Patent Publication Number: US-11028666-B2

Title: Apparatus for isolating one or more zones in a well

Description:
FIELD OF THE INVENTION 
     Preferred forms of the present invention are directed to bridge or frac plugs that are installed/set in a drilled open hole to isolate at least a portion of the drilled open hole (e.g., well bore) and setting tools for setting the plugs. A preferred form of the present invention includes a bridge or frac plug and a setting tool that are configured to prevent premature setting of the bridge or frac plug. A preferred form of the present invention includes a bridge or frac plug that includes one or more portions that directly connect the bridge or frac plug to a setting tool wherein the one or more portions of the bridge or frac plug shear during setting of the bridge or frac plug in an operating position. In a most preferred form of the present invention, the bridge or frac plug includes first and second longitudinally spaced portions that directly connect the bridge or frac plug to a setting tool wherein the first and second longitudinally spaced portions of the bridge or frac plug shear during setting of the bridge or frac plug in an operating position. In a most preferred form of the invention, no portion of the setting tool shears during installation of the bridge or frac plug and/or removal of the setting tool. In a most preferred form of the invention, neither the bridge/frac plug or the setting tool requires a collet to detachably connect the plug to the setting tool. 
     BACKGROUND OF THE INVENTION 
     Various tools (e.g., plugs) have been developed to isolate one or more portions of a well bore to facilitate the well-known frac process or operation. The frac process or operation results in the formation of fractures or cracks that allow hydrocarbons to be extracted. This process or operation may be repeated as desired until all target zones in the well bore are fractured. 
     The frac process is initiated by drilling an open hole. A shoe track consisting of a shoe guide and a latch down float may be inserted in the open hole and cemented therein to form a casing or tubular in the open hole. Applied pressure in the casing or tubular activates the launch to create communication between the casing and the open hole. Subsequently, a plug and a perf gun are inserted in the well bore by a setting tool. The setting tool sets the plug at a predetermined location in the well bore. The plug can be oriented horizontally or vertically. Once the plug is properly set the setting tool is disconnected from the plug. The perforation process can now commence. After the perforation process has been completed, the setting tool is removed from the well and a sealing element is inserted into the well to engage a top portion or an upper seat or end of the plug. The sealing element can be a ball which is removable or dissolvable. Once the sealing element is properly installed the frac can now begin. After all steps of the frac are completed, the sealing element dissolves or is removed depending upon the type of sealing element used clearing the path from production. 
     A significant concern in the process of installing the plug is premature setting of the plug. To address the significant concern of premature setting of the plug, a preferred form of the present invention provides a plug that prevents or significantly reduces premature setting of the plug. Further, previously developed plugs have a complex design requiring the setting tool and the plug to each have collets to install and set the plug in a well bore. In addition, prior devices have required the setting tool to have one or more elements that shear during the setting process to remove the setting tool requiring the sheared portions of the setting tool to be replaced before the setting tool can be reused. To address these concerns as well as other concerns, a preferred form the present invention provides a simplified construction wherein neither the setting tool nor the plug has a collet and no portion of the setting tool need shear to disconnect the setting tool from the plug allowing the setting tool to be readily reused without replacing any sheared component or portion of the setting tool. 
     OBJECTS AND SUMMARY OF THE INVENTION 
     An object of a preferred form of the present invention is to provide a novel and unobvious apparatus for installation in a well bore for isolating at least a portion of the well bore. 
     Another object of a preferred form of the present invention is to provide an apparatus having an isolation member which is to be set in a well bore at a predetermined location for isolating at least a portion of the well bore and a tool for setting the isolation member wherein the apparatus is configured to prevent or significantly reduce premature setting of the isolation member. 
     A further object of a preferred embodiment of the present invention is to provide a bridge or frac plug and/or setting tool that are configured to prevent or significantly reduce premature setting of the bridge or frac plug in a well bore. 
     Still another object of a preferred embodiment of the present invention is to provide a bridge or frac plug having a first portion and a second portion that are spaced from each other along a longitudinal axis of the plug that detachably connect the plug to a setting tool at two longitudinally spaced points or sections of the setting tool. 
     A further object of a preferred embodiment of the present invention is to provide a bridge or frac plug having a first portion and a second portion that are spaced from each other along a longitudinal axis of the plug and that connect the plug to a setting tool at two longitudinally spaced sections of the setting tool to allow the setting tool to precisely set the plug at a predetermined location in the well bore wherein the first and second portions of the plug are configured to shear during the plug setting process to disconnect the plug from the setting tool. 
     Yet another object of a preferred embodiment of the present invention is to provide a bridge or frac plug that is set in a predetermined location in a well bore by a setting tool wherein the plug and/or setting tool are configured such that no portion of the setting tool need shear to disconnect the setting tool from the plug. 
     Yet a further object of a preferred embodiment of the present invention is to provide a bridge or frac plug that is set in a predetermined location in a well bore by a setting tool wherein neither the plug nor the setting tool includes a collect to detachably connect the plug to the setting tool. 
     It must be understood that no one embodiment of the present invention need include all of the aforementioned objects of the present invention. Rather, a given embodiment may include one or none of the aforementioned objects. Accordingly, these objects are not to be used to limit the scope of the claims of the present invention. 
     In summary, one preferred embodiment of the present invention is directed to an apparatus for installation in a well bore for isolating at least a portion of the well bore. The apparatus includes a multi-piece plug configured to be installed in an operating position in a well bore by a setting tool detachably connected to the multi-piece plug. The multi-piece plug includes a first portion and a second portion. The first portion is offset along a longitudinal axis of the multi-piece plug from the second portion. The first portion of the multi-piece plug being configured to engage a first portion of the setting tool to connect the multi-piece plug to the setting tool at a first location while the multi-piece plug travels in the well bore to the operating position. The second portion of the multi-piece plug is configured to engage a second portion of the setting tool to connect the multi-piece plug to the setting tool at a second location while the multi-piece plug travels in the well bore to the operating position. The first portion and the second portion of the multi-piece plug prevent premature setting of the bridge plug. 
     Another preferred embodiment of the present invention is directed to a bridge plug configured to be installed in a well bore in an operating position by a setting tool for isolating a portion of the well bore. The bridge plug includes a multi-piece body configured to be installed in an operating position in a well bore wherein the multi-piece body is fixed to the well bore when installed in the operating position. The multi-piece body of the bridge plug has a first portion and a second portion. The first portion is offset along a longitudinal axis of the multi-piece body from the second portion. The first portion of the multi-piece body of the bridge plug is configured to engage a first portion of a setting tool to connect the bridge plug to the setting tool at a first location while the bridge plug travels in the well bore to the operating position. The second portion of the multi-piece body of the bridge plug is configured to engage a second portion of the setting tool to connect the bridge plug to the setting tool at a second location while the bridge plug travels in the well bore to the operating position, wherein the first portion and the second portion of the multi-piece body of the bridge plug are configured to shear during setting of the multi-piece body of the bridge plug in the operating position. 
     A further preferred embodiment of the present invention is directed to a bridge plug configured to be installed in a well bore in an operating position by a setting tool for isolating a portion of the well bore. The bridge plug includes a multi-piece body configured to be installed in an operating position in a well bore wherein the multi-piece body is fixed to the well bore when installed in the operating position. The multi-piece body of the bridge plug having an end cap. The end cap is positioned adjacent a terminal end of a setting tool and spaced from a sealing element configured to engage an end of the multi-piece body opposite an end of the multi-piece body adjacent the terminal end of the setting tool. The end cap of the multi-piece body has an inwardly projecting annular portion. The inwardly projecting annular portion is configured to shear during setting of the multi-piece body. 
     The preferred forms of the present invention described above provide various examples of preferred embodiments of the present invention and are not to be construed as limiting the present invention to any of the preferred forms described above. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an elevational, end view of a bridge or frac plug formed in accordance with a preferred embodiment of the present invention. 
         FIG. 2  is a cross-sectional view taken along lines A-A in  FIG. 1 . 
         FIG. 3  is an exploded, cross-sectional view of the plug depicted in  FIGS. 1 and 2 . 
         FIG. 4  is a cross-sectional view of the plug depicted in  FIGS. 1 to 3  connected to a setting tool formed in accordance with a preferred embodiment of the present invention. 
         FIG. 5  is an elevational view of an alternative form of a bridge or frac plug connected to a setting tool similar depicted in  FIG. 4 . 
         FIG. 6  is cross-sectional view of the alternative embodiment depicted in  FIG. 5 . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE INVENTION 
     The preferred forms of the invention will now be described with reference to  FIGS. 1-6 . The appended claims are not limited to the preferred forms and no term and/or phrase used herein is to be given a meaning other than its ordinary meaning unless it is expressly stated otherwise. In particular, “multi-piece” as used herein means more than one piece, e.g., a plug having two or more pieces is a multi-piece plug and a body having two or more pieces is a multi-piece body. 
     Two preferred embodiments are disclosed and described herein. The first preferred embodiment is depicted in  FIGS. 1 to 4  and the second preferred embodiment is depicted in  FIGS. 5 and 6 . While two preferred embodiments are depicted, the scope of the present invention includes numerous variations thereof. 
     A feature common to both preferred embodiments is the design of the frac or bridge plug to connect the frac plug to the plug setting tool in two different locations (e.g., longitudinally spaced locations) to keep the frac plug from setting prematurely. Another common feature of the preferred embodiments, is the design of the frac or bridge plug and the setting tool wherein no portion of the setting tool needs to shear to separate the frac or bridge plug from the setting tool. A further common feature of the preferred embodiments is the design of a frac or bridge plug to have an end cap at a terminal end of the frac or bridge plug having an inwardly extending annular portion that engages a corresponding portion of the setting tool to connect a terminal end of the plug to the setting tool wherein the inwardly extending annular portion is configured to shear during setting of the plug. Yet a further common feature of the preferred embodiments is the design of the plug and setting tool such that a first portion of the plug adjacent a first end of the plug removably connects the plug to a first section of the setting tool and a second portion of the plug adjacent a second end of the plug opposite the first end of the plug removably connects the plug to a second section of the setting tool. 
     FIGS.  1  Through  4   
     Referring to  FIGS. 1 to 4 , a well bore tool A employing a preferred form of the invention is illustrated in one of many possible configurations. Well bore tool A includes a sealing element B, a multi-piece plug C and a plug setting tool D. Preferably, multi-piece plug C is a bridge or frac plug configured to isolate a portion of a well bore to facilitate a fracing process or operation. The plug C can be oriented horizontally or vertically in a corresponding section of a well bore. Sealing element B is preferably a ball that seats on an upper portion of plug C subsequent to plug C being set in a predetermined location in the well bore as seen in  FIG. 2 . However, sealing element B can take any suitable form. Sealing element B can be configured to be removed or dissolved to clear the path for production. For example, sealing element B can be configured to dissolve after a predetermined period of time (e.g., ten days). One or more components of plug C can also be configured or formed to dissolve after a predetermined period of time. For example, the bulk/majority or all of the components of plug C can be configured or formed to dissolve after a predetermined period of time (e.g., ten days). If one or more slips with ceramic gripping elements partially embedded in the slip body are used, the slip body but not the ceramic gripping element will dissolve. However, non-ceramic gripping elements can be partially embedded in the slip body so that the gripping elements and slip body both dissolve. Also, if one or more rubber sealing components form a portion of plug C, these rubber sealing components also dissolve. 
     Referring to  FIGS. 1 to 4 , plug C includes a mandrel  2  preferably forming an upper terminal end of plug C and a lower end cap  4  forming a lower terminal end of plug C. A lock nut  6 , seats in lower inner section  8  of mandrel  2 . Lock nut  6  includes inner threads  10  that are complimentary to external threads  12  formed on the exterior of upper section  14  of end cap  4  to connect mandrel  2  to end cap  4  while allowing end cap  4  to move along a longitudinal axis of the well bore relative to mandrel  2  during the process of setting plug C. 
     Plug C further preferably includes one or more ceramic slips  16  (only one slip is shown) disposed between cone  18  and a lower section  20  of cap  4 . As seen in  FIG. 2 , slip  16  is disposed to ride/slide on an exterior surface of cone  18  during the process of setting plug C. Referring to  FIG. 3 , a plurality of slits  22  may be formed in slip  16  to facilitate or allow slip  16  to split or fracture into two or more sections to allow for radial expansion. Slip  16  may include a plurality of gripping or friction elements  24  (e.g., inserts) that facilitate setting of plug C in the well bore. 
     Plug C further preferably includes an upper expansion ring  26  and a lower expansion ring  28  disposed between cone  18  and upper section  30  of mandrel  2 . Rings  26  and  28  are configured to expand radially during the process of setting plug C. 
     Plug C preferably include two shear portions  32  and  34  that are spaced from each other along a longitudinal axis of plug C. Shear section or portion  32  is preferably formed on an inner surface of end cap  4  and can take the form on an inwardly projecting annular ring or shoulder. Shear portion  34  is preferably formed on an inner surface of mandrel  2  adjacent an upper end of plug C and can take the form of inwardly projecting threads that mate with complimentary threads on an adjacent portion of the plug setting tool D. Shear portions  32  and  34  detachably connect plug C to the setting tool D at two longitudinally spaced areas, sections or points. Shear portions  32  and  34  cooperate with corresponding portions of the setting tool to prevent premature setting of plug C. In this preferred embodiment, the shear portions  32  and  34  are disposed adjacent upper and lower end portions of the plug C. 
     Referring to  FIG. 4 , setting tool D preferably includes a setting gun  40 , a housing or setting sleeve  41 , an intermediate member or inner adapter  42 , a lower member or inner adapter rod  44  and a removable end cap  46 . Adapter  42 , as seen in  FIG. 4 , connects an end of gun  40  to adapter rod  44 . End cap  46  has internal threads that allow end cap  46  to be threaded on a threaded portion of adapter  44 . One or more set screws  48  detachably connect end cap  46  to adapter rod  44 . An uppermost radially extending surface  47  of end cap  46  directly abuts shear portion  32  of plug C. 
     The plug C and setting tool D are inserted as a unit into the well bore at a predetermined or desired location and the setting gun  40  is subsequently fired. Once the setting gun  40  is fired, the setting tool D will move to the left as viewed in  FIG. 4 . This movement of setting tool D will cause the internal threads  34  of mandrel  2  to shear. Further, leftward movement will cause elements  26 ,  28  and  16  to move outwardly a sufficient distance to set the frac plug. Element  16  will be forced outwardly by the conical shape of member  18 . Elements  26  and  28  will be forced outwardly by the conically shaped section of member  2 . This further leftward movement will also cause the inset or inwardly extending annular ring  32  of end cap  4  to shear. This allows all elements of the setting tool D to be freed or detached from plug C to allow the setting tool D to be moved relative to the plug C and removed from the well while the plug C is set in an operating position. 
     To mount the frac plug C on the setting tool D to install the plug in an operating position using setting tool D, plug C is mounted on or about adapter rod  44  by threading portion  34  onto a corresponding threaded portion of adapter  44 . End cap  46  of the setting tool D is then connected to a lower end of adapter rod  44  of setting tool D to engage the inwardly extending portion  32  of plug C. One or more set screws  48  are used to connect end cap  46  to adapter rod  44  so that the radially extending and annular surface of the upper portion of end cap  46  of setting tool D engages the lower annular and radially inwardly extending surface of portion  32  of end cap  4  of plug C. 
     FIGS.  5  and  6   
     Referring to  FIGS. 5 and 6 , another preferred embodiment will be described which is similar to the embodiment disclosed and described in connection with  FIGS. 1 to 4 . The setting tool is identical to the setting tool of the first embodiment depicted in  FIGS. 1 to 4 . The only difference between the first embodiment in  FIGS. 1 to 4  and the second embodiment in  FIGS. 5 and 6  is the bridge or frac plug. The same components/pieces/sections are given the same reference letters and numerals to designate the same components of the two embodiments. 
     Frac or bridge plug G will now be described in connection with  FIGS. 5 and 6 . The detachable connection of plug G and the setting tool D are identical to the first embodiment depicted in  FIGS. 1 to 4 , i.e. two longitudinally spaced portions  32  and  34  of the plug G connect plug G to the setting tool wherein portions  32  and  34  shear during setting of plug G in the same manner as described in connection with the first embodiment. Plug G includes mandrel  2 , end cap  4  and one or more slips  16  which are identical to the corresponding components of plug C. Plug G differs from plug C in that elements  18 ,  26  and  28  of plug C have been replaced with a rubber sealing element  50  interconnected to cone  52 . As seen in  FIG. 6 , a lower end of cone  52  interlocks with an upper end of rubber sealing element  50 . Rubber element  50  facilitates sealing of the well portion. Slip  16  and sealing element expand radially outward to set plug G. More specifically, during setting, an inner surface of slip  16  will ride/slide along the tapered external surface of cone  52  causing slip to move radially outward and rubber element  50  will be compressed causing element  50  to expand outwardly to set plug G. 
     While this invention has been described as having a preferred design, it is understood that the preferred design can be further modified or adapted following in general the principles of the invention and including but not limited to such departures from the present invention as come within the known or customary practice in the art to which the invention pertains. The claims are not limited to the preferred embodiment and have been written to preclude such a narrow construction using the principles of claim differentiation.