Abstract:
An adjustable sealing device including a housing configured to be engaged within an annulus of a rotating control device, at least one sealing element disposed within the housing, and a variable pressure control device configured to energize a fluid disposed within the housing to maintain a seal between the sealing element and a drill string is disclosed. A method of sealing a wellbore, the method including providing an adjustable sealing device to a rotating control device, positioning at least one sealing element of the adjustable sealing device between the wellbore and a drill string, tripping the drill string through the wellbore, sensing changes in a diameter of the drill string as it is tripped, and regulating a fluid pressure to maintain a seal between the at least one sealing element and the drill string when the drill string is tripped through the at least one sealing element is also disclosed.

Description:
BACKGROUND 
       [0001]    1. Field of the Disclosure 
         [0002]    Embodiments disclosed herein relate generally to apparatuses and methods for providing a seal during drilling operations. Specifically, embodiments disclosed herein relate to a sealing device that is configured to seal around a drill string. 
         [0003]    2. Background Art 
         [0004]    An earth-boring drill bit is typically mounted on the lower end of a drill string and is rotated by rotating the drill string at the surface or by actuation of downhole motors, turbines, or both. During operations, the drill string may be translated through the wellbore created by the drill bit. Further, during operation, high pressure fluid within the wellbore may need to be prevented from being released. As such, a seal may be provided that is capable of sealing the wellbore during drilling operations. 
         [0005]    Generally, a rotating control device (“RCD”) that seals around a drill string is used to seal the wellbore during operations. As shown in  FIG. 1 , the RCD  30  includes a stripping element  31  disposed within an annulus  32  of the RCD  30 . During operation, the annulus  32  of the RCD  30  is in fluid communication with the wellbore. As such, the pressure within the wellbore may be exerted upon the stripping element  31  of the RCD  30 . An example of a rotating control device may be found in U.S. patent application Ser. No. 11/556,938 filed on Nov. 6, 2006 and entitled Rotating Control Device Apparatus and Method, hereby incorporated by reference herein in its entirety. 
         [0006]    Further, during operation, the drill string may be translated through the RCD  30  and into the wellbore. Typically, the drill string includes a plurality of drill pipes connected by threaded connections located on both ends of the plurality of drill pipes. As such, threaded connections may be flush with the remainder of the drill string outer diameter or may be “upset,” having an outer diameter larger than the remainder of the drill string. As the drill string is translated through the wellbore and the RCD  30 , the stripping element  31  may squeeze against an outer surface of at least one of the plurality of drill pipes, thereby sealing the wellbore. Typically, the stripping element  31  is made up of an elastic material that may mechanically deform to seal around various diameters of drill pipe. However, over time the stripping element  31  may become worn and unable to substantially deform to provide a seal around the drill string. Consequently, the stripping element  31  must be replaced, which may lead to down time during drilling operations that can be costly to a drilling operator. 
         [0007]    Accordingly, there exists a need for methods and apparatuses for improving the sealing of a wellbore during stripping operations. 
       SUMMARY OF THE DISCLOSURE 
       [0008]    In one aspect, embodiments of the present disclosure relate to an adjustable sealing device including a housing configured to be engaged within an annulus of a rotating control device, at least one sealing element disposed within the housing, and a variable pressure control device configured to energize a fluid disposed within the housing to maintain a seal between the sealing element and a drill string. 
         [0009]    In another aspect, embodiments of the present disclosure relate to a rotating control device including an adjustable sealing device installed in an annulus between a drill string and a wellbore, the adjustable sealing device including a housing, at least one sealing element disposed within the housing, a variable pressure control device configure to energize a fluid disposed within the housing to maintain a seal between the sealing element and the drill string. 
         [0010]    In yet another aspect, embodiments of the present disclosure relate to a method of sealing a wellbore, the method including providing an adjustable sealing device to a rotating control device, positioning at least one sealing element of the adjustable sealing device between the wellbore and a drill string, tripping the drill string through the wellbore, sensing changes in a diameter of the drill string as it is tripped, and regulating a fluid pressure to maintain a seal between the at least one sealing element and the drill string when the drill string is tripped through the at east one sealing element. 
         [0011]    Other aspects and advantages of the invention will be apparent from the following description and the appended claims. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0012]      FIG. 1  shows a rotating control device in accordance with the prior art. 
           [0013]      FIG. 2  shows a cross-section of a sealing device in accordance with embodiments of the present disclosure. 
           [0014]      FIG. 3  shows a cross section of a sealing device in accordance with embodiments of the present disclosure. 
           [0015]      FIG. 4  shows a cross section of a sealing device in accordance with embodiments of the present disclosure. 
           [0016]      FIG. 5  shows a cross section of a sealing device in accordance with embodiments of the present disclosure. 
       
    
    
     DETAILED DESCRIPTION 
       [0017]    In one aspect, embodiments disclosed herein relate to apparatuses and methods to provide a seal during drilling operations. Specifically, embodiments disclosed herein relate to a sealing device that is configured to seal around a drill string. During operation, the sealing device is configured to maintain a seal with the drill string as the drill string is translated through the wellbore. Additionally, the sealing device may be configured to control a pressure of a fluid, thereby allowing the sealing device to seal around various shapes and sizes of components of the drill string. 
         [0018]    Referring now to  FIG. 2 , an adjustable sealing device  200  in accordance with embodiments of the present disclosure is shown. As shown, the adjustable sealing device  200  includes a housing  210 , a sealing element  220 , a fluid (e.g., hydraulic fluid)  230 , and a pressure control device (i.e., a pressurized fluid source)  240 . In one embodiment, the adjustable sealing device  200  may be in fluid communication with a wellbore (not shown) and configured to maintain a seal around a drill string  10  while the drill string  10  is translated through the wellbore and the adjustable sealing device  200 . 
         [0019]    Housing  210  may be configured to allow a drill string  10  to be translated through the adjustable sealing device  200 . In one embodiment, the housing  210  may include an annulus  212  that allows the drill string  10  to extend and be translated through the adjustable sealing device  200 . During operation, the annulus  212  of the housing  210  may be configured to be in fluid communication with the wellbore. As such, a pressure of the wellbore may be exerted on the sealing element  220  of the adjustable sealing device  200 . 
         [0020]    Further, the housing  210  may be configured receive the fluid  230  and the sealing element  220 . In one embodiment, the housing  210  includes a chamber  214  that is configured to receive the fluid  230  and at least a portion of the sealing element  220 . Moreover, the housing  210  may include an aperture  216  that allows the chamber  214  to be in fluid communication with at least one pressure control device  240 . 
         [0021]    Furthermore, in certain embodiments, the housing  210  may include at least two sections that allow the sealing element  220  to be removably disposed within the chamber  214  of the housing  210 . For example, the housing  210  may include upper and lower sections (not shown) coupled together through bolts, threads, or other attachments known in the art. Accordingly, the upper section may be disconnected from the lower section to allow sealing element  220  to be inserted or removed from chamber  214  of housing  210 . 
         [0022]    Additionally, in select embodiments, the housing  210  may include at least one connection (not shown) that is configured to couple the adjustable sealing device  200  to the wellbore. The at least one connection may include bolts, threads, bearings, or any other attachment method known in the art. In one embodiment, the at least one connection may be configured to removably connect the adjustable sealing device within an RCD coupled to the wellbore. 
         [0023]    In selected embodiments, sealing element  220  may be at least partially disposed within chamber  214  of housing  210  and configured to seal around drill string  10 , which may result in sealing the wellbore that is in fluid communication with adjustable sealing device  200 . For example, sealing element  220  may deform against an outer surface  12  of the drill string  10  extending through the adjustable sealing device  200 , thereby not allowing pressure within the well bore to be released through the adjustable sealing device  200 . As such, the sealing element  220  may include rubber, metal, or any other deformable materials that allow sealing element  220  to form a seal around the drill string  10 . Further, in selected embodiments, sealing element  220  may comprise a single piece of material, whereas in other embodiments, sealing element  220  may include multiple pieces of material coupled together to form a seal around drill string  10 . 
         [0024]    In certain embodiments, the sealing element  220  may include a circular shape, a rectangular shape, an irregular shape, or any other shape able to seal around drill string  10 . In further embodiments, the sealing element  220  may include chamfers  222  disposed proximate an inner surface  224  of sealing element  220 . One skilled in the art will appreciate that chamfers  222  may allow various shapes and diameters of the drill string to more effortlessly pass through sealing element  220 , while still maintaining the seal between the sealing element and outer surface  12  of the drill string  10 . 
         [0025]    Hydraulic fluid  230  may be disposed within in chamber  214  of housing  210  and configured to exert a pressure upon sealing element  220  to maintain the seal between it and the drill string  10 . For example, in one embodiment, fluid  230  may be pumped into the chamber  214  of the housing  210  through an aperture  216  that is in fluid communication with the fluid line  242  of the pressure control device  240 . As the fluid  230  is pumped into the chamber  214 , a pressure of the fluid  230  within the chamber  214  may increase, which may cause the sealing element  220  to deform against the outer surface  12  of the drill string  10 . In another embodiment, the fluid  230  may be released from the chamber  214  to allow the pressure of the fluid  230  within the chamber  214  to be decreased. One skilled in the art will appreciate that decreasing the pressure of the fluid  230  within the chamber  214  may allow a portion of the drill string  14  having a diameter greater (i.e., an upset portion) than the remainder of drill string  16  to pass through adjustable sealing device  200 , while maintaining the seal around drillstring  10 . In selected embodiments, fluid  230  may include hydraulic fluid, water, drilling mud, air, or any other fluid capable of applying pressure on sealing element  220 . 
         [0026]    The pressure control device  240  may be in fluid communication with the chamber  214  of the housing  210 . As shown, in one embodiment, the pressure control device  240  may be in connected to the housing  210  through the flow line  242 . Further, the pressure control device  240  may be configured to control the pressure of the fluid  230  within the chamber  214  of the housing  210 . For example, the pressure control device  240  may pump fluid  230  into the chamber  214  of the housing  210  through the fluid line  242 , thereby increasing the pressure of the fluid  230  within the chamber  214 . In addition, the pressure control device  240  may allow fluid  230  to be released from the chamber  214  of the housing  210  through fluid line  242 . One skilled in the art will appreciate that the pressure control device  240  may include a pump, a motor, a valve or any other components known in the art to control the pressure of the fluid  230 . 
         [0027]    Referring now to  FIG. 3 , in select embodiments, adjustable sealing device  200  may include at least one ring  250  to transfer the pressure of fluid  230  to sealing element  220 . For example, in one embodiment, as the pressure of fluid  230  within chamber  214  is increased, ring  250  may be configured to be translated in the U direction and exert a force on sealing element  230 . Additionally, in another embodiment, as the pressure of the fluid  230  within the chamber  214  is decreased, ring  250  may be configured to be translated in the D direction, which may decrease the force exerted on sealing element  220 . Ring  250  may comprise a metallic material or any other material capable (i.e., a rigid material) of transferring the pressure of the fluid  230  to the sealing element  220 . One skilled in the art will appreciate that ring  250  may be configured to seal the fluid  230  within the chamber  214  of the adjustable sealing device  200 . Furthermore, one skilled in the art will appreciate that the ring  250  may uniformly transfer the pressure of the fluid  230  to the sealing element  220 . 
         [0028]    In certain embodiments, the adjustable sealing device  200  may include sensors  260 ,  262  that configured to sense a diameter of the drill sting  10 , as shown in  FIG. 3 . In one embodiment, the adjustable sealing device  200  may include an upper sensor  260  disposed above the sealing element  220  on the housing  210  of the adjustable sealing device  200 . Accordingly, the upper sensor  260  may be configured to sense a diameter of the drillstring  10  above the sealing element  220 . In another embodiment, the adjustable sealing device  200  may include a lower sensor  262  disposed below the sealing element  220  on the housing  210  of the adjustable sealing device  200 . As such, the lower sensor  262  may be configured to sense a diameter of the drillstring  10  below the sealing element  220 . 
         [0029]    In select embodiments, the sensors  260 ,  262  may be electrically connected to the pressure control device  240  and configured to send a signal to the pressure control device  240 . The signal may then be used by the pressure control device  240  to regulate the pressure of fluid  230  within the chamber  214  of the housing  210 . One skilled in the art will appreciate that the sensors  260 ,  262  may include a trip switch, a limit switch, or any other sensor capable of sensing a diameter of the drill string  10 . As such, as a large diameter portion (e.g., a threaded connection or “tool joint”) is about to pass through adjustable sealing device  200  from below, lower sensor  262  may detect the increased diameter and instruct pressure control  240  to lower pressure of fluid  230  in chamber  214  to ease the passage of the tool joint. Once through, upper sensor  260  may instruct pressure control  240  to increase pressure of fluid  230  in chamber  214  to a level that is optimized for the remainder of the drill string. 
         [0030]    Referring now to  FIGS. 2 and 3 , during operation, the adjustable sealing device  200  is positioned to be in fluid communication with the wellbore. Further, during operation, the drillstring  10  may be translated through the adjustable sealing device  200  into or out of the wellbore. In one embodiment, as the drill string  10  is translated through the adjustable sealing device  200 , the pressure of the fluid  230  within the chamber  214  of the housing  210  may be increased or decreased to maintain the seal between the sealing element  220  and the outer surface  12  of the drill string  10 . This may be accomplished by pumping fluid  230  into and/or releasing fluid  230  out of the chamber  214  of the housing  210  using the pressure control device  240 . In another embodiment, at least one of the sensors  260 ,  262  may detect the diameter of the drill string  10  before the drill string  10  is translated through the adjustable sealing device  200 . The at least one sensor  260 ,  262  may then send a signal to the pressure control device  240  that may be used by the pressure control device  240  to control the pressure of the fluid  230  within the chamber  214 , thereby allowing the adjustable sealing device  200  to seal around various shapes and diameters of the drill string  10 . 
         [0031]    Referring now to  FIG. 4 , an adjustable sealing device  300  in accordance with embodiments of the present disclosure is shown. The adjustable sealing device  300  includes a housing  310 , a fluid  330 , and a pressure control device  340  similar to the adjustable sealing device  200  shown in  FIG. 2 . However, the adjustable sealing device  300  includes a plurality of sealing elements  320  that are configured maintain a seal around the outer surface  12  of the drillstring  10 . One skilled in the art will appreciate that the plurality of sealing elements  320  may increase the reliability of the adjustable sealing device  300  by providing multiple seals along the outer surface  12  of the drill string  10 . 
         [0032]    In certain embodiments, a housing  410  of an adjustable sealing device  400  may have various geometries that allow a fluid  430  from a pressure control device  440  to be disposed on various surfaces of a sealing element  420 , as shown in  FIG. 5 . One skilled in the will appreciate that the various geometries of the housing  420  and disposition of the fluid  430  does not depart from the present disclosure. 
         [0033]    Embodiments disclosed herein may provide for one or more of the following advantages. In particular, embodiments of the present disclosure enable an adjustable sealing device (e.g.,  200 ,  300 ,  400 ) to be used in conjunction with an RCD to prevent premature wear of the stripping element (e.g.,  31 ). If, during a drilling operation using an RCD, the drill string is to be retrieved, the stripping element may be removed and replaced with an adjustable sealing device in accordance with embodiments disclosed herein. As such, the adjustable sealing device (e.g.,  200 ,  300 , or  400 ) would be capable of adjusting the pressure of fluid ( 230 ,  330 , or  440 ) when upset threaded connection joints are passing therethrough so that sealing elements ( 220 ,  320 , or  420 ) are not damaged. Once the trip in or trip out operation is completed, the adjustable sealing device may be retrieved and the stripping element reinstalled. 
         [0034]    While the present disclosure has been described with respect to a limited number of embodiments, those skilled in the art, having benefit of this disclosure, will appreciate that other embodiments may be devised which do not depart from the scope of the disclosure as described herein. Accordingly, the scope of the disclosure should be limited only by the attached claims.