Patent Application
20230018892
The present disclosure generally relates to safety valves, and more particularly to safety valves having electrical actuators and fully electric safety valves.
Valves typically are used in a well for such purposes as fluid flow control, formation isolation, and safety functions. A common downhole valve is a hydraulically-operated valve, which is known for its reliable performance. However, hydraulically-operated valves have limitations.
For example, the use of a hydraulically-operated valve is depth-limited due to the high hydrostatic pressure acting against the valve at large depths, which may diminish the effective hydraulic pressure that is available to operate the valve. Furthermore, for deep applications, the viscous control fluid in a long hydraulic line may cause unacceptably long operating times for certain applications. In addition, a long hydraulic line and the associated connections provide little or no mechanism to determine, at the surface of the well, what is the true state of the valve. For example, if the valve is a safety valve, there may be no way to determine the on-off position of the valve, the pressure across the valve and the true operating pressure at the valve's operator at the installed depth.
In some configurations, a downhole valve assembly includes an electric safety valve and an actuator configured to open and/or close the valve. The actuator can be an electro hydraulic actuator, an electro mechanical actuator, or an electro hydraulic pump. In some configurations, the electric safety valve is fully electric and does not include any hydraulic components.
The electric safety valve can include a flapper, a return spring, and an internal tubing sleeve. In use, the actuator can be configured to extend to move the internal tubing sleeve from a closed position to an open position, thereby compressing the return spring and opening the flapper. The electric safety valve can further include downhole electronics configured to receive a signal from the surface and control the actuator.
The electric safety valve can include an electric magnet. The electric magnet can be configured to magnetically couple to a corresponding magnet disposed in or on a flange of the internal tubing sleeve, the flange configured to compress the return spring when the electric safety valve is in the open position. Alternatively, the electric magnet can be disposed in, on, or adjacent a movable shaft of the actuator and configured to magnetically couple to a corresponding magnet disposed in a wall of the internal tubing sleeve.
In some configurations, the electric magnet can be configured to be activated when the electric safety valve is in an open position, thereby allowing the actuator to be retracted while holding the internal tubing sleeve and flapper in the open position. In some configurations, the electric magnet is configured to be activated prior to extending the actuator and opening the electric safety valve, and during closure, the internal tubing sleeve is retracted prior to retraction of the actuator. Closing of the electric safety valve can be controlled by the electric magnet. The electric safety valve can be moved to a closed position by deactivating the electric magnet.
In some configurations, a method of operating an electric downhole safety valve, the electric downhole safety valve comprising a flapper, an internal tubing sleeve, a return spring, an actuator, and downhole electronics, can include providing a command from the surface to the downhole electronics; in response to the command from the surface, extending the actuator, thereby shifting the internal tubing sleeve from a closed position to an open position; compressing the return spring; and opening the flapper.
The actuator can be an electro-mechanical actuator. The electric downhole safety valve can include an electric magnet. The method can further include activating the electric magnet.
The method can include retracting the actuator while the internal tubing sleeve is held in the open position by the electric magnet. The method can include deactivating the electric magnet. Deactivating the electric magnet can allow the return spring to expand, thereby shifting the internal tubing sleeve to the closed position and allowing the flapper to close.
The method can include activating the electric magnet prior to extending the actuator. The method can further include deactivating the electric magnet, allowing the return spring to expand, thereby shifting the internal tubing sleeve to the closed position, and allowing the flapper to close, while the actuator is extended; and retracting the actuator after the flapper is closed.
Certain embodiments, features, aspects, and advantages of the disclosure will hereafter be described with reference to the accompanying drawings, wherein like reference numerals denote like elements. It should be understood that the accompanying figures illustrate the various implementations described herein and are not meant to limit the scope of various technologies described herein.
In the following description, numerous details are set forth to provide an understanding of some embodiments of the present disclosure. It is to be understood that the following disclosure provides many different embodiments, or examples, for implementing different features of various embodiments. Specific examples of components and arrangements are described below to simplify the disclosure. These are, of course, merely examples and are not intended to be limiting. However, it will be understood by those of ordinary skill in the art that the system and/or methodology may be practiced without these details and that numerous variations or modifications from the described embodiments are possible. This description is not to be taken in a limiting sense, but rather made merely for the purpose of describing general principles of the implementations. The scope of the described implementations should be ascertained with reference to the issued claims.
As used herein, the terms “connect”, “connection”, “connected”, “in connection with”, and “connecting” are used to mean “in direct connection with” or “in connection with via one or more elements”; and the term “set” is used to mean “one element” or “more than one element”. Further, the terms “couple”, “coupling”, “coupled”, “coupled together”, and “coupled with” are used to mean “directly coupled together” or “coupled together via one or more elements”. As used herein, the terms “up” and “down”; “upper” and “lower”; “top” and “bottom”; and other like terms indicating relative positions to a given point or element are utilized to more clearly describe some elements. Commonly, these terms relate to a reference point at the surface from which drilling operations are initiated as being the top point and the total depth being the lowest point, wherein the well (e.g., wellbore, borehole) is vertical, horizontal or slanted relative to the surface.
Well completions often include various valves, such as safety valves and flow control valves. Downhole or sub-surface safety valves are often deployed in an upper part of a well completion to provide a barrier against uncontrolled flow below the valve. The valve must be able to operate in a failsafe mode to close and stop well production in case of an emergency. Typically such valves have been hydraulically operated. However, hydraulically operated valves have limitations. For example, the use of a hydraulically-operated valve is depth-limited due to the high hydrostatic pressure acting against the valve at large depths, which may diminish the effective hydraulic pressure that is available to operate the valve. Furthermore, for deep applications, the viscous control fluid in a long hydraulic line may cause unacceptably long operating times for certain applications. In addition, a long hydraulic line and the associated connections provide little or no mechanism to determine, at the surface of the well, what is the true state of the valve. For example, if the valve is a safety valve, there may be no way to determine the on-off position of the valve, the pressure across the valve and the true operating pressure at the valve's operator at the installed depth.
Compared to hydraulic completion systems, electric completion systems can provide reduced capital expenditures, reduced operating expenditures, and reduced health, safety, and environmental problems. Electric completions can advantageously allow for the use of sensors and proactive decision making for well control.
The present disclosure provides electric safety valves, systems (e.g., well completions) including such electric safety valves, and methods of operating electric safety valves. In some configurations, an inductive coupler is used with an electric safety valve or completion including an electric safety valve. The safety valves can have a flapper valve design. The present disclosure also provides an electro-magnet disconnect system. The disconnect system enables a safe and reliable closing mechanism capable of withstanding extreme slam shutting.
Conventional downhole safety valves are typically operated via a hydraulic connection to or from a surface panel.
Hydraulic pressure applied from the surface via the control line 78 to the piston 76 causes the piston 76 to move the sleeve 74 downward, thereby compressing the return spring 72, and open the flapper 62. In the illustrated configuration, the sleeve 74 includes a radially outwardly projecting flange 75 that contacts and compresses the spring 72. Hydraulic pressure in the piston 76 maintains the sleeve's position and holds the valve open. As shown, at least a portion of the flapper 62 is shielded from flow through the production tubing by a portion of the sleeve 74, so the sleeve 74 protects the flapper 62 and tubing sealing area from flow erosion. If the hydraulic pressure in the control line 78 is released, whether intentionally or unintentionally, the spring 72 bias pushes the sleeve 74 upward, allowing the flapper 62 to close. The spring 72 and/or flapper 62 bias to the closed position provides a failsafe for the valve, as the spring 72 ensures valve closure in case of emergency, such as a catastrophic event on the surface leading to a pressure drop or loss in the hydraulic control line 78.
A subsurface safety valve assembly 22 may be attached to the tubing 20. The subsurface safety valve assembly 22 may include a flapper valve 24 or some other type of valve (e.g., a ball valve, sleeve valve, disk valve, and so forth). The flapper valve 24 is actuated opened or closed by an actuator assembly 26. During normal operation, the valve 24 is actuated to an open position to allow fluid flow in the bore of the production tubing 16. The safety valve 24 is designed to close should some failure condition be present in the wellbore 10 to prevent further damage to the well.
The actuator assembly 26 in the safety valve assembly 22 may be electrically activated by signals provided by a controller 12 at the surface to the actuator assembly 26 via an electrical cable 28. The controller 12 is therefore operatively connected to the actuator assembly 26 via the cable 28. Other types of signals and/or mechanisms for remote actuation of the actuator assembly 26 are also possible. Depending on the application, the controller 12 may be in the form of a computer-based control system, e.g. a microprocessor-based control system, a programmable logic control system, or another suitable control system for providing desired control signals to and/or from the actuator assembly 26. The control signals may be in the form of electric power and/or data signals delivered downhole to subsurface safety valve assembly 22 and/or uphole from subsurface safety valve assembly 22.
Additional details regarding safety valves can be found in, for example, U.S. Pat. No. 6,433,991 and WO 2019/089487, the entirety of each of which is hereby incorporated by reference herein. Although the present disclosure describes an actuator used with a subsurface safety valve, it is contemplated that further embodiments may include actuators used with other types of downhole devices. Such other types of downhole devices may include, as examples, flow control valves, packers, sensors, pumps, and so forth. Other embodiments may include actuators used with devices outside the well environment.
The actuator assembly 26 can be or include various types of actuators, such as electrical actuators. For example, in some configurations, the actuator assembly 26 is or includes an electro hydraulic actuator (EHA), an electro mechanical actuator (EMA), or an electro hydraulic pump (EHP). An EHA can allow for quick backdrive or actuation and therefore quick close functionality, which advantageously allows for rapid closure of the valve 24 when desired or required.
In some configurations, the actuator assembly 26 is fully electric and the safety valve assembly 22 is fully electric. In other words, the safety valve assembly 22 includes no hydraulic components. In some such configurations, the actuator assembly 26 is or includes an EMA.
In some configurations, the present disclosure advantageously provides a downhole electro-mechanical actuator in combination with an electrical magnet to control a valve, such as a downhole safety valve 22, for example as shown in
A force up to 40N can be induced by a magnetic field of 1 Tesla per cm2. As core materials commonly used are known to saturate above 1.3 Tesla, a force up to 1000 N can be achieved with a core section in the order of 15 cm2.
Activation of the E-magnet 80 can hold the internal tubing sleeve 74 in its shifted position (e.g., the position holding open and protecting the flapper 62, for example as shown in
In some valves according to the present disclosure, there is a magnetic coupling, for example, instead of a fixed mechanical link, between the actuator 26 and the internal tubing sleeve 74, which advantageously prevents or reduces the likelihood of damage to the actuator 26 during a slam closure. In some configurations, the downhole electronics 30 drive the actuator 26 in valve open mode only. In use, the actuator 26 can be set in extension mode to compress the spring 72, then retracted as soon as the e-magnet 80 is activated, thereby ensuring a failsafe operating mode. In use, the e-magnet 80 can be activated as soon as full open mode is reached. In other configurations, the e-magnet 80 is activated prior to extension of the actuator 26 to compress the spring 72. The e-magnet 80 can be released or powered off for valve shut-in to ensure failsafe operating mode. The e-magnet 80 can be strong enough to keep the spring 72 compressed. In some configurations, several magnets can be combined to achieve the desired or required strength. The e-magnet 80 retaining force (e.g., on the internal tubing sleeve 74 and/or spring 72) can be combined with additional mechanical friction if needed to compress the return spring 72. In some configurations, the e-magnet 80 is disposed in a housing mandrel (a non-moving part), which can facilitate connection to the downhole electronics 30. In other configurations, the e-magnet 80 is disposed on the shaft or piston 96 of the actuator 26 (a moving part). In some configurations, valve shut-in is not under control of the EMA 26, but instead advantageously under control of e-magnet 80 power release only. In other configurations, valve shut-in can be under control of both the EMA 26 and the e-magnet 80.
Language of degree used herein, such as the terms “approximately,” “about,” “generally,” and “substantially” as used herein represent a value, amount, or characteristic close to the stated value, amount, or characteristic that still performs a desired function or achieves a desired result. For example, the terms “approximately,” “about,” “generally,” and “substantially” may refer to an amount that is within less than 10% of, within less than 5% of, within less than 1% of, within less than 0.1% of, and/or within less than 0.01% of the stated amount. As another example, in certain embodiments, the terms “generally parallel” and “substantially parallel” or “generally perpendicular” and “substantially perpendicular” refer to a value, amount, or characteristic that departs from exactly parallel or perpendicular, respectively, by less than or equal to 15 degrees, 10 degrees, 5 degrees, 3 degrees, 1 degree, or 0.1 degree.
Although a few embodiments of the disclosure have been described in detail above, those of ordinary skill in the art will readily appreciate that many modifications are possible without materially departing from the teachings of this disclosure. Accordingly, such modifications are intended to be included within the scope of this disclosure as defined in the claims. It is also contemplated that various combinations or sub-combinations of the specific features and aspects of the embodiments described may be made and still fall within the scope of the disclosure. It should be understood that various features and aspects of the disclosed embodiments can be combined with, or substituted for, one another in order to form varying modes of the embodiments of the disclosure. Thus, it is intended that the scope of the disclosure herein should not be limited by the particular embodiments described above.
Any and all applications for which a foreign or domestic priority claim is identified in the Application Data Sheet as filed with the present application are hereby incorporated by reference under 37 CFR 1.57. The present application claims priority benefit of U.S. Provisional Application No. 62/980,931, filed Feb. 24, 2020, and U.S. Provisional Application No. 63/147,018, filed Feb. 8, 2021, the entirety of each of which is incorporated by reference herein and should be considered part of this specification.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/US2021/019432 | 2/24/2021 | WO |
| Number | Date | Country | |
|---|---|---|---|
| 62980931 | Feb 2020 | US | |
| 63147018 | Feb 2021 | US |
