Movable shale gas fine gas lift skid-mounted equipment and control method

Abstract

The invention relates to movable shale gas fine gas lift skid-mounted equipment and a control method, the movable shale gas fine gas lift skid-mounted equipment comprises a movable carrier and a flowmeter, a compressor, a plurality of temperature sensors, a pressure sensor, an electromagnetic valve, a frequency converter and a PLC control cabinet which are arranged on the movable carrier, and an inlet of the flowmeter is connected with a natural gas source end; an inlet of the compressor is connected with an outlet of the flowmeter, and an outlet of the compressor is connected with a wellhead gas lift end; the frequency converter is electrically connected with the compressor and is used for adjusting the power of the compressor; the PLC control cabinet is in communication connection with the flow meter, the frequency converter, the temperature sensor, the pressure sensor and the electromagnetic valve. Compared with the prior art, the problems that in the middle and later periods of shale gas well production, the formation pressure is gradually reduced, the yield is reduced, the water carrying capacity of self-spraying production is insufficient, liquid is gradually accumulated in a shaft, and the gas well is flooded to stop production when the liquid is seriously accumulated in the shaft are solved.

Description

Technical Field

[0001] This invention relates to the field of gas lift equipment technology, and in particular to a mobile shale gas fine gas lift skid-mounted equipment and control method. Background Technology

[0002] In the later stages of shale gas well production, a gradual decrease in formation pressure is a common phenomenon. This pressure drop directly leads to a reduction in well production, making the previously reliance on flowing gas production unsustainable. As production decreases, liquid gradually accumulates inside the wellbore due to the gas's insufficient water-carrying capacity, failing to effectively remove moisture from the wellbore. If this liquid accumulation is not addressed promptly and effectively, it will gradually worsen, potentially leading to the well being flooded, halting production, and causing significant economic losses for the company.

[0003] Traditional gas lift methods, such as membrane nitrogen truck-mounted gas lift and truck-mounted natural gas gas lift, can solve the problem of wellbore liquid accumulation to some extent, but their exhaust volume is fixed and cannot be flexibly adjusted according to the actual production conditions of the gas well. This means that in some cases, these traditional methods may not be able to meet the gas lift requirements under different well conditions, thus affecting the gas lift effect.

[0004] Furthermore, while stationary compressors can provide a stable gas supply, their operating range is relatively narrow, and their operation methods are relatively simple. This simplicity makes them unable to meet the needs of a refined production enhancement operation mode of "one well, one policy," that is, to formulate targeted production enhancement plans based on the specific conditions of each well. At the same time, because stationary compressors are fixed in location after installation, they cannot flexibly and dynamically implement gas lift operations for gas wells distributed in different locations, which also limits their effectiveness in practical applications.

[0005] In terms of power equipment, current membrane nitrogen and natural gas lift equipment typically use diesel-powered internal combustion engines. This method has relatively high operating costs, generates significant noise, and causes some environmental pollution. Similarly, the installation cost of stationary compressors is also high, which may be unaffordable for some economically disadvantaged regions or businesses. Summary of the Invention

[0006] The purpose of this invention is to overcome the defects of the existing technology and provide a mobile shale gas fine gas lift skid-mounted equipment and control method. This solves the problem that in the middle and late stages of shale gas well production, the formation pressure gradually decreases, the production rate decreases, the water carrying capacity of self-flowing production is insufficient, the wellbore gradually accumulates liquid, and when the liquid accumulation in the wellbore is severe, the gas well will be flooded and shut down.

[0007] The objective of this invention can be achieved through the following technical solutions:

[0008] The first aspect of this invention provides a mobile shale gas fine gas lift skid-mounted device, comprising a mobile carrier and mounted on the mobile carrier: a flow meter, a compressor, multiple temperature sensors, a pressure sensor, a solenoid valve, a frequency converter, and a PLC control cabinet, wherein specifically:

[0009] The flow meter's inlet is connected to the natural gas source.

[0010] The compressor has its inlet connected to the outlet of the flow meter, and the outlet of the compressor is connected to the wellhead gas lift end;

[0011] Multiple temperature sensors, pressure sensors, and solenoid valves are located on the compressor's inlet and outlet pipes;

[0012] A frequency converter, electrically connected to the compressor, is used for adjusting the power of the compressor;

[0013] The PLC control cabinet is communicatively connected to the flow meter, frequency converter, temperature sensor, pressure sensor, and solenoid valve.

[0014] Furthermore, the PLC control cabinet is equipped with a wireless transceiver, and the PLC control cabinet communicates with the user's mobile terminal through the wireless transceiver.

[0015] Furthermore, the mobile carrier is a motor vehicle or a handcart.

[0016] Furthermore, a cooling fan is provided on one side of the compressor, and the cooling fan is used to dissipate heat from the compressor.

[0017] A second aspect of the present invention provides a control method for a mobile shale gas fine gas lift skid-mounted device as described above, comprising the following steps:

[0018] S1: Based on gas well completion data and historical production data, a model is built to predict the remaining production capacity of gas wells;

[0019] S2: Establish a critical fluid carrying model for the working well to ensure that the gas lift operation can effectively carry the fluid at the bottom of the well;

[0020] S3: Based on the results of steps S1 and S2, compile PLC logic instructions to set the parameters and operating mechanism of the air lift operation, and adjust the inverter output power and solenoid valve opening through the operating mechanism set in step S1.

[0021] Furthermore, S1 specifically includes:

[0022] S1-1: Data Collection and Analysis: Collect well completion data and historical production data from gas wells.

[0023] The well completion data includes the well structure, well depth, and well diameter;

[0024] The historical production data includes data on changes in oil and gas production, pressure, and temperature over time.

[0025] S1-2: Model Establishment and Validation: Based on the collection and analysis of data, establish a mathematical model to predict the remaining production capacity of gas wells.

[0026] Furthermore, S2 specifically includes:

[0027] The fluid carrying capacity of the well is analyzed, including the study of the flow characteristics of gas and liquid in the wellbore and the interaction between them;

[0028] Based on the liquid-carrying capacity analysis, a critical liquid-carrying model is established. The critical liquid-carrying model describes the minimum gas flow rate or velocity required for gas to carry liquid under target conditions, i.e., the critical liquid-carrying point.

[0029] Furthermore, S3 specifically includes:

[0030] Based on the model established in step S1 and the critical liquid-carrying model established in step S2, the logic instructions of the PLC are compiled. The logic instructions are used to determine the parameters required for the gas lift operation. The parameters include the initial gas injection volume, the gas injection volume adjustment mechanism, and the production mechanism after the gas lift is completed.

[0031] The operating mechanism for air lift operations is set up using pre-programmed PLC logic instructions.

[0032] Furthermore, based on the model established in step S1 and the critical liquid-carrying model established in step S2, the specific process of developing the PLC logic instructions includes:

[0033] Analyze the gas well completion data and historical production data obtained in S1 to determine the gas well's production capacity and characteristics. Then, establish a mathematical model to predict the gas well's remaining production capacity. Based on the liquid carrying capacity analysis in S2, establish a critical liquid carrying mathematical model to determine the minimum gas flow rate and velocity required for gas lift operations to ensure effective carrying of bottom hole liquid. The analysis results of these two models are coded and written into the PLC system, so that the coded instructions will automatically adjust the operating parameters of the gas lift system according to the production capacity and liquid carrying requirements predicted by the model.

[0034] Furthermore, the operating mechanism includes changes in output power and changes in the opening degree of the solenoid valve according to a time sequence.

[0035] Adjusting the inverter's output power directly affects the compressor's operating speed, which in turn affects the gas injection volume and pressure. The opening degree of the solenoid valve controls the mixing ratio and flow path of the gas and liquid. The settings of these parameters and mechanisms need to be closely coordinated with PLC logic instructions to achieve automated and precise control of the gas lift operation.

[0036] Compared with the prior art, the present invention has the following technical advantages:

[0037] 1. Integrate and collect gas lift operation parameters and gas well production parameters, and improve the matching between gas lift system and gas well through fine gas lift system calculations, thereby increasing the success rate and efficiency of gas lift.

[0038] 2. This application uses the method of adjusting the motor frequency to adjust the air-lift injection volume, effectively reducing power consumption.

[0039] 3. This application uses an electric drive, allowing users to remotely monitor and adjust the system via a mobile device. Compared to traditional vehicle-mounted internal combustion engines, this reduces energy consumption and noise, enables unattended on-site operation, and saves on operating costs.

[0040] 4. Based on production changes during the gas lift process, automatically adjust the gas lift regime to reduce the inhibitory effect of gas lift on gas well production, extend the gas well self-flowing cycle, and increase gas well output and stable production time. Attached Figure Description

[0041] Figure 1 This is a schematic diagram of the structure of the mobile shale gas fine gas lift skid-mounted equipment in this invention.

[0042] In the diagram: 1-Flow meter, 2-Compressor, 3-Cooling fan, 4-Inverter, 5-PLC control cabinet, 6-Mobile client. Detailed Implementation

[0043] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. Component models, material names, connection structures, control methods, algorithms, and other features not explicitly described in this technical solution are considered common technical features disclosed in the prior art.

[0044] Example 1

[0045] The first aspect of this invention provides a mobile shale gas fine gas lift skid-mounted device, comprising a mobile carrier and mounted on the mobile carrier: a flow meter 1, a compressor 2, multiple temperature sensors, a pressure sensor, a solenoid valve, a frequency converter 4, and a PLC control cabinet 5, wherein specific details are provided below. Figure 1 .

[0046] The inlet of flow meter 1 is connected to the natural gas source; the inlet of compressor 2 is connected to the outlet of flow meter 1, and the outlet of compressor 2 is connected to the wellhead gas lift end, driven by 380V 50KW AC power. Multiple temperature sensors, pressure sensors, and solenoid valves are located on the inlet and outlet pipelines of compressor 2. Temperature sensors monitor the gas temperature in the compressor inlet and outlet pipelines, ensuring that the gas temperature is controlled within a safe and efficient range during compression. They provide real-time temperature data to the PLC control cabinet for temperature control and adjustment. Pressure sensors monitor the gas pressure levels at the compressor inlet and outlet, ensuring that the gas pressure meets the requirements of gas lift operations, preventing excessively high or low pressure from affecting operational efficiency and safety. They provide real-time pressure data to the PLC control cabinet for pressure control and regulation. Solenoid valves control the flow of gas and liquid in the pipelines, achieving precise flow control. Based on instructions from the PLC control cabinet, they adjust the gas flow rate and direction to adapt to different operational needs. The opening, closing, and adjustment capabilities of the solenoid valves allow gas lift operations to flexibly respond to different production conditions.

[0047] The frequency converter 4 is electrically connected to the compressor 2 and is used for power adjustment of the compressor 2. The PLC control cabinet 5 is communicatively connected to the flow meter 1, the frequency converter 4, the temperature sensor, the pressure sensor, and the solenoid valve. The PLC control cabinet 5 is equipped with a wireless transceiver, which is used to communicate with the user's mobile terminal.

[0048] In practice, the mobile carrier is a motor vehicle or a handcart. A cooling fan 3 is provided on one side of the compressor 2, and the cooling fan 3 is used to dissipate heat from the compressor 2.

[0049] The control method for the mobile shale gas fine gas lift skid-mounted equipment of the present invention includes the following steps:

[0050] S1: Based on gas well completion data and historical production data, a model is built to predict the remaining production capacity of gas wells;

[0051] S1 specifically includes:

[0052] S1-1: Data Collection and Analysis: Collect well completion data and historical production data from gas wells.

[0053] The well completion data includes the well structure, well depth, and well diameter;

[0054] The historical production data includes data on changes in oil and gas production, pressure, and temperature over time.

[0055] S1-2: Model Building and Validation: Based on the collected and analyzed data, a mathematical model is established to predict the remaining production capacity of gas wells. In practice, this first requires extracting key parameters from the gas well's completion data and historical production data, such as well structure, depth, diameter, and data on oil and gas production, pressure, and temperature changes over time. Then, using this data, a mathematical model reflecting the relationship between gas well production capacity and these parameters is constructed through statistical analysis, machine learning, or other mathematical modeling techniques. This model may involve complex algorithms and calculations to ensure its accuracy and reliability. Next, the model's predictive ability is validated by comparing it with actual production data, and model parameters are adjusted to improve prediction accuracy. Once the model is validated and its effectiveness proven, it can be used to predict the future production capacity of gas wells, providing a scientific basis for parameter setting and decision-making in gas lift operations.

[0056] S2: Establish a critical fluid carrying model for the working well to ensure that the gas lift operation can effectively carry the fluid at the bottom of the well;

[0057] S2 specifically includes:

[0058] The fluid carrying capacity of the well is analyzed, including the study of the flow characteristics of gas and liquid in the wellbore and the interaction between them;

[0059] Based on the liquid-carrying capacity analysis, a critical liquid-carrying model is established. The critical liquid-carrying model describes the minimum gas flow rate or velocity required for gas to carry liquid under target conditions, i.e., the critical liquid-carrying point.

[0060] S3: Based on the results of steps S1 and S2, compile PLC logic instructions to set the parameters and operating mechanism of the air lift operation, and adjust the output power of the frequency converter 4 and the opening degree of the solenoid valve through the operating mechanism set in step S1.

[0061] S3 specifically includes:

[0062] Based on the model established in step S1 and the critical liquid-carrying model established in step S2, the logic instructions of the PLC are compiled. The logic instructions are used to determine the parameters required for the gas lift operation. The parameters include the initial gas injection volume, the gas injection volume adjustment mechanism, and the production mechanism after the gas lift is completed.

[0063] The operating mechanism for air lift operations is set up using pre-programmed PLC logic instructions.

[0064] Based on the model established in step S1 and the critical liquid-carrying model established in step S2, the specific process of compiling the PLC logic instructions includes:

[0065] Analyze the gas well completion data and historical production data obtained in S1 to determine the gas well's production capacity and characteristics. Then, establish a mathematical model to predict the gas well's remaining production capacity. Based on the liquid carrying capacity analysis in S2, establish a critical liquid carrying mathematical model to determine the minimum gas flow rate and velocity required for gas lift operations to ensure effective carrying of bottom hole liquid. The analysis results of these two models are coded and written into the PLC system, so that the coded instructions will automatically adjust the operating parameters of the gas lift system according to the production capacity and liquid carrying requirements predicted by the model.

[0066] The operating mechanism includes changes in output power and solenoid valve opening according to a time-series setting.

[0067] Adjusting the inverter's output power directly affects the compressor's operating speed, which in turn affects the gas injection volume and pressure. The opening degree of the solenoid valve controls the mixing ratio and flow path of the gas and liquid. The settings of these parameters and mechanisms need to be closely coordinated with PLC logic instructions to achieve automated and precise control of the gas lift operation.

[0068] The above description of the embodiments is provided to enable those skilled in the art to understand and use the invention. It will be apparent to those skilled in the art that various modifications can be made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present invention is not limited to the above embodiments, and any improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the invention should be within the protection scope of the present invention.

Claims

1. A mobile fine shale gas lift skid device, characterized in that, The mobile carrier and the devices arranged on the mobile carrier include: A flow meter (1) connected to a natural gas source; A compressor (2) connected to the outlet of the flow meter (1), and the outlet of the compressor (2) is connected to a wellhead gas lifting end; A plurality of temperature sensors, pressure sensors, and electromagnetic valves are arranged on the inlet and outlet pipelines of the compressor (2); A frequency converter (4) electrically connected to the compressor (2) for power adjustment of the compressor (2); A PLC control cabinet (5) in communication connection with the flow meter (1), the frequency converter (4), the temperature sensors, the pressure sensors, and the electromagnetic valves.

2. The mobile fine shale gas lift skid device according to claim 1, wherein, The PLC control cabinet (5) is provided with a wireless signal transceiver, and the PLC control cabinet (5) is in communication connection with the user's mobile terminal through the wireless signal transceiver.

3. The mobile fine shale gas lift skid device of claim 1, wherein, The mobile carrier is a motor vehicle or a handcart.

4. The mobile fine shale gas lift skid device of claim 1, wherein, One side of the compressor (2) is provided with a cooling fan (3) for heat dissipation of the compressor (2).

5. A control method of the mobile shale gas fine gas lift rig-mounted device according to any one of claims 1 to 4, characterized by, The method comprises the following steps: S1: Based on the well completion data and historical production data, a model is established to predict the remaining capacity of the gas well; S2: A critical liquid carrying model of the working well is established to ensure that the gas lifting operation can effectively carry the liquid at the bottom of the well; S3: According to the results of steps S1 and S2, PLC logic instructions are compiled to set the parameters and operation mechanism of the gas lifting operation, and the output power of the frequency converter (4) and the opening degree of the electromagnetic valve are adjusted through the set operation mechanism.

6. The control method of a shale gas fine gas lift skid-mounted device according to claim 5, characterized by, In S1, specifically comprising: S1-1: Data collection and analysis: collecting well completion data and historical production data of the gas well, The well completion data includes the structure, depth, and diameter of the well; The historical production data includes oil and gas production, pressure, and temperature data changing with time; S1-2: Model establishment and verification: based on the collected and analyzed data, a mathematical model is established to predict the remaining capacity of the gas well.

7. The control method of a shale gas fine gas lift skid-mounted device according to claim 5, characterized by, In S2, specifically comprising: The liquid carrying capacity of the working well is analyzed, including the study of the flow characteristics of gas and liquid in the wellbore and their interaction; Based on the liquid carrying capacity analysis, a critical liquid carrying model is established, which describes the minimum gas flow or flow rate required for gas to carry liquid under target conditions, i.e., the critical liquid carrying point.

8. The control method of a shale gas fine gas lift skid-mounted device according to claim 5, characterized by, In S3, specifically comprising: According to the model established in step S1 and the critical liquid carrying model established in step S2, the logic instructions of the PLC are compiled, which are used to determine the parameters required for the gas lifting operation, including the initial gas injection amount, the gas injection amount adjustment mechanism, and the production mechanism after lifting; The operation mechanism of the gas lifting operation is set by using the compiled PLC logic instructions.

9. The control method of a shale gas fine gas lift skid-mounted device according to claim 8, characterized by, The specific process of compiling the logic instructions of the PLC according to the model established in step S1 and the critical liquid carrying model established in step S2 includes: The gas well completion data and the historical production data obtained in S1 are analyzed to determine the productivity and production characteristics of the gas well, and then a mathematical model is established to predict the remaining productivity of the gas well. Based on the liquid carrying capacity analysis in S2, a mathematical model of critical liquid carrying is established to determine the minimum gas flow rate and flow velocity required for the gas lift operation to ensure effective carrying of the bottom hole liquid. The analysis results of the two models are coded and written into the PLC system, so that the coded instructions will automatically adjust the operating parameters of the gas lift system according to the productivity predicted by the model and the liquid carrying demand.

10. The control method of a shale gas fine gas lift skid-mounted device according to claim 8, characterized by, The operation mechanism includes a change in output power and a change in opening degree of the magnetic valve according to a time sequence.

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