Patent Application
20210172274
In oil and gas wells, tubular strings such as casing string, liner strings, etc., are run into a well and may be cemented in place to support production. Further, other types of tubular strings may be run into the well, e.g., within and through the cemented strings, to perform operations within the well. In various applications, either type of string may include a one-way check valve, often referred to as a “back pressure” valve. Back pressure valves allow circulation of fluid, cement, etc., in one direction, generally a downhole direction, through the string, but prevent reverse fluid flow, e.g., back up through the string to the surface.
Typically, back pressure valves use a flapper valve that pivots open and closed. The advantage of a flapper valve is that it can permit actuation of tools below the valve, e.g., via a drop ball pumped through the flapper valve. However, flapper valves generally include a relatively small spring-loaded hinge arrangement to achieve the desired one-way flow. Due to cyclic loading in the workstring, the hinge wears out quickly.
Embodiments of the disclosure include a valve assembly for use in a wellbore includes a housing defining a bore that extends axially therethrough, a valve seat positioned in the housing, and a valve element movably positioned in the housing. The valve seat and the valve element are concentric to one another, but non-concentric with the housing, such that a centerline defined through the valve seat and the valve element is offset from a central axis of the housing. The valve element is linearly actuatable relative to the housing between a closed position in which the valve element engages the valve seat and blocks the bore and an open position in which the valve element permits flow of fluid therethrough.
Embodiments of the disclosure also include a method that includes positioning a valve seat in a first bore portion of a housing of a valve assembly, positioning a valve element in a second bore portion of the housing, the second bore portion having a larger radial dimension than the first bore portion. The first and second bore portions are radially offset. The method also includes linearly actuating the valve element from a closed position in which the valve element blocks fluid flow through the housing in at least one direction to an open position in which the valve element is spaced axially apart from the valve seat.
Embodiments of the disclosure further include a downhole valve. The valve includes a top sub including an upper connection for connecting to a superposed tubular of a workstring, a first valve assembly coupled to the top sub, a second valve assembly coupled to the first valve assembly, and a bottom sub coupled to the second valve assembly and including a lower connection for connecting to a subjacent tubular of the workstring. The top sub, first valve, second valve assembly, and the bottom sub cooperatively define at least a portion of a bore extending axially therethrough. The first valve assembly includes a housing coupled to the top sub and the spacer sub, and a module including a valve seat and a valve element, the module being non-concentrically disposed within the housing, such that a centerline defined through the valve seat and the valve element is offset from a central axis of the housing. The valve element is linearly actuatable between a closed position in which the valve element engages the valve seat and blocks the bore and an open position in which the valve element permits flow of fluid therethrough.
The present disclosure may best be understood by referring to the following description and accompanying drawings that are used to illustrate embodiments of the invention. In the drawings:
The following disclosure describes several embodiments for implementing different features, structures, or functions of the invention. Embodiments of components, arrangements, and configurations are described below to simplify the present disclosure; however, these embodiments are provided merely as examples and are not intended to limit the scope of the invention. Additionally, the present disclosure may repeat reference characters (e.g., numerals) and/or letters in the various embodiments and across the Figures provided herein. This repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and/or configurations discussed in the Figures. Moreover, the formation of a first feature over or on a second feature in the description that follows may include embodiments in which the first and second features are formed in direct contact, and may also include embodiments in which additional features may be formed interposing the first and second features, such that the first and second features may not be in direct contact. Finally, the embodiments presented below may be combined in any combination of ways, e.g., any element from one exemplary embodiment may be used in any other exemplary embodiment, without departing from the scope of the disclosure.
Additionally, certain terms are used throughout the following description and claims to refer to particular components. As one skilled in the art will appreciate, various entities may refer to the same component by different names, and as such, the naming convention for the elements described herein is not intended to limit the scope of the invention, unless otherwise specifically defined herein. Further, the naming convention used herein is not intended to distinguish between components that differ in name but not function. Additionally, in the following discussion and in the claims, the terms “including” and “comprising” are used in an open-ended fashion, and thus should be interpreted to mean “including, but not limited to.” All numerical values in this disclosure may be exact or approximate values unless otherwise specifically stated. Accordingly, various embodiments of the disclosure may deviate from the numbers, values, and ranges disclosed herein without departing from the intended scope. In addition, unless otherwise provided herein, “or” statements are intended to be non-exclusive; for example, the statement “A or B” should be considered to mean “A, B, or both A and B.”
The downhole valve 100 may further include one or more valve assemblies (two shown: 150A, 150B). The valve assembly 150A, for example, is axially between and connects together the top sub 105 and the spacer sub 110, and the valve assembly 150B is axially between and connects together the spacer sub 110 and the bottom sub 115. Although two valve assemblies 150A, 150B are shown in
Additional details will now be described for the valve assembly 150A, with it being appreciated that the valve assembly 150B may include the same or similar components and operate in the same or a similar manner. In particular, in the illustrated embodiment, the valve assembly 150A generally includes a cylindrical housing 155 that connects together the adjacent subs (in this case, the top sub 105 and the spacer sub 110) and defines a portion of the bore 135 therethrough. The valve assembly 150A further includes a valve seat 160 and a valve element 165 (e.g., a plunger) that are located within the housing 155. The valve element 165 is linearly movable in a direction parallel to a central longitudinal axis 125 of the valve 100, with respect to the housing 155 and the valve seat 160, between a closed position and an open position. In at least some embodiments, the valve element 165 is not pivotal between open and closed. When the valve element 165 is in the closed position, the valve element 165 engages the valve seat 160 and prevents fluid flow through the bore 135. When the valve element 165 is in the open position, the valve element 165 is separated axially apart from the valve seat 160, permitting fluid flow in the bore 135.
Furthermore, the valve seat 160 and the valve closure element 165 may be concentric to one another, and both eccentrically positioned within and with respect to the housing 155. For example, the housing 155 may be centered on the central axis 125. The centerline of the valve seat 160 and the valve closure element 165 may, by contrast, be radially offset (i.e., not collinear) with the central axis 125. This eccentric positioning may provide additional space for passage of the obstructing member(s) 130, as will be described in greater detail below.
As an example, the first bore portion 200 is smaller in radial dimension than the second bore portion 202. Further, the first bore portion 200 is radially offset from the second bore portion 202; thus, while both portions 200, 202 may define generally cylindrical passages, the centers thereof are not radially aligned (e.g., as viewed in a direction parallel to the central axis 125 of
The valve element 165 includes an enlarged, seat-engaging portion 303 and a post 305 extending therefrom. The seat-engaging portion 303 may be conical or, as shown, partially spherical to provide an effective, e.g., sealing, engagement with the valve seat 160. A biasing member 307, such as a helical spring, is received around the post 305 and biases the valve element 165 in an axial direction toward the valve seat 160.
The module 300 may further include an element retainer 304. The element retainer 304 may be integral (formed as a single piece) with the sleeve 302, but in other embodiments, may be separately formed and connected thereto. The element retainer 304 may include one or more (e.g., a pair of) axial supports 306, 308, which may be separated circumferentially, for example, by about 180 degrees. In other embodiments, other angular separations may be employed. The axial supports 306, 308 may extend past the seat-engaging portion 303 of the valve element 165, and thus may position the valve element 165 at least partially therebetween.
The element retainer 304 may also include a central support 310. The central support 310 may extend between the two axial supports 306, 308. The central support 310 may define a hole 312 therein. The hole 312 may be aligned with the center of the sleeve 302, and may include a bushing 314 at least partially therein. The post 305 of the valve element 165 may be received through the hole 312 and the bushing 314, and may be linearly movable therein. For example, the biasing member 307 may be retained axially between the seat-engaging portion 303 and the bushing 314 and/or the central support 310. In an embodiment, the hole 312 may be open on one lateral side, opposite to the view of the central support 310 shown in
The element retainer 304 further includes an arcuate end support 316 that defines two circumferentially-facing ends 318, 320. The area between the circumferential ends 318, 320 may be empty, representing a cutout from what might otherwise be an arcuate shape. The arcuate end support 316 may be cutaway (or otherwise arcuate, rather than annular) in order to facilitate passage of the obstructing member 130. The ends 318, 320 may be separated by an angle that is smaller than the angle separating the axial supports 306, 308, and the axial supports 306, 308 may be connected to or integrally formed with the arcuate end support 316 and/or the central support 310.
A spacer 500 may be provided in the first bore portion 200, as well, e.g., to position and retain the module 300 therein, e.g., prevent the module 300 from sliding in an uphole (left) direction. Further, an arcuate blocking member 502 may be positioned in the second bore portion 202. The arcuate blocking member 502 may extend in a circumferential direction between the axial supports 306, 308, around the valve element 165, so as to avoid impeding the linear, axial movement thereof. The blocking member 502 may serve to prevent the obstructing members 130 from becoming entrained between the valve element 165 and the housing 155, instead directing them away from the blocking member 502, and around the “bottom” (as shown) of the valve element 165.
As shown in
The obstructing members 130 (several are shown to illustrate movement thereof) may thus be received through the valve assembly 150A. For example, the obstructing members 130 may proceed into the housing 155 and into the first bore portion 200. In the first bore portion 200, the obstructing members 130 may proceed through the sleeve 302. Once out of the sleeve 302, the obstructing members 130 may proceed between the seat-engaging portion 303 and the valve seat 160, and then along the shoulder 204 (e.g., in the cutout 206) so as fit past the seat-engaging portion 303 and the rest of the valve element 165 and element retainer 304 in the second bore portion 202. The obstructing members 130 may then proceed down through the remainder of the bore 135, out through the end 118 of the bottom sub 115 (
Accordingly, it will be seen from
In other embodiments, however, the module 300 could be positioned concentrically within the housing 155. In such an embodiment, smaller obstructing members 130 may be used. another embodiment, the valve assembly 145 is disposed in the body of the valve cartridge. Such smaller obstructing members may be used in combination with a baffle (not shown) to actuate a subjacent tool.
The valve assembly 150A may be cycled many times between the opened position and the closed position with a low failure rate as compared to the conventional back pressure valve that uses a flapper valve which pivots around a hinge with a spring. Further, the configuration of the valve assembly 150A providing linear actuation (it will be appreciated that linear actuation may permit for some incidental rotation of the valve element 165 on its axis) may permit pumping at higher rates and using harder-hitting agitators to get farther into lateral wellbores with coil tubing and/or the ability to drill through plugs faster.
The method 700 may include positioning a valve seat in a first bore portion of a valve housing, as at 702. For example, as shown in
The method 700 may further include positioning a valve element in a second bore portion of the housing, the first and second bore portions being radially offset, as at 704. Still referring to
The method 700 may include linearly actuating the valve element from a closed position to an open position in the housing, as at 706. This may be done at least partially based on fluid flow, e.g., with fluid flow in a downhole direction serving to move the valve element linearly to the open position and reverse flow and/or a biasing force serving to move the valve element linearly to the closed position. This is again illustrated, by way of example, in
Before, during, or after actuating at 706, the method 700 may include deploying one or more obstructing members through the housing and past the valve element in the open position, as at 708. For example, as specifically shown in
As used herein, the terms “inner” and “outer”; “up” and “down”; “upper” and “lower”; “upward” and “downward”; “above” and “below”; “inward” and “outward”; “uphole” and “downhole”; and other like terms as used herein refer to relative positions to one another and are not intended to denote a particular direction or spatial orientation. The terms “couple,” “coupled,” “connect,” “connection,” “connected,” “in connection with,” and “connecting” refer to “in direct connection with” or “in connection with via one or more intermediate elements or members.”
The foregoing has outlined features of several embodiments so that those skilled in the art may better understand the present disclosure. Those skilled in the art should appreciate that they may readily use the present disclosure as a basis for designing or modifying other processes and structures for carrying out the same purposes and/or achieving the same advantages of the embodiments introduced herein. Those skilled in the art should also realize that such equivalent constructions do not depart from the spirit and scope of the present disclosure, and that they may make various changes, substitutions, and alterations herein without departing from the spirit and scope of the present disclosure.
This application claims priority to U.S. Provisional Patent Application Ser. No. 62/944,431, which was filed on Dec. 6, 2019, and is incorporated by reference in its entirety herein.
| Number | Date | Country | |
|---|---|---|---|
| 62944431 | Dec 2019 | US |
