a  is configured to receive and retain a biasing member  368 . The biasing member may be any biasing member known in the art including, but not limited to, a close coiled spring, a plurality of wrap springs, or a plurality of single circlips. The second cylindrical outer surface  348  extends axially to a third cylindrical outer surface  349  having a slightly larger diameter. A fourth cylindrical outer surface  351  extends axially from a downward-facing shoulder  350  to the release nut second end  340   b . The fourth cylindrical outer surface  351  includes a groove  351   a  disposed proximate shoulder  350  configured to receive a seal. The seal may be any type of seal known in the art including, but not limited to an O-ring, O-seal, T-seal with back up rings, polymeric spring energized lip seals, metallic lip seals, and C-rings. The fourth cylindrical outer surface  351  further includes a plurality of threaded radial bores  352  spaced circumferentially about the central axis  105  proximate the release nut second end  340   b.    
     The generally cylindrical inner surface  343  of release nut  340  comprises a threaded portion  355  that extends axially from the release nut first end  340   a  to a first inner cylindrical surface  356 . The first inner cylindrical surface  356  extends axially to a first upward-facing shoulder  357 . A second cylindrical surface  358  extends axially from first shoulder  357  to a second upward-facing shoulder  359 . A third inner cylindrical surface  360  extends axially from the second upward-facing shoulder  359  to the release nut second end  340   a . The second cylindrical surface  358  and second upward-facing shoulder  359  are configured to engage the retention member  339 . 
     The release nut further comprises a plurality of slots  365  that extend axially from the release nut first end  340   a  to the first shoulder  357 , and extend radially from outer surface  342  through to inner surface  343 , forming a plurality of fingers  366 . The slots allow the fingers  366  to slightly flex radially. Thus, the release nut  340  may also be referred to as a slotted release nut  340 . In the present embodiment, there are eight slots  365  and eight fingers  366  (not all slots  365  are shown). In other embodiments, there may be as few as two slots  365  and two fingers  366 , or there may be more than eight slots  365  and eight fingers  366 . 
     Referring now to  FIGS. 2, 3, and 13 , the protection sleeve  370  is tubular and comprises a first or upper end  370   a  opposite a second or lower end  370   b , a cylindrical outer surface  372 , and a generally cylindrical inner surface  373 . The generally cylindrical inner surface  373  of the protection sleeve  370  comprises a first cylindrical inner surface  374  extending axially from the first end  370   a  to a downward-facing shoulder  375 . A second cylindrical inner surface  376  extends axially from the downward-facing shoulder  375  to an upward-facing shoulder  377 ; and a third cylindrical inner surface  381  extends from the upward-facing shoulder  377  to protection sleeve second end  370   b . The third cylindrical inner surface  381  has a plurality of through bores  382  spaced circumferentially about the central axis  105  proximate the sleeve second end  370   b . In the present embodiment, the third cylindrical inner surface  381  has eight through bores  382 . In other embodiments, the third cylindrical surface  381  may comprise three or more through bores  382 . 
     The tool connection release system  100  when deployed with a service tool in a high pressure environment and before activation of the release system  100 , as shown in  FIG. 2 , includes the plug connector  210  coupled to the actuation cylinder housing  230 . The plurality of threaded bores  250  spaced circumferentially about the central axis  105  of the actuation housing first end  230   a  are configured to align with the plurality of circumferentially spaced through holes  223   a  of the flange  223  portion of the plug connector  210 . The threaded bores  250  are further configured to threadably couple to fasteners or bolts  251  to secure the flange  223  of the plug connector  210  to the first end  230   a  of the actuation housing  230 . When the plug connector  210  is fastened to the housing  230 , the plug connector third cylindrical outer surface  224  is disposed adjacent a portion of the housing first cylindrical surface  234  proximate the housing first end  230   a . Seals are disposed in grooves  224   a  to seal between the plug connector third cylindrical outer surface  224  and the housing first cylindrical surface  234 . A seal is disposed in groove  226   b  to seal between the plug connector fourth cylindrical outer surface  226  and the motor head second cylindrical inner surface  328 . 
     Referring now to  FIGS. 2 and 3 , a first annular space or cavity  385 , shown in  FIG. 3 , is formed between the first cylindrical surface  234  and second inner cylindrical surface  236  of the housing  230  and the fourth cylindrical outer surface  226  and fifth cylindrical outer surface  228  of the plug connector  210 ; the first cavity  385  extends axially from the first downward-facing shoulder  225  to the second end  210   b  of the plug connector  210 . 
     Referring now to  FIG. 2 , the piston cap  280  is configured to threadably engage the housing  230  such that the threaded portion  240  of the housing  230  engages the threaded portion  284  of the piston cap  280 , and housing second end  230   b  is adjacent the upward-facing shoulder  285  of the piston cap. In an alternative embodiment, the piston cap  280  may be welded to housing  230  proximate upward-facing shoulder  285  using any welding method known in the art including, but not limited to, electron beam, laser, or T.I.G.; in this alternative embodiment, other methods of sealing may also be applied. The annular piston cap  280  is radially disposed between a portion of the actuation cylinder housing  230 , a portion of the protection sleeve  370 , and the annular piston  260 . As the piston cap  280  is threadably coupled to the housing  230  and the housing is coupled to the plug connector  210  with bolts  251 , the first and second protrusions  264   a ,  264   b , respectively, of the piston  260  are retained by the annular piston cap first end  280   a  to prevent the piston  260  from separating from the housing  230  and plug connector  210 . 
     Referring still to  FIG. 2 , the annular piston  260  is radially disposed between the housing  230  and the motor head  310 . More specifically, the piston  260  is disposed in the actuation housing  230  such that the first and second annular protrusions or rings  264   a ,  264   b , respectively, of the piston  260  slidingly engage the housing third cylindrical surface  238 . A seal  281  is disposed in groove  288   a  of the first cylindrical surface  288  of the piston cap  280 , and sealingly engages the first cylindrical surface  264  of the piston  260 . 
     A second annular space or cavity  386  is formed radially between the housing third cylindrical surface  238  and the piston first cylindrical surface  264  and axially between the housing second downward-facing shoulder  237  and the first annular protrusion  264   a . The second cavity  386  is in fluid communication with the second elongate channel  244  in the housing  230 . The axial movement of the piston  260  is restricted in one direction by the housing second downward-facing shoulder  237  along with the housing first downward-facing shoulder  235 , and bound in the opposite direction by the annular piston cap first end  280   a  and the motor head outer upward-facing shoulder  319 . 
     A seal is disposed between the first and second annular protrusions  264   a ,  264   b , respectively, to sealingly engage the housing third cylindrical surface  238 . A seal is also disposed in the groove  236   a  of the housing second cylindrical surface  236  about the piston first cylindrical surface  264 . 
     A third annular space or cavity  387  is formed radially between the piston cap cylindrical surface  287  and the piston first cylindrical surface  264  and axially between the piston cap downward-facing shoulder  289  and the piston cap second end  280   b.    
     Referring still to  FIG. 2 , the motor head  310  is disposed in the annular piston  260  such that the motor head first cylindrical outer surface  314  slidingly engages the piston cylindrical inner surface  263 , and piston second end  260   b  is disposed adjacent the motor head outer upward-facing shoulder  319 . 
     The motor head  310  is disposed radially within the actuation cylindrical housing  230 , such that the motor head first end  310   a  is disposed adjacent the plug connector first downward-facing shoulder  225 . In addition, the three axial cutouts or slots  325   a  spaced about the first cylindrical inner surface  325  of the motor head  310  are configured to align with the three keys  226   a  disposed on the fourth cylindrical outer surface  226  of the plug connector  210 . The motor head  310  and the plug connector  210  remain in alignment during connections or disconnections across the axial length of the keys  226   a , which helps reduce possible damage to the tool connectors housed in the plug connector  210  by controlling the alignment during engagement and separation. In the present embodiment, the location of the keys  226   a  and corresponding slots  325   a  allow connection of the motor head  310  to the plug connector  210  in a single orientation; however, in other embodiments, different keying configurations may be used that employ more or less keys and corresponding slots with locations that may allow connection of the motor head to the plug connector in more than one orientation. 
     Referring still to  FIG. 2 , the motor head  310  is disposed in the annular piston  260  such that the motor head first cylindrical outer surface  314  slidingly engages the piston cylindrical inner surface  263 , and piston second end  260   b  is disposed adjacent the motor head outer upward-facing shoulder  319 . 
     Referring now to  FIGS. 2, 11, and 12 , the slotted release nut  340  is radially disposed between the motor head  310 , a portion of the piston  260 , and the protection sleeve  370 . A seal is disposed in groove  322   a  of the third cylindrical outer surface  322  of the motor head  310 , and sealingly engages the third inner cylindrical surface  360  of the slotted release nut  340 . The retention member  339  disposed in motor head indentation  321  extends radially outward past the motor head third cylindrical outer surface  322  to engage the second cylindrical surface  358  and the second upward-facing shoulder  359  of the release nut  340 . Retention member  339  restricts the axial movement of the release nut  340  toward the plug connector  210 . 
     The slotted release nut  340  is configured to threadably engage the piston  260  such that the threaded portion  355  of the slotted release nut  340  engages the threaded portion  268  of the piston  260 , and release nut first end  340   a  is adjacent the second cylindrical surface  266  of the annular piston  260 . The biasing member  368  disposed in the recess  344   a  of the release nut  340  is configured to maintain the threaded engagement of the piston  260  to the slotted release nut  340  until a sufficient axial force causes the threads  268  of the piston  260  to slide against the threads  355  of the release nut  340  and force the release nut threads to expand or move radially outward. The outward radial movement of the release nut threads  355  is possible due to the plurality slots  365  and resulting fingers  366  of the release nut  340 . In other words, the threads  268  of the piston  260  under a predetermined load will jump the threads  355  of the release nut  340 . The predetermined load is typically about 24,000 lbf and is governed by several factors including, but not limited to the design of the slots and resulting fingers (e.g., the width and axial length of the slots), the thread profile of the piston and release nut, and the spring reaction load. In an alternative embodiment, several wrap springs with a fewer number of turns to limit the clutch friction force or multiple single circlips could be used for the biasing member  368 . 
     A fourth annular space or cavity  388  is formed radially between the second cylindrical outer surface  320  of the motor head  310  and the first inner cylindrical surface  356  of the release nut  340 , and axially between the release nut threaded portion  355  and the first upward-facing shoulder  357  of the release nut  340 . 
     Referring now to  FIGS. 2 and 13 , the protection sleeve  370  is radially disposed about a portion of the annular piston cap  280  and the slotted release nut  340 . Fasteners or bolts  353  are configured to threadably couple the protection sleeve  370  to the slotted release nut  340  by passing through the sleeve through bores  382  and engaging the threaded bores  352  of the slotted release nut  340 . 
     The plurality of threaded bores  352  spaced circumferentially about the central axis  105  of the fourth cylindrical outer surface  351  of the release nut  340  are configured to align with the plurality of circumferentially spaced through holes  382  of the sleeve  370 . The threaded bores  352  are further configured to threadably couple to the fasteners or bolts  353  to secure the sleeve  370  to the release nut  340 . 
     A seal is disposed in groove  351   a  on the release nut fourth cylindrical outer surface  351  to sealingly engage the third cylindrical inner surface  381  of the protection sleeve  370 . A seal is also disposed in the groove  322   a  on the motor head third cylindrical outer surface  322  to sealingly engage the third inner cylindrical surface  360  of the release nut  340 . 
     A fifth annular space or cavity  389  is formed radially between the second cylindrical surface  266  of the piston  260  and the second cylindrical inner surface  376  of the sleeve  370 , and axially between the piston cap second end  280   b  and the release nut first end  340   a . A sixth annular space or cavity  390  is formed radially between the generally cylindrical outer surface  342  of the release nut  340  and the generally cylindrical inner surface  373  of the sleeve  370 . The third, fifth, and sixth cavities  387 ,  389 ,  390 , respectively, are in fluid communication with one another. 
     Referring now to  FIGS. 14 and 15 , the annular spaces or cavities  385 - 390  are pressure balanced to resist external pressure and facilitate movement and disconnection of the upper end  200  and lower end  300  of the connection release system  100 . The annular spaces or cavities  385 - 390  are pressure compensated by means of a pressure compensation system in the plug connector  210 , which has an oil reservoir  395  and bellows system incorporated therein (not shown). The cavities  385 - 390  are filled via check valves with oil prior to attaching the plug connector  210  at flange  223 . To balance the pressure between the release system  100  upper end  200  and lower end  300 , motor oil is fed via check valves (not shown) to a cavity  391  from a motor cavity  392 . The seals disposed in groove  226   b  ( FIGS. 2 and 4 ) and groove  287   a  ( FIG. 10 ) allow the upper and lower ends  200 ,  300 , respectively, to separate under high pressure, typically 9,000 to 24,000 psi. By filling the cavities  385 - 390  with oil, the piston  260  and the release nut  340  are fully enclosed and sealed to exclude sand, silt, and debris, which could cause sticking or jamming and hinder the movement or separation of the upper and lower ends  200 ,  300 , respectively. 
     Referring now to  FIGS. 6 and 7 , before activation, the first fluid chamber  248  is filled with hydraulic fluid from the control line or hydraulic fluid source (not shown) and the second fluid chamber  258  is filled with hydraulic fluid. The fluid in the first fluid chamber  248  is connected to fluid source (not shown) and separated from the fluid in the second fluid chamber  258  by the piston  260 . In particular, the hydraulic fluid in the first fluid chamber  248  acts on the piston  260  at the second protrusion  264   b  ( FIGS. 9 and 2 ), whereas the fluid in the second fluid chamber  258  acts oppositely on the piston at the first protrusion  264   a  such that the piston  260  is pressure-balanced. Thus, the fluid in the first fluid chamber  248  and the fluid in the second fluid chamber  258  act in opposite directions on the piston  260  to keep the piston  260  pressure-balanced. The sealed opening or burst disc  246  in housing  230  acts as a barrier to keep the hydraulic fluid in the second channel  244  out of the second chamber  242 , the plurality of connecting galleries  257 , and the plurality of overflow cavities  255 . The cavities  255  also provide structural strength for the annular piston  260  to resist the collapse pressure from the external environment, which is approximately 24,000 psi. The volume of the cavities  255  is configured to receive the displacement volume of the fluid from the piston  260  to stroke through its actuation length L ( FIG. 15 ) upon actuation of the release system  100 . Thus, overflow cavities  255  may also be referred to as buffer cavities or buffer chambers. 
     To actuate the release system  100 , hydraulic fluid is pressurized in the control line (not shown) and fed through inlet port  247  and added to the fluid already in the housing first cylindrical chamber  241  and the housing first elongate channel  243 , which is in fluid communication with the graduated downward-facing shoulder  239  and face  264   c  of the second annular piston protrusion  264   b . The additional pressurized fluid acts on the second protrusion  264   b  of the piston  260  to move the annular piston  260  axially toward the plug connector  210  while the first annular protrusion  264   a  transfers pressure along second elongate channel  244  to the burst disc  246 . The burst disc  246  is isolated from the pressure compensation fluid and, therefore, independent of the external pressure around the tool or motor. The burst disc is configured to rupture under a desired or predetermined pressure, for example, between 6,000-15,000 psi; factors that impact the rupture pressure include, but are not limited to, the application and the disc rating. As the piston  260  moves axially toward the plug connector  210  and the burst disk  246  ruptures, the hydraulic fluid flows into the second chamber  242  and into the cavities  255  through the connecting galleries  257 . While the piston  260  moves axially toward the plug connector  210 , the slotted release nut fingers  366  also move radially outward to allow the piston threads  268  to disengage the slotted release nut threads  355 . As the piston threads  268  disengage the slotted release nut threads  355 , a hydraulic signature is created that can be used to assess the success of the disconnection as the pressure will build and then fall when each thread disengages. Once the final thread is cleared, as shown in  FIG. 15 , the plug connector  210  can be separated from the motor head  310  by pulling the cable or coiled tubing  150  ( FIG. 1 ). 
     If the hydraulic line is not functioning for any reason, leakage or damage for example, a secondary release method without the use of a pressurized fluid is available by manually pulling on the cable or coiled tubing  150  to disengage the piston threads  268  from the slotted release nut threads  355 , which is configured to release at a predetermined load, for example, approximately 24,000 lb. 
     While various embodiments have been shown and described, modifications thereof can be made by one skilled in the art without departing from the scope or teachings herein. The embodiments described herein are exemplary only and are not limiting. Many variations and modifications of the systems, apparatus, and processes described herein are possible and are within the scope of the disclosure. For example, the relative dimensions of various parts, the materials from which the various parts are made, and other parameters can be varied. Accordingly, the scope of protection is not limited to the embodiments described herein, but is only limited by the claims that follow, the scope of which shall include all equivalents of the subject matter of the claims. Unless expressly stated otherwise, the steps in a method claim may be performed in any order, and disclosed features and components can be arranged in any suitable combination to achieve desired results.