The present disclosure generally relates to position sensors, and in particular, to a position sensor unit configured for use in a pneumatically actuated valve.
Flow control mechanisms such as valves are often placed within wellhead assemblies in order to regulate fluid or gas flow. Generally, valves accomplish this by being controlled to wholly or partially obstruct the wellheads, flowlines, headers, or some other oil/gas pipeline system. A frequently used valve for such applications is a valve pneumatically controlled by an actuator. The actuator controls the gate-valve-based on pneumatic pressure that displaces a diaphragm within it. The diaphragm displacement causes an actuator rod to move up or down depending on the amount of pneumatic pressure present in a pressurized chamber of the actuator. This up-and-down movement of the actuator rod causes the valve to respectively open or close.
Currently, existing wellheads that employ pneumatic valve actuation often use a mechanical indicator to visually determine the position of the valve based on the position of the diaphragm within the actuator. Such solutions not only require on-site observation of the position of the diaphragm using the mechanical indicator, but also lack the capacity to finely resolve and provide precise diaphragm displacement measurements. Additionally, the mechanical indicators in such systems provide faulty diaphragm position measurements due to equipment wear and tear, since such systems are generally not adapted to account for the aging of flow-control components coupled to the wellhead. Moreover, these solutions usually lack smart technology for accurately capturing valve position data and digitally processing this data for informative and for control purposes.
According to one aspect of the subject matter described in this disclosure, a position sensor unit for measuring diaphragm displacement in a pneumatic actuator wellhead and valve assembly is presented. The pneumatic actuator and wellhead valve assembly comprises an actuator capturing a pneumatically controlled diaphragm that drives an actuator rod. The actuator rod translates with a displacement of the pneumatically controlled diaphragm and is operable to mechanically actuate a valve to controllably pass gases or liquids according to one of an opening and a closing of the valve. The position sensor unit comprises a sensor housing including an optical port for allowing an optical pulse from within the sensor housing to be transmitted to the pneumatically controlled diaphragm. The optical port also allows the sensor housing to receive a reflected optical pulse from the pneumatically controlled diaphragm back into the sensor housing. The position sensor unit also comprises an optically transmissive seal engaged within the optical port. The optically transmissive seal is operable to pass the optical pulse from within the sensor housing to be transmitted to the pneumatically controlled diaphragm, and also, pass the reflected optical pulse from the pneumatically controlled diaphragm back into the sensor housing.
Additionally, the position sensor unit comprises an optical time-of-flight sensor comprising a light source and a light detector. The optical time-of-flight sensor is operable to measure a distance to the pneumatically controlled diaphragm and thereby determine the displacement of the pneumatically controlled diaphragm. The light source comprised in the optical time-of-flight sensor is operable to send one or more optical pulses to the pneumatically controlled diaphragm while the light detector comprised in the optical time-of-flight sensor is operable to detect reflected optical pulses from the pneumatically controlled diaphragm. The optical-time-of-flight sensor is operable to measure a round-trip propagation time of the one or more optical pulses in order to determine the displacement of the pneumatically controlled diaphragm. The position sensor unit further comprises an electronic control unit in electrical communication with the optical time-of-flight sensor. The electronic control unit is operable to control the optical-time-of-flight sensor and to provide detected measurements to an external monitoring device.
These and other implementations may each optionally include one or more of the following features. The electronic control unit further comprises a wireless transceiver for wirelessly transmitting the detected measurements to the external monitoring device. The optical port is configured within a threaded coupling to be mounted to the actuator capturing the pneumatically controlled diaphragm. The position sensor unit further comprises a modular power that supplies power to the optical time-of-flight sensor and to the electronic control unit. Also, the external monitoring device comprises a cloud-based computing resource that analyzes the detected measurements. Additionally, the cloud-based computing resource can analyze the detected measurements by comparing the detected measurements to baseline measurements in order to determine an operating state associated with the valve. The operating state associated with the valve can indicate that the valve is malfunctioning. In some implementations, the position sensor unit is coupled to one or more indicators that can indicate at least an operating state of the valve based on an alert received by the position sensor unit from the external monitoring device. In some embodiments, the one or more indicators provide a visual indication of a malfunction associated with the valve. Further, the detected measurements can be used to determine a pressure within a pressurized chamber of the actuator.
The disclosed embodiments provide a position sensor unit that combines digital detection of diaphragm displacement with connectivity to analytics devices to more accurately determine whether the valve is operating as configured. Additionally, the disclosed position sensor unit can coordinate with other sensors either integrated into its configuration, or external to the position sensor unit to validate valve position data, and also perform other sensing and control functionality on the valve. Furthermore, the disclosed position sensor unit allows stakeholders to be updated through the sensor unit's connectivity with other external devices without needing any stakeholder to be physically present on-site to manually determine the valve position.
The disclosure is illustrated by way of example, and not by way of limitation in the figures of the accompanying drawings in which like reference numerals are used to refer to similar elements. It is emphasized that various features may not be drawn to scale and the dimensions of various features may be arbitrarily increased or reduced for clarity of discussion.
The pneumatically controlled diaphragm 106 associated with the actuator 105 is operable through a pressurized air control line 107 to be translated upwardly under air pressure from the air control line 107. This in turn translates the actuator rod 104 upwardly. The movement of the actuator rod 104 upwardly is operable to open the valve 102 and allow production fluid to pass through the oil or gas line 109. Further illustrated in the cross-sectional view of
More specifically, the described embodiments measure the relative distance between the diaphragm 106 and the position sensor unit 101 based on the amount of time it takes an optical pulse to be transmitted 108a to the pneumatically controlled diaphragm 106 and reflected 108b back to the optical-time-of-flight sensor associated with the position sensor unit 101 as seen in
Further, it is appreciated that the position sensor unit 101 may be located or mated to the actuator 105 on the pressurized chamber 111b, and may be operable to use time-of-flight measurements to measure diaphragm displacement at the side of the pressurized chamber 111b of the actuator 105. In certain embodiments, the position sensor unit 101 might be provided in an integrated assembly, or in association with a pressure sensor such that a common housing and/or electronics could be conjoined in a single sensor assembly as further discussed below. In such cases, the data captured by the pressure sensor and position sensor unit 101 are combined to accurately estimate the position of the valve 102. Such configurations provide at least two data points that improve the accuracy of estimating the position of the valve 102 as further discussed below.
Additionally, the position sensor unit 101 may include electronics that enable wireless or wired communications with external monitoring devices such as computing systems. This advantageously allows: downstream monitoring of the valve position (i.e., the position of the valve plug 103); confirming whether the valve 102 is open or closed based on the position of the valve plug 103; determining whether the open or closed states of the valve 102 is as expected in accordance with expected settings determined by a well operator; etc.
Prior art systems have typically used visual inspection of the position of the actuator rod 104 (or some other on-site mechanical indicator) to determine the valve position. Other prior art systems have used resistive-based position sensors with actuator rods that can also determine the position of the pneumatically controlled diaphragm 106. However, such systems are not as robust and reliable as the pneumatic actuator and wellhead valve assembly 100 constructed using the position sensor unit 101 approach described in the present embodiments. In particular, an optical-time-of-flight sensor associated with the position sensor unit 101 unit can optically detect the relative position (e.g., vertical position) of the pneumatically controlled diaphragm 106, and accordingly the state of the valve 102, without the need for any visual on-site inspection.
In some prior art implementations, the valve position can be determined using a magnetic-based sensor that applies the Hall effect to address the mechanical and structural problems endemic to the resistive-based solutions. When implemented, magnetic-based sensors for valve position determination can be affected by the ambient magnetic response of the surrounding area in which they are located. For example, moving or changing the positions of metallic structures or objects around the magnetic-based sensor can significantly affect the reliable operation of the magnetic-based sensor. Unlike the magnetic-based sensor, the presently disclosed position sensor unit 101 is not only reliable but is also unaffected by its surroundings.
Another prior art solution uses a linear variable differential transformer (LVDT) to determine the valve position Like the magnetic-based sensor, the LVDT also addresses reliability issues associated with the resistive-based position sensors. However, the LVDT solutions are generally exorbitantly priced and often require power-hungry electronic components that are driven by alternating current (AC) power. Unlike the LVDT solutions for valve position determination, the electronics of the position sensor unit 101 are relatively cheap and can determine and communicate valve position data to external monitoring devices using very little electrical power.
Moreover, various connectors of similar and/or different configurations can connect the internal components of the position sensor unit 101 to each other and to external circuitry depending on the implementation. In one embodiment, the connectors communicatively coupling the internal components of the position sensor unit 101 comprise an inter-integrated circuit (I2C) serial bus cable. In another implementation, the connectors include a 4 conductor 1 mm pitch flat-flex cable and/or a 4 conductor 0.5 mm flat flex cable. In other embodiments, the connectors include combinations of I2C cables, 4 conductor 1 mm flat flex cables, and/or 4 conductor 0.5 mm flat flex cable. In some further instances, other flat flex cable types, hardwired connectors, other bus types, and/or other connector methodology may be used to communicatively couple the electronic components within the housing of the position sensor unit 101.
The optical-time-of-flight sensor 206 of the position sensor unit 101 may be configured for use with a diaphragm 106 associated with a valve 102, although it can also be used with different diaphragm types associated with different valve types. In the case of a pneumatically controlled diaphragm 106 (see
Seen at the other side of the optical-time-of-flight sensor 206 in
The optically transmissive seal 307 may comprise a glass lens or some other suitable material with a light transmissivity suited to the functions of the optically transmissive seal 307. It should be appreciated that although the optical glass lens is described as a “lens,” the optically transmissive seal 307 may be a flat glass piece without optical power. Further, so long as the material used to fabricate the optically transmissive seal 307 has a suitable light transmissivity and other material characteristics such as mechanical strength, durability, sealing capacity, appropriate melting temperature, and other material science characteristics, it may be of a material other than glass.
To hold in place the various components within the port cavity 203 of the port 201, a number of securing methodologies may be used. For instance, the optical-time-of-flight sensor 206 may be mounted on one or more support structures 302a and 302b that are bonded to the optically transmissive seal 307 to secure the optical-time-of-flight sensor 206 in place and to allow other components within the port cavity 203 to be accordingly positioned around the optical-time-of-flight sensor 206. In one implementation, the support structures may be made of insulator materials such as polyvinyl chloride, glass, asbestos, rigid laminate, Teflon, fiberglass and rubber.
Moreover, the port volume 305 surrounding the cable connector 301 may be filled with a sealant that minimizes the likelihood of ambient gases coming into contact with the electronics within the housing of the of the position sensor unit 101 through the port 201. This is because without this protection, intrusion gases from fluid or gas in an oil or gas pipeline to which the position sensor unit 101 is coupled, or other environmental gases or moisture, could otherwise bypass the optical-time-of-flight sensor 206 and the port volume 305 before coming into contact with other energized electronic circuitry such as the electronic control unit 202 within the housing of the position sensor unit 101. As such, applying a sealant to the port volume 305 can greatly minimize or prevent this “in-gassing.” Moreover, the sealant also prevents outgassing and/or sparking from within the housing of the position sensor unit 101 in the event of an electrical malfunction such as a blown fuse, a shorted circuit element, or an electronic failure of one or more components within the housing of the position sensor unit 101. In some cases, the sealant helps to fix in place the various internal components of the position sensor unit 101 such as the optical-time-of-flight sensor 206 and the cable connector 301. The sealant can be an epoxy-based material and/or a silicone-based material. In some implementations, the sealant is a urethane-modified epoxy material and/or a polysulfide-modified epoxy material. It should appreciated that the optically transmissive seal 307 and the support structures 302a and 302b, when used in combination with the sealant improve the robustness and the structural/material integrity of the position sensor unit 101.
Further, the port 201 may be configured with a threaded coupling to allow the position sensor unit 101 to be mounted on the actuator 105. More specifically, the port 201 may include a threading 407 such as those shown in
The optical-time-of-flight sensor 206 within the port 201 may be operable to estimate or calculate distance from the optical unit 306 to the diaphragm 106 based on transmitted and reflected light pulses 108a, 108b and thereby measure the diaphragm displacement. More specifically, the optical unit 306 includes a light source 320 that generates one or more optical pulses 108a and an optical detector 322 that detects one or more reflected optical pulses 108b. The light source 320 transmits the generated one or more optical pulses 108a to the diaphragm 106. The transmitted one or more optical pulses 108a are then partially reflected on the diaphragm 106 and return back as reflected optical pulses 108b to the optical unit 306, where they are detected by the optical detector 322 associated with the optical unit 306. The optical-time-of-flight sensor 206 then determines the time it took for optical pulses to travel from the light source 320 to the diaphragm 106 and back to the optical detector 322. This time may be referred to as a round-trip propagation time. The round-trip propagation time can be translated into a distance indicative of the diaphragm displacement. In one implementation, the distance by which the diaphragm is displaced is given by:
Distance=½×round−trip propagation time×c,
where c is the speed of light.
In some implementations, the optical-time-of-flight sensor 206 determines this distance, alone or in coordination with the electronic control unit 202. In other implementations, the optical-time-of-flight sensor 206 and/or the electronic control unit 202 include filters, samplers, or other signal processing logic or circuitry that aid in the calculation of the distance by which the pneumatically controlled diaphragm 106 is displaced. For example, the filters, samplers, or other signal processing logic or circuitry can improve the resolution of the optical-time-of-flight sensor 206. Resolution as used here refers to the smallest change in time it takes the light detector in the optical unit 306 to detect reflected light pulses. Additionally, the filters, samplers, or other signal processing logic or circuitry can remove noise from measurements captured by the optical-time-of-flight sensor 206 and/or other sensors coupled to the position sensor unit 101.
While the position sensor unit 101 has been described in the context of being housed by itself within the port 201, the principles described in this disclosure are also applicable to configurations where the housing of the position sensor unit 101 includes other sensors such as a pressure sensor, a vibration sensor, or some other sensor in combination with the optical-time-of-flight sensor 206. For example, the overall position sensor unit 101 assembly may include a pressure sensor (not shown) either directly integrated into its design or communicatively coupled to the position sensor unit 101. In such implementations, the position sensor unit 101 may be mounted on the lower side 110b (see
In implementations where the position sensor unit 101 is adapter-enabled, the optical-time-of-flight sensor 206 may be fitted to an external adapter 501 and communicatively coupled to the position sensor unit 101 via a cable 507 as shown in
The embodiment of
As seen in
It should be appreciated that the optical-time-of-flight sensor 206 described in this application can detect the current position of the valve plug 103 relative to a zero-point position based on the diaphragm displacement as previously noted. Additionally, positions such as a closed valve position and an open valve position can change due to wear and tear of the valve plug 103. For example, if a closed position of a new valve plug 103 is at a 0% position, over time the closed position may change to −1%, −3%, or −5%, which depending on design constraints may indicate that the valve plug 103 should be shut further with respect to the original closed position due to the wear on the internal valve components and can also indicate an ultimately impending failure condition that could be proactively avoided. The disclosed optical-time-of-flight sensor 206 may be directly correlated with the pressure in the pressurized chamber 111b through their respective measurements to make such adaptive determinations. For example, the embodiment shown in
postion sensor measurement (psm):pressure measurement (pm).
A determination of the psm:pm ratio can be used to automatically reconfigure the pneumatic actuator and wellhead valve assembly 100 even when the valve 102 ages. For example, given the embodiment of
In some embodiments, the pm stays constant relative to the psm during the lifetime of the valve 102. In such cases, the psm can change over the course of time that the valve 102 is used based on the wear and tear experienced by the internal components (e.g., valve plug 103) of the valve 102. For such implementations, it is assumed that the constancy of the pm depends, at least, on seals and other pressure control mechanisms associated with the actuator 105 not degrading.
In either of the embodiments shown in
The connector pins 602a and 602b can couple components of the position sensor unit 101 that are external to the PCB 600 to the PCB 600. For example, the connector pins 602a and 602b may be configured with pins to which a cable is attached to connect the PCB 600 to the optical-time-of-flight sensor 206. In one embodiment, the cable attached to the connector pins 602a and 602b is an I2C bus. In some implementations, the connector pins 602a and 602b provide data and clock lines to a cable such as the cable 507 of
The microcontroller 606 may communicate with onboard components of the PCB 600 and with other components external to the PCB 600. In one embodiment, the microcontroller communicates with components associated with the position sensor unit 101 via hardwired and/or wired connections whiles communicating with devices external to the position sensor unit 101 via wired and/or wireless connectivity. For example, the microcontroller 606 has an integrated wireless transceiver with wireless connectivity for communicating with monitoring devices external to the position sensor unit 101. The microcontroller 606 may receive captured measurements by the optical-time-of-flight sensor 206 and wirelessly transmit the captured measurements via a radio link using the wireless transceiver to a gateway device external to the position sensor unit 101. The gateway device may relay the captured measurements to other monitoring devices that further process the captured measurements. In some implementations, the microcontroller can also receive instructions transmitted from external monitoring devices to the position sensor unit 101. For example, the microcontroller can receive instructions via the integrated wireless transceiver to activate an indicator coupled to the position sensor unit 101, or perform some other control action associated with the position sensor unit 101.
In some implementations, the microcontroller 606 is a Digi International XB24CZPISB003 microcontroller that includes an NXP MC9S08QE32 microcontroller, a 2.4 GHz radio, and an integrated antenna. Additionally, power to the microcontroller 606 may be supplied directly from the modular power 204 and/or from some other power source at a nominal voltage such as 2.8 V or 3.0 V. The one or more switches 608a and 608b on the PCB 600 may be communicatively coupled to the microcontroller 606 to enable modifying network parameters of the position sensor unit 101 during execution of initial setup configuration operations while programming connectors 610 allow a data cable to be coupled to the microcontroller during execution of the initial setup configuration operations.
Sensors 612a and 612b may be sensors integrated into the PCB 600 and function independently or in coordination with other sensors coupled to the position sensor unit 101. These sensors may include a vibration sensor, a pressure sensor, and a temperature sensor. Further, the voltage regulator 614 shown in
Power to the electronic control unit 202 and to other electronic components of the position sensor unit 101 such as the optical-time-of-flight sensor 206 may be supplied by the modular power 204 (see
The gateway device 703 may be separate from the position sensor unit 101 and can be configured to relay received data to other devices within the system 700. For instance, the gateway device 703 may receive measured diaphragm displacement from the position sensor unit 101 following which it sends this information to devices such as the analysis server 704 and/or the one or more user devices 705. In some instances, the gateway device 703 can also send instructions or other information from devices like the user device 705 and/or the analysis server 704 to the position sensor unit 101. In one embodiment, the gateway device 703 packages received data or instructions before relaying them to appropriate devices within the system 700. In other embodiments, the gateway device filters received data before forwarding the received data to other devices within the system 700. Thus, the gateway device 703 can be thought of as a “gate” to and from the position sensor unit 101. In some implementations, the gateway device 703 is a router, a firewall server, or some other device that enables traffic flow to and from the position sensor unit 101.
The network 702 coupling the various devices in the system 700 may include a plurality of networks. For instance, the network 702 may include any wired/wireless communication link and in some instances, includes an Ethernet network, a cellular network, a computer network, the Internet, a Wi-Fi network, a light fidelity (Li-Fi) network, a Bluetooth network, a radio frequency identification (RFID) network, a near-field communication (NFC) network, a laser-based network, or other types of networks according to design needs.
The analysis server 704 can analyze data captured by the position sensor unit 101. The analysis server 704 can also send one or more instructions or results to other devices within the network 702. In one embodiment, the analysis server is equipped with tools and processing functionality that enable it to run analytics on data received from the position sensor unit 101. In some instances, the analysis server 704 operates as a cloud-based computing resource in the system 700. In such a case, the analysis server 704 functions as a remote network server hosted on the internet to store, manage or otherwise process data received from the position sensor unit 101 and/or other devices associated with the system 700.
Remotely processing or analyzing data away from the position sensor unit 101 has a number of benefits. For instance, doing this negates the need to directly couple bulky and usually expensive computing resources to the pneumatic actuator and wellhead valve assembly 100 which may be impracticable in some instances. Rather, low power consuming devices such as the position sensor unit 101 can be used to capture monitoring signals such as diaphragm displacement using the optical-time-of-flight sensor 206. The analysis server can also facilitate off-site monitoring of the pneumatic actuator and wellhead valve assembly 100 via the position sensor unit 101. In some embodiments, the analysis server 704 can execute analytics on monitoring signals from the position sensor unit 101 to detect certain statistical trends regarding operating states of the valve 102. In some instances, the analysis server 704 can also simultaneously transmit results from processing or analyzing of monitoring signals from the position sensor unit 101 to stakeholders such as valve operators, technicians, site administrators, and project managers at different locations via the one or more user devices 705a . . . 705n.
Analyzing monitoring signals transmitted from the position sensor unit 101 by the analysis server 704 can also include comparing the monitoring signals from sensors such as the optical-time-of-flight sensor 206 to baseline measurements to determine an operating state associated with the valve 102 of
In implementations where the monitoring signals include, for example, diaphragm displacement measurements captured by the optical-time-of-flight sensor 206, the monitoring signals can be used to determine the pressure within the pressurized chamber 111b of the actuator 105 (see
As another example, the analysis server 704 can analyze the captured distance associated with the diaphragm displacement within the pneumatic actuator and wellhead valve assembly 100 by processing the captured distance received from the position sensor unit 101 in association with previously gathered valve data associated with the valve 102 to determine trends of operation and to also revise psm:pm ratio associated with the valve 102. As a further example, the analysis server 704 can digitally resolve the captured distance associated with the diaphragm displacement of the pneumatically controlled diaphragm 106 within the pneumatic actuator and wellhead valve assembly 100 to generate a more accurate measurement of the diaphragm displacement. Other example functions of the analysis server 704 include automatically adapting valve actuation mechanisms associated with the pneumatic actuator and wellhead valve assembly to accommodate aging of components associated with the pneumatic actuator and wellhead valve assembly 100 using for example, a revised psm:pm ratio.
In other implementations, the analysis server 704 can generate one or more alerts or some other instructions and transmit the one or more alerts and/or instructions to the position sensor unit 101 and/or to the one or more user devices 705a . . . 705n. For example, after processing a captured diaphragm displacement associated with the pneumatically controlled diaphragm 106, the analysis server 704 can transmit an alert indicative of a malfunction associated with the valve 102 to one or more user devices 705 to notify stakeholders of the situation. Additionally or optionally, the analysis server 704 can transmit one or more alerts or instructions to the position sensor unit 101, or to some other electronic device associated with the pneumatic actuator and wellhead valve assembly 100 to activate one or more indicators that indicate the malfunction associated with the valve 102. The one or more alerts/instructions may also trigger an alarm/notification at a user device 705 and/or activate one or more indicators directly coupled to the position sensor unit 101 or to the pneumatic actuator and wellhead valve assembly 100.
In some embodiments, the one or more indicators when activated facilitate readily identifying the valve 102. The one or more indicators may include visual indictors such as light emitting diodes (LEDs that provide visual indications of the malfunction associated with the valve 102, and/or auditory indicators such as speaker alarms that provide sound alerts when the valve 102 malfunctions.
Although described in the context of a pneumatically actuated valve, the principles discussed in this disclosure are applicable to determining valve positions of other valve types. For example, the position sensor unit 101 can be used to determine the valve positions of valves such as ball valves, butterfly valves, control valves, gate valves, globe valves, needle valves, pinch valves, inlet valves, wellhead motor valves, safety relief valves, back pressure valves, and dump valves.
Reference in the specification to “one implementation” or “an implementation” means that a particular feature, structure, or characteristic described in connection with the implementation is included in at least one implementation of the disclosure. The appearances of the phrase “in one implementation,” “in some implementations,” “in one embodiment,” or “in some embodiments” in various places in the specification are not necessarily all referring to the same implementation.
Finally, the above descriptions of the implementations of the present disclosure has been presented for the purposes of illustration and description. It is not intended to be exhaustive or to limit the present disclosure to the precise form disclosed. Many modifications and variations are possible in light of the above teaching. It is intended that the scope of the present disclosure be limited not by this detailed description, but rather by the claims of this application. As will be understood by those familiar with the art, the present disclosure may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. Accordingly, the disclosure of the present disclosure is intended to be illustrative, but not limiting, of the scope of the present disclosure, which is set forth in the following claims.
This application claims the benefit of U.S. Provisional Application No. 62/753,514, filed Oct. 31, 2018. The contents of the above application are hereby incorporated in its entirety by reference.
Number | Date | Country | |
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62753514 | Oct 2018 | US |