Abstract:
A screen includes, a body having a permeable material with energy stored therein configured to change the body from a first volume to a second volume, and a binder in operable communication with the body configured to retain the body in the first volume until the binder is weakened sufficiently for the energy stored within the body to overcome the binder and allow the body to change from the first volume toward the second volume.

Description:
BACKGROUND 
       [0001]    Filtering contaminates from flowing fluids is a common exercise in systems involved in transportation of fluids. Many such systems employ screens as the filtering mechanism. Screens that expand to substantially fill an annular gap, for example, between concentric tubulars, is another common practice. Some of these systems use swaging equipment to radially expand the screen. Although such equipment serves its purpose it has limitations, including a limited amount of potential expansion, complex and costly equipment and an inability to expand to fill a nonsymmetrical space. Apparatuses and methods that overcome these and other limitations with existing systems are therefore desirable to operators in the field. 
       BRIEF DESCRIPTION 
       [0002]    Disclosed herein is a screen. The screen includes, a body having a permeable material with energy stored therein configured to change the body from a first volume to a second volume, and a binder in operable communication with the body configured to retain the body in the first volume until the binder is weakened sufficiently for the energy stored within the body to overcome the binder and allow the body to change from the first volume toward the second volume. 
         [0003]    Further disclosed herein is a method of expanding a screen. The method includes, generating energy within a permeable body sufficient to change the body from a first volume to a second volume, binding the permeable body to prevent the generated energy from expanding the permeable body from the first volume to the second volume, weakening the binding to a level sufficient to allow the generated energy to expand the permeable body from the first volume to the second volume, and expanding the body from the first volume toward the second volume. 
         [0004]    Further disclosed herein is a method of conforming a screen to a borehole. The method includes, positioning a screen within a borehole, weakening a binding maintaining the screen at a first volume, expanding the screen toward a second volume with energy stored within the screen, and contacting walls of the borehole with the screen. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0005]    The following descriptions should not be considered limiting in any way. With reference to the accompanying drawings, like elements are numbered alike: 
           [0006]      FIG. 1  depicts a quarter cross sectional view of a screen disclosed herein in an unexpanded configuration; and 
           [0007]      FIG. 2  depicts a quarter cross sectional view of the screen of  FIG. 1  in an expanded configuration. 
       
    
    
     DETAILED DESCRIPTION 
       [0008]    A detailed description of one or more embodiments of the disclosed apparatus and method are presented herein by way of exemplification and not limitation with reference to the Figures. 
         [0009]    Referring to  FIGS. 1 and 2 , an embodiment of a screen disclosed herein is illustrated generally at  10 . The screen  10  includes, a body  14  made of a fluid permeable material  18  with energy stored therein that allows the body  14  to expand from a first volume as illustrated in  FIG. 1  to a second volume that is a larger than the first volume. The body  14 , as illustrated in  FIG. 2 , has a larger volume than the first volume but is somewhat less than the second volume due to the body  14  contacting walls  22  of a borehole  26  within which the body  14  is positioned. A binder  30  made of a removable material  34  structurally constrains the body  14  at the first volume until the binder  30  is weakened sufficiently to allow the stored energy to be released. During release of the stored energy the body  14  expands toward the second volume. 
         [0010]    The binder  30 , in this embodiment, is a solid that is distributed within the body  14  thereby structurally constraining the body  14  at the first volume. Weakening of the binder  30  can be accomplished in different ways, depending upon the material that the binder  30  is made of. For example, when the binder  30  is made of a dissolvable material exposing the binder  30  to an applicable solvent will allow the binder  30  to dissolve thereby allowing the stored energy to be released and the body  14  to expand toward the second volume. One example of a usable binder material that is soluble in water is the synthetic polymer, polyvinyl alcohol. Dissolution of the binder  30  made of polyvinyl alcohol in water weakens the structural integrity thereof until the energy stored in the body  14  is able to break the binder  30  apart expanding the body  14  in the process. Dissolution of polyvinyl alcohol, like many soluble materials, is accelerated at increased temperatures. 
         [0011]    In an alternate embodiment, the binder  30  could be made of a material having a low melting temperature relative to that of the body  14 . Such an embodiment would allow an operator to release the energy stored in the body  14  by increasing the temperature sufficiently to melt the binder  30 . In still other embodiments, the binder  30  could be made of a material that can be chemically degraded when exposed to a chemical, such as an acid for example. An operator could then expose the binder  30  to an applicable acid to initiate the chemical degradation needed to release the energy within the body  14 . 
         [0012]    Generating energy in the body  14  can be achieved in different ways depending upon the material, chemical and physical characteristics of the body  14 . For example, the body  14  could be made of a material capable of regaining its original shape after being deformed, such as a polymer, that is made into a mat of substantially randomly oriented filaments extruded from one or more spinnerets, for example. The mat could then be compacted to the first volume where it is bound by the binder  30 . An alternate embodiment could employ open celled foam that is deformed through an extrusion process before being bound by the binder  30 . 
         [0013]    Regardless of the material or structure of the body  14 , the body  14  will have fluid filtration characteristics defined by the body  14 . The filtration characteristics, however, may differ depending upon what volume the body  14  is taking. As such, an operator may set the desired filtration characteristics at a volume that the body  14  is expected to have when fully deployed. 
         [0014]    Referring again to  FIGS. 1 and 2 , the screen  10 , as illustrated, is employed in a sand screen within the wellbore  26  in an earth formation  38 . The body  14  of the screen  10  is run into the borehole  26  while in the compacted first volume configuration as shown in  FIG. 1 . An annular gap  42  between an outer surface  46  of the body  14  and an inner surface  50  defined by the walls  22  of the borehole  26  allow the body  14  to be run without detrimentally scraping the walls  22 . Once the screen  10  is at the desired position within the borehole  26  initiation of degradation of the binder  30 , as discussed above, can begin. Upon sufficient degradation of the binder  30  the body  14  can expand into contact with the walls  22 . The nature of the structure of the body  14  allows it to contact the walls  22  regardless of whether the walls  22  are cylindrical or not and regardless of whether the annular gap  42  is of a consistent size or not. In fact, the walls  22  need not even be symmetrical about the body  14 . Additionally, since the volume of the body  14 , as illustrated in  FIG. 2 , is less than the second volume the body  14  will exert a force against the walls  22 . This force will help prevent erosion of the walls  22  that could occur due to fluid flow if a portion of the annular gap  42  were allowed to exist between the walls  22  and the outer surface  46  after the body  14  has expanded. 
         [0015]    In the sand screen application, the screen  10  is positioned on a tubular  54  having perforations  58  therethrough. Fluid, upon being filtered after it flows through the body  14  is able to flow through the perforations  58  and into an inside  62  of the tubular  54 . Once on the inside  62  the fluid can flow longitudinally through the tubular  54  as desired. 
         [0016]    While the invention has been described with reference to an exemplary embodiment or embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the claims. Also, in the drawings and the description, there have been disclosed exemplary embodiments of the invention and, although specific terms may have been employed, they are unless otherwise stated used in a generic and descriptive sense only and not for purposes of limitation, the scope of the invention therefore not being so limited. Moreover, the use of the terms first, second, etc. do not denote any order or importance, but rather the terms first, second, etc. are used to distinguish one element from another. Furthermore, the use of the terms a, an, etc. do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced item.