Compact FRAC plug

Abstract

A frac plug configured to isolate formation zones within a wellbore includes a plug body that has an integrated upper slip receiver in place of a separate upper cone. The frac plug includes an upper slip, a lower cone, a lower slip and a lower sub. The frac plug has a sealing element supported by the plug body. A setting tool is used to set the plug at a desired location in the wellbore. The setting tool includes a setting rod that initially supports the upper slip, lower cone and lower slip of the frac plug in place of a separate mandrel found in conventional frac plugs. Once the frac plug has been set in the wellbore, the setting tool can be removed from the frac plug.

Description

[0001] COMPACT FRAC PLUG

[0002] Related Applications

[0003]

[0001] This application claims the benefit of United States Provisional Patent Application Serial No. 63 / 627.701 filed January 31. 2024 and entitled, "Compact Frac Plug / ’ the disclosure of which is herein incorporated by reference.

[0004] Field of the Invention

[0005]

[0002] This invention relates generally to the field of hydraulic fracturing systems, and more particularly, but not by way of limitation, to a plug for controlling access to selective zones within a well during a hydraulic fracturing operation.

[0006] Background

[0007]

[0003] Hydrocarbons, such as oil and gas, may be recovered from various types of subsurface geological formations. The oil and gas is accessed through a well which is ty pically drilled from the surface to the producing formation. In many wells, hydraulic fracturing is used to promote the production of oil and gas from the formation. A process known as plug and perforation is used to isolate and independently stimulate specific zones within the well.

[0008]

[0004] When the well has been drilled to the desired depth, a steel casing is typically- installed and cemented within the wellbore to prevent the sides of the wellbore from collapsing and to control the flow of fluids from the formation into the wellbore. Once the casing is cemented in place, a section of the wellbore can be perforated to provide a path from the formation to the wellbore through the cement and casing. In most cases, explosive charges or high pressure fluids are used to perforate the casing and cement. Once the casing has been perforated, the adjacent and nearby formation can be stimulated through hydraulic fracturing by injecting high pressure fluid and proppant is injected into the formation to open and suspend small cracks in the formation. This generally improves the permeability of the producing formation near the well to increase the flow of hydrocarbons into the well.

[0009]

[0005] In wells that are drilled through multiple production zones, it may be desirable to sequentially stimulate the zones by conducting multiple hydraulic fracturing operations. Plugs or other zone isolation devices are used to control which zones are stimulated by blocking the flow of pressurized fracturing fluid to lower portions of the wellbore. Multiple plugs can be deployed and retrieved to carry out a strategic sequence of hydraulic fracturing.

[0010]

[0006] Several types of plugs have been used in the past. In some cases, the plug is a simple blocking device that must be removed or destroyed with a drill to permit flow of wellbore fluids through the plug. In other cases, the plug is provided with a controllable valve mechanism that can be closed to prevent flow through the plug during a stimulation exercise and opened to permit flow during the production phase of the hydrocarbon recovery' effort.

[0011]

[0007] A ty pical prior art frac plug 10 is depicted in FIG. 1. Like many conventional frac plugs, frac plug 10 includes a mandrel 12 that supports the various pieces of the frac plug 10, including a sealing element 14, an upper cone 16, a lower cone 18, an upper slip 20 and a lower slip 22. The upper slip 20 rides on the upper cone 16 and the lower slip 22 rides on the lower cone 18. When the upper and lower slips 20, 22 are draw n together by a setting tool, they expand radially outw ard over the conical surfaces of the upper and lower cones 16, 18. At the same time, the upper and lower cones 16, 18 compress the sealing element 14, which also expands in an outward radial direction. The sealing element 14 and upper and lower slips 20, 22 expand into contact with the well casing to prevent the movement fluids in the annular space around the outside of the frac plug. In this way, the frac plug 10 is capable of providing a reliable and removable fluid isolation device.

[0012]

[0008] Although widely adopted, the conventional frac plug 10 depicted in FIG. 1 may be unsuitable for certain applications. In particular, the conventional frac plug 10 is relatively long and requires the use of the mandrel 12 to support the various components before the frac plug 10 is deployed against the casing. This may frustrate installation in certain wells and the large number of components that remain in the well increase the risk of complications during subsequent treatment, removal and flowback operations. Accordingly, there is a need for an improved frac plug that overcomes these and other deficiencies in the prior art. It is to these and other objectives that the present invention is directed.

[0013] Summary of the Invention

[0014]

[0009] In exemplary embodiments, the plug and perforation system disclosed herein includes a setting tool that is connected to a plug, a perforation gun, and a wireline. The wireline lowers the perforation gun, setting tool and plug into a wellbore. The setting tool then sets the plug into the wellbore at the desired location. The plug is configured to isolate formation zones within the wellbore. The plug includes a plug body that has an integrated upper slip receiver, a central channel, a lateral channel connected to the central channel, a plunger seat in the central channel, and a plunger. The plug further includes an upper slip configured for engagement with the upper slip receiver of the plug body, a lower cone connected in sliding relationship to the plug body, a lower slip configured for a sliding relationship with the lower cone, and a lower sub. The plug further includes a sealing element on the plug body that is configured to be captured between the upper slip and the lower cone when the plug is deployed against the casing. In exemplary embodiments, the plug does not include a separate support mandrel, but instead relies on a setting rod of a setting tool to support the upper slip, lower slip and lower cone before the frac plug is set at a desired location in the casing.

[0015]

[0010] In other embodiments, the present disclosure is directed at a plug and perforation system configured to isolate formation zones within a wellbore that has a casing, where the plug and perforation system includes a frac plug. The frac plug includes a plug body, an upper slip, a lower cone, a lower slip, a lower sub and a sealing element. The plug body has an integrated upper slip receiver, a first lateral channel, a second lateral channel, and a central channel. The upper slip is configured for engagement with the upper slip receiver. The lower cone is initially supported by the plug body and the lower slip is configured to slide over the lower cone. The sealing element is configured to be captured between the upper slip receiver and the lower cone when the plug is deployed against the casing. The plug includes a first plunger releasably retained within the first lateral channel and a second plunger releasably retained within the second lateral channel.

[0016] [OH] In other embodiments, the present disclosure is directed at a plug and perforation system configured to isolate formation zones within a wellbore that has a casing. The plug and perforation system includes a setting tool and a frac plug. The setting tool includes a setting rod and a setting sleeve. The frac plug includes a plug body with an integrated upper slip receiver, an upper slip initially supported by the setting rod and configured for engagement with the upper slip receiver, a lower cone initially supported by the plug body and the setting rod, a lower slip configured to slide over the lower cone, a lower sub connected to the setting rod, and a sealing element. The sealing element is configured to be captured between the upper slip receiver and the lower cone when the plug is deployed against the casing. Brief Description of the Drawings

[0017]

[0012] FIG. 1 depicts a cross-sectional view of a conventional PRIOR ART frac plug.

[0013] FIG. 2 depicts a cross-sectional view of a formation with a horizontal wellbore and one perforated zone.

[0018]

[0014] FIG. 3 depicts a cross-sectional view of a formation with a horizontal wellbore with one perforated zone, two fractured zones, and three set plugs.

[0019]

[0015] FIG. 4 presents a side view of a frac plug and setting assembly constructed in accordance with an exemplary embodiment.

[0020]

[0016] FIG. 5 presents a side cross-sectional view of the frac plug of FIG. 4.

[0021]

[0017] FIG. 6 presents a partial perspective view of the frac plug of FIG. 4.

[0022]

[0018] FIG. 7 presents a perspective cross-sectional view of the frac plug of FIG. 4.

[0023]

[0019] FIG. 8 presents a side cross-sectional view of a frac plug constructed in accordance with a second embodiment.

[0024] Written Description

[0025]

[0020] In accordance with exemplary embodiments of the present invention, FIG. 2 depicts a plug and perforation system 100 installed within a wellbore 202, which is drilled for the production of a fluid such as water or petroleum from a geological formation 200. As used herein, the term "petroleum" refers broadly to all mineral hydrocarbons, such as crude oil, natural gas and combinations of oil and gas. The wellbore 202 is lined with a casing 204 which is set with cement 206. The casing 204 and cement 206 prevent the wellbore 202 from collapsing. After the casing 204 and cement 206 are set into the wellbore 202, the plug and perforation system 100 can be used to prepare the wellbore 202 for hydraulic fracturing.

[0026]

[0021] The plug and perforation system 100 prepares the wellbore 202 for hydraulic fracturing by perforating the casing 204 and cement 206 using a perforation gun 102 and isolating sections of the wellbore 202 using plugs 104. Using the plug and perforation system 100, sections of the wellbore 202 can be separately perforated. Each perforated section can then be isolated from other sections using one or more plugs 104 so that each perforated section can then be independently hydraulically fractured.

[0027]

[0022] In addition to the perforation gun 102 and the plug 104, the plug and perforation system 100 also includes a setting tool 106 that is connected between a wireline 108 and the plug 104 or perforation gun 102. The plug 104, perforation gun 102 and setting tool 106 can be referred to as downhole plug assembly 114. The downhole plug assembly 114 is deployed and retrieved using wireline 108. The wireline 108 runs from a wireline van 110 or other wireline deployment machine into the wellbore 202 through a wellhead 112. In some applications, it may be desirable to pump fluid through the wellhead 112 into the wellbore 202 to facilitate the deployment of the dow nhole plug assembly 114 into the wellbore 202.

[0028]

[0023] As seen in FIG. 2 the perforation gun 102, plug 104, and setting tool 106 have been lowered into a horizontal portion of the wellbore 202 and the perforation gun 102 has been used to create perforations 208 in the formation 200 through the casing 204 and cement 206. The perforation gun 102, and setting tool 106 can now be retrieved and the perforations 208 can be hydraulically fractured (“fracked”) to create fissures 210 in the formation 200. In the embodiment depicted in FIG. 2, the plug 104 remains in the casing 204 on the downhole side of the perforated section of the casing 204.

[0029]

[0024] As depicted in FIG. 3, after the perforated section of the formation 200 has been fracked, the perforation gun 102, plug 104, and setting tool 106 are again lowered into the wellbore 202 using the wireline 108, but this time at a new7depth uphole from the fractured section of the wellbore 202. The next plug 104 is then set into the casing 204 using the setting tool 106 in a position uphole from the earlier perforations 208. The perforation gun 102 can then be used again to perforate a new section of formation 200 uphole from the plug 104, to prepare the proximate section of the wellbore 202 for stimulation. This process of perforating, plugging, and fracking can be repeated until the formation 200 is sufficient fracked and ready for production. Three zones are illustrated in FIG. 3, with the third zone ready for the hydraulic fracturing operation.

[0030]

[0025] Turning to FIGS. 4-5, shown therein are side and side cross-sectional views, respectively, of the plug 104 and setting tool 106. FIGS. 6 and 7 depict perspective and perspective cross-sectional views, respectively, of the plug 104 and setting tool 106. As best illustrated in FIG. 5, the setting tool 106 includes a hydraulic setting module 302, a setting sleeve 304 and a setting rod 306. Generally, the hydraulic setting module 302 is configured to retract the setting rod 306 while simultaneously holding the frac plug 106 in a stationary position through the intermediate setting sleeve 304. In this way, when the setting tool 106 is activated, the setting tool 106 compresses the frac plug 106 to set the frac plug 106 in a desired location within the casing 204.

[0031]

[0026] The frac plug 104 generally includes a plug body 116, an upper slip 118, a lower slip 120, a lower cone 122, a sealing element 124, and a lower sub 126. The plug 104 may be constructed of a dissolvable material which will dissolve over time in the presence of wellbore or other fluids. Dissolvable materials include magnesium, aluminum dissolvable alloys, and other dissolvable materials which are able to suitably withstand the well conditions and specific job performance requirements. Alternatively, the plug 104 can alternatively be constructed from steel, cast iron, polymers, or composite materials which are substantially impervious or resistant to wellbore fluids.

[0027] The plug body 116 includes a cylindrical sealing element guide 128, an integrated upper slip receiver 130, a central channel 132 that extends through the plug body 116, and a lateral channel 134 that extends through the upper slip receiver 130 into the central channel 132. In the embodiment depicted, the lateral channel 134 and central channel 132 are substantially orthogonally aligned. As best illustrated in FIG. 5, the sealing element guide 128 is an integrated part of the plug body 116 and provides interior support to the sealing element 124 and lower cone 122. The setting rod 306 initially extends through the central channel 132.

[0032]

[0028] The plug 104 further includes a plunger 136, which initially resides in the lateral channel 134 of the plug body 116. As depicted in FIG. 5, the plunger 136 is substantially capsule shaped with rounded, hemispherical ends and a cylindrical middle section. In this way, the plunger 136 has a length between ends that is larger than the diameter of the cylindrical middle section. The plunger 136 is initially retained inside the lateral channel 134 by a holding mechanism, which is designed to release the plunger 136 into the central channel 132 when a sufficient force gradient is applied across the plunger 136 after the frac plug 104 has been set within the casing 204. The force required to release the plunger 136 from the lateral channel 134 can be generated from a positive force applied by fluid acting on the exterior side of the plunger 136, a negative (suction) force applied to the interior side of the plunger 136 by fluid passing through the central channel 132, or a combination of positive and negative forces acting on the plunger 136.

[0033]

[0029] Once the plunger 136 arrives in the central channel 132, the force of fluid moving through the central channel 132 forces the plunger 136 into contact with the plunger seat 138. The presence of the plunger 136 on the plunger seat 138 prevents fluid flow through the plug 104. The plug 104 can therefore be switched from an “open” state to a “closed” state by forcing the plunger 136 out of the lateral channel 134 and onto the plunger seat 138 in the central channel 132. The plunger 136 will remain seated on the plunger seat 138 as long as the plunger 136 is exposed to greater pressure on the uphole side of the plunger 136 than the downhole side of the plunger 136. That is, if fluid pressure is greater on the uphole side of the plug 104, the plunger 136 is pressed against the plunger seat 138 to stop the flow of fluid through the plug 104. If the fluid pressure is greater on the downhole side of the plug 104, e.g.. during a production phase, the plunger 136 is pressed off the plunger seat 138 and expelled from the plug 104 through the central channel 132. Unlike spherical balls used in prior art ball-in-place plugs, the capsule shape of the plunger 136 prevents the plunger 136 from unintentionally reentering the lateral channel 134, or reentering the central channel 132 once expelled from the plug 104. This mitigates the risk of unintentionally returning the plug 104 to a closed state once the plunger 136 has been dislodged from the plunger seat 138.

[0034]

[0030] The upper slip receiver 130 is integrated into the plug body 116. The upper slip receiver 130 includes one or more conical planar surfaces 140 that are presented as recesses in the upstream end of the plug body 116. In the embodiments depicted, the upper slip 118 includes a plurality of upper slip segments 142 that are held together by an upper slip retainer ring 144. Each of the upper slip segments 142 is configured to fit within a corresponding one of the plurality of upper conical planar surfaces 140 of the upper slip receiver 130 when the upper slip 118 and body 116 are drawn together and the upper slip retainer ring 144 fractures. The angled, conical geometry' of the conical planar surfaces 140 forces the upper slip segments 142 to expand radially outward when the upper slip segments 142 are forced over the upper conical planar surfaces 140. In this way, the upper slip receiver 130 integrated into the plug body 116 provides a compact replacement for the use of a separate upper slip that is found in conventional frac plugs.

[0031] As depicted in FIG. 5, the upper slip 118 and upper slip segments 142 are initially supported by the setting rod 306, which extends through the interior of the upper slip 118 before the plug 104 is deployed and the upper slip segments 142 are pressed into engagement with the upper slip receiver 130.

[0035]

[0032] The lower cone 122 includes a plurality of lower conical planar surfaces 146. an upstream interior aperture 148 and a downstream interior aperture 150. The upstream interior aperture 148 is sized to ride over the sealing element guide 128, while the downstream interior aperture 150 is supported by the setting rod 306. The lower slip 120 includes a plurality of lower slip segments 152 that are initially held together by a lower slip retainer ring 154. In other embodiments, the lower slip 120 is manufactured as a single, unitary component in which the plurality of lower slip segments 152 are joined by a connecting matrix or hub.

[0036]

[0033] The lower slip 120 is configured for a sliding engagement on the lower cone 122. Each of the lower slip segments 152 has an interior conical surface that matches the exterior lower conical surface 146 of the lower cone 122. As the lower slip 120 is forced onto the lower cone 122, the increasing radius of the lower conical surface 146 forces the lower slip segments 152 radially outward to fracture the lower slip retainer ring 154 and allow the lower slip segments to contact with the casing 204.

[0037]

[0034] As the lower slip segments 152 are drawn onto the lower cone 122, the lower cone 122 moves inward toward the sealing element 124 over the sealing element guide 128, which compresses the sealing element 124 betw een the low er cone 122 and the downstream side of the upper slip receiver 130. The movement of the low er slip 120 onto the sealing element guide 128 continues until the downstream interior aperture 150 of the lower cone 122 contacts the end of the plug body 116.

[0035] The movement of the lower cone 122 onto the sealing element guide 128 compresses the sealing element 124 against the stationary upper slip receiver 130 portion of the plug body 116, which causes the sealing element 124 to expand radially outward into contact with the casing 204. The sealing element 124 seals the plug 104 between the lower cone 122. the plug body 116 and the casing 204. thereby preventing fluid from flowing between the plug 104 and the casing 204. In this expanded position, the sealing element 124 seals the wellbore 202 by closing gaps between the plug 104 and the casing 204. This seal allows the wellbore 202 to be separated into distinct zones. The distinct zones can then be independently fractured.

[0038]

[0036] The lower sub 126 is connected to a distal end 308 of the setting rod 306. In the depicted embodiments, the lower sub 126 is threaded onto the distal end 308 of the setting rod 306 with intermeshed threads 314. A spacer 310 and lock nuts 312 are used to prevent the disengagement of the lower sub 126 from the setting rod 306. Before the setting tool 106 is activated, the lower sub 126 prevents the premature setting of the plug 104 by shielding the lower cone 122 from contact with fluid or debris in the wellbore 202. In this way, the engagement between the lower sub 126 and the setting rod 306 holds the plug 104 in an extended state to prevent the plug 104 from prematurely contracting and deploying, which is an undesirable occurrence sometimes referred to as a ‘‘pre-set” event. While the frac plug 104 is being placed into the wellbore 202, the upper retainer ring 144 abuts the upper slip receiver 130 to prevent the upper slip 118 from prematurely deploying by sliding over the outside of the upper slip receiver 130.

[0039]

[0037] When it is time to set the plug 104 in the casing 204, the setting rod 306 is retracted by the hydraulic setting module 302. The setting rod 306 pulls the lower sub 126, which then pulls the lower slip 120 into contact or further engagement with the lower cone 122, which in turn moves the lower cone 122 into a compressed state on the plug body 116. As the setting lower cone 122 and lower slip 120 are pulled by the setting rod 306 into the sealing element 124 and the integrated upper slip receiver 130 of the plug body 116. the entire plug body 116 is moved in an uphole direction to compress the upper slip 118 between the upper slip receiver 130 and the setting sleeve 304, which is held in a stationary position relative to the retracting setting rod 306. The stationary setting sleeve 304 forces the upper slip 118 against the upper slip receiver 130 of the plug body 116 as the plug body 116 moves under the upper slip 118. This breaks the upper slip retainer ring 144 and forces the upper slip segments 142 into the corresponding conical planar surfaces 140 of the upper slip receiver 130 to deploy the upper slip 118 against the casing 204. Once the plug 104 has been deployed or “set” within the casing 204, the plug body 116 will be captured between the setting sleeve 304 and the lower cone 122, and the lower sub 126 will be prohibited from further movement toward the setting sleeve 304.

[0040]

[0038] The engagement between the setting rod 306 and the lower sub 126 is designed to exert a “deployment force” sufficient to fully deploy the upper slip 118, lower slip 120 and sealing element 124 against the casing 204. Once the plug 104 has been deployed or “set” within the casing 204 and the lower sub 126 is prevented from further uphole movement by the low er cone 122 and plug body 116, the force applied by the hydraulic setting module 302 will increase until a “releasing force” is reached, at which time the engagement between the setting rod 306 and the lower sub 126 will fail and the setting rod 306, spacer 310 and lock nuts 312 are pulled through the low er sub 126. The low er sub 126 will then fall away from the balance of the frac plug 104 and the setting rod 306 can be fully retracted within the setting tool 106. The setting tool 106 can then be pulled away from the frac plug 104 with the setting rod 306, spacer 310 and lock nuts 312 passing through the central channel 132 of the frac plug 104.

[0041]

[0039] The setting tool 106 can then be removed from the wellbore 202 while the plug 104 remains securely retained within the casing 204 by the outward, wedge-driven forces created by the engagement of the lower slip 120 on the lower cone 122. the upper slip 118 on the upper slip receiver 130 ofthe plug body 116, and the compressed sealing element 124. Importantly, during the hydraulic fracturing operation, the application of fluid pressure on the plug 104 tends to force the plug body 116 and lower cone 122 into further engagement with the lower slip segments 152. which increases the radial holding force applied by the lower slip segments 152 to the interior of the casing 204. Once the setting tool 106 has been withdrawn, the frac plug 104 can be placed switched into an “open” state by moving the plunger 136 out of the lateral channel 134 into the plunger seat 138, as described above.

[0042]

[0040] It will be noted that although the plug and perforation system 100 is depicted in a horizontal deployment in FIGS. 1 and 2, the plug and perforation system 100 can also be used other applications, including in vertical and other non-horizontal wellbores 202. Accordingly, any references to “upper” or “higher” and “lower” or “deeper” within this disclosure are merely used to describe the relative positions of components within the plug and perforation system 100 and should not be construed as an indication that the plug and perforation system 100 must be deployed in a single orientation. It will be understood that the term “downhole” is a positional or directional reference to objects or movement in the wellbore 202 that are deeper or further from the surface, while the term “uphole” refers to objects or movements that are closer to the surface. For example, the “uphole” movement of fluid refers to the movement of fluid towards the surface, while the “downhole” movement of fluid refers to the movement of fluid in the wellbore 202 away from the surface.

[0043]

[0041] In this manner, a novel plug 104 and the incorporation of this novel plug 104 into plug and perforation systems 100 produces the various novel methods and apparatuses disclosed herein for controlling the flow of fluid through a plug 104 to provide a more versatile and efficient solution for isolating fracking zones and allowing fluid flow from a wellbore 202. For example, the plug 104 can be quickly assembled using the setting rod 306 without the need for the support mandrel found in prior art plugs. The upper slip 118. plug body 116, lower cone 122 and lower slip 120 can be placed over the setting rod 308. The lower sub 126 can then be threaded onto the distal end 308 of the setting rod 306 and locked into place with the spacer 310 and lock nuts 312. In addition to replacing the conventional support mandrel, the integration of the upper cone into the plug body 116 reduces the number of components left in the wellbore 202 after the plug 104 has been set.

[0044]

[0042] Turning to FIG. 8, shown therein is a cross-sectional view of the plug 104 constructed in accordance with a second embodiment. In this embodiment, the plug 104 includes a second lateral passage 156 that contains a second plunger 158. An equalization port 160 places the second lateral channel 154 in fluid communication with the annular space between the plug 104 and the casing 204. The equalization port 160 is sized and configured to prevent the second plunger 158 from exiting the frac plug 104 through the equalization port 160. The second lateral channel 156 can be located directly opposite the lateral channel 134 (as depicted in FIG. 8) and configured to intersect the central channel 132 in a substantially orthogonal relationship.

[0045]

[0043] Initially, the placement of the setting rod 306 within the frac plug 104 traps the second plunger 158 within the second lateral channel 156. When the setting rod 306 is retracted to deploy the plug 104 into contact with the casing 204, the absence of the setting rod 306 in the central channel 132 allows the second plunger 158 to be dislocated into the central channel 132. In some embodiments, the second plunger 158 is not retained within the second lateral channel 156 by a retention mechanism. In other embodiments, the second plunger 158 can be secured within the second lateral channel 156 by shear pins or another releasable retention mechanism. The equalization port 160 ensures that a vacuum is not created behind or radially outward of the second plunger 158 that would inhibit the movement of the second plunger 158 into the central channel 132.

[0046]

[0044] Once the second plunger 158 is drawn into the central channel 132. the second plunger 158 is forced into contact with the plunger seat 138 to prevent fluid flow through the plug 104. In this way, the second plunger 158 is capable of placing the plug 104 into a first closed state, w hich can be used to conduct a pressure test on the w ell bore 202 or to cany' out the hydraulic fracturing operation. Once the application of fluid pressure from uphole of the plug 104 recedes, greater pressure from downhole of the plug 104 will force the second plunger 158 off the plunger seat 138. The second plunger 158 is then ejected from the plug 104 through the central channel 156. The relative shapes and sizes of the second plunger 158 and second lateral channel 156 prevent the second plunger 158 from being recaptured within the second lateral channel 156.

[0047]

[0045] The plug 104 will remain in an open state until fluid flow7through the plug 104 draw s the plunger 136 (the “first plunger 136”) out of the lateral channel 134 (the “first lateral channel 134”) and into the central channel 132, as described above. A plunger retention mechanism in the lateral channel 134 can be configured to hold the plunger 136 within the lateral channel 134 until the pressure gradient acting across the plunger 136 forces the release of the second plunger 136 from the plunger retention mechanism. Suitable retention mechanisms include shear pins, frangible matrices, and spring- loaded buttons. Once the plunger retention mechanism fails or releases, the plunger 136 is drawn into the central channel 132 and forced into contact with the plunger seat 138. Once the plunger 136 is in contact with the plunger seat 138, the plug 104 is closed and fluid can no longer pass through the central channel 132. In this way, the first plunger 136 can be used to place the plug 104 into a second closed state.

[0048]

[0046] The plug 104 will remain in the closed state as long as the first plunger 136 is pressed against the plunger seat 138 by an uphole pressure that exceeds the force applied to the plunger 136 by a downhole pressure. Once the hydraulic fracturing or other operation is complete, the uphole pressure can be reduced so that the downhole pressure forces the plunger 136 off the plunger seat 138. through the central channel 132 and out of the plug 104. The shape and size of the plunger 136 prevents the plunger 136 from unintentionally reentering the plug 104.

[0049]

[0047] Accordingly, the embodiment of the plug 104 depicted in FIG. 8 permits an operator to deploy the plug 104 in the casing 204, place the plug 104 in a first closed state by moving the second plunger 158 onto the plunger seat 138, and then place the plug 104 in an intermediate open state by ejecting the second plunger 158 from the plug 104. The operator can then place the plug 104 into a second closed state by moving the first plunger 136 out of the first lateral channel 134 and onto the plunger seat 138. The operator can then place the plug 104 in a final open state by dislodging the first plunger 136 from the plunger seat 138 and ejecting the first plunger 136 from the plug 104.

[0050]

[0048] It is to be understood that even though numerous characteristics and advantages of various embodiments of the present invention have been set forth in the foregoing description, together with details of the structure and functions of various embodiments of the invention, this disclosure is illustrative only, and changes may be made in detail, especially in maters of structure and arrangement of parts within the principles of the present invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed. It will be appreciated by those skilled in the art that the teachings of the present invention can be applied to other systems without departing from the scope and spirit of the present invention.

Claims

What is claimed is:

1. A plug and perforation system configured to isolate formation zones within a wellbore that has a casing, the plug and perforation system comprising: a frac plug, wherein the frac plug comprises: a plug body, wherein the plug body comprises: an integrated upper slip receiver; and a central channel; an upper slip configured for engagement with the upper slip receiver; a lower cone initially supported by the plug body; a lower slip configured to slide over the lower cone; a lower sub; and a sealing element, wherein the sealing element is configured to be captured between the upper slip receiver and the lower cone when the plug is deployed against the casing.

2. The plug and perforation system of claim 1 , further comprising a setting tool, wherein the setting tool comprises: a setting rod; and a setting sleeve.

3. The plug and perforation system of claim 2, wherein the support slip is initially supported by the setting rod.

4. The plug and perforation system of claim 2, wherein the lower cone is initially supported by the setting rod.

5. The plug and perforation system of claim 2, wherein the lower sub is connected to the setting rod.

6. The plug and perforation system of claim 5, wherein the lower sub is connected to the setting rod with intermeshed threads.

7. The plug and perforation system of claim 6, wherein the lower sub is secured in place on the setting rod with one or more lock nuts.

8. The plug and perforation system of claim 1. wherein the plug body further comprises a lateral channel that intersects the central channel.

9. The plug and perforation system of claim 8. wherein the frac plug further comprises a plunger that is initially held within the lateral channel.

10. The plug and perforation system of claim 9, wherein the plunger is capsule shaped with a length that is greater than its diameter.

11. The plug and perforation system of claim 2, wherein the setting tool further comprises a hydraulic module configured to draw the setting rod inside the setting sleeve.

12. A plug and perforation system configured to isolate formation zones within a wellbore that has a casing, the plug and perforation system comprising: a setting tool, wherein the setting tool comprises: a setting rod; and a setting sleeve; and a frac plug, wherein the frac plug comprises:a plug body with an integrated upper slip receiver, wherein the plug body comprises: a central channel; a first lateral channel intersecting the central channel; and a second lateral channel intersecting the central channel; a first plunger initially retained in the first lateral channel; a second plunger initially retained in the second lateral channel; an upper slip initially supported by the setting rod and configured for engagement with the upper slip receiver; a lower cone initially supported by the plug body and the setting rod; a lower slip configured to slide over the lower cone; a lower sub, wherein the lower sub is connected to the setting rod; and a sealing element, wherein the sealing element is configured to be captured between the upper slip receiver and the lower cone when the plug is deployed against the casing.

13. The plug and perforation system of claim 12. wherein the setting tool further comprises a hydraulic module configured to draw the setting rod inside the setting sleeve.

14. The plug and perforation system of claim 13, wherein the lower sub is connected to the setting rod.

15. A plug and perforation system configured to isolate formation zones within a wellbore that has a casing, the plug and perforation system comprising: a setting tool, wherein the setting tool comprises: a setting rod;a seting sleeve; and a hydraulic module configured to draw the setting rod inside the seting sleeve; and a frac plug, wherein the frac plug comprises: a plug body, wherein the plug body comprises: an integrated upper slip receiver; a central channel; and a lateral channel that intersects the central channel; a plunger initially held within the lateral channel; an upper slip initially supported by the seting rod and configured for engagement with the upper slip receiver; a lower cone initially supported by the plug body and the seting rod; a lower slip configured to slide over the lower cone; a lower sub, wherein the lower sub is connected to the setting rod; and a sealing element, wherein the sealing element is configured to be captured between the upper slip receiver and the lower cone when the plug is deployed against the casing.

16. The plug and perforation system of claim 15, wherein the lateral channel and the central channel are oriented in a substantial orthogonal relationship.

17. The plug and perforation system of claim 15, wherein the plug body further comprises a plunger seat within the central channel and wherein the plunger is configured to prevent flow through the central channel when the plunger abuts the plunger seat.

Images