Choke Mechanism for a Lubricator

This application is a continuation of U.S. patent application Ser. No. 18/775,704, filed Jul. 17, 2024, which is itself a continuation of U.S. patent application Ser. No. 18/128,784, filed Mar. 30, 2023, the content of both of which are incorporated herein by reference.

The present disclosure relates to a plunger catcher mechanism that receive, holds and releases a plunger used in oil and gas wells. More specifically, the present disclosure relates to a choke mechanism that can be used to ensure that when a plunger arrives at a wellhead, the plunger is fully seated in the catcher mechanism.

The present disclosure is concerned with plunger catcher mechanism that is configured to hold and release a plunger used in oil and gas wells. As is well known to those of skill in the art, a manifold can be mounted on top of an oil or gas well, and a plunger catcher mechanism is then mounted on top of the manifold. Oil or gas produced by the well is routed through the manifold to a production line that typically leads to a collection tank.

When the downhole pressure of an oil or gas well is no longer high enough to force oil to gas to the surface at a satisfactory flow rate, one can employ a plunger to help bring oil or gas to the surface. A plunger is a device that is configured to freely descend and ascend within a well bore. The plunger operates to restore production to a well having insufficient pressure to lift the fluids to the surface. Some embodiments are configured as a “bypass” plunger, which may include a self-contained valve also called a “dart” or a “dart valve”-to control the descent and ascent. Typically the valve is opened to permit fluids in the well to flow through the valve and passages in the plunger body as the plunger descends through the well. Upon reaching the bottom of the well, the valve is closed, converting the plunger into a piston by blocking the passages that allow fluids to flow through the plunger. With the plunger converted to a piston, blocking the upward flow of fluids or gas, pressure in the fluid below the bypass plunger gradually increases until the pressure is sufficient to lift the plunger and the column of fluid in the well bore located above the bypass plunger to the surface. As fluid above the bypass plunger arrives at the surface, the fluid is routed by the manifold to a production line. While the above description applies to bypass plungers, other types of plungers can also be used to help restore production to an oil or gas well.

When a plunger arrives at the surface, it passes through the manifold and into a plunger catcher mounted on top of the manifold.illustrate an example of a manifold and plunger catcher mechanism.

As illustrated in, a manifoldis attached to the top of a well bore such that a plunger passagewayrunning from the bottom of the manifoldto the top of the manifoldis aligned with the well bore. While a plunger is ascending the well bore, pushing a column of fluid upward, the fluid is routed through the manifoldto a production passagewaythat leads to a production outlet apertureon a sidewall of the manifold. A production outlet lineis coupled to the sidewall of the manifoldby a production fixture. The fluid leaving the well bore is routed through the production outlet lineto a collection tank (not shown).

As illustrated in, an instrumentation passagewayin the manifoldleads to an instrumentation outlet apertureon another sidewall of the manifold. As illustrated in, an instrumentation outlet lineis coupled to the sidewall of the manifoldby an instrumentation fixture. Fluid leaving the well bore can be routed to various sensors or instruments via the instrumentation outlet line.

As illustrated in, fluid leaving the well bore can also be routed through the plunger passagewayto a hollow receiving boreof the plunger catcher. The plunger catcheris mounted on top of the manifoldby a catcher flangeand bolts. Fluid entering the hollow receiving borecan then travel into an internal passagewayof a return line fixturethat is mounted onto a side of the plunger catcher. The fluid then travels down the interior passagewayof a return lineand into a return passagewaythat is provided inside the manifold. The fluid then joins with fluid in the production passageway, which is routed into the production outlet line.

Fluid exiting the well bore is deliberately provided with this return circuit so that as a plunger leaves the well bore, passes through the manifoldand then travels up into the hollow receiving boreof the plunger catcher, the fluid located above the plunger will be able to travel through the return circuit and into the production outlet line. If the return circuit were not provided, there would be nowhere for the fluid above the plunger to go, which would mean the plunger would be prevented from entering the hollow receiving boreof the plunger catcher. In addition, by ensuring that there is a steady flow of fluid through this return circuit, the momentum of the fluid combined with the upward momentum of the plunger itself ensures that the plunger travels all the way up into the plunger catcher.

A holder mechanismof the plunger catcheris used to hold and release a plunger that travels up into the plunger catcher. A handleof the holder mechanismcould be used to manually operate or adjust the plunger holder.

illustrates a plungerafter it has been fully seated in the plunger catcher. The plungerillustrated inis a bypass plunger. However, the technology disclosed herein could be used in conjunction with any sort of plunger.

As illustrated in, an arrival bumper springis mounted in the lubricator spring housingof the plunger catcher. A shoulderof a reset rodbears against the lower part of the arrival bumper spring. The reset rodextends downward into the hollow receiving boreof the plunger catcher. As the plungermoves upward into the hollow receiving boreof the plunger catcher, the lower end of the reset rodenters the hollow interior of the plunger. Further upward movement of the plungerresults in the reset rod extending deeper into the interior of the plungeruntil the lower end of the reset rodhits the top of a valve dart, pushing the valve dartdownward to a reset position. Once the valve darthas been pushed into the reset position, fluid can travel through the interior of the plunger, which allows the plungerto descend back to the bottom of the well bore.

As the upper endof the plungerarrives at the top of its travel, the upper endof the plungerhits the shoulderof the reset rod. The shoulderof the reset rodbears against the lower end of the arrival bumper spring. The arrival bumper springoperates to help arrest upward movement of the plungerin a controlled matter, limiting any potential damage to the plungeror the plunger catcherdue to the impact of the plungerwhen it arrives and stops inside the plunger catcher.

In a well that has little pressure, which is the type of well where plungers are employed, the upward flow of the fluid may not be sufficient to cause the plungerto move upward enough to fully seat in the plunger catcher. This can result in a stuck condition, where the plungerblocks the flow of fluid out of the production passagewayof the manifold. Also, because the plungerdoes not travel sufficiently far enough upward into the plunger catcher, the reset rodcannot operate to push the valve dartinto the reset position. As a result, the passageways through the interior of the plungerare not opened and the plungercannot travel back down to the bottom of the well bore.

The present application discloses a choke mechanism that is mounted on the manifoldand which operates to increase the flow rate of fluid through the return circuit that travels through the hollow receiving boreand return lineof the plunger catcher. The increased the flow rate of fluid through this return circuit helps to preserve the upward momentum of the plungerwhen it arrives at the top of the well bore, thereby helping the plungerto move fully upward into the plunger catcher.

In a first embodiment as illustrated in, the choke mechanism includes a choke memberthat is slidably mounted in a choke passagewayof the manifold. As illustrated in, the choke passagewaycommunicates with the production passagewayof the manifold. A choke mount collaris mounted to the exterior of the manifold, and internal threads on the choke mount collarengage external threads on a middle portion of the choke member. A handleis attached to a proximal endof the choke member. By turning the handleclockwise and counterclockwise, one can cause the choke memberto rotate, and the internal threads on the choke mount collarand external threads on the choke memberconvert rotational motion of the chock member into axial movement of the choke memberalong the choke passagewayof the manifold. This allows one to cause the distal endof the choke memberto protrude into the production passagewayof the manifold.

When the distal endof the choke memberprotrudes into the production passageway, partially blocking the production passageway, more of the fluid exiting the well bore is routed through the return circuit that passes through the plunger catcher. As perhaps best seen in, fluid leaving the return circuit and arriving back at the manifoldwill enter the production passagewayon the downstream side of the distal endof the choke member. Thus, by selectively advancing and withdrawing the distal endof the choke memberinto and out of the production passageway, one can selectively vary the flow rate of fluid leaving the well bore that is routed through the return circuit passing through the plunger catcher.

If the flow rate of fluid leaving the well bore is not sufficient to cause a plunger to fully seat in the plunger catcher, one can advance the distal endof the choke memberinto the production passageway, thereby partially blocking the production passageway. This serves to increase the flow rate of fluid through the return circuit, which helps to ensure that the plunger will travel fully up into the plunger catcher. If pressure in the well increases such that the normal flow rate of fluid leaving the well bore is sufficient to cause the plunger to fully seat in the plunger catcher, the choke membercan be fully withdrawn from the production passageway, which helps to maximize flow out of the well into a collection tank.

The manifoldand/or the plunger catchermay include one or more sensors that are used to determine the location and movements of a plunger. For example, an arrival sensormay be mounted on the manifold. The arrival sensorwould output an arrival signal when a plunger emerges from the well bore and passes into the plunger passagewayof the manifold. Likewise, an arrival sensormay be provided on the plunger catcher. The arrival sensoron the plunger catcheroutputs an arrival signal when a plunger is located partway in the hollow receiving bore. Further, a seated sensorcould be located near the upper end of the hollow receiving boreof the plunger catcher. The seated sensoroutputs a seated signal when a plunger is fully seated in the plunger catcher.

A controller coupled to the arrival sensors,and the seated sensorcould determine whether a plunger is not fully seating in the plunger catcherupon arriving at the surface. For example, if the controller notes that the seated sensordid not output a seated signal shortly after one or both of the arrival sensors,output an arrival signal, this would likely mean that the flow rate of fluid out of the well head and through the return circuit passing through the plunger catcherwas not sufficient to carry the plunger up into a fully seated position within the plunger catcher. This would be an indicate that the choke mechanism should be reset to advance the distal endof the choke memberfurther into the production passagewayof the manifoldto increase the flow rate of fluid through the return circuit passing through the plunger catcher.

illustrate an alternate embodiment in which the manually operated choke mechanism illustrated inis replaced with a choke mechanism that is operated by a pneumatic or hydraulic actuator. As illustrated in, the choke mechanism still includes a choke memberslidably mounted in the choke passagewayof the manifold. A choke mount collaris mounted to the exterior sidewall of the manifold. A proximal endof the choke memberextends from the choke mount collar. The proximal endof the choke memberis coupled to an actuator memberof the pneumatic/hydraulic actuator mechanism. The pneumatic/hydraulic actuator mechanismcan operate to cause the distal endof the choke memberto extend into and retract from the production passagewayof the manifoldin essentially the same way as the first embodiment discussed above. Thus, pneumatic/hydraulic actuatorcan be used to selectively vary the flow rate of fluid through the return circuit passing through the plunger catcher.

illustrate another embodiment that includes an electrically operated choke mechanism. In this embodiment, a choke mount collaris mounted to a sidewall of the manifold, and a choke memberis slidably mounted in the choke mount collarand the choke passagewayof the manifold. The distal endof the choke membercan be advanced into and retracted from the production passagewayof the manifoldby the electrically operated actuator.

A proximal endof the choke memberis covered by a cam follower. A return springurges the choke memberinto a retracted position, and also serves to keep the cam followerpressed against a rotatably mounted cam. The camis located in a cam housingand the camis mounted onto a rotating shaftof an electric motor of the electrically operated actuator. When the motor rotates the cam, the surface of the campushes the cam followerand the choke memberfurther into the manifoldso that the distal endof the choke memberprotrudes into the production passagewayof the manifold. Thus, selectively operating the motor of the electrically operated actuatorallows one to control the extent to which the distal endof the choke memberblocks the production passageway, and thus the flow rate of fluid through the return circuit passing through the plunger catcher.

In some embodiments, a controller coupled to an arrival sensor/and a seated sensorcould be used to automatically adjust the position of the choke member. If the controller does not receive a seated signal from the seated sensorimmediately after receiving an arrival signal from an arrival sensor,, this would indicate that the flow rate of fluid through the return circuit passing through the plunger catcherwas not sufficient to cause the plunger to fully seat in the plunger catcher. Under those conditions, the controller could send a signal to an actuator of a choke mechanism to cause a distal end of a choke member to protrude further into the production passagewayof the manifold. This would serve to increase the flow rate of fluid through the return passageway, thereby aiding the plunger in fully seating in the plunger catcher.

Conditional language, such as, “can,” “could,” “might,” or “may,” unless specifically stated otherwise, or otherwise understood within the context as used, is generally intended to convey that certain implementations could, but do not necessarily, include certain features and/or elements while other implementations may not. Thus, such conditional language generally is not intended to imply that features and/or elements are in any way required for one or more implementations or that one or more implementations necessarily include these features and/or elements. It is also intended that, unless expressly stated, the features and/or elements presented in certain implementations may be used in combination with other features and/or elements disclosed herein.

The specification and annexed drawings disclose example embodiments of the present disclosure. Detail features shown in the drawings may be enlarged herein to more clearly depict the feature. Thus, several of the drawings are not precisely to scale. Additionally, the examples illustrate various features of the disclosure, but those of ordinary skill in the art will recognize that many further combinations and permutations of the disclosed features are possible. Accordingly, various modifications may be made to the disclosure without departing from the scope or spirit thereof. Further, other embodiments may be apparent from the specification and annexed drawings, and practice of disclosed embodiments as presented herein. Examples disclosed in the specification and the annexed drawings should be considered, in all respects, as illustrative and not limiting. Although specific terms are employed herein, they are used in a generic and descriptive sense only, and not intended to the limit the present disclosure.