Patent Publication Number: US-2018031129-A1

Title: Bonded seal with integral backup ring

Description:
FIELD 
     The present disclosure relates to a bonded seal with integral backup ring. 
     BACKGROUND 
     This section provides background information related to the present disclosure which is not necessarily prior art. 
     When oil field tools are deployed down hole and need to engage a sealing component, the rigid portion of the sealing component needs to have a certain amount of annular clearance with respect to the seal surface of the traveling component to prevent contact that may cause damage. This annular clearance makes it very challenging to seal with a conventional bonded, elastomeric seal at elevated temperatures and pressure differentials. The elastomeric seal will tend to be damaged and can fail by extrusion. 
     SUMMARY 
     This section provides a general summary of the disclosure, and is not a comprehensive disclosure of its full scope or all of its features. 
     The present disclosure provides a sealing solution that features an elastomer bonded to a rigid carrier. The bonded elastomer has, within the low pressure side of the seal, an insert made from thermoplastic, which acts to move as the elastomer is deformed under a pressure differential and eliminate the annular extrusion gap between two concentric tubular members to form a more robust seal than if it were not present. 
     Further areas of applicability will become apparent from the description provided herein. The description and specific examples in this summary are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure. 
    
    
     
       DRAWINGS 
       The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure. 
         FIG. 1  is a partial cross-sectional view of a seal for engaging a tool mandrel received in a seal bore according to a first embodiment; 
         FIG. 2  is a partial cross-sectional view of a seal for engaging a tool mandrel received in a seal bore according to a second embodiment; and 
         FIG. 3  is a partial cross-sectional view of a seal for engaging a tool mandrel received in a seal bore according to a third embodiment. 
     
    
    
     Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings. 
     DETAILED DESCRIPTION 
     Example embodiments will now be described more fully with reference to the accompanying drawings. 
     Example embodiments are provided so that this disclosure will be thorough, and will fully convey the scope to those who are skilled in the art. Numerous specific details are set forth such as examples of specific components, devices, and methods, to provide a thorough understanding of embodiments of the present disclosure. It will be apparent to those skilled in the art that specific details need not be employed, that example embodiments may be embodied in many different forms and that neither should be construed to limit the scope of the disclosure. In some example embodiments, well-known processes, well-known device structures, and well-known technologies are not described in detail. 
     The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting. As used herein, the singular forms “a,” “an,” and “the” may be intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms “comprises,” “comprising,” “including,” and “having,” are inclusive and therefore specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. The method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order discussed or illustrated, unless specifically identified as an order of performance. It is also to be understood that additional or alternative steps may be employed. 
     When an element or layer is referred to as being “on,” “engaged to,” “connected to,” or “coupled to” another element or layer, it may be directly on, engaged, connected or coupled to the other element or layer, or intervening elements or layers may be present. In contrast, when an element is referred to as being “directly on,” “directly engaged to,” “directly connected to,” or “directly coupled to” another element or layer, there may be no intervening elements or layers present. Other words used to describe the relationship between elements should be interpreted in a like fashion (e.g., “between” versus “directly between,” “adjacent” versus “directly adjacent,” etc.). As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. 
     Although the terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms may be only used to distinguish one element, component, region, layer or section from another region, layer or section. Terms such as “first,” “second,” and other numerical terms when used herein do not imply a sequence or order unless clearly indicated by the context. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the example embodiments. 
     Spatially relative terms, such as “inner,” “outer,” “beneath,” “below,” “lower,” “above,” “upper,” and the like, may be used herein for ease of description to describe one element or feature&#39;s relationship to another element(s) or feature(s) as illustrated in the figures. Spatially relative terms may be intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as “below” or “beneath” other elements or features would then be oriented “above” the other elements or features. Thus, the example term “below” can encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly. 
     With reference to  FIG. 1 , a seal assembly  10  is shown for sealing between a generally cylindrical outer surface of a mandrel tool  12  and an outer bore. The seal assembly  10  includes an annular rigid carrier  14  defining a radially outwardly extending annular recess  16  on an inner diameter surface thereof with an elastomer seal member  18  bonded within the annular recess  16 . An annular thermoplastic insert  20  is axially provided on a low pressure side of the elastomer seal member  18  with the elastomer seal member including a portion  18   a  disposed between an outer diameter surface  20   a  of the thermoplastic insert  20  and the annular recess  16 . When the elastomer  18  is deformed under a pressure differential, the thermoplastic insert  20  is pressed by the elastomer  18  to move in a radial inward direction to engage the outer diameter surface of the mandrel tool  12  and eliminate the annular gap between the concentric mandrel tool  12  and seal assembly  10  members to prevent extrusion of the elastomer  18  therethrough and provide for a more robust seal. In the embodiment shown in  FIG. 1 , the elastomer seal member  18  is disposed along the outer diameter surface  20   a  and the side surface  20   b  facing the high pressure side of the thermoplastic insert  20 . A side surface  20   c  facing the low pressure side is disposed against a side wall  16   a  of the recess  16 . The side surface  20   c  and the side wall  16   a  can be angled relative to a plane orthogonal to an axis of the mandrel tool  12  in order to facilitate the movement of the thermoplastic insert  20  in a radially inward direction as illustrated in broken lines. 
     With reference to  FIG. 2 , a second embodiment of the present disclosure provides an elastomer seal member  118  which is disposed along a side surface  20   b  of the thermoplastic insert  20  and along a portion, and more specifically one-half, of the outer diameter surface  20   a  of the thermoplastic insert  20 . The amount of elastomer material of the seal member  118  can be specifically selected to provide a certain amount of travel of the thermoplastic insert  20  when the elastomer seal member  118  is deformed under pressure. A sidewall  116   a  of the annular recess  116  in the rigid carrier  114  includes a step region  116   b  for receiving the thermoplastic insert  20 . The side surface  20   c  and the side wall  116   c  can be angled relative to a plane orthogonal to an axis of the mandrel tool  12  in order to facilitate the movement of the thermoplastic insert  20  in a radially inward direction (illustrated in broken lines) toward the mandrel tool  12  when pressure is applied to the seal assembly  10 . 
     With reference to  FIG. 3 , the thermoplastic insert can be modified to include multiple annular thermoplastic insert members  120  that are axially aligned and can provide a series of backup rings for preventing extrusion of the elastomer seal member  118  through a gap formed between the rigid carrier  14  and the tool mandrel  12 . In the example shown, three insert members  120  are shown, although more or fewer insert members can be used. Each of the insert members  120  are shown with a rectangular cross section. Elastomer material  118  is disposed between the insert members  120  which allows for limited relative radial movement (illustrated in broken lines) between the insert members  120  when pressure is applied to the seal assembly  10 . 
     The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure.