Patent Publication Number: US-9404337-B1

Title: Caged ball fractionation plug

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     The current application is a Continuation of co-pending U.S. patent application Ser. No. 13/774,727 filed on Feb. 22, 2013, entitled “CAGED BALL FRACTIONATION PLUG,” which claims priority to and the benefit of U.S. Provisional Patent Application Ser. No. 61/602,031 filed on Feb. 22, 2012, entitled “CAGED BALL FRACTIONATION PLUG”. These references are incorporated in its entirety. 
    
    
     FIELD 
     The present embodiments generally relate to a caged ball fractionation plug for use in fractionation of a wellbore. 
     BACKGROUND 
     A need exists for a fractionation plug which can avoid becoming preset in the wellbore, especially when performing directional drilling or if there are variations in elevation of the wellbore, while simultaneously separating the wellbore into separate zones. 
     A further need exists for a fractionation plug that can quickly and securely engage with the crown engagement of another fractionation plug, and prevent fractionation plugs from spinning during drill-out. 
     The present embodiments meet these needs. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The detailed description will be better understood in conjunction with the accompanying drawings as follows: 
         FIG. 1A  depicts a mandrel according to one or more embodiments. 
         FIG. 1B  depicts another embodiment of a mandrel. 
         FIG. 1C  depicts an additional mandrel according to one or more embodiments. 
         FIG. 2  is an isometric view of an illustrative fractionation plug according to one or more embodiments. 
         FIG. 3  is cut view of the fractionation plug along X-X with a caged ball setting mechanism inserted therein. 
         FIG. 4A  depicts a schematic of a first caged ball setting mechanism according to one or more embodiments. 
         FIG. 4B  depicts a schematic of a second caged ball setting mechanism according to one or more embodiments. 
         FIG. 4C  depicts a schematic of a third caged ball setting mechanism according to one or more embodiments. 
         FIG. 5  is a schematic of two fractionation plugs disposed within a wellbore. 
         FIG. 6  depicts a cross sectional view of a load ring disposed about a mandrel wherein one or more set screws are disposed through the load ring. 
         FIG. 7  depicts a tapered nose cone having a beveled distal end. 
     
    
    
     The present embodiments are detailed below with reference to the listed figures. 
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     Before explaining the present apparatus in detail, it is to be understood that the apparatus is not limited to the particular embodiments and that it can be practiced or carried out in various ways. 
     The present embodiments generally relate to a fractionation plug with a caged ball configuration. The fractionation plug with a caged ball setting mechanism can be used in a wellbore and can include a mandrel. 
     The caged ball configuration of the fractionation plug can allow a work over team to pressure up on well bore casing before perforating a fractionation zone to ensure that the plug is holding; enabling successful separation of two zones adjacent the pay zone. 
     The caged ball configuration can allow pressure to flow back from a lower zone through the fractionation plug without having to drill out the fractionation plug. 
     The mandrel can include a crown engagement and a setting mechanism receiving end. 
     The crown engagement can have a diameter larger than the setting mechanism receiving end. 
     A mandrel shoulder can be formed between the crown engagement and the setting mechanism receiving end. A load ring can rest on the mandrel shoulder. 
     A first slip can be adjacent to the load ring. A first slip backup can be adjacent to the first slip. A first lubricating spacer can be adjacent to the first slip backup and a first secondary seal. 
     A primary seal can be adjacent to the first secondary seal. A second secondary seal can be adjacent to the primary seal. 
     A second lubricating spacer can be adjacent to the second secondary seal, which can include a second slip backup adjacent to the second lubricating spacer. The second slip can be adjacent to the second slip backup. 
     A removable nose cone can be disposed over the mandrel and can be adjacent to the second slip backup. 
     The removable nose cone can include a double bevel or tapered engagement. The tapered engagement can be composed of a first sloped face, a second sloped face, and a tapered face. 
     A central opening can be formed in the center of the sloped faces of the tapered engagement. The tapered engagement can be integrated with a nose cone body which can form a pump down ring groove. 
     An embodiment can include a plurality of pressure relief grooves which can extend longitudinally. The pressure relief grooves can be disposed on an outer surface of the tapered engagement. 
     A facial seal can be formed in the setting mechanism receiving end of the mandrel where a caged ball setting mechanism can be threaded into the setting mechanism receiving end between the facial seal and the removable nose cone. 
     The caged ball setting mechanism can engage the facial seal. The caged ball setting mechanism can also include a setting mechanism load shoulder. 
     An extension can extend from the setting mechanism load shoulder into the removable nose cone. For example, in one or more embodiments the extension can be about 0.47 inches long from the setting mechanism load shoulder to the face of the extension. 
     Engaging threads can extend over an outer surface of the caged ball setting mechanism body. The engaging threads can extend over at least a portion of the caged ball setting mechanism body. 
     The engaging threads of the caged ball caged ball setting mechanism can screw into the internal threads of the setting mechanism receiving portion. 
     The caged ball setting mechanism body can include a first caged ball chamber with a first diameter and a second caged ball chamber with a second diameter. The engaging threads can extend into the caged ball setting mechanism first chamber covering part or the entire thereof, such as extending 0.59 inches into the chamber. 
     The second diameter can be larger than the first diameter, which can create a caged ball shoulder. For example, in one or more embodiments the first diameter can be 0.95 inches and the second diameter can be 1.145 inches. 
     Shear threads can be formed around the second caged ball chamber. 
     A caged ball seat can be formed in the interface between the first caged ball chamber and the extension. The caged ball seat can have a first diameter which can be smaller than the first caged ball chamber diameter. A caged ball seat guide can be adjacent the caged ball seat. 
     A caged ball retaining rod can be adjacent the first caged ball chamber. The caged ball retaining rod can prevent the caged ball from exiting the first caged ball chamber. 
     The caged ball setting mechanism can have a second caged ball chamber. The second caged ball chamber can have a second diameter which can be larger than the first diameter of the first caged ball chamber. 
     Shear threads can be formed around the second caged ball chamber. 
     The caged ball setting mechanism can include a caged ball retaining rod which can have a diameter less than the central opening. 
     The caged ball setting mechanism can have a caged ball body with various thread coverage and thread spacing, such as a caged ball body that is all threaded, with threads at twenty threads per inch. 
     The caged ball setting mechanism can have left handed threads. The left handed threading can be used to prevent loosening of the caged ball setting mechanism, such as when the setting rod is inserted and tightened into the second caged ball chamber. 
     Turning now to the Figures,  FIG. 1A  depicts a mandrel according to one or more embodiments. 
     The mandrel  12   a  can be used to form a portion of the bridge fractionation plug. 
     The mandrel  12   a  can have a first end  102  and a second end  150 . The mandrel  12   a  can have an overall length from 1 foot to 4 feet. The outer diameter of the mandrel  12   a  can be from 2 inches to 10 inches. 
     The mandrel  12   a  can have a crown engagement  20  formed in the first end  102 . 
     The first end  120  can have a first diameter that is larger than a second diameter of the second end  150 . For example, in one or more embodiments, the first diameter can be 0.75 inches and the second diameter can be 2.25 inches for a 3½ inch mandrel. 
     A mandrel shoulder  142  can be formed between the first end  102  and the second end  150 . The mandrel shoulder  142  can be of varying angles, such as from about 10 degrees to about 25 degrees. 
     The second end  150  can have a first setting mechanism receiving portion  152   a , which can have a facial seal  156   a  and first internal threads  154   a . The facial seal can be made from an elastomer, urethane, TEFLON™ brand polytetrafluoroethylene, or similar durable materials. The facial seal  156   a  can be one or more of O-rings, E-rings, C-rings, gaskets, end face mechanical seals, or combinations thereof. The first setting mechanism receiving portion can be used when the operating pressure is less than 8,000 psi. Any plug described herein can be used with the first setting mechanism receiving portion  152   a.    
     An anti-rotation ring groove  140  can be formed into the first end  102 . The anti-rotation ring groove  140  can secure an anti-rotation ring, not shown in this Figure, about the mandrel  12   a . The anti-rotation groove prevents the fractionation plug from becoming loose and falling off of a plug setting mechanism. The anti-rotation groove creates a tight fit between the anti-rotation seal and the fractionation plug setting sleeve. The anti-rotation ring can made from elastomeric, TEFLON™ brand polytetrafluoroethylene, urethane, or a similar sealing material that is durable and able to handle high temperatures. 
       FIG. 1B  depicts another embodiment of a mandrel  12   b . The mandrel  12   b  can be substantially similar to the mandrel  12   a . The mandrel  12   b , however, can have a second setting mechanism receiving portion  152   b  formed adjacent to the first end  102 . The second setting mechanism receiving portion  152   b  can have one or more seals  159 . The second setting mechanism receiving portion  152   b  can be used at any pressure. Any plug described herein can be used with the second setting mechanism receiving portion  152   b . The second setting mechanism receiving portion  152   b  can have second internal threads  154   b.    
       FIG. 1C  depicts another embodiment of a mandrel  12   c . The mandrel  12   c  can be substantially similar to the mandrel  12   a , but can include the first setting mechanism receiving portion  152   a  and the second setting mechanism receiving portion  152   b . Any plug described herein can be used with the first setting mechanism receiving portion  152   a  and the second setting mechanism receiving portion  152   b . The first setting mechanism receiving portion  152   a  can have first internal threads  154   a , and the second setting mechanism receiving portion  152   b  can have second internal threads  154   b.    
       FIG. 2  is an isometric view of an illustrative fractionation plug according to one or more embodiments. 
     The fractionation plug can include a mandrel  12  which can be any mandrel described herein. One or more slips, such as a first slip  310  and a second slip  312 , can be disposed on the mandrel  12 . 
     The slips  310  and  312  can be made from metallic or non-metallic material. The slips  310  and  312  can have segments that bite into the inner diameter of a casing of a wellbore. The first slip  310  can be adjacent a load ring  380 , and the second slip  312  can be adjacent a removable nose cone  348 . The first slip  310  and the second slip  312  can be bidirectional slips, unidirectional slips, or any other slips that are used in downhole operations. 
     The mandrel  12  can also have one or more slip backups disposed thereon. A first slip backup  320  can be adjacent to the first slip  310 . At least a portion of the first slip backup  320  can be tapered to at least partially nest within a portion of the inner diameter of the first slip  310 . A second slip backup  322  can be adjacent the second slip  312 . At least a portion of the second slip backup  322  can be tapered to at least partially nest within a portion of the inner diameter of the second slip  312 . The slip backups can force the adjacent slip to expand into the inner diameter of the casing of the wellbore. 
     The slip backups can expand the first secondary seal  339 , the second secondary seal  341 , and the large primary seal  340 . These seals can be made of any sealing material. Illustrative sealing material can include rubber, elastomeric material, composite material, or the like. These seals can be configured to withstand high temperatures, such as 180 degrees Fahrenheit to 450 degrees Fahrenheit. 
     A first lubricating spacer  342  and a second lubricating spacer  344  can be disposed on the mandrel  12 . The lubricating spacers can be made of a material that can allow free movement of the adjacent components, such as TEFLON™ brand polytetrafluoroethylene, plastic, and polyurethane. The first and second lubricating spacers are each tapered on one side and fit into the slip backups. The first and second lubricating spacers can range in length from 1 inch to 3 inches. 
     The first lubricating spacer  342  can be disposed adjacent the first slip back up 320. The first lubricating spacer  342  can be disposed between the first slip back up 320 and the first secondary seal  339 . 
     The second lubricating spacer  344  can be disposed about the mandrel  12  adjacent the second slip backup  322 . The second lubricating spacer  344  can be disposed between the large seal  340  and the second slip backup  322 . 
     The mandrel  12  can also have a removable nose cone  348  disposed thereon. The removable nose cone  348  can have one or more pressure relief grooves  359  formed therein. The removable nose cone  348  can be of various lengths and have faces of various angles. The removable nose cone can be 6 inches long and can have a first sloped face of 45 degrees and a second sloped face of 45 degrees tapering to a point together. The removable nose cone  348  can have a central opening  352 . The diameter of the central opening can range from ⅝ of an inch to 2 inches. The removable nose cone  348  can be disposed about or connected with the mandrel  12  opposite the crown engagement  20 . A pump down ring  360  can be disposed about the removable nose cone  348 . 
     The load ring  380  can be disposed about the mandrel  12  adjacent or proximate to the crown engagement  20 . The load ring  380  can reinforce a portion of the mandrel  12  to enable the mandrel  12  to withstand high pressures. The load ring  380  can be made from a composite material containing glass and epoxy resin cured material that is able to be machined, milled, cut, or combinations thereof. The load ring can be from 1 inch to 3 inches in length and 2 inches to 8 inches in diameter. 
       FIG. 3  is a cut view of the fractionation plug of  FIG. 2  along line X-X with a caged ball setting mechanism inserted therein. 
     The fraction plug  300  can include the mandrel  12 . The mandrel  12  can have a first setting mechanism receiving portion  152   a.    
     A caged ball setting mechanism  391  can be inserted in the first setting mechanism receiving portion  152   a . The caged ball setting mechanism  391  can threadably connect to the first setting mechanism receiving portion  152   a . The caged ball setting mechanism  391  can be any caged ball setting mechanism, such as those described herein. 
     The removable nose cone  348  can be supported by the mandrel, the caged ball setting mechanism  391 , or any combination thereof. 
     An anti-rotation ring  370  can be secured in the anti-rotation ring groove  140 . 
     The load ring  380  can use a load ring seat  382  to rest on a mandrel load shoulder. 
     Also shown are pump down ring  360 , the pump down ring groove  1359 , the first slip  310 , the second slip  312 , the first slip backup  320 , the second slip backup  322 , a large primary seal  340 , the first lubricating spacer  342 , the second lubricating spacer  344 , and the central opening  352 . 
     The crown engagement  20  is also viewable in this Figure. The crown can be integral with the mandrel  12  as a one piece structure. In an embodiment, such as the 4½ inch in diameter mandrel, the crown can have 6 grooves formed by 6 points that extend away from the mandrel  12  create an engagement that securely holds another nose cone to the plug for a linear connection of two plugs in series. 
       FIG. 4A  depicts a schematic of a first caged ball setting mechanism  800  according to one or more embodiments. 
     The first caged ball setting mechanism  800  can include an extension  302  with an extension portal  394 , a caged ball retaining rod  358  and a caged ball  396 . The extension portal  394  can be used to allow for differential pressure between zones in a wellbore. 
     The caged ball setting mechanism  800  can also include the setting mechanism load shoulder  301  and the engaging threads  393 . 
     The first caged ball setting mechanism  800  can have a caged ball chamber  807  with a first diameter. The caged ball retaining rod  358  can be secured adjacent to the caged ball chamber  807 . The caged ball retaining rod  358  can keep the caged ball  396  within the caged ball chamber  807 . 
     An upper chamber  811  can be formed into the first caged ball setting mechanism  800 . The caged ball chamber  807  can have a smaller diameter than the upper chamber  811 . 
     A setting tool stop  812  can be formed between the caged ball retaining rod  358  and the upper chamber  811 . 
     The upper chamber  811  can have shear threads  313  to engage with the setting rod. 
     The first caged ball setting mechanism  396  can be guided by a caged ball seat guide  306  into the caged ball seat  395  when fluid pressure is applied. 
       FIG. 4B  depicts a schematic of a second caged ball setting mechanism  900  according to one or more embodiments. 
     The second caged ball setting mechanism  900  can include the extension  302  with the extension portal  394 , a caged ball retaining rod  358 , and a caged ball  396 . The extension portal  394  can be used to allow for differential pressure between zones in a wellbore. 
     The second caged ball setting mechanism  900  can also include the setting mechanism load shoulder  301  and the engaging threads  393 . 
     The second caged ball setting mechanism  900  can have a caged ball chamber  807  with a first diameter. A caged ball retaining rod  358  can be secured adjacent to the caged ball chamber  807 . The caged ball retaining rod  358  can keep the caged ball  396  within the caged ball chamber  807 . 
     An upper chamber  811  can be formed into the second caged ball setting mechanism  900 . The caged ball chamber  307  can have a smaller diameter than the upper chamber  811 . 
     A setting tool stop  812  can be formed between the caged ball retaining rod  358  and the upper chamber  811 . 
     The upper chamber  811  can have shear threads  313  to engage with the setting rod. 
     The caged ball  396  can be guided by a caged ball seat guide  306  into the caged ball seat  395  when fluid pressure is applied. 
     The extension  302  can include one or more seal grooves  914 . Each seal groove can have a seal  915  secured therein. The seals can be O-rings or the like. 
       FIG. 4C  depicts a schematic of a third caged ball setting mechanism  1000  according to one or more embodiments. 
     The third caged ball setting mechanism  1000  can include the extension  302  with an extension portal  394 , a caged ball retaining rod  358  and a caged ball  396 . The extension portal  394  can be used to allow for differential pressure between zones in a wellbore. 
     The third caged ball setting mechanism  1000  can also include the setting mechanism load shoulder  301  and the engaging threads  393 . 
     The third caged ball setting mechanism  1000  can have a caged ball chamber  807  with a first diameter. The caged ball retaining rod  358  can be secured adjacent to the caged ball chamber  807 . The caged ball retaining rod  358  can keep the caged ball  396  within the caged ball chamber  807 . 
     An upper chamber  811  can be formed into the third caged ball plug  1000 . 
     A setting tool stop  812  can be formed between the caged ball retaining rod  358  and the upper chamber  811 . 
     The upper chamber  811  can have shear threads  313  formed therein. 
     The caged ball  396  can be guided by a caged ball seat guide  306  into the caged ball seat  395  when fluid pressure is applied. 
     The extension  302  can include one or more seal grooves  914 . Each seal groove can have a seal  915  secured therein. The seals can be O-rings or the like. 
     The third caged ball setting mechanism  1000  can have a tightening groove  1024 . 
       FIG. 5  is a schematic of two fractionation plugs disposed within a wellbore. 
     As depicted, the wellbore  501  can have a perforated casing  500  and two hydrocarbon bearing zones  530  and  532 . 
     The embodiments of the fractionation plug described herein can be used within casing or within production tubing. For example, in one or more embodiments, the fractionation plug can be used within the wellbore casing. 
     In operation, coil tubing, wire lines, or other devices, which are not shown, can be used to place the fractionation plugs  510  and  520  into the wellbore  501 . The fractionation plugs  510  and  520  can isolate the hydrocarbon bearing zones  530  and  532  from one another. 
     Once the plug is at a designated location, the setting tool can pull the mandrel, holding the outer components on the mandrel, which can compress the outer components, the slips, and the slip backups for engagement with the casing of the wellbore. 
     Once the plug is set in place, the casing in the wellbore can be perforated, such as with a well perforating gun. 
     Fractionation can be initiated by pumping water, sand and chemical through the wellbore into the plug forcing the caged ball to seat on the caged ball seat sealing off the lower fractionation zone from an upper fractionations zone. The plug can be left in place until the fractionation stage is completed. 
       FIG. 6  depicts a cross sectional view of a load ring disposed about a mandrel wherein one or more set screws are disposed through the load ring. The load ring  380  can be disposed about the mandrel  12 . One or more shear pins  700   a  and  700   b  can be disposed through the load ring  380  and engage the mandrel  12 . For example, the shear pins can extend ⅛ th  of an inch into the mandrel  12 . The shear pins  700   a  and  700   b  can prevent premature movement of the load ring  380 . 
       FIG. 7  depicts a tapered nose cone having a beveled distal end. The removable nose cone  348  can have two slanted faces, one slanted face  709  is shown, and a pair of bevels  710  and  712  on a distal end thereof. The bevels  710  and  712  can be twenty degree bevels. The bevels help to reduce the risk of the removable nose cone  348  catching on a portion of a wellbore, reducing the likelihood of a premature set. 
     While these embodiments have been described with emphasis on the embodiments, it should be understood that within the scope of the appended claims, the embodiments might be practiced other than as described herein.