Patent Application
20170268318
This disclosure relates generally to oil and gas well systems, and more specifically to well plunger systems.
It is well known that production from oil and gas wells can suffer due to the build-up of fluids at the bottom of the well. Various methods and devices have been developed to remove those fluids so as to improve the well's productivity. See e.g., U.S. Pat. No. 6,148,923, which is incorporated herein by reference.
One such device is known as a plunger, of which there are many variants known to those skilled in the art. For example, an auto-cycling plunger operates as follows: (1) it is dropped into the well (at the well's surface); (2) it free-falls down the well until it stops upon impact at the bottom of the well; and (3) it thereafter is caused (by pressure in the well) to travel back toward the surface of the well, pushing a “load” of liquid above it for removal at the well's surface by a lubricator assembly. The plunger then is allowed to repeat that cycle, thereby ultimately removing enough fluid from the well to improve its production.
A number of problems have arisen from the use of prior art plungers. For example, due to the typically great distance between the surface and bottom of a well, and high pressures within the well system, the plunger often travels at a great rate of speed when it is received by the lubricator at the top of the well and/or received by a bumper assembly at the bottom of the well. Impacts between the plunger and the lubricator and/or bumper assembly can be violent. They often are so violent that damage occurs (either immediately or over time due to repeated use) to the lubricator, the bumper assembly, and/or the plunger itself.
Additionally, components of the plunger may be susceptible to damage from repeated use or adverse use conditions. For example, a shuttle ball plunger may include a shuttle ball that is configured to insert into an opening in the plunger, thereby closing the plunger to fluid flow and causing the plunger to rise to the surface of the well. The fluid found in the well typically includes dirt, grime, and other debris, which can cause excess wear to surfaces interfacing between the shuttle ball and the plunger body.
Still further, some shuttle ball plungers include an o-ring retention mechanism for retaining the shuttle ball within the opening of the plunger until the plunger rises to the wellhead and the shuttle ball is ejected (against the force exerted by the o-ring) from the plunger by the lubricator system. Other shuttle ball plungers include a metal c-clip having square or rectangular edges for receiving and then holding the shuttle ball in place until the plunger reaches the lubricator. It has been discovered, however, that after repeated high energy use, these retention mechanisms either failed due to wear and/or (in the case of the metal c-clip having square edges) damaged the interior side walls of the plunger, thereby limiting the useful life of the plunger assembly in both cases.
Embodiments of well plunger systems, assemblies, and apparatuses are described. In an embodiment, the apparatus includes a body having a first open end, a second open end, and a channel extending from the first open end through the body to the second open end, the channel for passing fluid and debris from an oil or gas well. The apparatus may also include a receiver disposed at the first open end, the receiver configured to receive a stopper configured to at least partially (i.e., partially or fully) seal off the first open end, the receiver comprising a retention member receiver configured to receive one or more specially adapted retention members for applying a retention force to the stopper when the stopper is engaged with the receiver.
An embodiment of a plunger assembly also may include a body having a first open end, a second open end, and a channel extending from the first open end through the body to the second open end, the channel for passing fluid and debris from an oil or gas well, a receiver disposed at the first open end, the receiver configured to receive a stopper configured to at least partially seal off the first open end, the receiver comprising a retention member receiver configured to receive a plurality of specially adapted retention members, a first retention member disposed within the retention member receiver for applying a retention force to the stopper when the stopper is engaged with the receiver, and a second retention member disposed adjacent the first retention member within the retention member receiver.
Embodiments of a system may include a well assembly comprising a well bottom, a wellhead, and a well pipe coupling the wellhead to the well bottom. The system may also include a plunger lift assembly configured to lift fluid from the well bottom to the wellhead. In an embodiment, the plunger lift assembly may include a plunger assembly having a body with a first open end, a second open end, and a channel extending from the first open end through the body to the second open end, the channel for passing fluid and debris from an oil or gas well, a receiver disposed at the first open end, the receiver configured to receive a stopper configured to at least partially seal off the first open end, the receiver comprising a retention member receiver configured to receive a one or more specially adapted retention members, a first retention member disposed within the retention member receiver for applying a retention force to the stopper when the stopper is engaged with the receiver, and an optional second retention member disposed adjacent the first retention member within the retention member receiver. The system may also include a bumper assembly disposed proximate to the well bottom and configure to catch the plunger lift assembly before reaching the well bottom, and a lubricator disposed proximate to the wellhead, the lubricator configured to eject the stopper from the plunger in response to the plunger reaching the lubricator.
The following drawings form part of the present specification and are included to further demonstrate certain aspects of the present invention. The invention may be better understood by reference to one or more of these drawings in combination with the detailed description of specific embodiments presented herein.
Various features and advantageous details are explained more fully with reference to the nonlimiting embodiments that are illustrated in the accompanying drawings and detailed in the following description. Descriptions of well-known starting materials, processing techniques, components, and equipment are omitted so as not to unnecessarily obscure the invention in detail. It should be understood, however, that the detailed description and the specific examples, while indicating embodiments of the invention, are given by way of illustration only, and not by way of limitation. Various substitutions, modifications, additions, and/or rearrangements within the spirit and/or scope of the underlying inventive concept will become apparent to those skilled in the art from this disclosure.
The present embodiments include a well system for oil and/or gas production. In an embodiment, the well system includes a well assembly comprising a well bottom, a wellhead, and a well pipe coupling the wellhead to the well bottom. The system may also include a plunger lift assembly configured to lift fluid from the well bottom to the wellhead. In an embodiment, the system includes a bumper assembly disposed proximate to the well bottom and configured to catch the plunger lift assembly at or before reaching the well bottom. The system may also include a lubricator disposed proximate to the wellhead.
The system 100 may include a bumper assembly 114 proximate to the well bottom 106. In an embodiment, the plunger 116 may be configured to lift fluid 120 from the well bottom 106 to the wellhead 104. The fluid 120 is received by the lubricator 102 and expelled through one or more ports to peripheral components (not shown). In an embodiment, the plunger 116 may engage with a stopper, such as the stopper ball 118. In some embodiments, the stopper ball 118 may be a steel sphere configured to be received by a portion of the plunger 116. The stopper may restrict flow of fluid and/or gas through or around the plunger 116, thereby causing the plunger to rise to the lubricator 102. The lubricator 102 may cause the stopper 118 to be released, thereby allowing passage of fluids through or around the plunger 116, and causing the plunger 116 to fall back to the bumper 114. The bumper 114 may dampen the impact forces when the plunger 116 approaches the bottom of the well 106. The stopper 118 may be received by the plunger 116 again, and the process may repeat, thereby cyclically lifting fluid 120 to be expelled by the lubricator 102.
In an embodiment, the system may include a plunger 218. The plunger 218 may be a ball and sleeve plunger in some embodiments. The plunger 218 may include an assembly of parts, including a retention assembly for retaining the stopper 118, which may be a ball in some embodiments, within a portion of the body of the plunger assembly 218 during use. The stopper 118 may be ejected from the plunger 218 by components of the lubricator 102 in some embodiments. When both the stopper 118 and the plunger 218 collide at the well bottom 106, the stopper 118 may be retained within the portion of the plunger 218 again, until the plunger 218 reaches the lubricator 102 where the stopper 118 is once again ejected from the plunger 218. This process may repeat continuously, or nearly continuously, in some embodiments.
In an embodiment, the bumper 222 may include a progressive rate spring 224. One example of a bumper 222 which may be suitable for use with the present embodiments is described in U.S. patent application Ser. No. 14/333,058 entitled “Bumper Assembly Having Progressive Rate Spring,” filed on Jul. 16, 2014, which is incorporated herein by reference in its entirety. Although the progressive rate bumper 224 is one embodiment of a bumper 114 that may be included with the present embodiments, one of ordinary skill will recognize alternative embodiments of bumpers 114 which may be equally suitable depending on the applicable well conditions.
In the embodiment of
In an embodiment, the main body 302 may include one or more turbulence inducing features 304 configured to interact with fluid passing over the surface of the main body 302. The turbulence inducing features 304 may be spaced apart according to a pattern calculated to affect the rate of fluid flow over the surface of the main body 302 when the plunger is in operation within the well pipe 108. In such an embodiment, the turbulence inducing features 304 also may affect the rate of decent of the plunger from the wellhead 104 to the well bottom 106.
Additionally, the plunger 218 may include one or more rifling features 306 configured to cause the plunger 218 to rotate within the well pipe 108 during decent and/or ascent. Such an embodiment is intended to cause more uniform wear on the outer diameter of the plunger 218, particularly when the plunger 218 is deployed in a deviated well system.
In one embodiment, the plunger 218 may include one or more features for clearing debris during use. For example, in an embodiment, the main body 302 may include a taper region 310 configured to taper from the outer diameter of the main body to a recess region 312. In an embodiment, a port 308 may be disposed at or near the recess region 312. In such an embodiment, fluid may flow through the port 308 and clear debris from the inner surface of the main body 302, thereby reducing clogging of debris within the main body 302.
In an embodiment, the first end 402 may include a receiver 408 for receiving the stopper ball 118. In such an embodiment, the receiver 408 may include a curved surface configured to receive at least a portion of the same or similarly curved surface of the stopper ball 118. Additionally, a retention mechanism may be disposed at or near the first end 402 for retaining the stopper ball 118 within the receiver 408 as shown in further detail in
During operation, fluid in the well may pass through the channel 410 while the plunger 218 is descending to the well bottom 106. Upon reaching the well bottom 106, the plunger 218 collides with the stopper ball 118, which blocks the flow path through the channel 410. When the channel 410 is blocked, fluid and debris above the plunger is pushed by the closed plunger to the wellhead 104 and out of the well through the lubricator 102. The lubricator ejects the stopper ball 118 from the plunger 218, and the process cycles. One of ordinary skill will recognize that various sizes and shapes of plungers and stoppers may be suitable for use with the present embodiments. For example, the stopper may be bullet shaped, egg shaped, or the like. Alternatively, complex stopper geometries may be used for various fluid dynamics benefits, and for various retention or interface characteristics with the plunger 218. Accordingly, the shape or dimensions of the plunger 218 may be varied based on use conditions and/or in response to the geometry of the stopper.
In an embodiment, fluid and debris may pass from the channel 410 through the port(s) 308. In such an embodiment, the channel 410 may remain relatively clear of debris during ascent, thereby avoiding clogging or blockage of the channel 410. In such an embodiment, the channel 410 may be better capable of receiving the ejector rod of the lubricator 102.
The first c-ring also includes an inside edge 1010 configured to apply a retention force to the stopper ball 118 when engaged with the stopper ball. Additionally, the first c-ring includes an outside edge 1006 configured to be captured within the retention member receiver 904. As described above in connection with
Although the invention(s) is/are described herein with reference to specific embodiments, various modifications and changes can be made without departing from the scope of the present invention(s), as set forth in the claims below. Accordingly, the specification and figures are to be regarded in an illustrative rather than a restrictive sense, and all such modifications are intended to be included within the scope of the present invention(s). Any benefits, advantages, or solutions to problems that are described herein with regard to specific embodiments are not intended to be construed as a critical, required, or essential feature or element of any or all the claims.
Unless stated otherwise, terms such as “first” and “second” are used to arbitrarily distinguish between the elements such terms describe. Thus, these terms are not necessarily intended to indicate temporal or other prioritization of such elements. The terms “coupled” or “operably coupled” are defined as connected, although not necessarily directly, and not necessarily mechanically. The terms “a” and “an” are defined as one or more unless stated otherwise. The terms “comprise” (and any form of comprise, such as “comprises” and “comprising”), “have” (and any form of have, such as “has” and “having”), “include” (and any form of include, such as “includes” and “including”) and “contain” (and any form of contain, such as “contains” and “containing”) are open-ended linking verbs. As a result, a system, device, or apparatus that “comprises,” “has,” “includes” or “contains” one or more elements possesses those one or more elements but is not limited to possessing only those one or more elements. Similarly, a method or process that “comprises,” “has,” “includes” or “contains” one or more operations possesses those one or more operations but is not limited to possessing only those one or more operations.
