Patent Publication Number: US-10781651-B2

Title: FRAC plug system with integrated setting tool

Description:
BACKGROUND 
     In the resource exploration and recovery industry, boreholes are formed to test for and recover formation fluids. During testing and extraction, various tools are deployed into the borehole. A frac plug may be set against a casing and used as part of a process that initiates a fracture in a formation. Setting a frac plug, or other seal may require the use of drop balls, explosive charges, or other tools that increase an overall cost and complexity of operation. 
     Typically, a force, which may be initiated by the explosive charge, may urge a setting member into a seal. After the frac plug is set, guns are fired to perforate the casing. Pressure may then be applied to a drop ball causing fluids to pass through perforations to create a fracture in the formation. Plugging and perforating the casing and fracturing the formation includes multiple steps. Accordingly, the art would be receptive of alternative methods for setting seals/plugs in a borehole. 
     SUMMARY 
     Disclosed is a downhole tool comprising: a setting cone including a body having an outer surface, the body having a first end, a second end and an intermediate portion, at least a portion of the body including a taper at the second end, a passage extending through the body from the first end to the second end; an anchor arranged at the second end of the setting cone, the anchor including a first end section receptive of the setting cone and a second end section; a mandrel extending through the passage of the setting cone and the anchor, the mandrel including a first end portion, a second end portion and an intermediate section, a conduit extends from the first end portion toward the second end portion, an opening extends from the conduit through the mandrel; and a bottom sub arranged at the second end section of the anchor, the bottom sub including a first member fixedly mounted to the mandrel and a second member that is shiftable relative to the mandrel. 
     Disclosed is a downhole tool including a setting cone having a body including an outer surface. The body has a first end, a second end and an intermediate portion. At least a portion of the body includes a taper at the second end. A passage extends through the body from the first end to the second end. An anchor is arranged at the second end of the setting cone. The anchor includes a first end section receptive of the setting cone and a second end section. A mandrel extends through the passage of the setting cone and the anchor. The mandrel includes a first end portion, a second end portion and an intermediate section. A conduit extends from the first end portion toward the second end portion. An opening extends from the conduit through the mandrel. A bottom sub is arranged at the second end section of the anchor. The bottom sub includes a first member fixedly mounted to the mandrel and a second member that is shiftable relative to the mandrel. 
     Also disclosed is a resource exploration and recovery system including a first system, and a second system fluidically connected to the first system through a wireline. The wireline supports a downhole tool including a setting cone having a body including an outer surface. The body has a first end, a second end and an intermediate portion. At least a portion of the body includes a taper at the second end. A passage extends through the body from the first end to the second end. An anchor is arranged at the second end of the setting cone. The anchor includes a first end section receptive of the setting cone and a second end section. A mandrel extends through the passage of the setting cone and the anchor. The mandrel includes a first end portion, a second end portion and an intermediate section. A conduit extends from the first end portion toward the second end portion. An opening extends from the conduit through the mandrel. A bottom sub is arranged at the second end section of the anchor. The bottom sub includes a first member fixedly mounted to the mandrel and a second member that is shiftable relative to the mandrel. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The following descriptions should not be considered limiting in any way. With reference to the accompanying drawings, like elements are numbered alike: 
         FIG. 1  depicts a resource exploration and recovery system including a frac plug system having an integrated setting tool, in accordance with an aspect of an exemplary embodiment; 
         FIG. 2  depicts the frag plug system of  FIG. 1 , in accordance with an aspect of an exemplary embodiment; 
         FIG. 3  depicts a cross-sectional view of the frac plug of  FIG. 2 , in accordance with an aspect of an exemplary embodiment; and 
         FIG. 4  depicts a cross-sectional view of the frac plug of  FIG. 2 , in accordance with another aspect of an exemplary embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     A detailed description of one or more embodiments of the disclosed apparatus and method are presented herein by way of exemplification and not limitation with reference to the Figures. 
     A resource exploration and recovery system, in accordance with an exemplary embodiment, is indicated generally at  10 , in  FIG. 1 . Resource exploration and recovery system  10  should be understood to include well drilling operations, completions, resource extraction and recovery, CO 2  sequestration, and the like. Resource exploration and recovery system  10  may include a first system  14  which, in some environments, may take the form of a surface system  16  operatively and fluidically connected to a second system  18  which, in some environments, may take the form of a subterranean system. 
     First system  14  may include a control system  23  that may provide power to, monitor, communicate with, and/or activate one or more downhole operations as will be discussed herein. Surface system  16  may include additional systems such as pumps, fluid storage systems, cranes and the like (not shown). Second system  18  may include a tubular string or wireline  30  that extends into a wellbore  34  formed in a formation  36 . Wireline  30  may be operatively connected to control system  23 . Wellbore  34  includes an annular wall  38  which may be defined by a surface of formation  36 , or a casing tubular  40  such as shown. 
     In an exemplary aspect, wireline  30  supports a downhole tool  50 . As will be detailed herein, downhole tool  50  may take the form of a frac plug system  54  that may be selectively engaged with annular wall  38 . Referring to  FIG. 2 , and with continued reference to  FIG. 1 , frac plug system  54  includes a setting cone  60  that may force an anchor  63  into engagement with annular wall  38 . Anchor  63  may take the form of a slip  65  having a plurality of wickers  68 . Wickers  68  “bite” into annular wall  38  when slip  65  moves along setting cone  60 . Anchor  63  includes a first end section  69  that receives setting cone  60  and a second end section  70 . Setting cone  60  also supports a seal  72  and a backup ring  74 . Backup ring  74  urges seal  72  along setting cone  60 . Seal  72  may seal against annular wall  38 . 
     A mandrel  80  extends through setting cone  60  and supports an actuator head  82 . Mandrel  80  also extends through a bottom sub  85 . As will be detailed herein, actuator head  82  establishes a force that drives anchor  63  along setting cone  60 . 
     Reference will now follow to  FIG. 3 , with continued reference to  FIGS. 1 and 2  in further describing frac plug system  54 . Setting cone  60  includes a body  94  having an outer surface  96  including a first end  98 , a second end  99 , and an intermediate portion  100 . A portion of body  94  includes a taper  102 . In an embodiment, taper  102  defines a frusto-conical surface  104  that extends from second end  99  toward first end  98 . A passage  108  extends through body  94 . Passage  108  includes an enlarged diameter portion (not separately labeled) that is receptive to a firing mechanism  110  of actuator head  82 . Mandrel  80  extends through passage  108 . 
     Mandrel  80  includes a first end portion  118 , second end portion  119 , and an intermediate section  120  extending therebetween. A conduit  122  extends through mandrel  80 . A first portion (not separately labeled) of conduit  122  defines an actuation chamber  124 . Actuation chamber  124  may take the form of a powder charge chamber (not separately labeled) housing power charge  125  that may take the form of an amount of propellant (also not separately labeled) which, when ignited, produces high pressure gases. Conduit  122  terminates at a blind end  130  within mandrel  80 . A port  132  extends radially outwardly of conduit  122  through mandrel  80  at intermediate section  120 . 
     In an embodiment, depicted in  FIG. 3  bottom sub  85  includes a first member  136  and a second member  138 . First member  136  includes an outer surface section  140  and an inner surface section  142  that defines an interior portion  144 . First member  136  includes an opening  148  that is receptive of mandrel  80 . A seal  149  is arranged in opening  148 . Seal  149  seals against an outer surface (not separately labeled) of mandrel  80 . Second member  138  includes a first end section  151  and a second end section  152 . A shearable thread  153  attaches second member  138  to mandrel  80 . 
     A first seal  154  extends about an exterior (not separately labeled) of second member  138  adjacent first end section  151 . First seal  154  seals against inner surface section  142  of first member  136 . A second seal  156  extends about an interior passage (not separately labeled) of second member  138 . Second seal  156  seals against the outer surface of mandrel  80 . A chamber  160  is formed between first end section  151  of second member  138  and an inner axial end wall (not separately labeled) of first member  136 . 
     Second member  138  includes a recess  165  in second end section  152 . A frangible element  168  is arranged about second end portion  119  of mandrel  80  in recess  165 . Frangible element  168  prevents second member  138  from unthreading from mandrel  80  when pumping downhole tool  50  into wellbore  34 . 
     In an embodiment, frac plug system  54  is introduced into wellbore  34  and moved to a selected depth/position on, for example, wireline  30 . Once in position, control system  23  may send a signal to actuator head  82  to activate firing mechanism  110  to set off the amount or propellant in actuation chamber  124 . Once ignited, the propellant or other substance produces a pressure wave that may travel down conduit  122  towards second end portion  119 . The pressure wave passes through port  132  into chamber  160 . The pressure wave causes slip  65  to break into segmented pieces (not separately labeled) allowing first member  136  to travel axially along mandrel  80  driving anchor  63  along setting cone  60 . 
     Anchor  63  expands radially outwardly into contact with annular wall  38 . In addition to setting anchor  63 , first member  136  drives seal  72  and, in some embodiments, a backup ring (not shown) along setting cone  60 . Seal  72  expands radially outwardly into contact with annular wall  38  forming a plug. Once casing wall  38  prevents anchor  63  from expanding pressure applied in chamber  160  will increase until enough axial force is created to break shearable threads  153  and frangible element  168 . Once set, downhole tool  50  may be withdrawn. At this point, bottom sub  85  may drop towards a toe (not shown) of wellbore  34 . Mandrel  80  along with actuator head  82  may be withdrawn from wellbore  34 . A plurality of fasteners, one of which is indicated at  172 , keeps first member  136  from separating from second member  138  so that the plug will be easier to mill up. 
     In another embodiment, actuator head  82  may allow hydrostatic pressure to enter into actuation chamber  124  and chamber  160  to apply a pressure differential against a chamber with atmospheric pressure in bottom sub (not shown) to shift first member  136  upward to set frac plug system  54 . 
     Reference will now follow to  FIG. 4 , wherein like reference numbers present corresponding parts in the respective views, in describing a bottom sub assembly  200  in accordance with another aspect of an exemplary embodiment. Bottom sub assembly  200  includes first member  136  and a second member  204  having a first end section  211  and a second end section  212 . A shearable thread  223  attaches second member  204  to mandrel  80 . A first seal  234  extends about an exterior (not separately labeled) of second member  204  adjacent first end section  211 . First seal  234  seals against inner surface section  142  of first member  136 . A second seal  236  extends about an interior passage (not separately labeled) of second member  204 . Second seal  236  seals against the outer surface of mandrel  80 . 
     In an embodiment, a chamber  260  is formed between first end section  211  of second member  204  and an inner axial end wall (not separately labeled) of first member  136 . In an embodiment, a power charge  270 , which could take the form of an amount of propellant, is arranged in chamber  260 . Power charge  270  may be operatively connected to firing mechanism  110  of actuator head  82  via actuation chamber  124 . In a manner similar to that discussed herein, control system  23  may send a signal to actuator head  82  to activate firing mechanism  110  to ignite power charge  270 . Once ignited, power charge  270  produces a pressure that causes slip  65  to break into segmented pieces allowing first member  136  to travel axially along mandrel  80  driving anchor  63  into along setting cone  60 . 
     Anchor  63  expands radially outwardly into contact with annular wall  38 . In addition to setting anchor  63 , first member  136  drives seal  72 , and, in some embodiments, a backup ring (not shown) along setting cone  60 . Seal  72  expands radially outwardly into contact with annular wall  38  forming a plug. Once casing wall  38  prevents anchor  63  from expanding pressure applied in chamber  260  will increase until enough axial force is created to break shearable threads  153  and frangible element  168 . Once set, downhole tool  50  may be withdrawn. At this point, bottom sub  85  may drop towards a toe (not shown) of wellbore  34 . Mandrel  80  along with actuator head  82  may be withdrawn from wellbore  34 . 
     Set forth below are some embodiments of the foregoing disclosure: 
     Embodiment 1 
     A downhole tool comprising: a setting cone including a body having an outer surface, the body having a first end, a second end and an intermediate portion, at least a portion of the body including a taper at the second end, a passage extending through the body from the first end to the second end; an anchor arranged at the second end of the setting cone, the anchor including a first end section receptive of the setting cone and a second end section; a mandrel extending through the passage of the setting cone and the anchor, the mandrel including a first end portion, a second end portion and an intermediate section, a conduit extends from the first end portion toward the second end portion, an opening extends from the conduit through the mandrel; and a bottom sub arranged at the second end section of the anchor, the bottom sub including a first member fixedly mounted to the mandrel and a second member that is shiftable relative to the mandrel. 
     Embodiment 2 
     The downhole tool according to any previous embodiment, wherein the first member of the bottom sub is spaced from the second member of the bottom sub, the bottom sub including a chamber arranged between the first member and the second member. 
     Embodiment 3 
     The downhole tool according to any previous embodiment, further comprising: a firing mechanism arranged at the first end portion of the mandrel. 
     Embodiment 4 
     The downhole tool according to any previous embodiment, wherein the opening in the mandrel fluidically connects the conduit and the chamber. 
     Embodiment 5 
     The downhole tool according to any previous embodiment, wherein a portion of the conduit defines an actuation chamber. 
     Embodiment 6 
     The downhole tool according to any previous embodiment, further comprising: an amount of propellant arranged in the actuation chamber, the amount of propellant being operatively connected to the firing mechanism. 
     Embodiment 7 
     The downhole tool according to any previous embodiment, further comprising: a power charge arranged in the chamber defined between the first member and the second member of the bottom sub, the power charge being operatively connected to the firing mechanism through the conduit. 
     Embodiment 8 
     The downhole tool according to any previous embodiment, further comprising: one or more fasteners preventing separation between the first member of the bottom sub and the second member of the bottom sub. 
     Embodiment 9 
     The downhole tool according to any previous embodiment, further comprising: a frangible element connecting the second end portion of the mandrel and the second member of the bottom sub. 
     Embodiment 10 
     The downhole tool according to any previous embodiment, wherein the first member of the bottom sub includes an interior portion, the second member of the bottom sub being selectively arranged in the interior portion of the bottom sub. 
     Embodiment 11 
     A resource exploration and recovery system comprising: a first system; and a second system fluidically connected to the first system through a wireline, the wireline supporting a downhole tool comprising: a setting cone including a body having an outer surface, the body having a first end, a second end and an intermediate portion, at least a portion of the body including a taper at the second end, a passage extending through the body from the first end to the second end; an anchor arranged at the second end of the setting cone, the anchor including a first end section receptive of the setting cone and a second end section; a mandrel extending through the passage of the setting cone and the anchor, the mandrel including a first end portion, a second end portion and an intermediate section, a conduit extends from the first end portion toward the second end portion, an opening extends from the conduit through the mandrel; and a bottom sub arranged at the second end section of the anchor, the bottom sub including a first member fixedly mounted to the mandrel and a second member that is shiftable relative to the mandrel. 
     Embodiment 12 
     The resource exploration and recovery system according to any previous embodiment, wherein the first member of the bottom sub is spaced from the second member of the bottom sub, the bottom sub including a chamber arranged between the first member and the second member. 
     Embodiment 13 
     The resource exploration and recovery system according to any previous embodiment, further comprising: a firing mechanism arranged at the first end portion of the mandrel. 
     Embodiment 14 
     The resource exploration and recovery system according to any previous embodiment, wherein the opening in the mandrel fluidically connects the conduit and the chamber. 
     Embodiment 15 
     The resource exploration and recovery system according to any previous embodiment, wherein a portion of the conduit defines an actuation chamber. 
     Embodiment 16 
     The downhole tool according to any previous embodiment, further comprising: an amount of propellant arranged in the actuation chamber, the amount of propellant being operatively connected to the firing mechanism. 
     Embodiment 17 
     The downhole tool according to any previous embodiment, further comprising: a power charge arranged in the chamber defined between the first member and the second member of the bottom sub, the power charge being operatively connected to the firing mechanism through the conduit. 
     Embodiment 18 
     The resource exploration and recovery system according to any previous embodiment, further comprising: one or more fasteners preventing separation between the first member of the bottom sub and the second member of the bottom sub. 
     Embodiment 19 
     The resource exploration and recovery system according to any previous embodiment, further comprising: a frangible element connecting the second end portion of the mandrel and the second member of the bottom sub. 
     Embodiment 20 
     The resource exploration and recovery system according to any previous embodiment, wherein the first member of the bottom sub includes an interior portion, the second member of the bottom sub being selectively arranged in the interior portion of the bottom sub. 
     The terms “about” and “substantially” are intended to include the degree of error associated with measurement of the particular quantity based upon the equipment available at the time of filing the application. For example, “about” and/or “substantially” can include a range of +8% or 5%, or 2% of a given value. 
     The use of the terms “a” and “an” and “the” and similar referents in the context of describing the invention (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. Further, it should be noted that the terms “first,” “second,” and the like herein do not denote any order, quantity, or importance, but rather are used to distinguish one element from another. The modifier “about” used in connection with a quantity is inclusive of the stated value and has the meaning dictated by the context (e.g., it includes the degree of error associated with measurement of the particular quantity). 
     The teachings of the present disclosure may be used in a variety of well operations. These operations may involve using one or more treatment agents to treat a formation, the fluids resident in a formation, a wellbore, and/or equipment in the wellbore, such as production tubing. The treatment agents may be in the form of liquids, gases, solids, semi-solids, and mixtures thereof. Illustrative treatment agents include, but are not limited to, fracturing fluids, acids, steam, water, brine, anti-corrosion agents, cement, permeability modifiers, drilling muds, emulsifiers, demulsifiers, tracers, flow improvers etc. Illustrative well operations include, but are not limited to, hydraulic fracturing, stimulation, tracer injection, cleaning, acidizing, steam injection, water flooding, cementing, etc. 
     While the invention has been described with reference to an exemplary embodiment or embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the claims. Also, in the drawings and the description, there have been disclosed exemplary embodiments of the invention and, although specific terms may have been employed, they are unless otherwise stated used in a generic and descriptive sense only and not for purposes of limitation, the scope of the invention therefore not being so limited.