An automatic salt control system and method for depleted oil and gas reservoir gas storage facilities

Abstract

This invention provides an automatic salt prevention system for depleted oil and gas reservoirs. The system includes: a salt prevention actuator that injects salt-preventing fluid into the high-pressure pipeline of the gas storage facility during gas injection operations; an information acquisition module that collects real-time gas-liquid information from the pipeline during the gas injection and production operations; a data analysis module that analyzes the salt formation status and injection information of the gas storage facility based on the gas-liquid information during the production operations; and a decision-making module that determines the control and adjustment parameters of the salt prevention actuator based on the analysis results, thereby achieving intelligent and controllable salt prevention for the gas storage facility. Applying this system and method allows for automatic salt prevention operations during normal gas injection and production operations without human intervention, overcoming the limitations of existing technologies in salt prevention scenarios. It is also precise and efficient, significantly improving the operational efficiency of the gas storage facility.

Description

Technical Field

[0001] This invention relates to the field of gas storage injection and production operations and optimization technology, and in particular to an automatic salt prevention system and method for depleted oil and gas reservoirs. Background Technology

[0002] After depleted oil and gas reservoirs containing highly saline formation water are converted into gas storage facilities, the continuous "concentration" effect of injected (drying) natural gas often leads to varying degrees of salt deposition after several operating cycles. Salt deposition in gas storage facilities can narrow or even completely block the natural gas injection and production flow channels, affecting the operational efficiency and safety of the storage facility. Currently, methods for preventing salt deposition in gas storage facilities mainly draw on experience from the oil and gas reservoir development stage. Depending on the different rates and degrees of salt deposition in the reservoir, common methods include periodic water washing, pre-injection of salt-suppressing agents, continuous water injection, salt dissolution with salt-suppressing agents, and mechanical desalination. In traditional applications, when performing water-based salt prevention operations on production tubing in gas wells during the development stage, a fluid circulation channel can be established using the casing. Water or salt-suppressing agents are injected into the annulus, and then a high-speed gas flow carries the salt-dissolved liquid out of the tubing. This method is simple to operate, has low operating costs, and provides good salt removal and prevention effects. Furthermore, the operation does not require well shut-in, therefore, it is widely used in gas well salt prevention operations. However, gas storage production wells typically use integrated injection and production tubing, which is usually a stationary string. An external packer is designed and installed on the tubing to isolate the casing and tubing, ensuring operational safety. This, however, prevents the injection fluid from establishing an effective circulation system. Water or salt suppressants can only be injected through the tubing and then backflowed through the tubing. Therefore, well shutdown measures must be taken during operations. Applying such salt control methods to gas storage facilities can significantly and adversely affect the injection and production efficiency and normal operation of the gas storage facility.

[0003] The information disclosed in the background section of this invention is intended only to enhance the understanding of the general background of this invention, and should not be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art. Summary of the Invention

[0004] To address the above problems, the present invention provides an automatic salt control system for depleted oil and gas reservoirs. In one embodiment, the system includes:

[0005] A salt-proof actuator is configured to inject salt-proof fluid into the high-pressure pipeline of the gas storage facility during the gas injection operation.

[0006] The information acquisition module is configured to collect pipeline gas-liquid information during the gas extraction operation of the gas storage facility and pipeline liquid injection information of the anti-salt actuator during the gas injection operation in real time.

[0007] The data analysis module, which is communicatively connected to the information acquisition module, is configured to analyze the current salt formation status of the gas storage tank based on the pipeline gas-liquid information during the gas extraction operation, and to analyze the injection status of the anti-salt fluid based on the pipeline liquid injection information of the anti-salt actuator during the gas injection operation.

[0008] The scheme decision module is configured to determine the activation status and control parameters of the anti-salt actuator based on the analysis results of the data analysis module, so as to realize intelligent and controllable anti-salt in the gas storage.

[0009] Preferably, in one embodiment, the anti-salt actuator includes: a liquid storage tank, a high-pressure fluid pipeline, and a fluid valve;

[0010] The storage tank is connected to the downhole tubing of the gas storage tank via a high-pressure fluid pipeline and is used to store and provide replenishment fluid for salt prevention.

[0011] The fluid valve is installed on the high-pressure fluid pipeline and connected to the downstream end of the storage tank. It is used to control the injection of anti-salt fluid by adjusting the valve opening and duration.

[0012] Furthermore, in one embodiment, the high-pressure fluid pipeline includes a surface high-pressure pipeline and a wellbore high-pressure pipeline, which are interconnected by a set wellhead device, and the downstream end of the wellbore high-pressure pipeline is connected to the tubing by a set fluid valve.

[0013] The fluid valve is installed on the high-pressure pipeline on the ground between the storage tank and the wellhead connection device.

[0014] In an optional embodiment, the salt-proof actuator further includes:

[0015] A booster pump is installed on the high-pressure pipeline on the ground between the fluid valve and the wellhead connection device. It is used to cooperate with the solenoid valve to control the pressure of the fluid in the pipeline as needed.

[0016] Specifically, in one embodiment, the wellhead connection device adopts the wellhead gas production tree device of an oil and gas well to realize the professional connection between the surface high-pressure pipeline and the wellbore high-pressure pipeline.

[0017] In a preferred embodiment, the downstream end of the high-pressure pipeline in the wellbore is connected to the tubing via a threaded gas-tight connection using a high-pressure full-bore check valve. The valve's inner diameter is the same as that of the tubing, and an outlet hole with a certain angle is provided on the inner wall surface. The outlet hole is unidirectionally connected to the inlet end of the check valve.

[0018] Furthermore, in one embodiment, the information acquisition module includes: a gas-liquid separation device installed on the main gas transmission line of the gas storage facility, located at the downstream end of the main gas transmission line, used to separate the fluid produced during the gas extraction operation of the gas storage facility into gas phase and liquid phase;

[0019] The gas phase branch formed by separation continues to connect to the main gas transmission line, while the liquid phase branch is connected to the recovery tank through the liquid transmission line, realizing the environmentally friendly collection of liquid produced during gas extraction operations in the gas storage facility.

[0020] Specifically, in one embodiment, the information acquisition module includes: a gas flow meter, a first pressure gauge, and a first liquid flow meter;

[0021] Both the gas flow meter and the first pressure gauge are installed on the main gas transmission line of the gas storage tank and connected to the downstream end of the gas phase branch of the gas-liquid separator. The gas flow meter is used to collect gas flow data in the gas phase branch in real time; the first pressure gauge is used to collect pressure data in the gas phase branch in real time.

[0022] The first liquid flow meter is installed on the liquid delivery pipeline of the liquid phase branch and connected to the downstream end of the liquid phase branch of the gas-liquid separation device, and is used to collect liquid flow data in the liquid phase branch in real time.

[0023] Optionally, in one embodiment, the information acquisition module further includes: a second liquid flow meter and a second pressure gauge;

[0024] The second liquid flow meter and the second pressure gauge are both installed on the ground high-pressure pipeline of the anti-salt actuator and connected to the downstream end of the fluid valve. The second liquid flow meter is used to collect the flow information of the anti-salt fluid in the pipeline of the anti-salt actuator in real time; the second pressure gauge is used to collect the fluid pressure information in the pipeline of the anti-salt actuator in real time.

[0025] Furthermore, in one embodiment, the information acquisition module further includes: data acquisition software, which is used to receive and organize various pipeline gas-liquid information and pipeline liquid injection information transmitted from the information acquisition module, and transmit them to the data analysis module.

[0026] In a preferred embodiment, the data analysis module is configured as follows:

[0027] During gas extraction operations at the gas storage facility, data analysis software is used to intelligently analyze the gas and liquid data of the gas extraction pipeline transmitted from the data acquisition software. The software also plots the relationship curves between gas production and water precipitation during the gas extraction process, as well as the relationship curves between daily gas production and pressure changes. Combined with preset salt formation alarm thresholds, the software generates trigger commands for the scheme decision-making software, and transmits the analysis results to the scheme decision-making module.

[0028] Specifically, in one embodiment, the data analysis module is further configured as follows:

[0029] During the gas injection operation of the gas storage facility, after the anti-salt actuator is activated, the data analysis software intelligently analyzes the liquid data of the injection pipeline transmitted by the data acquisition software. Combined with the original formation fluid replenishment plan, it determines whether the fluid data of the current anti-salt actuator needs to be adjusted. If so, it generates fluid replenishment adjustment parameters and transmits them to the plan decision module in conjunction with the analysis results.

[0030] In a preferred embodiment, the scheme decision module is configured as follows:

[0031] Upon receiving the trigger command from the data analysis module, the system combines the analysis results with the gas storage facility's operating mode to formulate a matching formation fluid replenishment plan and generate control commands for the anti-salt actuator, which are then transmitted to the fluid valves; or

[0032] The data analysis module generates adjustment and control commands for the anti-salt actuator based on the replenishment adjustment parameters and transmits them to the fluid valve.

[0033] Based on other aspects of the system described in any one or more of the above embodiments, the present invention also provides an automatic salt prevention method for depleted oil and gas reservoirs, the method comprising:

[0034] Gas extraction information collection steps: Real-time collection of pipeline gas and liquid information during the gas extraction operation of the gas storage facility through the information collection module;

[0035] Gas extraction analysis steps: Based on the pipeline gas-liquid information during the gas extraction operation, analyze the current salt deposition status of the gas storage facility;

[0036] The decision-making process controls the start-up and operation parameters of the gas storage anti-salinity actuator based on the analysis results of the gas extraction analysis process and the operation mode of the gas storage facility.

[0037] After the injection information collection steps and the start of the anti-salt actuator, the pipeline injection information of the anti-salt actuator during the gas injection operation of the gas storage is collected in real time through the information collection module.

[0038] The injection analysis steps involve analyzing the injection status of the anti-salt fluid based on the pipeline injection information of the anti-salt actuator during the gas injection operation.

[0039] The adjustment decision-making steps and the analysis results of the liquid injection analysis steps determine the control parameters of the anti-salt actuator to achieve intelligent and controllable anti-salt measures in the gas storage facility.

[0040] Compared with the closest prior art, the present invention also has the following beneficial effects:

[0041] The present invention provides an automatic anti-salinity system for a depleted oil and gas reservoir. The system uses an anti-salinity actuator to inject anti-salinity fluid into the high-pressure pipeline of the gas storage during the gas injection operation. This overcomes the limitations of existing technologies in anti-salinity scenarios, does not require shutting down the normal injection and production process of the gas storage, and can automatically carry out salt formation prevention and control operations while the gas storage is in normal injection and production operation.

[0042] In addition, the present invention sets up an information acquisition system to collect gas-liquid information of the gas pipeline during the gas extraction process of the gas storage facility in real time as the basis for decision-making on the anti-salinity liquid replenishment plan. This can effectively understand the water evaporation, condensation or production status of the formation during the gas extraction period of the gas storage facility, fundamentally ensuring the matching of the liquid replenishment plan with the current anti-salinity needs of the gas storage facility, and ensuring the quality of anti-salinity operations.

[0043] Furthermore, the present invention also monitors the flow rate and pressure data of the fluid during the anti-salt injection process in real time, analyzes the rationality of the current replenishment parameters in real time, and adjusts the replenishment parameters according to actual needs. This can maximize the functional advantages of the anti-salt actuator of the present invention, improve the timeliness of anti-salt management of gas storage facilities, and effectively reduce the consumption of time and cost resources.

[0044] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the description, claims, and drawings. Attached Figure Description

[0045] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with the embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:

[0046] Figure 1 This is a schematic diagram of the automatic salt-proof system for a depleted oil and gas reservoir provided in one embodiment of the present invention;

[0047] Figure 2 This is a detailed diagram illustrating the connection principle of an automatic salt-proof system for a depleted oil and gas reservoir provided in another embodiment of the present invention;

[0048] Figure 3 This is a schematic diagram illustrating the application setup of the automatic salt-proof system for depleted oil and gas reservoirs provided in this embodiment of the invention.

[0049] Figure 4 This is a schematic flowchart of an automatic salt prevention method for a depleted oil and gas reservoir-type gas storage facility provided in an embodiment of the present invention;

[0050] Appendix Figure 3In the middle, 1-Central control system of gas storage, 2-Gas storage injection and production platform, 3-Gas storage injection and production well, 4-Anti-salt command receiver, 5-Data transmission line. Detailed Implementation

[0051] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings and examples. Those skilled in the art will then fully understand how the present invention uses technical means to solve technical problems and achieve technical effects, and will be able to implement the present invention specifically based on the above-described implementation process. It should be noted that, as long as there is no conflict, the various embodiments and features of the present invention can be combined with each other, and the resulting technical solutions are all within the protection scope of the present invention.

[0052] Although the flowchart describes the operations as sequential processes, many of these operations can be performed in parallel, concurrently, or simultaneously. The order of the operations can be rearranged. A process can terminate when its operation is complete, but it may also have additional steps not included in the diagram. A process can correspond to a method, function, procedure, subroutine, subroutine, etc.

[0053] Computer equipment includes user equipment and network equipment. User equipment or clients include, but are not limited to, computers, smartphones, PDAs, etc.; network equipment includes, but is not limited to, a single network server, a server group consisting of multiple network servers, or a cloud based on cloud computing consisting of a large number of computers or network servers. Computer equipment can operate independently to implement this invention, or it can connect to a network and implement this invention through interaction with other computer equipment in the network. The network in which the computer equipment is located includes, but is not limited to, the Internet, wide area network, metropolitan area network, local area network, VPN network, etc.

[0054] The terms “first,” “second,” etc., may be used herein to describe various units, but these units should not be limited by these terms; they are used merely to distinguish one unit from another. The term “and / or” as used herein includes any and all combinations of one or more of the associated listed items. When a unit is referred to as “connected” or “coupled” to another unit, it may be directly connected or coupled to said other unit, or there may be intermediate units present.

[0055] After depleted oil and gas reservoirs containing highly saline formation water are converted into gas storage facilities, the continuous "concentration" effect of injected (drying) natural gas often leads to varying degrees of salt deposition after several operating cycles. Salt deposition narrows or even completely blocks the natural gas injection and production flow channels, affecting the operational efficiency and safety of the gas storage facility. Current methods for salt prevention in gas storage facilities mainly draw on experience from the oil and gas reservoir development phase. Depending on the rate and degree of salt deposition, common methods include periodic water washing, pre-injection of salt inhibitors, continuous water injection, salt dissolution with salt inhibitors, and mechanical desalination. When performing salt removal and prevention operations on production tubing in gas wells during the development phase, a fluid circulation channel can be established using the casing. Water or salt inhibitors are injected into the annulus, and then a high-speed gas flow carries the salt-dissolved liquid out of the tubing. This method is simple to operate, has low operating costs, and provides good salt removal and prevention effects, and the operation does not require well shut-in. Therefore, it is widely used in gas well salt prevention operations. Gas storage production wells typically use integrated injection and production tubing strings. These strings are usually stationary, and an external packer is designed and installed on the tubing to isolate the casing and tubing, ensuring operational safety. However, this prevents the injection fluid from establishing effective circulation; water or salt suppressants can only be injected through the tubing and then backflowed through the tubing. Therefore, well shutdown measures must be taken during operations. This adversely affects the injection and production efficiency and normal operation of the gas storage facility.

[0056] To address the challenges of complex processes, high operating costs, and difficulty in accurately determining the timing of salt deposition prevention in depleted oil and gas reservoirs, this invention proposes an automated salt deposition prevention system and method for such reservoirs. The system allows for salt deposition prevention operations to be performed while the reservoir is operating normally. The entire process is fully automated, requiring no human intervention, and is characterized by precision, efficiency, and intelligence. It minimizes the damage caused by salt deposition to the reservoir, improves operational efficiency, reduces on-site personnel workload, and saves on reservoir operating costs.

[0057] The structure and implementation principle of the system according to embodiments of the present invention will now be described in detail with reference to the accompanying drawings. Although the connection order of the various structures is shown in the structural diagram, in some cases, the claimed functional components may be constructed in a different order than that shown here.

[0058] Example 1

[0059] Figure 1 This diagram illustrates the structure of the automatic salt control system for depleted oil and gas reservoirs provided in Embodiment 1 of the present invention. (Refer to...) Figure 1 It can be seen that the system includes:

[0060] A salt-proof actuator is configured to inject salt-proof fluid into the high-pressure pipeline of the gas storage facility during the gas injection operation.

[0061] The information acquisition module is configured to collect pipeline gas-liquid information during the gas extraction operation of the gas storage facility and pipeline liquid injection information of the anti-salt actuator during the gas injection operation in real time.

[0062] The data analysis module, which is communicatively connected to the information acquisition module, is configured to analyze the current salt formation status of the gas storage tank based on the pipeline gas-liquid information during the gas extraction operation, and to analyze the injection status of the anti-salt fluid based on the pipeline liquid injection information of the anti-salt actuator during the gas injection operation.

[0063] The scheme decision module is configured to determine the activation status and control parameters of the anti-salt actuator based on the analysis results of the data analysis module, so as to realize intelligent and controllable anti-salt in the gas storage.

[0064] The automatic salt prevention system provided in the above embodiments integrates functions such as gas-liquid separation, all-weather monitoring, analysis of precipitated water patterns, calculation and timing optimization of replenishment water volume, and automatic water replenishment. It mainly comprises four functions: information acquisition, data analysis, scheme decision-making, and execution mechanisms. Operating in conjunction with the existing pipeline structure of the gas storage facility, the system will run continuously during the gas storage facility's injection and production processes. During the gas production phase, the information acquisition and data analysis modules are the main working modules, while the scheme decision-making and execution mechanism modules are in standby mode. During the gas injection phase, the information acquisition, data analysis, scheme decision-making, and execution mechanism modules are the main working modules. The system modules are mainly distributed on the surface and inside the wellbore, with the information acquisition, data analysis, and scheme decision-making modules located on the surface; the salt prevention execution mechanism is distributed both on the surface and inside the wellbore. Utilizing this system and its implementation principles, real-time monitoring and timely handling of salt formation in the gas storage facility can be achieved, preventing serious wellbore or formation salt formation problems and ensuring the continuous, stable, and safe operation of the gas storage facility. Simultaneously, it significantly reduces the complexity and cost of salt formation prevention operations in the gas storage facility.

[0065] Figure 2 The diagram shows a detailed connection principle diagram of the automatic salt control system for depleted oil and gas reservoirs provided in this embodiment of the invention. Figure 2 As shown, in a practical application, in one embodiment, the anti-salt actuator includes: a liquid storage tank, a high-pressure fluid pipeline, and a fluid valve;

[0066] The storage tank is connected to the downhole tubing of the gas storage tank via a high-pressure fluid pipeline and is used to store and provide replenishment fluid for salt prevention.

[0067] The fluid valve is installed on the high-pressure fluid pipeline and connected to the downstream end of the storage tank. It is used to control the injection of anti-salt fluid by adjusting the valve opening and duration.

[0068] Based on the above embodiments, the controllable high-pressure injection of anti-salt fluid can be automatically realized in response to the control command of the fluid valve, thereby reducing the damage caused by salt formation to the gas storage facility, improving the operating efficiency of the gas storage facility, reducing the workload of on-site personnel, and saving the operating cost of the gas storage facility.

[0069] Furthermore, considering that if the fluid valve is installed in the wellbore, it will inevitably be difficult to operate and control in actual application, and the installation and maintenance work will be complicated, the researchers of this invention have decided that in a preferred embodiment, the fluid high-pressure pipeline includes a surface high-pressure pipeline and a wellbore high-pressure pipeline, which are connected to each other through a set wellhead device, and the downstream end of the wellbore high-pressure pipeline is connected to the oil pipe through a set fluid valve.

[0070] The fluid valve is installed on the high-pressure pipeline on the ground between the storage tank and the wellhead connection device.

[0071] Specifically, in one embodiment, the fluid valve is an electromagnetic valve, and the wellhead connection device is a wellhead gas production tree device for oil and gas wells, realizing a professional connection between the surface high-pressure pipeline and the wellbore high-pressure pipeline.

[0072] In a preferred embodiment, the downstream end of the high-pressure pipeline in the wellbore is connected to the tubing via a threaded gas-tight connection using a high-pressure full-bore check valve. The valve's inner diameter is the same as that of the tubing, and an outlet hole with a certain angle is provided on the inner wall surface. The outlet hole is unidirectionally connected to the inlet end of the check valve.

[0073] Furthermore, considering the limitations of using electromagnetic valves to regulate fluid flow in high-pressure pipelines—typically only adjusting the fluid flow rate within a set timeframe—the advantages of high-pressure pipelines can be maximized and the operational efficiency and performance of the anti-salt actuator can be improved only when the fluid pressure meets set conditions. To overcome the limitations of the fluid's own flow pressure, in a preferred embodiment, the anti-salt actuator further includes:

[0074] A booster pump is installed on the high-pressure pipeline on the ground between the fluid valve and the wellhead connection device. It is used to cooperate with the solenoid valve to control the pressure of the fluid in the pipeline as needed.

[0075] Based on the anti-salt actuator provided in the above embodiments, it is possible to achieve efficient and accurate replenishment of anti-salt fluid, and there is no need to worry about the reverse transmission of anti-salt fluid.

[0076] In practical applications, the anti-salt actuator module consists of two parts: a surface unit and an internal unit. The surface unit includes a high-pressure fluid delivery pipeline, a command receiver, a solenoid valve, a storage tank, and a booster pump. The internal unit includes a high-pressure fluid delivery pipeline and a high-pressure full-bore single-flow valve. The system includes a command receiver that receives commands from the system's decision-making module. The downstream end of the command receiver is connected to the solenoid valve and / or booster pump via wired or wireless data lines. The solenoid valve is connected to the storage tank via a high-pressure fluid pipeline. The solenoid valve can control the opening and closing degree according to commands, thereby controlling the fluid flow rate. The downstream end of the solenoid valve is connected to the booster pump via a high-pressure pipeline. The downstream end of the booster pump is connected to the surface high-pressure fluid delivery pipeline at the wellhead via a high-pressure pipeline. The downstream end of the surface high-pressure fluid delivery pipeline is connected to a designated wellhead connection device. The downstream end of the wellhead connection device is connected to the high-pressure fluid delivery pipeline inside the wellbore. The high-pressure fluid delivery pipeline inside the wellbore is connected to a high-pressure full-bore check valve. The high-pressure full-bore check valve is a one-way flow valve that can be connected to the tubing with a threaded gas seal. The inner diameter of the check valve is the same as the inner diameter of the tubing, and its inner wall has an outlet hole at a certain angle. The outlet hole is unidirectionally connected to the inlet end of the check valve. Its pressure resistance specification can be selected according to the injection and production well pressure conditions.

[0077] Furthermore, the system of the present invention collects pipeline gas-liquid information during the gas extraction operation of the gas storage facility and pipeline liquid injection information of the anti-salt actuator during the gas injection operation in real time through the information acquisition module;

[0078] Specifically, in one embodiment, the information acquisition module includes: a gas-liquid separation device installed on the main gas transmission line of the gas storage facility, which is located at the downstream end of the main gas transmission line and is used to separate the fluid produced during the gas extraction operation of the gas storage facility into gas phase and liquid phase;

[0079] The gas phase branch formed by separation continues to connect to the main gas transmission line, while the liquid phase branch is connected to the recovery tank through the liquid transmission line, realizing the environmentally friendly collection of liquid produced during gas extraction operations in the gas storage facility.

[0080] Furthermore, in one embodiment, the information acquisition module includes: a gas flow meter, a first pressure gauge, and a first liquid flow meter;

[0081] Both the gas flow meter and the first pressure gauge are installed on the main gas transmission line of the gas storage tank and connected to the downstream end of the gas phase branch of the gas-liquid separator. The gas flow meter is used to collect gas flow data in the gas phase branch in real time; the first pressure gauge is used to collect pressure data in the gas phase branch in real time.

[0082] The first liquid flow meter is installed on the liquid delivery pipeline of the liquid phase branch and connected to the downstream end of the liquid phase branch of the gas-liquid separation device, and is used to collect liquid flow data in the liquid phase branch in real time.

[0083] The gas flow meter, the first pressure gauge, and the first liquid flow meter all have remote data transmission capabilities, enabling them to transmit the collected data remotely to the data acquisition software of the control system in real time, so that the data can be processed and used to provide data services for the data analysis module.

[0084] In the above embodiments, a gas-liquid separation device is used to divert the produced liquid from the gas extraction and transmission pipeline. This not only avoids the impact of liquid on gas transmission efficiency when water and gas are transported simultaneously, but also overcomes the interference of liquid factors in the gas flow meter, improving gas extraction and transmission efficiency while ensuring the accuracy of information acquisition by the gas flow meter and gas pressure gauge. Furthermore, this invention collects the separated liquid through a liquid phase branch to a dedicated produced liquid recovery tank, and installs corresponding fluid flow meters on the liquid phase pipeline. This avoids environmental pollution from the produced liquid while providing an effective strategy for accurately collecting produced liquid data during gas extraction operations. The combined gas flow and pressure data from the gas extraction operation provide data support for subsequent data analysis modules, facilitating reliable and accurate analysis of control commands for the anti-salt actuator.

[0085] In practical applications, the system modules are mainly distributed on the surface and inside the wellbore. The information acquisition module, data analysis module, and solution decision-making module are located on the surface; the salt control actuators are distributed both on the surface and inside the wellbore. Using this system and method, real-time monitoring and timely handling of salt deposits in gas storage facilities can be achieved, preventing serious wellbore or formation salt deposit problems and ensuring the continuous, stable, and safe operation of the gas storage facility. At the same time, it significantly reduces the complexity and cost of salt control operations in gas storage facilities.

[0086] The system operates continuously during the gas injection and extraction process of the gas storage facility. The anti-salt actuator mainly operates during the gas injection operation. However, during the gas extraction process of the gas storage facility, the scheme decision module and the actuator module are in standby mode. The information acquisition module collects pipeline gas and liquid data during the gas extraction process. The information acquisition module includes a gas-liquid separation device, a computer, a gas flow meter with remote transmission function, a liquid flow meter and a pressure sensor, and a liquid recovery device.

[0087] The gas-liquid separation device is connected to the main pipeline at the injection / production wellhead. The device has two outlets: a gas outlet (primary outlet, connected to the main pipeline at the injection / production wellhead) and a liquid outlet (secondary outlet, connected to the liquid recovery device). A gas flow meter with remote transmission capability and a first pressure gauge are installed on the gas outlet pipeline, and a first liquid flow meter with remote transmission capability is installed on the liquid outlet pipeline. The gas flow meter can be set to an accuracy of 1.5 class, and the first liquid flow meter to an accuracy of 1 class. The sensors of the gas and liquid flow meters are connected to the control system computer via data cables.

[0088] In actual setup, the first pressure gauge can be connected to the downstream end of the gas flow meter. Furthermore, the downstream end of the first pressure gauge can be connected to the external transmission pipeline of the gas sampling pipeline.

[0089] However, the inventors would like to point out that in other embodiments, the gas flow meter and the first pressure gauge may be connected in a different order, and this part is not particularly limited by the present invention.

[0090] In addition, considering that real-time acquisition of flow rate and pressure data of fluid in injection pipeline during the start-up and operation of the anti-salt actuator can achieve the function of monitoring and adjusting the injection status, in a preferred embodiment, the information acquisition module further includes: a second liquid flow meter and a second pressure gauge;

[0091] The second liquid flow meter and the second pressure gauge are both installed on the ground high-pressure pipeline of the anti-salt actuator and connected to the downstream end of the fluid valve. The second liquid flow meter is used to collect the flow information of the anti-salt fluid in the pipeline of the anti-salt actuator in real time; the second pressure gauge is used to collect the fluid pressure information in the pipeline of the anti-salt actuator in real time.

[0092] The second liquid flow meter and the second pressure meter both have data remote transmission function. In actual application, the second pressure meter can be set to be connected to the downstream end of the second liquid flow meter. Furthermore, the downstream end of the second pressure meter is connected to the surface high-pressure fluid delivery pipeline at the wellhead through a high-pressure pipeline.

[0093] However, the inventors would like to point out that in other embodiments, the second liquid flow meter and the second pressure gauge may be connected in other orders, and this part is not particularly limited by the present invention.

[0094] Since multiple data sources from various devices are involved, in order to achieve synchronous and orderly data analysis, in a specific embodiment, the information acquisition module is further provided with: data acquisition software, which is used to receive and organize various pipeline gas-liquid information and pipeline liquid injection information transmitted from the information acquisition module, and then transmit them to the data analysis module.

[0095] In practical applications, the data acquisition software is installed on the central control system computer. The sensors of various flow meters and pressure gauges are connected to the interface of the central control computer through data lines. The information acquisition software is used to acquire, process, and record (store) the data sent by the flow meter sensors and pressure gauge sensors.

[0096] When put into application, the system of this invention is combined with the central control system in the injection-production well cluster of the reservoir area, as shown in the attached diagram. Figure 3As shown, multiple gas storage injection and production platforms are connected to the central control system. The anti-salt actuator, information acquisition hardware, and sensors of the automatic anti-salt system of this invention are installed in each gas storage injection and production platform. They receive control commands generated by the scheme decision module of the central control system through the set command receiver.

[0097] Furthermore, the scheme decision module is typically in standby mode during the gas extraction phase of the gas storage facility, and is activated by specific analysis results from the data analysis module. Specifically, in one embodiment, the data analysis module includes data analysis software. During gas extraction operations at the gas storage facility, the data analysis software intelligently analyzes the gas-liquid data of the gas extraction pipeline transmitted by the data acquisition software, and plots the relationship curves between gas production and water precipitation, and between daily gas production and pressure changes during the gas extraction process. Combined with a preset salt deposition alarm threshold, it generates a trigger command for the scheme decision software, which, along with the analysis results, is then transmitted to the scheme decision module.

[0098] This invention system collects data on gas production, liquid production, and gas pipeline pressure (equivalent to wellhead pressure data) during the gas production period of a gas storage facility using an information acquisition module. Then, it uses a data analysis module to analyze the correlation between gas production and liquid production, and between gas production and wellhead pressure, to understand the formation water evaporation, condensation, or production patterns during the gas production period. Finally, it uses a scheme decision-making module to formulate a formation liquid replenishment plan for the gas injection period, including the total replenishment amount, single replenishment volume, and replenishment timing. Finally, it uses an actuator to receive signal commands from the scheme decision-making module and automatically execute the liquid replenishment operation.

[0099] In another embodiment, the data analysis module is further configured as follows:

[0100] During the gas injection operation of the gas storage facility, after the anti-salt actuator is activated, the data analysis software intelligently analyzes the liquid data of the injection pipeline transmitted by the data acquisition software. Combined with the existing formation fluid replenishment plan, it determines whether the fluid data of the current anti-salt actuator needs to be adjusted. If so, it generates fluid replenishment adjustment parameters and transmits them to the plan decision module in combination with the analysis results.

[0101] In practical applications, a data analysis module, including a computer and corresponding data analysis software, can be set up to automatically read, save, and analyze the information collected by the sensors in the information acquisition module. Furthermore, based on the actual needs of the salt control scenario, the data analysis software can not only analyze the relationship between gas production and wellhead pressure and plot the relationship curve between gas production and precipitated water, but also provide alarms for data anomalies during the gas storage injection and production operation. When a fault occurs during the injection and production operation (for example, a significant decrease in both gas and liquid flow rates during gas production indicates a severe blockage in the gas production path), it allows staff to promptly detect the problem and adjust the gas storage injection and production operation strategy accordingly. Additionally, when one or more structural functions of the automatic salt control system of this invention malfunction, it can also be reflected in the real-time collected information, enabling staff to promptly detect and perform maintenance.

[0102] Furthermore, in a preferred embodiment, the scheme decision module is configured as follows:

[0103] Upon receiving the trigger command from the data analysis module, the system combines the analysis results with the gas storage facility's operating mode to formulate a matching formation fluid replenishment plan and generate control commands for the anti-salt actuator, which are then transmitted to the fluid valves; or

[0104] The data analysis module generates adjustment and control commands for the anti-salt actuator based on the replenishment adjustment parameters and transmits them to the fluid valve.

[0105] Specifically, the scheme decision-making module can be configured to include a computer and corresponding scheme decision-making software. The scheme decision-making software can read the analysis results from the data analysis software and formulate corresponding control and regulation decision-making schemes. The scheme decision-making software has functions such as calculating cumulative water replenishment volume, determining the number of water replenishments, and determining the water replenishment time. The scheme decision-making module can directly transmit decision instructions to the instruction receiving module of the execution mechanism module. The scheme decision-making module generally operates during the gas injection period of the gas storage facility. In particular, when the data analysis module issues an alarm indication during the gas extraction period of the gas storage facility, it can also trigger the scheme decision-making module to start or implement other solutions during the gas extraction period of the gas storage facility, based on actual needs. In this case, the scheme decision-making module is also configured to provide a scheme decision report and a report on the expected results of scheme implementation.

[0106] Example Case:

[0107] Taking a gas storage platform as an example, in practical application, the working principle of the automatic salt prevention system for depleted oil and gas reservoirs of this invention is as follows: The information acquisition module collects data on gas production, liquid production, and wellhead pressure during the gas production period; the data analysis module analyzes the correlation between gas production and liquid production, and between gas production and wellhead pressure during the gas production period, to understand the formation water evaporation, condensation, or production patterns during the gas production period; the scheme decision module formulates a formation liquid replenishment scheme during the gas injection period, including the total liquid replenishment amount, single liquid replenishment amount, and liquid replenishment timing; and the actuator receives signal commands from the scheme decision module and automatically executes the liquid replenishment operation.

[0108] The gas-liquid separation unit is connected to the main gas pipeline at the wellhead. It separates the produced fluid from the gas storage facility during the gas extraction period into gas and liquid phases. The gas phase branch is reconnected to the main gas pipeline, and the liquid phase branch is connected to the liquid pipeline. A remote-reading gas flow meter is connected to the downstream end of the gas phase branch to collect flow data. A remote-reading liquid flow meter is also connected to the downstream end of the liquid phase branch. A recovery tank is connected to the downstream end of the remote-reading liquid flow meter to collect the liquid produced during gas extraction. A remote-reading pressure gauge is connected to the downstream end of the remote-reading gas flow meter to collect pressure data from the gas phase branch. Data acquisition software is installed on the central control computer. The flow meter and pressure gauge sensors are connected to the central control computer interface via data cables, and the software collects the data transmitted by the flow meter and pressure gauge sensors.

[0109] Analyze the data collected by the information acquisition software using data analysis software and plot the curves; use the solution decision-making software to read the results of the data analysis software and make an implementation design plan.

[0110] The system receives command signals from the scheme decision software using a command receiver and sends the commands to the solenoid valve. The solenoid valve is connected to the liquid storage tank via a pipeline, and the solenoid valve controls the liquid flow rate in the pipeline. In practical applications, considering the high cost of high-pressure pipelines, when designing the anti-salt actuator, it is optional to set its ground pipeline, including both ordinary ground pipelines and high-pressure ground pipelines, and have them professionally connected before the booster pump. This controls the cost of hardware consumption without affecting the normal operation of the mechanism.

[0111] A reservoir is used to store the makeup fluid, which can be, but is not limited to, clean water, deionized water, or liquid salt suppressant. A booster pump is connected downstream of a solenoid valve to pressurize the makeup fluid to a pressure higher than the injection point, allowing the makeup fluid to smoothly enter the oil pipe. A remote-reading liquid flow meter is connected downstream of the booster pump to collect flow data from the makeup pipeline. A remote-reading pressure gauge is connected downstream of the remote-reading liquid flow meter to collect pressure data from the makeup pipeline.

[0112] The surface high-pressure fluid delivery pipeline is connected to the downstream end of a pressure gauge with remote transmission capability. The surface high-pressure fluid delivery pipeline is used to transmit the makeup fluid to the wellhead. The downstream end of the surface high-pressure fluid delivery pipeline is connected to the upper end of a dedicated wellhead connection device. The upstream end of the high-pressure fluid delivery pipeline inside the wellbore is connected to the lower end of the dedicated wellhead connection device. The high-pressure fluid delivery pipeline inside the wellbore is used to transmit the makeup fluid to a high-pressure full-bore single-flow valve. The high-pressure full-bore single-flow valve has a dedicated interface that can be connected to the downstream end of the high-pressure fluid delivery pipeline inside the wellbore. The high-pressure full-bore single-flow valve is used to inject the makeup fluid into the tubing. After entering the tubing, the makeup fluid mixes and atomizes with the high-speed flowing natural gas and is carried to the depths of the wellbore until it penetrates the formation. After entering the wellbore, the makeup fluid has a dissolving and flushing effect on areas where salt has formed on the wellbore wall, and a diluting and reducing the salinity of the formation water. In particular, if the injected makeup fluid is a liquid salt inhibitor, in addition to the above functions, it also has the effect of delaying salt crystallization and preventing salt crystal adhesion and aggregation.

[0113] During the gas production stage of the gas storage facility, natural gas enters the wellhead gas tree from the reservoir through tubing and a high-pressure full-bore single-flow valve, and then flows along the main gas pipeline to the gas-liquid separation unit. The gas-liquid separation unit separates the produced gas-liquid two-phase mixture, with the separated phases flowing out along the main gas branch and the secondary liquid branch. The separated natural gas continues to flow along the main gas branch, passing through a gas flow meter and a pressure gauge with remote transmission capabilities before entering the external transmission pipeline. The separated liquid flows along the secondary liquid branch, passing through a liquid flow meter with remote transmission capabilities before entering the recovery tank. During gas production operation, the gas flow meter, pressure gauge, and liquid flow meter with remote transmission capabilities continuously transmit metering data to the data acquisition software. The data acquisition software processes and integrates the data before transmitting it to the data analysis software. The data analysis software performs intelligent analysis of the data, plotting curves showing the relationship between gas production and water precipitation, and the relationship between daily gas production and pressure changes, etc. The data analysis software sets a salt deposition alarm threshold. When the salt deposition alarm threshold is not reached, the data analysis software records the analysis results and saves them temporarily. When the salt deposition alarm threshold is reached or exceeded, the data analysis software will trigger the solution decision software, which will then generate a solution report.

[0114] During the gas injection phase of the gas storage facility, the data analysis software is activated and transmits the injection period data results to the scheme decision software. The scheme decision software formulates a corresponding decision plan based on the data analysis results and then transmits the formulated decision plan to the command receiver. The command receiver transmits signals to the solenoid valves and booster pumps, thereby controlling the opening degree and duration of the solenoid valves, thus controlling the volume of liquid entering the pipeline from the storage tank, i.e., controlling the liquid injection rate and total volume in a single operation. The liquid passing through the solenoid valves flows downstream into the booster pump. The booster pump receives signals from the command receiver and pressurizes the liquid entering the pump to a specified pressure value. After exiting the booster pump, the liquid passes through a second liquid flow meter and a second pressure gauge with remote transmission capabilities before entering the high-pressure delivery pipeline on the ground. The liquid flow meter and pressure gauge with remote transmission capabilities transmit data to the data acquisition software. The liquid enters the wellhead gas production tree along the surface high-pressure fluid delivery pipeline, and then enters the high-pressure full-bore one-way valve along the high-pressure fluid delivery pipeline inside the wellbore. Under pressure, the liquid entering the one-way valve enters the tubing from the outlet of the one-way valve. Carried by the injected natural gas flow, the liquid flows along the tubing to the bottom of the well. During the flow process, it can wash away the salt crystal particles attached to the well wall. After reaching the bottom of the well, under pressure, the liquid will penetrate a certain distance into the near-wellbore formation to dissolve the salt crystal particles near the near-wellbore formation or to prevent salt formation during the gas production period.

[0115] Meanwhile, the data acquisition module also receives real-time data from the second liquid flow meter and the second pressure gauge, monitors and analyzes the liquid replenishment execution status, and further, the solution decision module makes a liquid replenishment adjustment plan based on the analysis results according to actual needs, so as to control the optimized operation of the solenoid valve and / or booster pump.

[0116] The automatic salt prevention system and its principle for depleted oil and gas reservoirs provided by this invention can be effectively applied to the salt prevention and injection / production operations of gas reservoirs. This automatic salt prevention system integrates functions such as gas-liquid separation, all-weather monitoring, analysis of precipitated water patterns, calculation and timing optimization of replenishment water volume, and automatic replenishment. It mainly consists of four modules: information acquisition, data analysis, scheme decision-making, and execution mechanism. The system will operate continuously during the gas reservoir injection / production process. Through information acquisition and data analysis, it collects and analyzes fluid information during the gas reservoir injection / production operation, serving to determine the control scheme of the salt prevention execution mechanism. The system modules of this invention are mainly distributed on the surface and inside the wellbore. The information acquisition module, data analysis module, and scheme decision-making module are located on the surface; the execution mechanism is located on the surface and inside the wellbore. Applying this system and method allows for salt prevention and control operations during normal operation of the gas reservoir. The entire process is fully automatic, requiring no human intervention, and features precision, efficiency, and intelligence. It can minimize the damage caused by salt formation to the gas reservoir, improve the operating efficiency of the gas reservoir, reduce the workload of on-site personnel, and save on the operating costs of the gas reservoir.

[0117] In the automatic salt prevention system for depleted oil and gas reservoirs provided in this embodiment of the invention, each module or unit structure can operate independently or in combination according to actual operation and analysis needs to achieve the corresponding technical effects.

[0118] Example 2

[0119] The above-disclosed embodiments of the present invention describe the system structure and connection relationships in detail. Based on the application guidance of the system described in any one or more of the above embodiments, the present invention also provides an automatic salt prevention method for depleted oil and gas reservoirs. This method is applied to the automatic salt prevention system for depleted oil and gas reservoirs described in any one or more of the above embodiments. Specific embodiments are given below for detailed description.

[0120] Specifically, Figure 4 The diagram shows a flow chart of the automatic salt prevention method for depleted oil and gas reservoirs provided in an embodiment of the present invention. Figure 4 As shown, the method includes the following operations:

[0121] Gas extraction information collection steps: Real-time collection of pipeline gas and liquid information during the gas extraction operation of the gas storage facility through the information collection module;

[0122] Gas extraction analysis steps: Based on the pipeline gas-liquid information during the gas extraction operation, analyze the current salt deposition status of the gas storage facility;

[0123] The decision-making process controls the start-up and operation parameters of the gas storage anti-salinity actuator based on the analysis results of the gas extraction analysis process and the operation mode of the gas storage facility.

[0124] After the injection information collection steps and the start of the anti-salt actuator, the pipeline injection information of the anti-salt actuator during the gas injection operation of the gas storage is collected in real time through the information collection module.

[0125] The injection analysis steps involve analyzing the injection status of the anti-salt fluid based on the pipeline injection information of the anti-salt actuator during the gas injection operation.

[0126] The adjustment decision-making steps and the analysis results of the liquid injection analysis steps determine the control parameters of the anti-salt actuator to achieve intelligent and controllable anti-salt measures in the gas storage facility.

[0127] In a specific application, in one embodiment, the anti-salt actuator includes: a liquid storage tank, a high-pressure fluid pipeline, and a fluid valve;

[0128] The storage tank is connected to the downhole tubing of the gas storage tank via a high-pressure fluid pipeline and is used to store and provide replenishment fluid for salt prevention.

[0129] The fluid valve is installed on the high-pressure fluid pipeline and connected to the downstream end of the storage tank. It is used to control the injection of anti-salt fluid by adjusting the valve opening and duration.

[0130] The high-pressure fluid pipeline includes a surface high-pressure pipeline and a wellbore high-pressure pipeline, which are interconnected by a set wellhead device. The downstream end of the wellbore high-pressure pipeline is connected to the tubing through a set fluid valve.

[0131] The fluid valve is installed on the high-pressure pipeline on the ground between the storage tank and the wellhead connection device.

[0132] In a preferred embodiment, the anti-salt actuator further includes a booster pump, which is installed on the high-pressure pipeline on the ground between the fluid valve and the wellhead connection device, and is used to cooperate with the solenoid valve to achieve pressure control of the fluid in the pipeline as needed.

[0133] Specifically, the wellhead connection device is a wellhead gas production tree device for oil and gas wells, which enables a professional connection between the surface high-pressure pipeline and the wellbore high-pressure pipeline.

[0134] The downstream end of the high-pressure pipeline in the wellbore is connected to the tubing by a high-pressure full-bore single-flow valve with a threaded gas seal. Its inner diameter is the same as that of the tubing, and an outlet hole with a certain angle is provided on the inner wall. The outlet hole is unidirectionally connected to the inlet end of the single-flow valve.

[0135] Furthermore, in one embodiment, during the gas extraction information collection step, a gas-liquid separation device installed on the main gas transmission line of the gas storage facility separates the fluid produced during the gas extraction operation of the gas storage facility into gas phase and liquid phase; the gas phase branch formed by separation continues to be connected to the main gas transmission line, and the liquid phase branch is connected to the recovery tank through the liquid transmission pipeline, thereby realizing the environmentally friendly collection of the liquid produced during the gas extraction operation of the gas storage facility.

[0136] Then, the gas flow meter and the first pressure gauge installed on the main gas transmission line of the gas storage are used to collect gas and liquid information of the gas extraction operation of the gas storage. Specifically, the gas flow meter collects the gas flow data in the gas phase branch in real time, and the first pressure gauge collects the pressure data in the gas phase branch in real time.

[0137] Simultaneously, the first liquid flow meter connected to the downstream end of the liquid phase branch of the gas-liquid separation device is used to collect the liquid flow data in the liquid phase branch in real time.

[0138] Furthermore, in one embodiment, data acquisition software receives and organizes various gas-liquid information collected by the information acquisition module from gas extraction operations, and transmits it to the data analysis module.

[0139] Next, in the gas production analysis step, data analysis software is used to intelligently analyze the gas-liquid data of the gas production pipeline transmitted by the data acquisition software, and plot the relationship curves between gas production and water precipitation during the gas production operation, as well as the relationship curves between daily gas production and pressure changes. Combined with the preset salt formation alarm threshold, trigger instructions are generated for the scheme decision software, and the analysis results are transmitted to the scheme decision module.

[0140] Furthermore, in one embodiment, in the control decision-making step, after the scheme decision-making module receives the trigger instruction from the data analysis module, it combines the analysis results and the operation mode of the gas storage to formulate a matching formation fluid replenishment scheme and generate control instructions for the anti-salt actuator, which are then transmitted to the fluid valve; the anti-salt actuator is controlled to start and operate according to the matching formation fluid replenishment scheme.

[0141] In a preferred embodiment, after the anti-salt actuator is activated, during the liquid injection information acquisition step, the second liquid flow meter and the second pressure gauge of the information acquisition module are used to collect the liquid replenishment status information in real time during the liquid injection operation. Both are installed on the ground high-pressure pipeline of the anti-salt actuator. Specifically, the second liquid flow meter is used to collect the flow information of the anti-salt fluid in the pipeline of the anti-salt actuator in real time; the second pressure gauge is used to collect the fluid pressure information in the pipeline of the anti-salt actuator in real time.

[0142] Furthermore, data acquisition software is used to receive and process various pipeline gas-liquid information and pipeline liquid injection information transmitted from the information acquisition module, and then transmit them to the data analysis module.

[0143] In one optional embodiment, during the gas injection operation of the gas storage facility, after the anti-salt actuator is activated, in the liquid injection analysis step, data analysis software is used to intelligently analyze the liquid data of the injection pipeline transmitted by the data acquisition software, and combined with the original formation liquid replenishment plan to determine whether the current fluid data of the anti-salt actuator needs to be adjusted. If so, liquid replenishment adjustment parameters are generated and transmitted to the plan decision module in combination with the analysis results.

[0144] Furthermore, in one embodiment, in the adjustment decision step, the scheme decision module generates adjustment control commands for the anti-salt actuator based on the liquid replenishment adjustment parameters of the data analysis module, and transmits them to the fluid valve to realize real-time liquid replenishment control of the anti-salt actuator.

[0145] For the foregoing method embodiments, in order to simplify the description, they are all described as a series of actions. However, those skilled in the art should understand that the present invention is not limited to the described order of actions, because according to the present invention, some steps can be performed in other orders or simultaneously. Furthermore, those skilled in the art should also understand that the embodiments described in the specification are preferred embodiments, and the actions and modules involved are not necessarily essential to the present invention.

[0146] It should be noted that, in other embodiments of the present invention, the method can also be combined with one or more of the above embodiments to obtain a new automatic salt prevention method for gas storage, so as to optimize the salt prevention and control of oil and gas wells in the gas storage.

[0147] It should be noted that, based on the methods in any one or more embodiments of the present invention described above, the present invention also provides a storage medium storing program code that can implement the methods described in any one or more embodiments. When the program code is executed by the operating system, it can implement the automatic salt prevention method for depleted oil and gas reservoirs as described above.

[0148] It should be understood that the embodiments disclosed herein are not limited to the specific structures, processing steps, or materials disclosed herein, but should be extended to equivalent substitutions of these features as understood by those skilled in the art. It should also be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting.

[0149] The phrase "an embodiment" in the specification means that a specific feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the invention. Therefore, the phrase "an embodiment" appearing in various places throughout the specification does not necessarily refer to the same embodiment.

[0150] While the embodiments disclosed in this invention are as described above, the content is merely for the purpose of facilitating understanding of the invention and is not intended to limit the invention. Any person skilled in the art to which this invention pertains may make any modifications and variations in form and detail of the implementation without departing from the spirit and scope disclosed herein; however, the scope of patent protection for this invention shall still be determined by the scope defined in the appended claims.

Claims

1. An automatic salt-proof system for a depleted oil and gas reservoir-type gas storage facility, characterized in that, The system includes: A salt-proof actuator is configured to inject salt-proof fluid into the high-pressure pipeline of the gas storage facility during the gas injection operation. The information acquisition module is configured to collect pipeline gas-liquid information during the gas extraction operation of the gas storage facility and pipeline liquid injection information of the anti-salt actuator during the gas injection operation in real time. The data analysis module, which is communicatively connected to the information acquisition module, is configured to analyze the current salt formation status of the gas storage tank based on the pipeline gas-liquid information during the gas extraction operation, and to analyze the injection status of the anti-salt fluid based on the pipeline liquid injection information of the anti-salt actuator during the gas injection operation. The scheme decision module is configured to determine the activation status and control parameters of the anti-salt actuator based on the analysis results of the data analysis module, so as to realize intelligent and controllable anti-salt in the gas storage facility; The data analysis module is configured as follows: during gas extraction operations at the gas storage facility, the data analysis software intelligently analyzes the gas-liquid data of the gas extraction pipeline transmitted by the data acquisition software, and plots the relationship curves between gas production and water precipitation during the gas extraction operation, as well as the relationship curves between daily gas production and pressure changes. It also generates trigger commands for the scheme decision software based on preset salt formation alarm thresholds, and transmits the analysis results to the scheme decision module. The data analysis module is also configured to: after the anti-salt actuator is activated during the gas injection operation of the gas storage facility, use data analysis software to intelligently analyze the liquid data of the injection pipeline transmitted by the data acquisition software, and combine it with the original formation fluid replenishment plan to determine whether the fluid data of the current anti-salt actuator needs to be adjusted. If so, generate fluid replenishment adjustment parameters and transmit them to the plan decision module in combination with the analysis results; wherein the formation fluid replenishment plan includes the total amount of fluid replenishment, the amount of fluid replenishment per time, and the timing of fluid replenishment.

2. The system according to claim 1, characterized in that, The anti-salt actuator includes: a liquid storage tank, a high-pressure fluid pipeline, and a fluid valve; The storage tank is connected to the downhole tubing of the gas storage tank via a high-pressure fluid pipeline and is used to store and provide replenishment fluid for salt prevention. The fluid valve is installed on the high-pressure fluid pipeline and connected to the downstream end of the storage tank. It is used to control the injection of anti-salt fluid by adjusting the valve opening and duration.

3. The system according to claim 2, characterized in that, The high-pressure fluid pipeline includes a surface high-pressure pipeline and a wellbore high-pressure pipeline, which are connected to each other through a set wellhead connection device. The downstream end of the wellbore high-pressure pipeline is connected to the tubing through a set fluid valve. The fluid valve is installed on the high-pressure pipeline on the ground between the storage tank and the wellhead connection device.

4. The system according to claim 3, characterized in that, The salt-prevention actuator also includes: A booster pump is installed on the high-pressure pipeline on the ground between the fluid valve and the wellhead connection device. It is used to cooperate with the solenoid valve to control the pressure of the fluid in the pipeline as needed.

5. The system according to claim 3, characterized in that, The wellhead connection device adopts the wellhead gas production tree device of oil and gas wells to realize the professional connection between the surface high-pressure pipeline and the wellbore high-pressure pipeline.

6. The system according to claim 3, characterized in that, The downstream end of the high-pressure pipeline in the wellbore is connected to the tubing by a high-pressure full-bore single-flow valve with a threaded gas seal. Its inner diameter is the same as that of the tubing, and an outlet hole with a certain angle is provided on the inner wall. The outlet hole is unidirectionally connected to the inlet end of the single-flow valve.

7. The system according to claim 1, characterized in that, The information acquisition module includes: a gas-liquid separation device installed on the main gas transmission line of the gas storage facility, which is located at the downstream end of the main gas transmission line and is used to separate the fluid produced during the gas extraction operation of the gas storage facility into gas phase and liquid phase; The gas phase branch formed by separation continues to connect to the main gas transmission line, while the liquid phase branch is connected to the recovery tank through the liquid transmission line, realizing the environmentally friendly collection of liquid produced during gas extraction operations in the gas storage facility.

8. The system according to claim 7, characterized in that, The information acquisition module includes: a gas flow meter, a first pressure gauge, and a first liquid flow meter; Both the gas flow meter and the first pressure gauge are installed on the main gas transmission line of the gas storage tank and connected to the downstream end of the gas phase branch of the gas-liquid separator. The gas flow meter is used to collect gas flow data in the gas phase branch in real time; the first pressure gauge is used to collect pressure data in the gas phase branch in real time. The first liquid flow meter is installed on the liquid delivery pipeline of the liquid phase branch and connected to the downstream end of the liquid phase branch of the gas-liquid separation device, and is used to collect liquid flow data in the liquid phase branch in real time.

9. The system according to claim 3, characterized in that, The information acquisition module also includes: a second liquid flow meter and a second pressure gauge; The second liquid flow meter and the second pressure gauge are both installed on the ground high-pressure pipeline of the anti-salt actuator and connected to the downstream end of the fluid valve. The second liquid flow meter is used to collect the flow information of the anti-salt fluid in the pipeline of the anti-salt actuator in real time; the second pressure gauge is used to collect the fluid pressure information in the pipeline of the anti-salt actuator in real time.

10. The system according to claim 1, characterized in that, The information acquisition module also includes: data acquisition software, which is used to receive and process various pipeline gas-liquid information and pipeline liquid injection information transmitted from the information acquisition module, and then transmit them to the data analysis module.

11. The system according to claim 1, characterized in that, The scheme decision module is configured as follows: Upon receiving the trigger command from the data analysis module, the system combines the analysis results with the gas storage facility's operating mode to formulate a matching formation fluid replenishment plan and generate control commands for the anti-salt actuator, which are then transmitted to the fluid valves; or The data analysis module generates adjustment and control commands for the anti-salt actuator based on the replenishment adjustment parameters and transmits them to the fluid valve.

12. An automatic salt control method for depleted oil and gas reservoir-type gas storage facilities, characterized in that, The method is implemented using the system described in any one of claims 1-11, and the method includes: Gas extraction information collection steps: Real-time collection of pipeline gas and liquid information during the gas extraction operation of the gas storage facility through the information collection module; Gas extraction analysis steps: Analyze the current salt deposition status of the gas storage facility based on pipeline gas-liquid information during the gas extraction operation. The decision-making process controls the start-up and operation parameters of the gas storage anti-salinity actuator based on the analysis results of the gas extraction analysis process and the operation mode of the gas storage facility. After the injection information collection steps and the start of the anti-salt actuator, the pipeline injection information of the anti-salt actuator during the gas injection operation of the gas storage is collected in real time through the information collection module. The injection analysis steps involve analyzing the injection status of the anti-salt fluid based on the pipeline injection information of the anti-salt actuator during the gas injection operation. The adjustment decision-making steps and the analysis results of the liquid injection analysis steps determine the control parameters of the anti-salt actuator to achieve intelligent and controllable anti-salt measures in the gas storage facility.

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