Abstract:
A seal includes a mandrel; an element disposed radially adjacent the mandrel; a chamber defined between the mandrel and the element; and a pressure regulator in fluid communication with the chamber, the regulator configured to resist fluid flow to a selected threshold pressure related to element expansion and method.

Description:
BACKGROUND 
       [0001]    In the hydrocarbon recovery industry, sealing structures such as packers have long been used for various sealing duties. While the ultimate purpose of sealing is the same, there have been many different kinds of structures used. Indeed, entire development arms have built up over the years for different types of packers/seals. These structures may be mechanical, inflatable, etc. While all of the currently available packers/seals have an environment in which they function well, the industry as a whole continues to evolve and produce new environments in which such devices are meant to function. This often exposes a need for new technology to ensure reliable service for an acceptably long period of time. 
       SUMMARY 
       [0002]    A seal includes a mandrel; an element disposed radially adjacent the mandrel; a chamber defined between the mandrel and the element; and a pressure regulator in fluid communication with the chamber, the regulator configured to resist fluid flow to a selected threshold pressure related to element expansion. 
         [0003]    A method for setting a seal with particulate matter includes pressurizing the seal with a particulate laden fluid; expanding the seal to an intended final set of dimensions; flowing the fluid; and depositing the particulate in the seal. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0004]    Referring now to the drawings wherein like elements are numbered alike in the several Figures: 
           [0005]      FIG. 1  is a schematic view of a packer as disclosed herein during an expansion phase of the filling process; and 
           [0006]      FIG. 2  is the device of  FIG. 1  during a packing phase of the filling process. 
       
    
    
     DETAILED DESCRIPTION 
       [0007]    Referring to  FIG. 1 , a particulate filled seal  10  is illustrated in an expansion phase a filling process. The seal  10  is illustrated in position within another structure  12  with which a seal is to be affected. One such structure  12  is a casing tubular in a hydrocarbon wellbore. The seal  10  comprises a mandrel  14  and a substantially fluid impermeable element  16  disposed radially spaced from the mandrel  14 . A chamber  18  defined between the element  16  and the mandrel  14  is configured to accept a fluid  20  and to regulate the exit of that fluid. The regulated exit is a pressure regulator  22 . The pressure regulator  22  may be configured in many different types of commercially available regulators. A biased flapper valve is one example while other examples include: a rupture disk, adjustable spring check valve, pilot operated relief valve, etc. Whatever regulator is selected its purpose is to hold pressure until a threshold pressure is reached by fluid  20  within the chamber  18 . Holding pressure until the threshold pressure causes the element  16  to respond to the full applied pressure of the fluid in order to ensure that the element is expanded fully against the structure  12  (or simply expanded to an intended final set of dimensions) prior to the filling of the element  16  with particulate matter. While grain-to-grain contact of the particulate matter in the element  16  will make the element solidly inflated, the contact pressure against the structure  12  is in some cases less than adequate when simply relying on grain loaded particles to effect the expansion the element  16 . As disclosed herein, then, the expansion is ensured using the fluid pressure rather than solely the grain contact. 
         [0008]    Still referring to  FIG. 1 , it is desirable to provide a screen  24  sufficient to prevent any particulate  26  from escaping from the chamber  18 . The screen is placed just upstream of the regulator  22  in one embodiment, as illustrated, though it is to be understood that the regulator need only be downstream of the element  16  to provide its specific purpose of expansion of the element  16 . If the regulator  22  is placed upstream of the screen  24 , consideration of the particulate matter  26  interaction with the regulator  22  must be given. If the regulator  22  is positioned downstream of the screen as illustrated, the regulator need be less robust as the particulate  26  is screened out of the fluid  20  before fluid  20  reaches the regulator  22 . In one embodiment, the regulator  22  is also configured to close after the filling operation is complete but it is to be understood that such is not necessary since once the particulate  26  fills the chamber  18  a check valve  28  closes preventing the particulate matter  26  from migrating out of the element  16  in the direction from which it was introduced thereto and the screen  24  prevents that particulate from exiting the element at the downstream end. In the event that a fluid leak path through the seal  10  is a concern, then a closeable regulator  22  will be desirable to prevent fluid from migrating through the particulate matter in an upstream direction relative to the original direction of filling. 
         [0009]    While any type of particulate material is possible for use with the seal and method of this invention, it is noted that in one particular embodiment, a resilient particulate material is selected. Such a resilient particulate material may comprise an elastomeric material, such as nitrile rubber, fluoroelastomer, etc. Resilient material utilized as the particulate  26  or at least as a component of the particulate  26  provides a rebound force to the seal  10  that is useful to allow the seal to remain sealed during pressure reversals. Resilience significantly enhances reliability of the seal  10 . 
         [0010]    While preferred embodiments have been shown and described, modifications and substitutions may be made thereto without departing from the spirit and scope of the invention. Accordingly, it is to be understood that the present invention has been described by way of illustrations and not limitation.