Patent Publication Number: US-2023151714-A1

Title: Safety valve

Description:
CROSS-REFERENCE PARAGRAPH 
     This application claims the benefit of U.S. Provisional Application No. 62/980,839 entitled “Safety Valve,” filed Feb. 24, 2020, the disclosure of which is incorporated herein by reference in its entirety. 
    
    
     BACKGROUND 
     Field 
     The present disclosure generally relates to safety valves, and more particularly to use of inductive couplers with electrical safety valves. 
     Description of the Related Art 
     Hydrocarbon fluids such as oil and natural gas are obtained from a subterranean geologic formation, referred to as a reservoir, by drilling a wellbore that penetrates the hydrocarbon-bearing formation. Once the wellbore is drilled, various forms of well completion components may be installed to control and enhance the efficiency of producing the various fluids from the reservoir. Valves typically are used in a well for such purposes as fluid flow control, formation isolation, and safety functions. In some wells, for example, valves are actuated between open and closed states to compensate or balance fluid flow across multiple zones in the wellbore. In other wells, an isolation valve may be actuated to a closed position to shut in or suspend a well for a period of time and then opened when desired. Often a well includes a subsurface valve to prevent or limit the flow of fluids in an undesired direction. 
     SUMMARY 
     In some configurations, a well completion includes: a tubing hanger; tubing extending from the tubing hanger; an electric safety valve disposed along the tubing; and a female inductive coupler disposed along the tubing between the tubing hanger and the electric safety valve. 
     The electric safety valve can include a valve and an actuator. The actuator can be an electro-hydraulic pump, an electro-hydraulic actuator, or an electro-mechanical actuator. The electric safety valve can include a flapper valve. 
     The well completion can further include a service male inductive coupler configured to be disposed within the tubing during deployment of the well completion such that the service male inductive coupler is aligned with the female inductive coupler, the service male inductive coupler configured to facilitate transfer of power and/or telemetry data to and/or from the electric safety valve. The well completion can further include one or more wires extending between and connecting the electric safety valve and the tubing hanger, wherein in normal operation, the female inductive coupler is configured to be transparent and allow for a wired connected between the electric safety valve and the tubing hanger. The one or more wires can include a first wire extending between and connecting the tubing hanger and the female inductive coupler and a second wire extending between and connecting the female inductive coupler and the electric safety valve. 
     The well completion can further include a workstring configured to be disposed within the tubing during an intervention operation of the well completion, the workstring comprising an intervention male inductive coupler and a contingency electric safety valve connected by a wire, the workstring disposed within the tubing such that the intervention male inductive coupler is aligned with the female inductive coupler. In some configurations, there is no electrical wiring extending from the intervention male inductive coupler to the surface and power and/or telemetry is provided to the contingency electric safety valve via the female inductive coupler. An outer diameter of the contingency electric safety valve can be smaller than an inner diameter of the electric safety valve. 
     A method of intervention for such a well completion in the case of failure of the electric safety valve can include deploying a workstring in the tubing, the workstring comprising a contingency electric safety valve and an intervention male inductive coupler, until the intervention male inductive coupler is aligned with the female inductive coupler; and providing power and/or telemetry to and/or from the contingency electric safety valve via the intervention male inductive coupler and the female inductive coupler. 
     In some configurations, a method of deploying a well completion includes disposing a tubing string in a well, the tubing string comprising an electric safety valve and a female inductive coupler disposed above the electric safety valve; inserting a service male inductive coupler within the tubing string such that the service inductive male coupler is aligned with the female inductive coupler; and retrieving the service male inductive coupler. 
     The method can further include transferring power and/or telemetry to and/or from the electric safety valve via the female inductive coupler and the service male inductive coupler. After retrieving the service male inductive coupler, the method can include transferring power and/or telemetry to and/or from the electric safety valve via a wired connection between the surface and the electric safety valve during normal operation. Transferring power and/or telemetry to and/or from the electric safety valve via the wired connection can include transferring power and/or telemetry via a first wire extending from a tubing hanger to the female inductive coupler and a second wire extending from the female inductive coupler to the electric safety valve. 
     In some configurations, a method of intervention for a well completion includes deploying a workstring within tubing of the well completion, the well completion comprising an electric safety valve and a female inductive coupler positioned along the tubing, and the workstring comprising an intervention male inductive coupler, a contingency electric safety valve, and a wire extending between and connecting the intervention male inductive coupler and the contingency electric safety valve; and positioning the workstring within the tubing such that the intervention male inductive coupler is aligned with the female inductive coupler. 
     The method can further include positioning the workstring within the tubing such that the contingency electric safety valve is positioned at least partially below the electric safety valve such that production fluid flows through the contingency electric safety valve, bypassing the electric safety valve. The method can include providing power and/or telemetry to and/or from the contingency electric safety valve via the intervention male inductive coupler and the female inductive coupler. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
       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. 
         FIG.  1 A  illustrates an example conventional downhole safety valve in an open position. 
         FIG.  1 B  illustrates the conventional downhole safety valve of  FIG.  1 A  in a closed position. 
         FIG.  2    illustrates an embodiment of a completion string having a sub-surface safety valve in a wellbore. 
         FIG.  3    is a cross-sectional illustration of an example of a flapper valve which may be utilized in a downhole system. 
         FIG.  4    schematically shows an example completion string deployed or installed in a well. 
         FIG.  5    schematically shows an example intervention assembly inserted into a completion installed in a well. 
     
    
    
     DETAILED DESCRIPTION 
     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&#39;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 deploying, operating, and providing intervention for electric safety valves. In some configurations, an inductive coupler is used with an electric safety valve or completion including an electric safety valve. 
     Conventional downhole safety valves are typically operated via a hydraulic connection to or from a surface panel.  FIGS.  1 A and  1 B  illustrate an example hydraulic safety valve having a flapper valve design in open and closed positions, respectively. As shown, the safety valve assembly includes a flapper  62 , a return spring  72 , a flow tube or sleeve  74 , a piston  76 , and a control line  78 . The position (open or closed) of the flapper  62  is controlled via the flow tube or sleeve  74  sliding up and down inside the production tubing. The sleeve position is controlled or moved by the return spring  72  and/or the piston  76 . The flapper  62  and return spring  72  are biased to the closed position. 
     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 . Hydraulic pressure in the piston  76  maintains the sleeve&#39;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 . 
       FIG.  2    illustrates an example completion string including a safety valve according to the present disclosure positioned in a wellbore  10 . The wellbore  10  may be part of a vertical well, deviated well, horizontal well, or a multilateral well. The wellbore  10  may be lined with casing  14  (or other suitable liner) and may include a production tubing  16  (or other type of pipe or tubing) that runs from the surface to a hydrocarbon-bearing formation downhole. A production packer  18  may be employed to isolate an annulus region  20  between the production tubing  16  and the casing  14 . 
     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 . 
       FIG.  3    illustrates an example flapper valve  24 . In this embodiment, the flapper  62  is pivotably mounted along a flapper housing  64  having an internal passage  66  therethrough and having a hard sealing surface  68 . The flapper  62  is pivotably coupled to the flapper housing  64 , for example, via a hinge pin  70 , for movement between an open position and a closed position. By pivotably coupled, it should be understood the flapper  62  may be directly coupled to housing  64  or indirectly coupled to the housing  64  via an intermediate member. 
     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. 
       FIG.  4    schematically shows an example completion string deployed or installed within a casing  14  in a well. The completion string includes one or more sections of tubing  16  disposed within the casing  14 . As shown, a female inductive coupler  110  is mounted between (e.g., axially between) a tubing hanger  15  and an electric safety valve  22 . The female inductive coupler  110  can be mounted along the tubing  16  as shown, for example, in, on, or along a section of tubing  16  or between sections of tubing  16 . The female inductive coupler  110  is therefore mounted above the electric safety valve  22 . The female inductive coupler  110  can be a permanent component in the completion string. 
     The electric safety valve  22  can have various configurations, features, and structures. For example, systems and methods according to the present disclosure can include an electric safety valve and/or features as described in, for example, PCT Publication WO 2019/089487, U.S. Pat. No. 6,433,991, or U.S. Pat. No. 8,555,956, the entirety of each of which is hereby incorporated by reference herein, the present application, and/or any other appropriate safety valve or features. 
     During deployment or installation of the completion string, a service male inductive coupler  120  allows or provides for the transfer of power and/or telemetry to and/or from the electric safety valve  22 , e.g., to or from the surface. The service male inductive coupler  120  can transfer power and/or telemetry to the electric safety valve  22  without interfering with the electrical connector of the tubing hanger  15 . In some configurations, the service male inductive coupler  120  receives and/or transmits power and/or telemetry data to or from the surface via a wire  30 . In some configurations, the service male inductive coupler  120  transmits and/or receives power and/or telemetry data to or from the safety valve  22  via the female inductive coupler  110  and a wire  130   b . The male inductive coupler  120  can transmit and/or receive power and/or telemetry data to or from the female inductive coupler  110 , and the female inductive coupler  110  can transmit and/or receive power and/or telemetry data to or from the electric safety valve  22  via wire  130   b.    
     The service male inductive coupler  120  can be coupled to an inner work string  122  as shown in  FIG.  4    (for example, an end of the inner work string). The inner work string  122  and/or service male inductive coupler  120  are deployed or inserted within the tubing  16  until the service male inductive coupler  120  is aligned with, e.g., radially aligned with and/or at generally or about the same axial depth as, the female inductive coupler  110 . The service male coupler  120  and/or inner work string  122  can be wired to the deployment string, e.g., tubing  16 , via the tubing hanger  15  and a tubing hanger running tool  124 . 
     Once an integrity check during deployment or installation is completed, the service male coupler  120  can be retrieved and removed with the tubing hanger running tool  124 . For normal operation, the female coupler  110  can be transparent and act as a wired connection to the tubing hanger  15 . When there is no corresponding male coupler in normal operation, power and/or telemetry can be transmitted or passed from the tubing hanger  15  to the safety valve  22  via a direct wired connection, e.g., via wires  130   a  and  130   b  as shown in  FIG.  4   . 
     In some circumstances, intervention of the completion string might be needed, for example, due to failure of the safety valve  22 . Traditionally, intervention of a hydraulic safety valve requires several trips to lock open the failed safety valve, puncture the hydraulic line to later power a contingency safety valve, and to deliver the contingency safety valve. 
     With an electric safety valve  22 , for example according to the present disclosure, a contingency electric safety valve  222  can be deployed inside the primary failed safety valve  22  without extra trips or steps to lock open the failed safety valve and/or to sever or disconnect the electrical line. As shown in  FIG.  5   , a workstring including a production or intervention male inductive coupler  220  and a contingency electric safety valve  222  (which may be a smaller electric safety valve and have a smaller outer diameter than an inner diameter of the electric safety valve  22 ) wired together (e.g., via wire(s)  132 ) can be deployed or inserted in the completion, e.g., tubing  16 . 
     The workstring is positioned in the completion, e.g., tubing  16 , such that the intervention male inductive coupler  220  is aligned with, e.g., radially aligned with and/or at generally or about the same axial depth as, the female inductive coupler  110 . Such an intervention would not require electrical wiring from the male coupler  220  to the surface. Instead, power and telemetry is provided via the female coupler  110  once the production/intervention male coupler  220  is aligned with (e.g., radially aligned with or placed at the same or about the same axial depth as) the female coupler  110 . In some configurations, the female inductive coupler  110  can transmit and/or receive power and/or telemetry data to or from the surface via wire  130   a . The intervention male inductive coupler  220  can transmit and/or receive power and/or telemetry data to or from the female inductive coupler  110 . The contingency electric safety valve  222  can transmit and/or receive power and/or telemetry data to or from the intervention male inductive coupler  220  via wire  132 . 
     As shown, the workstring can include a workstring tubing  216 . The workstring tubing  216  can extend between the intervention male inductive coupler  220  and the contingency electric safety valve  222 . In other words, the intervention male inductive coupler  220  and the contingency electric safety valve  222  can be disposed along and/or coupled to the workstring tubing  216 , for example, at opposite ends of the workstring tubing  216 . The wire(s)  132  can be disposed outside of an extend along an exterior of the workstring tubing  216 . The production/intervention male coupler  220  and contingency safety valve  222  can be deployed on, for example, a drillpipe that can be disconnected, and then left behind. 
     As shown in  FIG.  5   , the contingency electric safety valve  222  can be positioned at least partially below, lower than, or downhole of the electric safety valve  22 . This arrangement directs production fluid flow through the contingency electric safety valve  222  (and possibly through workstring tubing  216 ), bypassing the failed electric safety valve  22 . 
     In some variations, the female inductive coupler  110  is made of or includes a simple monocable (instead of a twisted pair) that allows for transmission of power but not telemetry. Such a configuration would allow for a simple on/off electric safety valve  22 ,  222 . In some configurations in which a completion includes a primary and redundant actuator on the electric safety valve tool, the primary actuator can be connected directly to the tubing hanger  15 , and the redundant actuator can be connected to the female inductive coupler  110 . Such a configuration allows for flexibility of deployment and intervention. Alternatively, a completion could include two female couplers  110 , such that the primary and redundant actuators are the same. Only one male coupler assembly would be required for intervention. Selective no-go equipment (PSLT) can locate onto the desired female coupler  110 . 
     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.