A gas injection device

Abstract

This invention relates to a gas injection dispenser, comprising: an inner shell, an outer shell, and a cable connection module, a motor and transmission module, a gas nozzle adjusting plunger, a circuit measurement and control module, a thermal flow test module, and a differential pressure flow test module disposed between the inner shell and the outer shell. The cable connection module is used to achieve a sealed connection with a cable. The motor and transmission module is connected to the gas nozzle adjusting plunger, and the opening of the gas nozzle channel is adjusted by the rotation of the motor. The thermal flow test module and the differential pressure flow test module are respectively connected to the circuit measurement and control module through communication interfaces to transmit gas injection flow test data. This invention improves the reliability of cable connections by replacing traditional cable connectors with a direct-plug cable connection method, and improves the reliability of downhole gas flow testing by integrating both thermal and differential pressure flow test methods.

Description

Technical Field

[0001] This invention relates to the field of downhole gas injection equipment technology for oilfield gas injection development, specifically to a gas injection dispenser with high reliability cable connection and flow testing. Background Technology

[0002] Low-permeability oilfield development suffers from high injection pressure and poor displacement due to the low reservoir permeability. Currently, China is gradually expanding the scale of gas injection development in low-permeability oilfields. Early gas injection methods generally adopted a general gas injection process, which achieved better results compared to water injection development. However, with the expansion of application scale, problems such as uneven inter-layer utilization and gas channeling have been exposed. To effectively solve these problems, major oilfields in China have carried out research and application exploration of stratified gas injection technology. The core technology of stratified gas injection is the stratified gas injection distributor, which is responsible for the precise measurement and control of gas injection volume in each downhole layer. Currently, a cable-mounted, permanently installed method is generally adopted.

[0003] However, the inventors of this application discovered in their research that in field applications, cables and injectors are generally connected using cable connectors, which cannot guarantee long-term sealing reliability. Once a failure occurs, communication between the surface and the downhole injector cannot be established. Furthermore, some reservoirs in gas injection wells have relatively high bottom-hole temperatures due to their deep burial depth, which has a significant impact on the reliability of downhole flow testing sensors. In applications, flow testing failures sometimes occur, resulting in the inability to obtain downhole gas injection volume, thereby affecting the stratified gas injection allocation. Summary of the Invention

[0004] To address the aforementioned problems, the purpose of this invention is to provide a gas injection and distribution device. Firstly, it improves the reliability of cable connections by replacing the traditional cable connection joint method with a direct cable plug-in connection. Secondly, it improves the reliability of downhole gas flow testing by integrating both thermal and differential pressure flow testing methods.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] This application provides a gas injection dispenser, comprising: an inner shell, an outer shell, and a cable connection module, a motor and transmission module, a gas nozzle adjusting plunger, a circuit measurement and control module, a thermal flow test module, and a differential pressure flow test module disposed between the inner shell and the outer shell; the cable connection module is used to achieve a sealed connection with a cable; the motor and transmission module is connected to the gas nozzle adjusting plunger, and the opening of the gas nozzle channel is adjusted by rotating the motor; the thermal flow test module and the differential pressure flow test module are respectively connected to the circuit measurement and control module through communication interfaces to realize the transmission of gas injection flow test data.

[0007] In one implementation of this application, the outer shell and the inner shell are configured to be coaxial with the oil pipe.

[0008] In one implementation of this application, the cable connection module includes a sealing plug, an outer sealing ring, an inner sealing ring, a rubber plug, a sealing pressure seat, and an upper connector; the inner sealing ring is used to seal the cable, the outer sealing ring is used to seal the upper connector, and the sealing pressure seat and the upper connector are threadedly connected to each other to reseal the cable by squeezing the rubber plug through the connecting threads.

[0009] In one implementation of this application, the motor and transmission module are connected to the air nozzle adjusting plunger. The motor rotates to drive the air nozzle adjusting plunger to move axially, thereby achieving stepless adjustment of the air nozzle channel opening.

[0010] In one implementation of this application, the computational processing of the thermal flow test module and the differential pressure flow test module is integrated into the same central processing unit.

[0011] In one implementation of this application, the thermal flow rate testing module measures fluid flow rate based on a formula for heat exchange relationships, the formula including:

[0012]

[0013] In the formula, ΔT The temperature rise of the gas being measured; Δq The heat absorbed by the gas being measured as it flows through; m The mass of the gas being measured flowing through it; Cp This is the isobaric specific heat capacity of the gas being measured.

[0014] In one implementation of this application, the thermal flow rate testing module uses the temperature signal before heating and the temperature signal after heating as inputs to a differential amplifier circuit. The differential circuit amplifies the minute temperature change ΔT signal value and converts it into a digital signal through A / D sampling, which is then input to the subsequent thermal flow rate calculation circuit.

[0015] In one implementation of this application, the differential pressure flow rate testing module tests the gas flow rate based on the relationship between differential pressure and fluid flow rate.

[0016] In one implementation of this application, the differential pressure flow rate testing module calculates the gas flow rate based on the following conversion relationship:

[0017]

[0018] In the formula, q vi —The volumetric flow rate of the fluid being measured; β —The ratio of the orifice diameter of the throttling element to the pipe diameter;d —Throttling element orifice diameter; ΔP —Differential pressure across the throttling element; ρ —The density of the fluid being measured.

[0019] In one implementation of this application, the communication interface is an RS485 interface.

[0020] The present invention, by adopting the above technical solutions, has the following advantages: The cable connection module of this application adopts a direct cable insertion connection method, and uses multiple sets of sealing plugs and a rubber plug within the module to achieve sealing of the cable steel pipe. This sealing structure, due to its multi-stage sealing principle, significantly improves the long-term reliability of the seal. Simultaneously, the flow testing module of this application adopts both thermal and differential pressure flow testing methods, using dual-channel signal independent communication to improve the reliability of flow testing. Furthermore, the pressure data obtained from the differential pressure flow test is used to correct the results of the thermal flow test, improving the accuracy of the thermal flow test. The thermal flow test results are also used to assist in improving the accuracy of the differential pressure flow test's large range ratio test. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the high-reliability cable connection and flow test gas injector of the present invention;

[0022] Figure 2 This is a schematic diagram of the cable connection module structure of the present invention;

[0023] Figure 3 This is a schematic diagram of the thermal flow test and differential pressure flow test circuit of the present invention. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the described embodiments of the present invention are within the scope of protection of the present invention.

[0025] To address the issues of insufficient sealing reliability and inaccurate gas flow rate acquisition in existing gas injector cables, this application provides a gas injector comprising: an inner shell, an outer shell, and a cable connection module, a motor and transmission module, a gas nozzle adjusting plunger, a circuit measurement and control module, a thermal flow rate testing module, and a differential pressure flow rate testing module disposed between the inner shell and the outer shell. The cable connection module is used to achieve a sealed connection with the cable. The motor and transmission module is connected to the gas nozzle adjusting plunger, and the opening of the gas nozzle channel is adjusted by the rotation of the motor. The thermal flow rate testing module and the differential pressure flow rate testing module are respectively connected to the circuit measurement and control module through communication interfaces to transmit gas injection flow rate test data. This application's technical solution improves the reliability of the cable connection by replacing the traditional cable connector method with a direct-insertion cable connection, and improves the reliability of downhole gas flow rate testing by integrating both thermal and differential pressure flow rate testing methods.

[0026] Please see also Figures 1 to 3 In one aspect of this application, a high-reliability cable connection and flow test gas injector structure is provided, mainly comprising a steel pipe cable 1, a cable connection module 2, an RS485 line 3, a power supply line 4, a motor and transmission module 5, a gas nozzle adjusting plunger 6, a gas nozzle channel 7, a circuit measurement and control module 8, a thermal flow test module 9, a differential pressure flow test module 10, an oil pipe 11, a housing 12, and an inner housing 13. The cable connection module 2 includes a sealing plug 201, an outer sealing ring 202, an inner sealing ring 203, a rubber plug 204, a sealing pressure seat 205, and an upper connector 206.

[0027] The cable connection module 2 uses the inner sealing ring 203 to seal the steel pipe cable 1 and the outer sealing ring 202 to seal the upper connector 206. By tightening the connecting thread between the sealing pressure seat 205 and the upper connector 206, the rubber plug 204 is squeezed, thereby achieving a second seal for the steel pipe cable 1.

[0028] The motor and transmission module 5 are connected to the air nozzle adjusting plunger 6. The motor rotates to drive the air nozzle adjusting plunger to move axially, thereby achieving stepless adjustment of the opening of the air nozzle channel 7.

[0029] The thermal flow test module 9 and the differential pressure flow test module 10 establish communication with the circuit measurement and control module 8 via RS485 to realize the transmission of test data.

[0030] The thermal flow rate testing module 9 utilizes King's law, which states that the flowing fluid alters the amount of heat dissipation (cooling) from the heat source, to measure the fluid flow rate through heat exchange relationships. The specific conversion relationship is shown in the following formula.

[0031]

[0032] In the formula, ΔT —Temperature rise of the gas being measured; Δq —The heat absorbed by the gas being tested as it flows through; m —The mass of the gas being measured flowing through; Cp —This represents the isobaric specific heat capacity of the gas being tested. The isobaric specific heat capacity is closely related to pressure and must be determined using the pressure under test conditions. In this invention, as... Figure 3 As shown, the temperature signals before and after heating measured by two high-precision temperature sensors are used as inputs to a differential amplifier circuit. The differential circuit amplifies the minute temperature change signal value ΔT and converts it into a digital signal through A / D sampling, which is then input to the subsequent thermal flow calculation circuit. At the same time, the actual measured pipe pressure signal is also converted into a digital signal through A / D sampling and input to the thermal flow calculation circuit, thereby determining the constant pressure specific heat capacity value under this pressure value and ensuring the accuracy of thermal flow measurement.

[0033] The differential pressure flow rate testing module 10 measures the flow rate by utilizing the relationship between the differential pressure generated upstream and downstream of the throttling device and the fluid flow rate. For incompressible fluids, the specific conversion relationship is shown in the following formula.

[0034]

[0035] In the formula, q vi —The volumetric flow rate of the fluid being measured; β —The ratio of the orifice diameter of the throttling element to the pipe diameter; d —Throttling element orifice diameter; ΔP —Differential pressure across the throttling element; ρ —The density of the fluid being measured.

[0036] For a compressible fluid (ideal gas), the fluid passes through a throttling device in an isentropic process, and the relationship between density and pressure is shown in the following formula.

[0037]

[0038] In the formula, k —Isoentropy index.

[0039] The conversion relationship is transformed into

[0040]

[0041] In the formula, ε —Expandability coefficient.

[0042] The actual flow equation introduces an outflow coefficient C to correct the difference between the actual flow and the theoretical flow. The actual flow equation is shown below.

[0043]

[0044] In the formula, the proportionality coefficient K The range ratio of differential pressure flow measurement is a key factor affecting the measurement range, and it is related to many factors such as the shape and size of the throttling device, the pressure tap location, the pipeline and installation conditions, and the flow state. In this invention, such as Figure 3 As shown, the flow rate result obtained from the thermal flow rate test is introduced into the differential pressure flow rate calculation circuit, and the proportionality coefficient is adjusted. K Corrections are made to improve the differential pressure flow rate measurement range ratio, enabling accurate measurement of differential pressure flow rate under a wide flow rate range.

[0045] In summary, the cable connection module adopts a direct cable insertion connection method, utilizing multiple sets of sealing plugs and a rubber plug within the module to achieve sealing of the cable conduit. This sealing structure, employing a multi-stage sealing principle, significantly improves long-term sealing reliability. Simultaneously, the flow testing module of this application integrates both thermal and differential pressure flow testing methods, using dual-channel signal independent communication to enhance flow testing reliability. Furthermore, the pressure data obtained from the differential pressure flow test is used to correct the thermal flow test results, improving the accuracy of the thermal flow test. The thermal flow test results are also used to assist in improving the accuracy of the differential pressure flow test's large range ratio.

[0046] In the several embodiments provided by this invention, it should be understood that the disclosed apparatus can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative. For instance, the division of the units described above is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between devices or units may be electrical, mechanical, or other forms.

[0047] The integrated units implemented as software functional units described above can be stored in a computer-readable storage medium. These software functional units, stored in a storage medium, include several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) or processor to execute some steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0048] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A gas injection device, characterized in that, include: The system comprises an inner shell, an outer shell, and a cable connection module, a motor and transmission module, a nozzle adjustment plunger, a circuit measurement and control module, a thermal flow test module, and a differential pressure flow test module disposed between the inner shell and the outer shell. The cable connection module is used to achieve a sealed connection with the cable. The motor and transmission module is connected to the nozzle adjustment plunger, and the opening of the nozzle channel is adjusted by rotating the motor. The thermal flow test module and the differential pressure flow test module are respectively connected to the circuit measurement and control module through communication interfaces to realize the transmission of air injection flow test data. The calculation and processing of the thermal flow test module and the differential pressure flow test module are integrated in the same central processing unit; The thermal flow rate testing module measures fluid flow rate based on a formula for heat exchange relationships, which includes: In the formula, ΔT The temperature rise of the gas being measured; Δq The heat absorbed by the gas being measured as it flows through; m The mass of the gas being measured flowing through it; Cp The specific heat capacity at constant pressure of the gas being measured; The thermal flow rate testing module uses the temperature signals before and after heating as inputs to a differential amplifier circuit. The differential circuit amplifies the minute temperature change ΔT signal value and converts it into a digital signal through A / D sampling, which is then input to the subsequent thermal flow rate calculation circuit. The differential pressure flow rate testing module measures gas flow rate based on the relationship between differential pressure and fluid flow rate. The actual flow rate equation of the differential pressure flow rate testing module is as follows: In the formula, q v —The volumetric flow rate of the fluid being measured; β —The ratio of the orifice diameter of the throttling element to the pipe diameter; d —Diameter of the orifice of the throttling element; ΔP —Pressure difference across the throttling element; ρ —Density of the fluid being measured; - Expandability coefficient; C - Discharge coefficient; K - Proportional coefficient; The flow rate result obtained from the thermal flow rate testing module is introduced into the differential pressure flow rate calculation circuit, and the proportionality coefficient is compared. K Corrections are made to improve the differential pressure flow rate measurement range ratio, enabling accurate measurement of differential pressure flow rate under a wide flow rate range.

2. The gas injection device according to claim 1, characterized in that, The outer shell and the inner shell are designed to be coaxial with the oil pipe.

3. The gas injection device according to claim 2, characterized in that, The cable connection module includes a sealing plug, an outer sealing ring, an inner sealing ring, a rubber plug, a sealing pressure seat, and an upper connector; the inner sealing ring is used to seal the cable, the outer sealing ring is used to seal the upper connector, and the sealing pressure seat and the upper connector are threaded together to press the rubber plug through the connecting threads to reseal the cable.

4. The gas injection device according to claim 2, characterized in that, The motor and transmission module are connected to the air nozzle adjusting plunger. The motor rotates to drive the air nozzle adjusting plunger to move axially, thereby achieving stepless adjustment of the air nozzle channel opening.

5. The gas injection device according to claim 1, characterized in that, The communication interface is an RS485 interface.

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