Patent Publication Number: US-2022235623-A1

Title: Systems and Methods for Plugging an Oil Well

Description:
TECHNICAL FIELD 
     The present disclosure relates to a holding and crushing device for a plug device in hydrocarbon wells, the plug device comprising a frangible element and a support media. 
     BACKGROUND 
     For a variety of oil well drilling operations, a plug is used in a tool string that is capable of being opened in a controlled manner. An example of such a plug is a flotation plug used to float casing into highly-deviated or horizontal wellbores. In such applications, the plug can be installed in the tool string as the tool string is run downhole. 
     Existing barrier plugs and similar devices are brought into an open or plugged state by a mechanical or hydraulic translation of an activation signal and/or force from the upper side of the plug to the lower side of the plug. This mechanical or hydraulic translation takes place though a channel or bore that bypasses the sealing devices of the plug. Such configurations comprise many parts and potential points of failure, in the form of sleeves, seals, rings etc. Also, configurations based on bypass channels and bores are inherently vulnerable, since they provide potential paths of fluid loss, pressure drops, and other forms of leakage. In addition, such complicated and vulnerable plug arrangements are dependent on tight tolerances and movement of several parts. 
     In order to reduce or eliminate the above mentioned disadvantages of known techniques, there is a need for an improved plug arrangement comprising a frangible barrier material. Particularly, there is a need for a plug arrangement comprising an activation system that is simple to manufacture, and reliably opens when triggered. While some embodiments of the present disclosure are applicable to barrier plugs, the same mechanisms described herein are also useful in other applications in hydrocarbon wells where a plugging device is needed to separate and then controllably open two regions. 
     SUMMARY 
     It is an object of the present disclosure to mitigate, alleviate or eliminate one or more of the above-identified deficiencies and disadvantages. 
     In one aspect a plug assembly for opening a subterranean wellbore is disclosed. The plug assembly may include a tubular housing having an uphole end and a downhole end and configured for internal fluid communication from the uphole end to the downhole end, and a first frangible element disposed in the tubular housing, the first frangible element having a first orifice in an uphole side of the first frangible element. In the plug assembly, the first orifice may extend at least partially through the first frangible element. The plug assembly may further include an activation component configured for sealing the first orifice and located at the uphole side of the first frangible element. In the plug assembly, the activation component may initially seal the first orifice to prevent fluid communication from the uphole side of the first frangible element with the first orifice. After the activation component is activated, the activation component may enable fluid communication from the uphole side of the first frangible element with the first orifice. 
     In any of the disclosed embodiments of the plug assembly, the first frangible element may be a glass disc. 
     In any of the disclosed embodiments of the plug assembly, the first orifice may extend completely through the first frangible element. 
     In any of the disclosed embodiments of the plug assembly, the first orifice may be located off-center of the first frangible element. 
     In any of the disclosed embodiments of the plug assembly, the activation component may be a burst disc. 
     In any of the disclosed embodiments of the plug assembly, the first frangible element may be disposed on a beveled seat in the tubular housing. 
     In any of the disclosed embodiments, the plug assembly may further include first support media located in the tubular housing downhole from the first frangible element. In the plug assembly, an uphole side of the first support media may be in physical contact with a downhole side of the first frangible element, while the first support media may further include a first fluid passageway through the first support media, and the first support media may be configured for disintegrating when a fluid passes through the first fluid passageway. 
     In any of the disclosed embodiments of the plug assembly, the first support media may be housed in a first tapered cavity in the tubular housing, while the first support media may be correspondingly tapered to the first tapered cavity to enable detention of the first support media in the first tapered cavity. 
     In any of the disclosed embodiments, the plug assembly may further include a second frangible element located on a beveled seat formed in the tubular housing. In the plug assembly, the second frangible element may be in physical contact with a downhole surface of the first frangible element. 
     In any of the disclosed embodiments of the plug assembly, the second frangible element may include a second orifice that extends partially through the second frangible element. In any of the disclosed embodiments of the plug assembly, the second orifice may be aligned with the first orifice. In any of the disclosed embodiments of the plug assembly, the second frangible element may include a glass disc. 
     In any of the disclosed embodiments, the plug assembly may further include a conformal layer located between the first frangible element and the second frangible element. In the plug assembly, conformal layer may maintain physical contact with both the first frangible element and the second frangible element. 
     In any of the disclosed embodiments, the plug assembly may further include second support media located in the tubular housing downhole from the first support media. In the plug assembly, an uphole side of the second support media may be in physical contact with a downhole side of the first support media. The plug assembly may further include a third frangible element located in the tubular housing and enabled to seal the tubular housing to prevent the internal fluid communication, the third frangible element having a third orifice in an uphole side of the third frangible element. In the plug assembly, the third orifice may extend partially through the third frangible element, while an uphole side of the third frangible element may be in physical contact with a downhole side of the second support media. 
     In any of the disclosed embodiments of the plug assembly, the second support media may be housed in a second tapered cavity in the tubular housing. In the plug assembly, the second support media is correspondingly tapered to the second tapered cavity to enable detention of the second support media in the second tapered cavity, while the second tapered cavity may be tapered in an opposite orientation to the first tapered cavity. 
     In another aspect, a method of enabling fluid communication through a subterranean wellbore using a plug assembly is disclosed. The method may begin after installing a plug assembly in a subterranean wellbore, the plug assembly being installed in an initial condition that seals the subterranean wellbore to prevent fluid communication through the subterranean wellbore. Responsive to an increase in pressure of a fluid above a threshold pressure value at an uphole side of the plug assembly, the method may include activating an activation component located in a tubular housing of the plug assembly, the tubular housing enabling fluid communication with the fluid and the activation component. Upon activating the activation component, the method may include subjecting a first orifice extending at least partially through a first frangible element to the pressure from the fluid. In the method, prior to the activating, the activation component may be configured to seal the first orifice from the fluid. Responsive to the pressure of the fluid impacting the first orifice, the method may include causing the fluid to penetrate the first frangible element at the first orifice, such that the first frangible element is shattered. 
     In any of the disclosed embodiments of the method, the activation component and the first orifice may be centered on the tubular housing. 
     In any of the disclosed embodiments of the method, the activation component and the first orifice may be located eccentrically with respect to the tubular housing. 
     In any of the disclosed embodiments of the method, the first frangible element may be a glass disc. 
     In any of the disclosed embodiments of the method, the activation component may be a burst disc. 
     In any of the disclosed embodiments of the method, the first frangible element may be disposed on a beveled seat in the tubular housing.? 
     In any of the disclosed embodiments, the method may further include causing the fluid under the pressure to flow through a first fluid passageway of first support media in physical contact with the first frangible element. In the method, the first fluid passageway may be aligned with the first orifice, while the fluid may disintegrate the first support media until the first support media is flushed downhole by the fluid. After the first support media is removed, the method may include flushing the first frangible element downhole by the fluid, while the tubular housing may be fully opened to enable the fluid communication through the tubular housing. 
     In any of the disclosed embodiments of the method, the first support media may be housed in a first tapered cavity in the tubular housing, while the first support media may be correspondingly tapered to the first tapered cavity to enable detention of the first support media in the first tapered cavity. 
     In any of the disclosed embodiments, the method may further include causing the fluid under the pressure to impact a second frangible element in physical contact with the first frangible element. In the method, fluid may impact the second frangible element at the location of the first orifice, and the fluid may disintegrate the second frangible element until the second frangible element is flushed downhole by the fluid. After the second frangible element is removed, the method may include flushing the first frangible element downhole by the fluid, while the tubular housing may be fully opened to enable the fluid communication through the subterranean wellbore. 
     In any of the disclosed embodiments of the method, the second frangible element may include a second orifice that extends partially through the second frangible element, while the second orifice may be aligned with the first orifice. 
     In any of the disclosed embodiments of the method, the second frangible element may be a glass disc seated on a beveled seat formed in the tubular housing. 
     In any of the disclosed embodiments, the method may further include causing the fluid under the pressure to flow through a second fluid passageway of second support media in physical contact with the first support media, while the second fluid passageway may be in fluid communication with the first fluid passageway. Upon the fluid under the pressure flowing through the second fluid passageway, the method may include subjecting a second orifice extending partially through a second frangible element to the pressure from the fluid, where the second frangible element may be shattered and flushed downhole by the fluid. Responsive to the second frangible element being shattered, the method may include causing the fluid under pressure to disintegrate the second support media and the first support media until the second support media and the first support media are flushed downhole by the fluid. After the second support media and the first support media are removed, the method may include flushing the first frangible element downhole by the fluid, such that the tubular housing may be fully opened to enable the fluid communication through the subterranean wellbore. 
     In any of the disclosed embodiments of the method, the second support media may be housed in a second tapered cavity in the tubular housing, while the second support media may be correspondingly tapered to the second tapered cavity to enable detention of the second support media in the second tapered cavity, and the second tapered cavity may be tapered in an opposite orientation to the first tapered cavity. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1A  depicts a plug in accordance with embodiments having a frangible element with an orifice passing completely through the frangible element, sealed to the casing by an O-ring disposed in a recess in the casing, and supported by support media. 
         FIG. 1B  is an inset drawing of the plug of  FIG. 1A , depicting the activation component of the plug. 
         FIG. 1C  depicts the plug of  FIG. 1A  after the activation component has been activated, the frangible element has been shattered, and the support media is partially eroded. 
         FIG. 1D  depicts the plug of  FIG. 1A  after the plug has been fully opened. 
         FIG. 2A  depicts a plug in accordance with embodiments having a frangible element with an orifice passing completely through the frangible element, sealed to the casing by an O-ring disposed in a recess in the frangible element, and supported by support media. 
         FIG. 2B  is an inset drawing of the plug of  FIG. 2A , depicting the activation component of the plug. 
         FIG. 2C  depicts the plug of  FIG. 2A  after the activation component has been activated, the frangible element has been shattered, and the support media is partially eroded. 
         FIG. 2D  depicts the plug of  FIG. 2A  after the plug has been fully opened. 
         FIG. 3A  depicts a plug in accordance with embodiments having a frangible element with an orifice passing partially through the frangible element, sealed to the casing by an O-ring disposed in a recess in the casing, and supported by support media. 
         FIG. 3B  is an inset drawing of the plug of  FIG. 3A , depicting the activation component of the plug. 
         FIG. 3C  depicts the plug of  FIG. 3A  after the activation component has been activated, the frangible element has been shattered, and the support media is partially eroded. 
         FIG. 3D  depicts the plug of  FIG. 3A  after the plug has been fully opened. 
         FIG. 4A  depicts a plug in accordance with embodiments configured to resist pressure from both directions, having two frangible elements with orifices passing partially through the frangible elements, with an activation component in the frangible element on the uphole side of the plug, sealed to the casing by an O-ring disposed in a recess in the casing, and supported by two support media. 
         FIG. 4B  is an inset drawing of the plug of  FIG. 4A , depicting the activation component of the plug. 
         FIG. 4C  depicts the plug of  FIG. 4A  after the activation component has been activated, and the frangible elements have been shattered. 
         FIG. 4D  depicts the plug of  FIG. 4A  after the activation component has been activated, the frangible elements have been shattered, the downhole frangible element has been flushed away, and the support media are partially eroded. 
         FIG. 4E  depicts the plug of  FIG. 4A  after the plug has been fully opened. 
         FIG. 5A  depicts a plug in accordance with embodiments having a frangible element with an orifice passing partially through the frangible element, disposed on a beveled seat, and an activation component. 
         FIG. 5B  is an inset drawing of the plug of  FIG. 5A , depicting the activation component of the plug. 
         FIG. 5C  depicts the plug of  FIG. 5A  after the activation component has been activated, and the frangible element has been fractured. 
         FIG. 5D  depicts the plug of  FIG. 5A  after the plug has been fully opened. 
         FIG. 6A  depicts a plug in accordance with embodiments having a frangible element with an orifice passing partially through the frangible element, and located off-center of the frangible element, disposed on a beveled seat, and an activation component. 
         FIG. 6B  is an inset drawing of the plug of  FIG. 6A , depicting the activation component of the plug. 
         FIG. 7A  depicts a plug in accordance with embodiments having two frangible elements, each with an orifice passing partially through the frangible element, the downhole frangible element disposed on a beveled seat, and an activation component. 
         FIG. 7B  is an inset drawing of the plug of  FIG. 7A , depicting the activation component of the plug. 
         FIG. 7C  depicts the plug of  FIG. 7A  after the activation component has been activated, and the uphole frangible element has been fractured. 
         FIG. 7D  depicts the plug of  FIG. 7A  after both frangible elements have been fractured. 
         FIG. 7E  depicts the plug of  FIG. 7A  after the plug has been fully opened. 
         FIG. 8A  depicts a plug in accordance with embodiments having two frangible elements, having a conformal layer between the first and second frangible elements. 
         FIG. 8B  is an inset drawing of the plug of  FIG. 8A , depicting the activation component of the plug. 
         FIG. 9A  depicts a plug in accordance with embodiments having two frangible elements, the uphole frangible element having an orifice passing partially through the frangible element, and the downhole frangible element having no orifice, and disposed on a beveled seat, and an activation component. 
         FIG. 9B  is an inset drawing of the plug of  FIG. 9A , depicting the activation component of the plug. 
         FIG. 9C  depicts the plug of  FIG. 9A  after the activation component has been activated, and the downhole frangible element has been fractured. 
         FIG. 9D  depicts the plug of  FIG. 9A  after both frangible elements have been fractured. 
         FIG. 9E  depicts the plug of  FIG. 9A  after the plug has been fully opened. 
         FIG. 10A  depicts a plug in accordance with embodiments having a frangible element with an orifice passing partially through the frangible element, disposed on a beveled seat, and an activation device, where the activation device includes a dart. 
         FIG. 10B  is an inset drawing of the plug of  FIG. 10A , depicting the activation device of the plug. 
         FIG. 11A  depicts a plug in accordance with embodiments having a frangible element with an orifice passing partially through the frangible element, disposed on a beveled seat, and an activation device, where the activation device includes a multi-cycle pressure valve. 
         FIG. 11B  is an inset drawing of the plug of  FIG. 11A , depicting the activation device of the plug. 
     
    
    
     DETAILED DESCRIPTION 
     The following detailed description is submitted with reference to the accompanying drawings, in which certain example embodiments are shown. There may, however, be other embodied forms and the present disclosure should not be construed as limited to the herein disclosed embodiments. Although example embodiments of the present disclosure are explained in detail, it is to be understood that other embodiments are contemplated within the scope of the disclosure. Accordingly, it is not intended that the present disclosure be limited in its scope to the details of construction and arrangement of components set forth in the following description or illustrated in the drawings. The present disclosure is capable of other embodiments and of being practiced or carried out in various ways. 
     Throughout this disclosure, a hyphenated form of a reference numeral refers to a specific instance of an element and the un-hyphenated form of the reference numeral refers to the element generically or collectively. Thus, as an example (not shown in the drawings), device “12-1” refers to an instance of a device class, which may be referred to collectively as devices “12” and any one of which may be referred to generically as a device “12”. In the figures and the description, like numerals are intended to represent like elements. 
     It must also be noted that, as used in the specification and the appended claims, the singular forms “a,” “an” and “the” include plural referents unless the context clearly dictates otherwise. Moreover, titles or subtitles may be used in this specification for the convenience of a reader, which have no influence on the scope of the present disclosure. 
     By “comprising” or “containing” or “including” is meant that at least the named compound, element, particle, or method step is present in the composition or article or method, but does not exclude the presence of other compounds, materials, particles, method steps, even if the other such compounds, material, particles, method steps have the same function as what is named. 
     In describing example embodiments, terminology will be resorted to for the sake of clarity. It is intended that each term contemplates its broadest meaning and includes all technical equivalents that operate in a similar manner to accomplish a similar purpose. Where a tool, component, or direction is referred to as “uphole,” the term refers to a direction along the course of the wellbore that leads to the surface, and “downhole” refers to a direction along the course of the wellbore that leads to the end of the wellbore furthest from the surface. These terms retain the same meaning, even if the wellbore is highly deviated, or horizontal. 
     In the following detailed description, references are made to the accompanying drawings that form a part hereof and that show, by way of illustration, specific embodiments or examples. In referring to the drawings, like numerals represent like elements throughout the several figures. 
       FIG. 1A  depicts a plug  100  in accordance with the disclosed technology. The plug consists of a first tubular component  101  having a fluid passageway  102  therethrough and a second tubular component  103 , having a second fluid passageway  104  therethrough. The first tubular component  101  and second tubular component  102  are joined together to create the outer casing of the plug  100 . 
     When joined together, the first and second tubular components  101  and  103  can form a cavity having a first recess  105  configured to hold a frangible element  106 . In this embodiment, the frangible element  106  has an orifice  107  passing through the frangible element  106 . 
     The first and second tubular components  101  and  103  can also form a second cavity  108  configured to hold a support media  109 . The second cavity  108  can be configured to hold the support media  107  by being tapered, as depicted in  FIG. 1 . The support media  109  is also configured to have a fluid passageway  110  which allows fluid to pass through, and erode or dissolve the support media  109 . Numerous other configurations can be used in embodiments to hold the support media, such as molding the support media to have teeth that interlock with teeth machined into one of the first and second tubular components  101  and  103 . Any configuration of the second cavity  108  can be used, such that the support media  109  can withstand pressure applied to the surface of the frangible element  106  opposite the support media  109 . 
     The frangible element  106  can be made from a frangible material such that, in the absence of the support media  109 , the frangible element  106  breaks into pieces, allowing fluid communication between the fluid passageways between the first and second tubular components  101  and  103 . In some embodiments, the frangible material can be glass, ceramics, polymers, or other similar materials. In some embodiments, the frangible material can be configured such that, when it breaks, it breaks into small pieces capable of being circulated out of the wellbore, such as a glass disc having a high internal tension, or a component having pre-scored lines or other indentations to facilitate fragmenting into small pieces. The frangible element  106  is intended to break, or in other words, for at least one fracture to be initiated in the frangible element. In embodiments, this fracture is intended to cause at least a portion of the frangible element  106  to separate and be flushed into the wellbore, allowing fluid to pass through the tubular housing. 
     The support media  109  can be made from any material capable of being eroded or dissolved by fluid flow through fluid passageway  110 . Examples of materials that support media may be comprised of include salt (such as NaCl), hard-pressed sand, magnesium, and other materials capable of dissolution or erosion. 
       FIG. 1B . depicts an activation component  111  in accordance with embodiments installed in frangible element  106 . The activation component  111  seals the orifice  107  of the frangible element  106  to prevent fluid from the uphole direction from entering the orifice  107 , and when activated, allows fluid from the uphole direction to enter the orifice  107 . The activation component  111  can be a pressure-activated valve that seals the orifice in the frangible element  106 . The pressure-activated valve can be any kind of valve known in the art to trigger when the pressure applied across the valve exceeds a known value. An example of such a pressure-activated valve is a burst disc. Another example of an activation component  111  is a plug made of a dissolvable material. Such an activation component  111  can serve to open the plug as a result of the passage of time, rather than an increase in pressure. 
     To use plug  100 , the plug  100  is installed in a tool string, such as a casing string, drill string, or other similar string of tubulars. The plug  100  provides isolation between the first and second fluid passageways  102  and  104  on either side of the frangible element  106 . When the operator wishes to open the plug  100 , additional pressure is applied to the uphole surface of frangible element  106  such that the activation component  111  is activated. When the activation component  111  is activated, fluid from the uphole end of the plug  100  is allowed to pass through the orifice  107  to the downhole end of the plug  100 . This rapid flow of fluid also passes through fluid passageway  110  through support media  109 , and causes the support media  109  to erode and/or dissolve, as depicted in  FIG. 1C . Once a sufficient amount of the support media  109  has dissolved such that it can no longer support the frangible element  106 , the frangible element  106  breaks, further accelerating the flow of fluid through the plug  100 . Once the support media  109  has eroded/dissolved and the frangible element  106  has shattered, the plug is fully opened, as shown in  FIG. 1D , allowing further operations to be performed through the opened plug. 
       FIG. 2A  depicts another plug  200  in accordance with embodiments. Plug  200  is similar to plug  100 , differing in the configuration of the seal between frangible element and the outer casing. Elements of plug  200  which are similar to plug  100  are depicted with like reference numerals. In the embodiment of  FIG. 1A , the O-ring seal  112  around the circumference of frangible element is located in a recess of the outer casing. In the embodiment of  FIG. 2A , the O-ring seal  212  is located in a recess around the circumference of the frangible element.  FIG. 2B  depicts the activation component  111  of plug  200 . The plug  200  can be operated in a similar manner as plug  100 .  FIG. 2C  depicts plug  200  after the activation component  111  has been opened, the support media  109  is eroded, and the frangible element  106  is beginning to break. Once the plug  200  is fully opened, the frangible element  106  and support media  109  are flushed through the plug  200 , allowing further operations to be performed through the opened plug, as shown in  FIG. 2D . 
       FIG. 3A  depicts another plug  300  in accordance with embodiments. Plug  300  is similar to plug  100 , differing in the configuration of the frangible element. Elements of plug  300  which are similar to plug  100  are depicted with like reference numerals. In plug  300 , a frangible element  306  does not have an orifice that passes completely through frangible element  306 . Instead, frangible element  306  has an orifice  307  that does not pass completely through the frangible element  306 . In this configuration, the activation component  111  seals the outer surface of the orifice  307 . This orifice  307  also creates a weak spot in the frangible element  306 . When the activation component  111  is activated, and fluid is allowed to pass into the orifice  307 , the fluid pressure applied to the bottom of orifice  307 , in the weak spot of frangible element  306 , causes the frangible element  306  to break before the fluid reaches the support media  109 . In this configuration, the fluid breaking through the frangible element  306  provides an initial fracturing of the frangible element  306 , which can facilitate breaking the frangible element  306  into smaller pieces once the support media  109  is eroded.  FIG. 3B  is an inset drawing of  FIG. 3A , and depicts the activation component  111  of plug  300 .  FIG. 3C  depicts plug  300  after the activation component  111  has been opened, the support media  109  is eroded, and the frangible element  306  is beginning to break. Once the plug  300  is fully opened, the frangible element  306  and support media  109  are flushed through the plug  300 , allowing further operations to be performed through the opened plug, as shown in  FIG. 3D . 
       FIG. 4A  depicts another plug  400  in accordance with embodiments. Plug  400  is similar to plug  300 , but is modified to allow the plug to hold pressure from both the uphole and downhole directions. Elements of plug  400  which are similar to plug  100  are depicted with like reference numerals. 
     Plug  400  is comprised of a sleeve  402  that may be inserted between a first tubular component  101  and a second tubular component  403 . The first tubular component  101  and second tubular component  403  are joined together on either end of the sleeve  402  to create the outer casing of the plug  400 . In a similar manner as mounted within the tubular component  103  shown in  FIG. 1A , the sleeve  402  further comprises a first frangible element  406 - 1  supported by a first support media  409 - 1  having a first fluid passageway  410 - 1  therethrough. The first support media  409 - 1  is housed in a first cavity  408 - 1  at an uphole end of the sleeve  402  that is tapered to retain the first support media  409 - 1 . At the uphole end of sleeve  402 , a first recess  405 - 1  may house a first frangible element  406 - 1  in physical contact with the first support media  409 - 1 . 
     Further in the embodiment shown in  FIG. 4A , the sleeve  402  further comprises a second frangible element  406 - 2  supported by a second support media  409 - 2  located uphole of, and in physical contact with the second frangible element  406 - 2 . The second support media  409 - 2  has a second fluid passageway  410 - 2  therethrough. The second support media  409 - 2  is housed in a second cavity  408 - 2  that is tapered in a reverse manner as first cavity  408 - 1 . The second support media  409 - 2  is oriented opposite the first support media  409 - 1 , while the first support media  409 - 1  and the second support media  409 - 2  are in physical contact at a midpoint of sleeve  402 . When both the support media  409  are installed in sleeve  402 , the first fluid passageway  410 - 1  and the second fluid passageway  410 - 2  are in fluid communication with each other. 
     When joined together at the uphole end of sleeve  402 , the first tubular component  101  and sleeve  402  can form a first cavity having a first recess  405 - 1  configured to hold the first frangible element  406 - 1 . When joined together at the downhole end of sleeve  402 , the second tubular component  403  and sleeve  402  can also form a second cavity having a second recess  405 - 2  configured to hold the second frangible element  406 - 2 . Similar to plug  300  shown in  FIG. 3A , the first frangible element  406 - 1  has a first orifice  407 - 1  that does not pass completely through the first frangible element  406 - 1 . In this configuration, the activation component  111  seals the outer surface of the first orifice  407 - 1 . The second frangible element  406 - 2  can have a second orifice  407 - 2  in its uphole surface that passes partially through the second frangible element  406 - 2 , creating a weak spot in the second frangible element  406 - 2 .  FIG. 4B  is an inset drawing of  FIG. 4A , and depicts the activation component  111  of plug  400 .  FIG. 4C  depicts the plug  400  after the activation component  111  has been activated. When activation occurs, fluid from the uphole side of the plug  400  is allowed to pass through first fluid passageway  410 - 1  and then through second fluid passageway  410 - 2 , striking the second frangible element  406 - 2  at the bottom of the second orifice  407 - 2  in the second frangible element  406 - 2 , causing the second frangible element  406 - 2  to break. As depicted in  FIG. 4D , once the second frangible element  406 - 2  is broken, a fluid pathway is opened through the plug  400 , allowing fluid from the uphole direction to erode the first and second support media  409 . As depicted in  FIG. 4D , once the first and second support media  409  are dissolved or eroded away, the first frangible element  406 - 1  also breaks and is flushed away by the fluid.  FIG. 4E  depicts the plug  400  once fully opened. 
       FIG. 5A  depicts another plug  500  in accordance with embodiments. Plug  500  omits the support media, and is instead supported by a beveled seat  513  in a tubular component  503 . Elements of plug  500  which are similar to plug  300  are depicted with like reference numerals. The frangible element  306  has an orifice  307  passing partially through frangible element  306 , and thus, partially through the plug  500 , with an activation component  111  installed in the opening of the orifice  307 .  FIG. 5B  depicts the activation component of plug  500 .  FIG. 5C  depicts plug  500  after it has been activated, where fluid from the uphole side of the plug  500  has impacted the bottom of the orifice  307  and caused the frangible element  306  to shatter.  FIG. 5D  depicts the plug  500  after fluid from the uphole side of the plug  500  has washed away the fragments of the frangible element  306 , fully opening the plug. 
       FIG. 6A  depicts another plug  600  in accordance with embodiments. Plug  600  is substantially similar to plug  500 , but is modified in that the orifice  307  in the frangible element  306  is not centered in the frangible element  306 . Instead, the orifice  307  is offset from the center of frangible element  306 , and thus, from the center of plug  600 . Elements of plug  600  which are similar to plug  500  are depicted with like reference numerals. This illustrates that the orifice  307  through the frangible element  306 , or support media  109  in embodiments, need not be centered in the tubular casing, but can be offset from center, without changing the functionality of plugs in accordance with embodiments. Indeed, plugs with offset orifices, along with offset fluid passageway  110  when present, (in any of the frangible element, support media, or other supporting devices of certain plugs described herein) are within the scope of embodiments contemplated by this disclosure.  FIG. 6B  depicts the activation component of plug  600 . 
       FIG. 7A  depicts another plug  700  in accordance with embodiments. Plug  700  is similar to plugs  500  and  600 , but differs in that the first frangible element  306  is seated on a second frangible element  706 , which sits on a beveled seat  712 . Elements of plug  700  which are similar to plug  500  are depicted with like reference numerals. In this embodiment, both the first and second frangible elements  306 ,  706  have respective orifices  307 ,  707  that pass partly through them.  FIG. 7B  depicts the activation component  111  of plug  700 , showing the alignment of the respective orifices  307 ,  707  of the first and second frangible elements  306 ,  706 .  FIG. 7C  depicts the plug  700  after the activation component  111  has been activated. First, fluid from the uphole side of the first frangible element  306  strikes the bottom of the first frangible element  306 , causing it to break. As depicted in  FIG. 7D , once the first frangible element  306  is broken, fluid from the uphole direction can enter the orifice  707  of the second frangible element  706 , causing it to break as well. As depicted in  FIG. 7E , once both the first and second frangible elements  306 ,  706  are broken, fluid from the uphole direction can flush the broken fragments of the first and second frangible elements  306 ,  706  out of the plug  700 , resulting in a fully opened plug. 
       FIG. 8A  depicts another plug  800  in accordance with embodiments. Plug  800  is similar to plug  700 , but differs in that a conformal layer  814  of material is inserted between the first and second frangible elements. Elements of plug  800  which are similar to plug  700  are depicted with like reference numerals. This conformal layer  814  of material assists in transferring loads applied from the first frangible element  306  to the second frangible element  706 . As shown and described, the first and second frangible elements  306 ,  706  are prone to breaking at the point where they are physically in contact with one another. If the two frangible elements  306 ,  706  are not carefully manufactured to nearly perfectly rest on one another, point loads can be developed between the two frangible elements  306 ,  706 , which can lead to failure. In plug  700 , the interface between the first and second frangible elements  306 ,  706  are flat surfaces that directly abut each other. If those surfaces are not extremely flat, then any prominences or depressions in the surface can result in point loads that may result in failure. This source of potential failure can be mitigated by manufacturing the first and second frangible elements  306 ,  706  to tight tolerances, such as by polishing. However, this adds cost and manufacturing time, which may not be desirable. 
     As an alternative, plug  800  adds a conformal layer  814  of material between the first and second frangible elements  306 ,  706  that can prevent the formation of point loads, and assists in spreading the load applied to the first frangible element across the entire surface of the second frangible element. The presence of the conformal layer  814  can also increase the total strength of the assembly of the first and second frangible elements  306 ,  706  to resist pressure, and can increase the consistency of that strength by accommodating manufacturing variation in the contact areas between the first and second frangible elements  306 ,  706 . The conformal layer  814  of material can be conformal such that it substantially fills in the space between the first and second frangible elements. The conformal layer  814  can be made of a single sheet of material or molded component inserted between the two, or can be made of a ductile substance compressed between the first and second frangible elements  306 ,  706 , among other embodiments. This conformal layer  814  can be made of a dissolvable or erodible material, such that, when the plug  800  is opened, the conformal layer  814  is also cleared from the opened plug  800 . Conformal layer  814  can be added or used with any plug in accordance with this disclosure where two frangible elements are adjacent or where loads must be transferred from one frangible element to another frangible element. 
       FIG. 9A  depicts another plug  900  in accordance with embodiments. Plug  900  is similar to plug  700 , but differs in that the orifice  907  in the first frangible element  306  passes completely through it, and the second frangible element  906  does not have an orifice at all. Elements of plug  900  which are similar to plug  700  are depicted with like reference numerals. In embodiments, the second frangible element  906  can have an orifice that passes partially through the second frangible element.  FIG. 9B  depicts the activation component  111  of plug  800 . When the activation component  111  is activated, fluid from the uphole side of the plug is allowed to pass through the first frangible element  306 , striking the second frangible element  906 . As depicted in  FIG. 9C , this fluid fractures the second frangible element  906 , and the continued flow of fluid flushes it away. As depicted in  FIG. 9D , with the second frangible element  906  washed away, the first frangible element  306  is freed to slide in the tubular housing in the downhole direction, striking the beveled seat  913  in which the second frangible element  906  was seated. This impact causes the first frangible element  306  to break. As depicted in  FIG. 9E , the continued flow of fluid from the uphole direction flushes the broken fragments of the first frangible element  306 , resulting in a fully opened plug. 
       FIG. 10A  depicts a plug  1000  in accordance with embodiments, and illustrates an alternative activation method for use with embodiments. Elements of plug  1000  which are similar to plug  500  are depicted with like reference numerals.  FIG. 10B  shows a detailed drawing of this alternative activation device  1015 . In this embodiment, a tube  1016  is installed in the orifice  307  of the frangible element  306 , and a dart  1017  is placed in the tube  1015  at the uphole end of the tube  1016 . In some embodiments, the tube  1016  and the dart  1017  can be made of a frangible material. An activation component  111  is installed in the uphole end of the tube. When the activation component  111  is opened, fluid from the uphole direction rushes into the tube  1016 , accelerating the dart  1017  down the tube, where it impacts the bottom of the orifice  307  of the frangible element  306 , causing the frangible element  306  to break. The activation device  1015  depicted in  FIG. 10A  can be used with other embodiments previously described. 
       FIG. 11A  depicts a plug  1000  in accordance with embodiments, and illustrates another alternative activation method for use with embodiments. Elements of plug  1000  which are similar to plug  500  are depicted with like reference numerals.  FIG. 11B  shows a detailed drawing of an alternative activation device  1115 . In this embodiment, a multi-cycle pressure-activated valve  1116  is installed in the orifice  307  of the frangible element  306 . This multi-cycle pressure-activated valve  1116  allows operators to open the wellbore after the activation pressure of the multi-cycle valve  1116  has been exceeded a predetermined number of times. The activation device depicted in  FIG. 11A  can be used with other embodiments previously described. 
     The present disclosure is not limited to the embodiments described above. Modifications and variations are possible within the scope of the appended claims. Additionally, variations to the disclosed embodiments can be understood and effected from the drawings, the disclosure, and the appended claims.