Patent Publication Number: US-2022220824-A1

Title: Voided moldable buttons

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     The present document is based on and claims priority to U.S. Provisional Application Ser. No. 62/829,208, filed Apr. 4, 2019, which is incorporated herein by reference in its entirety. 
    
    
     BACKGROUND 
     In a variety of well fracturing applications, a wellbore is initially drilled and cased. A frac plug is then pumped down and actuated to form a seal with the surrounding casing. Once the casing is perforated, the frac plug is used to prevent fracturing fluid from flowing farther downhole, thus forcing the fracturing fluid out through the perforations and into the surrounding formation. In some applications, multiple frac plugs may be deployed to enable fracturing at different well zones. Each frac plug includes a sealing element, which is deformed into sealing engagement with the surrounding casing. The frac plug also includes one or more slip assemblies having a plurality of slips. The slips may include buttons, which are used to anchor the frac plug in the casing. To ensure sealing and sufficient anchoring with the casing, the frac plug tends to be formed with relatively precise and expensive components. In addition to the expense, the construction of such a frac plug also can lead to difficulties associated with milling out the frac plug after completion of the fracturing operation. 
     SUMMARY 
     According to one or more embodiments of the present disclosure, a button includes a body comprising a void, wherein the void pierces the body completely therethrough, and wherein the body is made of a moldable material. 
     According to one or more embodiments of the present disclosure, a method includes deploying a downhole tool into a cased wellbore, and anchoring the downhole tool to the cased wellbore, wherein the downhole tool includes: a plurality of slips, each slip of the plurality of slips including: a slip body; and at least one button disposed in the slip body, wherein the at least one button includes: a body including a void, wherein the void pierces the body completely therethrough, and wherein the body of the at least one button is made of a moldable material. 
     According to one or more embodiments of the present disclosure, a method of manufacturing a button includes using a mold to form a body including a void, wherein the void pierces the body completely therethrough. 
     However, many modifications are possible without materially departing from the teachings of this disclosure. Accordingly, such modifications are intended to be included within the scope of this disclosure as defined in the claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Certain embodiments of the disclosure will hereafter be described with reference to the accompanying drawings, wherein like reference numerals denote like elements. It should be understood, however, that the accompanying figures illustrate the various implementations described herein and are not meant to limit the scope of various technologies described herein, and: 
         FIG. 1  is a schematic illustration of an example of a downhole tool deployed in a wellbore according to one or more embodiments of the present disclosure; 
         FIG. 2  is a perspective view of a frac plug having voided moldable buttons according to one or more embodiments of the present disclosure; 
         FIG. 3  is the frac plug of  FIG. 2  set in casing according to one or more embodiments of the present disclosure; 
         FIG. 4( a )  is a perspective view of a voided moldable button according to one or more embodiments of the present disclosure; 
         FIG. 4( b )  is a top view of a voided moldable button according to one or more embodiments of the present disclosure; 
         FIG. 5( a )  is a perspective view of a solid button; and 
         FIG. 5( b )  is a top view of a solid button. 
     
    
    
     DETAILED DESCRIPTION 
     In the following description, numerous details are set forth to provide an understanding of some embodiments of the present disclosure. However, it will be understood by those of ordinary skill in the art that the apparatus and/or method may be practiced without these details and that numerous variations or modifications from the described embodiments may be possible. 
     In the specification and appended claims: the terms “up” and “down,” “upper” and “lower,” “upwardly” and “downwardly,” “upstream” and “downstream,” “uphole” and “downhole,” “above” and “below,” and other like terms indicating relative positions above or below a given point or element are used in this description to more clearly describe some embodiments of the disclosure. 
     The present disclosure generally relates to an apparatus and method for facilitating a fracturing operation. Specifically, one or more embodiments of the present disclosure are directed to voided buttons made out of a moldable material, such as a powder metal material or a ceramic material, for use in a downhole tool during a fracturing operation. Because the voided button is made out of a moldable material, no machining of the button is required, which provides a significant cost savings. Moreover, the voided button exhibits improved performance during drill out. 
     Referring generally to  FIG. 1 , an embodiment of a downhole tool  20  is illustrated deployed in a well  21 . According to one or more embodiments of the present disclosure, the downhole tool  20  is a frac plug. For example, the frac plug  20  may be deployed in a wellbore  22  to facilitate a fracturing operation. In the example illustrated, the frac plug  20  is deployed in the wellbore  22  so as to isolate a zone of the wellbore  22  so that fracturing fluid  24  may be directed through perforations  26  and into a surrounding formation  28  uphole of the frac plug  20  for fracturing of the surrounding formation  28 . It should be noted that the frac plug  20  according to one or more embodiments of the present disclosure may be used in many types of wellbores, such as deviated, e.g., horizontal, wellbores to facilitate fracturing of desired well zones along the horizontal or otherwise deviated wellbore. 
     Still referring to  FIG. 1 , the wellbore  22  may be lined with a casing  30 , and each frac plug  20  may be actuated to grip into and seal against the casing  30 , thereby sealing or substantially restricting flow of the fracturing fluid  24  downhole of the frac plug  20  in the wellbore  22 . As a result, during a fracturing operation, the fracturing fluid  24  is directed through the perforations  26  into the surrounding formation  28  while the frac plug  20  remains anchored to the casing  30 . Once the fracturing operation is completed and a given frac plug  20  is no longer of use, the frac plug may be milled and removed from the wellbore  22 . 
     Referring now to  FIG. 2 , a perspective view of a frac plug having voided moldable buttons according to one or more embodiments of the present disclosure is shown. Specifically,  FIG. 2  shows the frac plug  200  in an unset position. Referring also to  FIG. 3 , the frac plug  200  of  FIG. 2  is shown set in the casing  30 . According to one or more embodiments, the frac plug  200  may include a mandrel (not shown) and at least upper and lower slip assemblies  202   a,    202   b,  upper and lower cones  204   a,    204   b,  a sealing element  206 , and at least one barrier ring  208  disposed around the mandrel. In one or more embodiments, the at least one barrier ring  208  is disposed adjacent the sealing element  206 , and the at least one barrier ring  208  may include a plurality of flanges  210 , which may radially expand against an inner wall of the casing  30  and create a circumferential barrier to keep the sealing element  206  from extruding. The frac plug  200  may also include a bottom sub  212  having a chamfered end  214  according to one or more embodiments. 
     Still referring to  FIGS. 2-3 , the upper and lower slip assemblies  202   a,    202   b  of the frac plug  200  may include a plurality of slips  216 . Further, each slip  216  may include a slip body  218  and at least one voided button  220  disposed in the slip body  218 . The voided button  220  is further described below with reference to  FIGS. 4 a    and  4   b.    
     When the frac plug  200  transitions from the run-in-hole unset position of  FIG. 2  to the set position of  FIG. 3 , the upper slip assembly  202   a  ramps down the upper cone  204   a,  and the lower slip assembly  202   b  ramps up the lower cone  204   b,  causing the upper and lower slip assemblies  202   a,    202   b  to radially expand. The radial expansion of the upper and lower slip assemblies  202   a,    202   b  causes the at least one voided button  220  disposed in the slip body  218  of a given slip  216  to grip and bite into the inner diameter of the casing  30 . Further, when the frac plug  200  is in the set position, the sealing element  206  is deformed into sealing engagement with the surrounding casing  30 . According to one or more embodiments of the present disclosure, the sealing element  206  may be formed of an elastomeric material or metal material, which is deformed in a radially outward direction until forming a permanent seal with the inside surface of the casing  30 . Due to the gripping and biting of the at least one voided button  220  and the sealing of the sealing element  206 , the frac plug  200  is able to be effectively anchored to the inside surface of the casing  30  when the frac plug  200  is in the set position. The frac plug  200  may remain anchored to the inside surface of the casing  30  during a fracturing operation, and after the fracturing operation, the frac plug  200  may be drilled out, as previously described. 
     Referring now to  FIGS. 4( a ) and 4( b ) , perspective and top views of a voided button  220  according to one or more embodiments of the present disclosure are shown, respectively. As shown, the voided button  220  includes a body  222 , which may be cylindrical, for example, and a void  224  that pierces the body  222  completely therethrough. Although the body  222  is shown as being cylindrical in  FIG. 4( a ) , other shapes and configurations of the body  222  are feasible and are within the scope of the present disclosure. As also shown in  FIG. 4( b ) , the void  224  pierces the body  222  through a flat surface of the body  222 , according to one or more embodiments of the present disclosure. 
     Still referring to  FIGS. 4( a ) and 4( b ) , the body  222  of the voided button  220  is made out of a moldable material according to one or more embodiments of the present disclosure. In one or more embodiments, the moldable material may be a powder metal material or a ceramic material, for example. That is, according to one or more embodiments of the present disclosure, the void  224  is not machined into the body  222  to create the voided button  220 . Instead, the voided button  220  is manufactured using powder metal or ceramic during a molding process with the void  220  already present in the mold. Stated another way, powder metal (or ceramic) molding can produce the button in its current form, including voids, without the need for machining. Further, powder metal and ceramic materials have a requisite hardness such that the resulting voided button  220  is sufficiently hard enough to grip and bite the inside surface of the casing  30  when the frac plug  200  is in the set position. 
     Due to the affordability of powder metal and the potential to eliminate machine work, the powder metal molding process as previously described may reduce the cost of the voided button  220  by up to 90%. There are commercially available powdered metals, which have low elongation, but comparable tensile strength to 8620 steel. As appreciated by those having ordinary skill in the art, low elongation generally indicates that a material will fracture and mill more easily. 
     In other embodiments,  3 D printing or additive manufacturing are other manufacturing methods that could be used to manufacture the voided button  220 . 
     Still referring to  FIGS. 4( a ) and 4( b ) , the void  224  facilitates drill out of the voided button  220  and the frac plug  200  after a fracturing operation, for example. That is, the voided buttons  220  according to one or more embodiments of the present disclosure exhibit significantly improved performance during drill out over the solid and un-voided prior art button  500  shown in  FIGS. 5( a ) and 5( b ) , for example. In particular, the void  224  allows the voided button  220  to drill out faster and into smaller pieces than the solid and un-voided prior art button  500 . As appreciated by those having ordinary skill in the art, the ability to drill out a frac plug quickly is an extremely critical aspect of frac plug performance. The addition of voids  224  to the buttons  220 , according to one or more embodiments of the present disclosure, make the voided buttons  220  easier to chip away at while still anchoring the frac plug  200  in place during the fracturing operation. 
     Moreover, the synergy of combining a button molded out of powdered metal (or ceramic) with a void completely piercing the body of the button therethrough, according to one or more embodiments of the present disclosure, achieves superior results and exhibits an unmistakable improvement in average fracture size during impact testing over the solid and un-voided prior art button of  FIGS. 5( a ) and 5( b ) , for example. 
     Although a few embodiments of the disclosure have been described in detail above, those of ordinary skill in the art will readily appreciate that many modifications are possible without materially departing from the teachings of this disclosure. Accordingly, such modifications are intended to be included within the scope of this disclosure as defined in the claims.