Patent Application
20210372566
The present disclosure relates to technology for, a cryogenic nitrogen sources gas-driven pneumatic device. Current solutions for gas driven pneumatic devices rely on natural gas powered devices. A major component of remote, automated control of natural gas and petroleum industry facilities is the operation of control valves, which are often powered and actuated by natural gas through pneumatic controllers. In addition, there are natural gas-powered pumps used for injecting chemicals and other purposes. Several types of these existing solutions release or “bleed” natural gas to the atmosphere by design. In addition to emissions by design, pneumatic controller loops and pneumatic pumps can also emit gas because they have a defect or a maintenance issue. In some existing solutions, recent field measurement studies have pointed out that a large fraction of total emissions from pneumatic devices are a result of devices that are not operating as designed (due to a defect or maintenance issue).
Because millions of pneumatic controllers are used in the oil and gas industry worldwide, they collectively comprise a major source of methane emissions. Depending on a device's function, design, and operation, the emission rate can vary (e.g., a controller's bleed, valve actuation gas vent, and a pneumatic-driven pump's actuation gas).
Controllers and pumps may be powered by compressed air or utility-supplied electricity. At remote production, gathering, and gas transmission facilities, compressed air or electricity may not be available and economical. In such cases, operators may use the available inherent energy of pressurized natural gas to power these devices. Natural gas driven chemical injection pumps are common equipment in the natural gas industry where there is no reliable electricity available. These pumps inject methanol and other chemicals into wells and pipelines, and are vital to the production process. For example, methanol prevents crystalline methane hydrate formation that can lead to blockages in pipelines. Pneumatic pumps use gas pressure to alternately push on one side and then on the other side of a diaphragm connected to a piston pump. The gas is then vented at each pump movement.
Most pneumatic controllers in oil and gas production are designed to vent gas as part of normal operation. Sufficient, pressurized natural gas available in the operating facility, called supply gas or power gas—typically pressure regulated to 20-50 pounds per square inch gage (psig), (1.4-3.6 kilograms per square centimeter (kg/cm2))—is sent to a pneumatic controller loop. Pneumatic control loops consist primarily of a gas pressure actuated valve and a system to regulate the actuation gas. Pneumatic gas pressure pushes against a diaphragm in the valve actuator, which pushes a connecting rod to move the valve plug open or closed. Venting this gas to the atmosphere at the controller allows a spring to push the diaphragm back, closing or opening the valve. The valve regulates various process parameters such as temperature, pressure, flow rate, and liquid level. Examples include liquid level in separators, suction and discharge pressures for compressors, and temperature in heaters or gas dehydrator regenerators.
Current solutions are limited since producers are averse to having large high-pressure tanks on their leases. These high-pressure tanks create expensive lease sizing issues and the handling and servicing of high pressure is a significant safety issue. There are sensitivities to water contamination especially in winter environments. Service technicians would have to account for that with the fill pressure. They could only fill them to a pressure relative to a high ambient.
According to one innovative aspect of the subject matter described in this disclosure, one general aspect includes a cryogenic nitrogen sourced gas-driven pneumatic device. The cryogenic nitrogen sourced gas-driven pneumatic device also includes a cryogenic storage tank that stores liquid nitrogen under pressure; a pressure build circuit configured to build and hold pressure in the cryogenic storage tank, an economizer circuit configured to draw gas that forms in the cryogenic storage tank for an end device, and a vaporizer is configured to convert the liquid nitrogen into a gas as it is drawn through the vaporizer.
Implementations may include one or more of the following features. The cryogenic nitrogen sourced gas-driven pneumatic device where the pressure build circuit builds and holds pressure in the cryogenic storage tank by opening a regulator when the pressure drops that allows liquid nitrogen to flow from a bottom of the cryogenic storage tank through a pressure build coil and back into a top of the cryogenic storage tank. The liquid nitrogen also flows through a strainer to remove any unwanted solids when the liquid nitrogen flows from the bottom of the cryogenic storage tank through the pressure build coil and back into the top of the cryogenic storage tank. The cryogenic storage tank is a double walled tank including an inner wall and an outer wall with a vacuum situated between the inner wall and the outer wall. One or more of the pressure build circuit and the economizer circuit are located between the inner wall and the outer wall of the double walled tank. The cryogenic storage tank may be in one of a vertical configuration and a horizontal configuration. The gas that the economizer circuit draws from the cryogenic storage tank is formed because of natural heat leak into the cryogenic storage tank that converts the liquid nitrogen to gas. The economizer circuit draws the formed gas from a top of an interior of the cryogenic storage tank. The economizer circuit can help reduce the pressure of the cryogenic storage tank by drawing the formed gas from the top of the interior of the cryogenic storage tank until the pressure of the cryogenic storage tank reaches a set pressure value. The cryogenic nitrogen sourced gas-driven pneumatic device may include: one or more gas connections configured to be attached to pneumatic end devices. The cryogenic nitrogen sourced gas-driven pneumatic device may include: a rapid fill feature that uses a top fill valve and a bottom fill valve to fill the cryogenic storage tank without a loss of pressure. During a fill process, the pressure of the cryogenic storage tank is controlled by adjusting a flow of one or more of the top fill valve and the bottom fill valve to hold a may include pressure during the fill process and prevent the loss of pressure. The cryogenic nitrogen sourced gas-driven pneumatic device may include: a pressure regulating station that includes an inlet pressure gauge and an outlet pressure gauge and one or more pressure relief valves that can open to reduce the pressure if one of the inlet pressure gauge and the outlet pressure gauge exceeds a threshold value. The cryogenic nitrogen sourced gas-driven pneumatic device may include: a communication device that is configured to transmit tank information to a remote device. The tank information includes one or more of fill detect, low level, critical low level, rate of change, and low battery. A cryogenic storage tank that stores liquid nitrogen under pressure, the liquid nitrogen is used in place of natural gas used by pneumatic devices, the liquid nitrogen being converted into a gas as it is drawn from the cryogenic storage tank and provided to an end device; a pressure build circuit configured to build and hold pressure in the cryogenic storage tank as the liquid nitrogen is stored; and an economizer circuit configured to draw a formed gas that forms in the cryogenic storage tank. the Eliminates harmful gases that are vented by end devices that previously operated with natural gas. The cryogenic storage tank is mobile and mounted on one or more of a trailer and a skid.
One general aspect includes a method of filling a cryogenic nitrogen sourced gas-driven pneumatic device. The method of filling also includes connecting a transfer hose to a rapid fill connection on a tank; opening a top fill valve, delivering liquid nitrogen into the tank through the rapid fill connection, adjusting the top fill valve to change a pressure of the tank as the liquid nitrogen is delivered, opening a trycock valve, halting delivery of the liquid nitrogen into the tank when the trycock valve emits a liquid, closing the trycock valve and the top fill valve, and disconnecting the transfer hose from the rapid fill connection. The filling also includes the other embodiments of this aspect include corresponding computer systems, apparatus, and computer programs recorded on one or more computer storage devices, each configured to perform the actions of the methods.
Implementations may include one or more of the following features. The method where adjusting the top fill valve to change the pressure of the tank as the liquid nitrogen is delivered further may include adjusting a bottom fill valve to maintain the pressure of the tank as the liquid nitrogen is delivered.
The features and advantages described herein are not all-inclusive and many additional features and advantages will be apparent to one or ordinary skill in the art in view of the figures and description. Moreover, it should be noted that the language used in the specification has been selected for readability and instructional purposes and not to limit the scope of the inventive subject matter.
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.
The technology disclosed in this application describes a cryogenic nitrogen sourced gas-driven pneumatic device.
In some implementations, the pneumatic control system 150 is able to provide a method for the use of low-cost reliable source of gas to operate the pneumatic controls of a wellsite, as well as eliminate some and/or all potential methane and/or other gas emissions that are present in previous solutions. In some implementations, the pneumatic control system 150 may be able to eliminate one or more of the corrosive agents shown in
Nitrogen makes up a major portion of our atmosphere, 78% by volume. Liquid nitrogen (LN2) is cryogenic and boils at −196 C (−320 F). During the liquefaction process, impurities including water are removed. Since liquid nitrogen is noncorrosive and waterless, it is the ideal candidate to replace natural gas used by pneumatic end devices, such as controllers, valves, and pumps. Liquid nitrogen becomes gas naturally when exposed to everyday temperatures, even during winter. In addition, liquid nitrogen, when stored in a tank, will build pressure as it becomes gas. The pneumatic control system 150 uses these properties of Nitrogen to eliminate harmful gases vented by pneumatic end devices.
The pneumatic control system 150 as shown in
In some implementations, the pressure build circuits 520 and 570 may be used to build pressure in the tank 100 after a delivery or to maintain pressure as liquid is withdrawn from the tank 100. The tank 100 pressure may be set by adjusting the liquid regulator 30. As the tank 100 pressure drops below the set pressure, the liquid regulator 30 may open and allow liquid to flow from the bottom 106 of the tank 100, through the pressure build coils 200 and back into the top 108 of the tank 100. In some implementations, the pressure build circuits 520 and 570 can be isolated by closing valves 24 or 40. In some implementations, the pressure build circuits 520 and 570 can be protected by pressure relief valves 28 and 38 and backflow may be prevented by check valves 32 and 36. In some implementations, any unwanted solids may be removed by the strainer 26.
In some implementations, the gas circuit 540 has a gas use valve 64 and a vaporizer 210 to supply gaseous product from the liquid circuit 530 to pneumatic end devices such as controllers, valves, and/or pumps. In some implementations, the liquid circuit 530 can be isolated from the gas use circuit 540 by a closing valve 34. The vaporizer 210 may deliver gas at various flow rates and temperatures for different end devices. In some implementations, liquid nitrogen may be drawn through the vaporizer 210 and become a gas when heated by ambient air or another heating source. The liquid regulator 30 may maintain a predetermined set pressure. In some implementations, if the pressure exceeds the set pressure, the liquid regulator 30 may close and nitrogen gas may be drawn off the top 110 of the tank 100 through the economizer circuit 560. As gas is removed from the tank 100, the pressure decreases. When the pressure falls below the liquid regulator 30 set pressure, the liquid regulator 30 reopens and allows liquid to flow again. The various end devices that are being supplied gas from the tank, control the flow rate. In some implementations, if the gas requirements are sufficiently low, the liquid regulator 30 may remain closed and gas may be solely supplied by the economizer circuit 560. In some implementations, the economizer circuit 560 may also include a back-pressure regulator 94, which may be set between 15-20 psi above the liquid regulator 30 set point, which ensures a smooth operation.
In some implementations, over time, cryogenic liquid will become gas as a result of the natural heat leaking into the cryogenic storage vessel. The economizer circuit 560 may allow the operator to use this gas for end devices. When the economizer isolation valve 42 is open, gas is drawn directly off the top 110 of the tank 100. This allows the gas to travel through the vaporizer 210, to warm the cold gas, before exiting the end use valve 64. Back flow into the tank 100 may be prevented by the check valve 44. The economizer circuit 560 can be isolated by closing the valve 42. Gas may be drawn through the economizer circuit 560 until tank pressure drops below the liquid regulator 30 set point. Then, liquid may begin flowing through the vaporizer 210.
In some implementations, the gas pressure regulator 56 may regulate the gas pressure of the outlet circuit 540, ensuring downstream equipment can be operated safely. The gas pressure regulator 56 may be equipped with an inlet pressure gauge 50 and/or an outlet pressure gauge 60, isolation valves 54 and/or 58, and/or a bypass valve 52 for easy servicing. The circuit may be protected by pressure relief valves 48 and/or 62, and backflow may be prevented by the check valve 46.
In some implementations, the liquid use circuit can be used to transfer liquid from the tank 100 to other cryogenic equipment. This may circuit draw liquid directly up the bottom 104 fill line of the tank 100 and through the liquid use valve 22. In some implementations, the tank 100 may be equipped a safety circuit 550 equipped with dual spring operated relief valves 80 and/or 88 and dual rupture discs 82 and/or 86. The diverter valve 84 may allow for change out of safety relief devices without emptying the tank. These devices may be used to automatically relieve excess pressure in the tank 100. In some implementations, a double wall tank is equipped with an outer vessel rupture disc 94.
In some implementations, the vent valve 74 may be used to relieve excess pressure in the tank 100. The fill trycock valve 72 may be connected to the full trycock line 112 and used during the filling process. When liquid starts to spit out of the fill trycock valve 72 during filling, it indicates that the tank 100 is full and the filling process can terminate.
In some implementations, the tank 100 may be equipped with both a low-pressure line 580 located on the top 114 of the tank 100 and a high-pressure line 590 located on the bottom 116 of the tank 100. These lines may be connected to a differential pressure gauge 90 which may be used to indicate the amount of liquid in the tank 100 (level indication). Isolation valves 66 and/or 70 may be used to isolate the differential pressure gauge 90 from the tank 100. The equalization valve 68 may provide a simple method to check the zero on the differential pressure gauge 90. Gauge isolation and equalization can also be accomplished with a four-way valve.
In some implementations, a pressure gauge 92 may be connected to the low-pressure line 580 which provides the operator a reading of the gas pressure in the tank 100. This pressure gauge can be isolated by closing valves 66 and/or 70. In some implementations, to limit the pressure during transit the tank 100 may be equipped with a road relief regulator 78. The road relief regulator 78 can be isolated by closing valve 76.
In some implementations, for double wall tanks 100 with a vacuum between the inner and outer tank wall, a vacuum test port 98 may be provided. Vacuum levels can be checked by opening valve 96 and connecting an appropriate device to the vacuum test port 98.
In some implementations, the tank 100 may be equipped with a communication device (not shown) that is capable of transmitting information over a network (not shown) to the owner, dispatch center, or other remote device capable of receiving signals over the network. In some implementations, the tank information may include fill detect, low level, critical low level, rate of change, and/or low battery.
In some implementations, a method for preparing the tank 100 for relocating includes one or more of the following steps. First, an operator ensures that the gas use valve 64 and main isolation valve 24 are closed. Second, the operator ensures that the pressure has been relieved from the connecting piping or hoses 900. Third, the operator disconnects all piping or hoses 900 from the gas use valve 64 or gas use manifold. Fourth, the operator closes the economizer isolation valve 42 and pressure building valve 40. Fifth, the operator opens the vent valve 74 until the tank pressure is at or below 15 psig. Sixth, the operator closes the vent valve 74. Seventh, the operator opens the road relief isolation valve 76. Eight, the operator connects the trailer 300 to the towing vehicle. Ninth, the operator raises the drop legs on the front 310 and rear 320 of the trailer 300. Once the process is completed, the unit can be transported on public roads.
In some implementations, a method for liquid removal may allow cryogenic liquid to be pressure transferred from the tank 100 to other cryogenic tanks (not shown) in one example implementation, the steps of the method may include, first having the operator connect one end of the transfer hose to the liquid valve 22. Second, the operator may connect the other end of the hose to the receiving equipment. Third, the operator may open the fill valve and vent valve of the receiving equipment. Fourth, the operator may open the liquid valve 22 and adjust valve to obtain the proper liquid flow rate. Fifth, the operator may open the main isolation 24 and pressure building valve 40 to build and maintain a higher transfer pressure, if required. Sixth, when the transfer is complete, the operator may close the receiving equipment inlet valve followed by the tank liquid valve 22 and relieve pressure from the hose. Last, the operator may disconnect and remove the hose from the equipment.
In some implementations, the pressure build circuit 520 and vaporizer exchanger of the pneumatic control system 10 can vary in color to promote additional heat transfer and/or ice shedding. For example, those results could be obtained by anodizing aluminum to an appropriate color. In some implementations, the tank 100 configuration could be horizontal or vertical. In some implementations, the cryogenic storage tank 100 may be single walled with various external insulation options to protect the tank 100 from external heat influences. One benefit of this is it allows different tank 100 configurations for various layouts and sizes of trailers 300. In some implementations, the pressure build circuit 520 and/or the vaporizer exchanger can be internal, for example, located in the vacuum space of the double walled tank 100, or the components can be located externally.
In some implementations, the economizer circuit 560 can prioritize N2 produced from natural evaporation, over liquid withdrawal and/or vaporization. In some implementations, a vaporizer may not be used for low-bleed (low-flow) pneumatic applications.
Nitrogen is rated excellent to use with all elastomers. Because nitriles (Buna-N) permeation and swell resistance is only rated fair to good, nitrile will permeate (and absorb) small molecules like water when natural gas is used as instrument gas. As a result, when switching from natural gas to dry nitrogen at retrofit locations, it is recommended, where appropriate, to replace the old nitrile O-rings and diaphragms in instrument gas regulator(s), with new nitrile or Viton. This eliminates any “drying out” and ensures long term performance by the regulator(s).
In some implementations, the double walled tanks 100 can be manufactured from a stainless steel or aluminum inner tank and stainless steel, aluminum, or carbon steel outer tank. In some anticipated situations, where the tank 100 could not be refilled, such as a hurricane, flooding, road closure, etc., the wellsite can simply switch back to using natural gas during the interim.
In some implementations, the vaporizer and pressure build circuits 520 can be integrated together. In further implementations, the vaporizer and pressure build circuits 520 can be independent. In the case of independent circuits, the circuit with the smaller exchanger surface area should have the lower regulator set pressure.
It should be understood that the above-described example activities are provided by way of illustration and not limitation and that numerous additional use cases are contemplated and encompassed by the present disclosure. In the above description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the present disclosure. However, it should be understood that the technology described herein may be practiced without these specific details. Further, various systems, devices, and structures are shown in block diagram form in order to avoid obscuring the description. For instance, various implementations are described as having particular hardware, software, and user interfaces. However, the present disclosure applies to any type of display device that can receive data and commands, and to any peripheral devices providing services.
In some instances, various implementations may be presented herein in terms of algorithms and symbolic representations of operations on data bits within a computer memory. An algorithm is here, and generally, conceived to be a self-consistent set of operations leading to a desired result. The operations are those requiring physical manipulations of physical quantities. Usually, though not necessarily, these quantities take the form of electrical or magnetic signals capable of being stored, transferred, combined, compared, and otherwise manipulated. It has proven convenient at times, principally for reasons of common usage, to refer to these signals as bits, values, elements, symbols, characters, terms, numbers, or the like.
It should be borne in mind, however, that all of these and similar terms are to be associated with the appropriate physical quantities and are merely convenient labels applied to these quantities. Unless specifically stated otherwise as apparent from the following discussion, it is appreciated that throughout this disclosure, discussions utilizing terms including “processing,” “computing,” “calculating,” “determining,” “displaying,” or the like, refer to the action and processes of a computer system, or similar electronic display device, that manipulates and transforms data represented as physical (electronic) quantities within the computer system's registers and memories into other data similarly represented as physical quantities within the computer system memories or registers or other such information storage, transmission or display devices.
Various implementations described herein may relate to an apparatus for performing the operations herein. This apparatus may be specially constructed for the required purposes, or it may comprise a general-purpose computer selectively activated or reconfigured by a computer program stored in the computer. Such a computer program may be stored in a computer readable storage medium, including, but is not limited to, any type of disk including floppy disks, optical disks, CD-ROMs, and magnetic disks, read-only memories (ROMs), random access memories (RAMs), EPROMs, EEPROMs, magnetic or optical cards, flash memories including USB keys with non-volatile memory or any type of media suitable for storing electronic instructions, each coupled to a computer system bus.
The technology described herein can take the form of a hardware implementation, a software implementation, or implementations containing both hardware and software elements. For instance, the technology may be implemented in software, which includes but is not limited to firmware, resident software, microcode, etc. Furthermore, the technology can take the form of a computer program product accessible from a computer-usable or computer-readable medium providing program code for use by or in connection with a computer or any instruction execution system. For the purposes of this description, a computer-usable or computer readable medium can be any non-transitory storage apparatus that can contain, store, communicate, propagate, or transport the program for use by or in connection with the instruction execution system, apparatus, or device.
A data processing system suitable for storing and/or executing program code may include at least one processor coupled directly or indirectly to memory elements through a system bus. The memory elements can include local memory employed during actual execution of the program code, bulk storage, and cache memories that provide temporary storage of at least some program code in order to reduce the number of times code must be retrieved from bulk storage during execution. Input/output or I/O devices (including but not limited to keyboards, displays, pointing devices, etc.) can be coupled to the system either directly or through intervening I/O controllers.
Network adapters may also be coupled to the system to enable the data processing system to become coupled to other data processing systems, storage devices, remote printers, etc., through intervening private and/or public networks. Wireless (e.g., Wi-Fi™) transceivers, Ethernet adapters, and modems, are just a few examples of network adapters. The private and public networks may have any number of configurations and/or topologies. Data may be transmitted between these devices via the networks using a variety of different communication protocols including, for example, various Internet layer, transport layer, or application layer protocols. For example, data may be transmitted via the networks using transmission control protocol/Internet protocol (TCP/IP), user datagram protocol (UDP), transmission control protocol (TCP), hypertext transfer protocol (HTTP), secure hypertext transfer protocol (HTTPS), dynamic adaptive streaming over HTTP (DASH), real-time streaming protocol (RTSP), real-time transport protocol (RTP) and the real-time transport control protocol (RTCP), voice over Internet protocol (VOIP), file transfer protocol (FTP), WebSocket (WS), wireless access protocol (WAP), various messaging protocols (SMS, MMS, XMS, IMAP, SMTP, POP, WebDAV, etc.), or other known protocols.
Finally, the structure, algorithms, and/or interfaces presented herein are not inherently related to any particular computer or other apparatus. Various general-purpose systems may be used with programs in accordance with the teachings herein, or it may prove convenient to construct more specialized apparatus to perform the required method blocks. The required structure for a variety of these systems will appear from the description above. In addition, the specification is not described with reference to any particular programming language. It will be appreciated that a variety of programming languages may be used to implement the teachings of the specification as described herein.
The foregoing description has been presented for the purposes of illustration and description. It is not intended to be exhaustive or to limit the specification 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 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 specification may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. Likewise, the particular naming and division of the modules, routines, features, attributes, methodologies and other aspects are not mandatory or significant, and the mechanisms that implement the specification or its features may have different names, divisions and/or formats.
Furthermore, the modules, routines, features, attributes, methodologies and other aspects of the disclosure can be implemented as software, hardware, firmware, or any combination of the foregoing. Also, wherever an element, an example of which is a module, of the specification is implemented as software, the element can be implemented as a standalone program, as part of a larger program, as a plurality of separate programs, as a statically or dynamically linked library, as a kernel loadable module, as a device driver, and/or in every and any other way known now or in the future. Additionally, the disclosure is in no way limited to implementation in any specific programming language, or for any specific operating system or environment. Accordingly, the disclosure is intended to be illustrative, but not limiting, of the scope of the subject matter set forth in the following claims.
The present application claims the benefit under 35 U.S.C. 119(e) of U.S. Provisional Patent Application Ser. No. 63/030,079, titled “Cryogenic Nitrogen Sourced Gas-Driven Pneumatic Controllers and Pumps”, filed on May 26, 2020, the entire contents of which are incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| 63030079 | May 2020 | US |
