Patent Application
20170122055
The present disclosure relates to a unitized lip seal for a wash pipe stuffing box sealing system.
This section provides background information related to the present disclosure which is not necessarily prior art.
In the drilling of oil and gas wells, a drill bit is rotated in a borehole by means of a string of drill pipe. The drill pipe can be rotated on the surface mechanically by a rotating table mounted on a drilling platform or by a hydraulic motor, commonly referred to as a top drive. As is common in such oil and gas well drilling, drilling fluid or mud can be circulated through the drill pipe and the drill bit to cool the drill bit and remove the cuttings, which are then recirculated to the surface. The drilling fluid can be at pressures that can range to several thousand psi.
The rotary drilling swivel commonly used in the drilling of oil and gas wells provides rotating support for the drill string suspended from it and a sealed passageway for circulating drilling fluids into the drill string. The drill pipe is in open-flow communication with a wash pipe, through which the drilling fluid flows, the wash pipe usually being stationary. A packing assembly forming part of the swivel rotates with the drill pipe, and is in scaling engagement with the wash pipe to prevent loss of drilling fluid out of the swivel assembly.
Drilling fluid pressures can reach several thousand psi, and at these high pressures, conventional, prior art packing assemblies used to seal between the wash pipe and the rotary head to which the drill pipe is secured have reduced life, resulting in leaking. Pumps employing rotary shafts, e.g., centrifugal pumps, generally employ lip type seals that are generally in a stacked configuration and employ various types of spacers or back-up rings, an adjustable gland being used to force the lips of the seals into engagement with the stuffing box or the like in which the seals are carried and the rotating shaft that extends through the stuffing box. In many cases, these pumps are in environments where change-out of the seal rings is difficult and results in costly downtime.
This section provides a general summary of the disclosure, and is not a comprehensive disclosure of its full scope or all of its features.
A wash pipe stuffing box sealing assembly according to the present disclosure includes a wash pipe stuffing box having a bore extending there through. A mandrel sleeve is disposed in the aperture in the wash pipe stuffing box. A plurality of stuffing box adapter rings are disposed in the wash pipe stuffing box and surrounding the mandrel sleeve. A plurality of annular seal rings are dispersed between the plurality of stuffing box adapter rings. The annular seal rings each include an annular seal body made of a first material including a radially outer portion and an annular radially inner portion extending radially inward from the outer portion at an acute angle relative to an axis of the mandrel sleeve. The inner portion includes an inner surface with an annular contact lip portion and an annular recess portion disposed adjacent to the annular contact lip portion. A secondary sealing ring made of a second material different than the first material is disposed in the annular recess portion of the inner portion of the annular seal body.
Finite element analysis has shown the highest contact stress is at the tip of the lip seal so that this point is in contact with the drilling fluid and will run cooler with lubrication and last longer. In addition, the secondary sealing ring is energized against the rotating mandrel sleeve by the differential pressure acting on the lip seal. This will create additional sealing action from a thermally stable, low friction coefficient material. These features extend the life of the annular seal rings as compared to conventional designs.
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.
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.
Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings.
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'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
A plurality of stuffing box adapter rings 24a-c are disposed in the large diameter cylindrical portion of the wash pipe stuffing box 12 and surrounding the mandrel sleeve 22. A stuffing box end adaptor 26 is disposed at an end of the larger diameter cylindrical portion 16A of the wash pipe stuffing box 12.
A plurality of an annular seal rings 28a-d are disposed in the larger diameter cylindrical portion 16A of the wash pipe stuffing box with the annular seal ring 28a being disposed between the stepped portion 16C and the adaptor ring 24a. The annular seal ring 28b is disposed between the adaptor ring 24 a and the adaptor ring 24b. The annular seal ring 28c is disposed between the adaptor ring 24b and the adaptor ring 24c. The annular seal ring 28d is disposed between the adaptor ring 24c and the box end adaptor 26.
With reference to
With reference to
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.
