Same-well intelligent gas production and reinjection integrated system and same-well intelligent gas production and reinjection method

Abstract

The invention discloses a same-well intelligent gas production and reinjection integrated system and a same-well intelligent gas production and reinjection method, and belongs to the technical field of intelligent production. The underground pipe column comprises an oil pipe, a power pipe arranged in the oil pipe, two penetrable isolation packers connected to the oil pipe in series, a multi-stage flow control valve arranged between the two packers and a hydraulic jet pump connected to the lower end of the power pipe. Wherein the two packers are used for packing a water injection layer, and the lower portion of the lower packer corresponds to a gas production layer; the hydraulic jet pump is provided with a liquid production port and is used for pumping a liquid-gas mixture of a gas production layer; the packers are provided with gas production channel holes, and the gas production channel holes of the two packers are connected through a gas production channel pipe and used for guiding gas to cross the packing section. The method solves the problems of high ground treatment cost of produced water and serious environmental pollution in the traditional process, and improves the gas well exploitation efficiency and the resource utilization rate.

Description

Technical Field

[0001] This invention relates to the field of intelligent oil and gas field development technology, specifically to an integrated intelligent gas production and reinjection system for the same well. This invention also relates to an intelligent gas production and reinjection method for gas well drainage and gas production. Background Technology

[0002] During gas field development, as formation pressure decreases, wellbore fluid can accumulate, affecting normal production. Currently, the commonly used drainage and gas production process involves using a jet pump to lift the accumulated fluid to the surface for further treatment. The maximum drainage capacity of the jet pump is 1500 m³ / d, and the maximum pump depth is generally 3500 m. This process is effective, with advantages including suitability for installation in water-producing wells that are producing sand, ease of management due to the absence of moving parts downhole, and convenient adjustment of downhole design parameters via rope-assisted deployment and reverse circulation for pump replacement. However, the following problems exist: 1. The system design is complex, the initial investment is large, and the operation and maintenance costs are high; 2. With a large amount of extracted water returning to the surface, the water treatment cost is extremely high, and it also causes certain environmental pollution. 3. Unable to maximize production capacity and increase recovery rate; 4. Jet pumps have limited drainage capacity and limited pump depth, making them unsuitable for high-yield water and gas wells.

[0003] Therefore, there is an urgent need for an intelligent gas production process that can enable the direct reinjection of produced water within the wellbore, reduce surface treatment, and improve recovery rate. Summary of the Invention

[0004] The purpose of this section is to outline some aspects of embodiments of the present invention and to briefly describe some preferred embodiments. Simplifications or omissions may be made in this section, as well as in the abstract and title of this application, and such simplifications or omissions should not be construed as limiting the scope of the invention.

[0005] In view of the problems existing in the above and / or prior art, the present invention is proposed.

[0006] The primary objective of this invention is to provide an integrated intelligent gas production and reinjection system for the same well, which solves the problems of high produced water treatment costs, severe environmental pollution, and low system efficiency in existing technologies.

[0007] To solve the above technical problems, the present invention adopts the following technical solution: A smart gas production and reinjection integrated system in the same well includes a downhole tubing string, which includes tubing, a power pipe installed inside the tubing, two cross-passage packers connected in series on the tubing, a multi-stage flow control valve installed between the two cross-passage packers, and a hydraulic jet pump connected to the lower end of the power pipe. Among them, the two permeable isolation packers are used to isolate the water injection layer, and the lower permeable isolation packer corresponds to the gas production layer below it; The hydraulic jet pump is equipped with a liquid production port for drawing liquid-gas mixture from the gas-producing layer; The permeable isolation packer is provided with a gas sampling channel hole. The gas sampling channel holes of the two permeable isolation packers are connected by a gas sampling channel pipe to guide gas across the packer section.

[0008] Furthermore, the wellhead surface is equipped with a water injection pump, a liquid-gas separator, a liquid storage tank, and a surface control cabinet. The inlet of the water injection pump is connected to the outlet of the liquid storage tank, and the outlet of the water injection pump is connected to the upper end of the power pipe through a water injection pipeline. The upper end of the annulus between the oil pipe and the power pipe is connected to the inlet of the liquid-gas separator through a return liquid pipeline, and the liquid outlet of the liquid-gas separator is connected to the liquid storage tank.

[0009] Furthermore, the ground control cabinet is connected to the ground end of the hydraulic control line, and the hydraulic control line passes through the through hole on the permeable isolation packer and connects to the multi-stage flow control valve for adjusting the opening of the multi-stage flow control valve.

[0010] Furthermore, the hydraulic jet pump generates negative pressure at the nozzle by injecting high-speed fluid into the power pipe, thereby drawing in the liquid-gas mixture from the gas-producing layer. The mixed fluid then enters the annulus between the oil pipe and the power pipe.

[0011] Furthermore, the multi-stage flow control valve is positioned directly opposite the water injection layer and receives control signals from the ground control cabinet via the hydraulic control pipeline to automatically adjust the proportion of reinjected water.

[0012] Furthermore, a liquid level sensor is installed in the storage tank, and the liquid level sensor is connected to the ground control cabinet via a signal cable.

[0013] Furthermore, the ground control cabinet includes a PLC control system, which outputs control signals to the water injection pump frequency converter control system and the hydraulic pump servo drive control system through PID calculation based on the liquid level and pressure signals, so as to automatically adjust the speed of the water injection pump and the opening degree of the multi-stage flow control valve.

[0014] Furthermore, the passable isolation packer adopts a three-channel structure, providing a power fluid channel, a return fluid channel, and a gas extraction channel.

[0015] Furthermore, the system is applicable to high water-cut gas wells, enabling the produced water to be directly reinjected into the injection layer within the wellbore.

[0016] Another objective of this invention is to provide a method for intelligent gas production and reinjection from the same well, which solves the problems of high production water treatment costs, serious environmental pollution, and low system efficiency in the prior art.

[0017] To solve the above technical problems, the present invention provides a method for intelligent gas production and reinjection from the same well, comprising the following steps: Step S1: The water injection pump injects high-pressure power fluid into the power pipe through the water injection pipeline. The negative pressure is generated by the nozzle of the hydraulic jet pump to draw the liquid-gas mixture from the gas-producing layer. Step S2: The mixed fluid rises along the annulus between the oil pipe and the power pipe. Part of it is reinjected back to the water injection layer through the multi-stage flow control valve, and the rest enters the liquid-gas separator through the return pipeline for gas-liquid separation. Step S3: The separated liquid enters the storage tank and is then pumped out by the water injection pump for recycling; Step S4: The ground control cabinet monitors system parameters through sensors and automatically adjusts the speed of the water injection pump and the opening of the multi-stage flow control valve to achieve balanced system operation.

[0018] Compared to the prior art, the advantages or beneficial effects of the embodiments of this application include at least the following: 1. It can realize the simultaneous drainage and gas extraction of gas wells using jet pumps, without the extracted water returning to the surface. Instead, it is automatically reinjected into the upper water layer within the wellbore. This achieves self-recirculation within the well without affecting pump efficiency, thus avoiding the extracted water returning to the surface. This greatly solves the problem of surface pollution caused by extracted water and the huge economic losses caused by wastewater treatment.

[0019] 2. Two packers are installed above the gas-producing layer. These three-channel packers effectively isolate the upper and lower parts of the water layer while providing channels for dynamic fluid, return fluid, and gas production. A multi-stage flow control valve is connected between the packers. This valve faces the water injection layer and uses surface sensors to detect the produced water volume, automatically controlling the valve's opening and closing and orifice size. This allows excess produced water to be directly reinjected into the formation through this valve. The design is reasonable, the isolation is reliable, and it enables separate gas and liquid production and injection, maximizing the gas well's productivity.

[0020] 3. The multi-stage flow control valve is controlled by a hydraulic line fixed to the outer wall of the oil pipe, and the reinjection water volume is automatically controlled through a ground control system. The intelligent control system achieves automatic matching between the injection water volume and the production fluid volume, improving system operating efficiency and stability.

[0021] 4. It is applicable to gas wells with high water content, providing a new direction for gas well drainage and gas production technology. It has strong promotion and application value and will surely play a significant role in future gas production technology. Attached Figure Description

[0022] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. The drawings are provided for reference and illustration only and are not intended to limit the present invention. Wherein: Figure 1 This is a schematic diagram of the integrated intelligent gas production and reinjection system of the same well according to the present invention; Figure 2 This is a front view of the permeable isolation packer in this invention; Figure 3 for Figure 2 Top view; Figure 4 This is a structural diagram of the ground control cabinet in this invention; Figure 5 This is a block diagram of the control system in the ground control cabinet; Figure 6 This is a schematic diagram of the PLC control principle in the ground control cabinet. Figure 7 This is a diagram of the water injection pump frequency converter control system in this invention; Figure 8 This is a diagram of the servo driver control system for the hydraulic pump in this invention.

[0023] In the diagram: 1. Water injection pump; 2. Water injection pipeline; 3. Liquid-gas separator; 4. Storage tank; 5. Signal cable; 6. Return pipeline; 7. Ground control cabinet; 8. Power pipe; 9. Oil pipe; 10. Passable isolation packer; 11. Multi-stage flow control valve; 12. Hydraulic jet pump; 13. Production port; 14. Hydraulic control pipeline; 15. Gas production channel pipe; 16. Water injection layer; 17. Gas production layer; 18. Through hole; 19. Gas production channel hole. Detailed Implementation

[0024] In the following description of the present invention, the terms "upper", "lower", "front", "rear", "left", "right", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not mean that the device must have a specific orientation.

[0025] To make the technical means, creative features, objectives, and effects of this invention easier to understand, the invention is further described below with reference to specific illustrations. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them.

[0026] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

[0027] like Figures 1 to 3 As shown, the integrated intelligent gas production and reinjection string of this invention includes tubing 9, a power pipe 8, two cross-penetrating packers 10, a multi-stage flow control valve 11, and a hydraulic jet pump 12. The power pipe 8 is located inside the tubing 9, with its upper end extending out of the wellhead. The hydraulic jet pump 12 is installed at the lower end of the power pipe 8. The hydraulic jet pump 12 is equipped with a nozzle and a throat, injecting high-speed fluid into the power pipe 8. Through the nozzle and throat, its velocity increases dramatically, simultaneously generating a large negative pressure. This negative pressure draws in low-velocity water and gas from the gas production layer 17 through the production port 13. As the mixed fluid passes through the nozzle outlet section, its velocity decreases while the static pressure increases, causing the low-velocity fluid to flow out and enter the annulus between the tubing 9 and the power pipe 8.

[0028] Two cross-through packers 10 are connected in series, one above the other, in the tubing 9. The area between the two cross-through packers 10 corresponds to the water injection layer 16 outside the casing, and the area below the lower packer corresponds to the gas production layer 17 outside the casing. The lower end of the hydraulic control line 14 passes through the through hole 18 of the cross-through packer 10 and connects to the multi-stage flow control valve 11. The ground end of the hydraulic control line 14 is connected to the hydraulic station in the ground control cabinet 7. The ground control cabinet 7 adjusts the opening of the nozzle of the multi-stage flow control valve 11 through the hydraulic control line 14 to control the proportion of reinjected water.

[0029] Multiple radially penetrating gas production channel holes 19 are provided on the circumference of the permeable isolation packer 10. The gas production channel holes 19 of the two permeable isolation packers 10 are connected by a gas production channel pipe 15, so that the gas from the gas production layer 17 can pass through the gas production channel pipe 15, cross the two permeable isolation packers 10, reach the top of the packing section, and finally be discharged from the wellhead.

[0030] The ground equipment includes a water injection pump 1, a liquid-gas separator 3, a storage tank 4, and a ground control cabinet 7. The outlet of the storage tank 4 is connected to the inlet of the water injection pump 1. The outlet of the water injection pump 1 is connected to the inlet valve at the upper end of the power pipe 8 via a water injection pipeline 2. The upper end of the annulus between the power pipe 8 and the oil pipe 9 is connected to the inlet of the liquid-gas separator 3 via a return pipeline 6. The separated liquid enters the storage tank 4 from the bottom outlet of the liquid-gas separator 3 for recycling. A hydraulic gauge or level sensor is installed in the storage tank 4, and the level sensor is connected to the ground control cabinet 7 via a signal cable 5.

[0031] During operation, the water injection pump 1 injects high-pressure power fluid into the power pipe 8 through the water injection pipeline 2. The nozzle of the hydraulic jet pump 12 generates negative pressure, drawing in the liquid-gas mixture from the gas production layer 17. The mixed fluid rises along the annulus between the oil pipe 9 and the power pipe 8. A portion is reinjected into the water injection layer 16 through the multi-stage flow control valve 11, while the remainder enters the liquid-gas separator 3 through the return liquid pipeline 6 for separation. The separated liquid is then pumped out and circulated by the water injection pump 1.

[0032] like Figure 4 As shown, the bottom left side of the ground control cabinet 7 is used to install the frequency converter (VFD) for the water injection pump, and the bottom right side of the ground control cabinet 7 is the control cabinet component box; the middle of the ground control cabinet 7 is equipped with the servo driver that drives the servo motor of the hydraulic pump station; the upper right side of the ground control cabinet 7 is equipped with a touch screen (HMI), and the upper left side of the ground control cabinet 7 is the instrument area, which has two pressure gauges and one liquid level display installed from top to bottom. The two pressure gauges display the outlet pressure of the water injection pump 1 and the pressure of the hydraulic control line 14, respectively, and the liquid level display displays the liquid level in the storage tank 4; the hydraulic pump station is integrated at the bottom rear of the cabinet.

[0033] like Figure 5 , Figure 6 As shown, a Siemens 288-1SR30-0AA0 PLC controller is used. The PLC controller has a built-in CPU, memory, RTC real-time clock, and RS485 communication interface. The RS485 communication interface is used for communication with the water injection pump frequency converter and the hydraulic pump station servo drive. The PLC controller's DQa module controls the energization of the coils of AC contactors KM1 and KM2. The normally open contact of AC contactor KM1 controls the power input of the frequency converter, and the normally open contact of AC contactor KM2 controls the power input of the hydraulic pump station servo drive.

[0034] The PLC controller's switching module includes a start / stop switch, a manual / automatic switch, a reset switch, a manual switch one, a manual switch two, and a backup switch. The PLC controller's ANALOG INPUTS interface provides analog signal input from pressure transmitters, level transmitters, and temperature transmitters. These signals are converted into digital signals by the AD module and provided to the CPU for calculation to obtain the outlet pressure of water pump 1, the pressure of hydraulic control line 14, and the liquid level in storage tank 4.

[0035] The control valve group for controlling the pressure of the hydraulic control line 14 includes solenoid valves YV1 and YV2. Solenoid valve YV1 is a pressure-pressurizing valve, and solenoid valve YV2 is a pressure-relieving valve. The PLC controller controls the pressure of the hydraulic control line 14 by opening and closing solenoid valves YV1 and YV2, thereby controlling the opening degree of the nozzle of the multi-stage flow control valve 11.

[0036] like Figure 6 , Figure 7As shown, the motor of water injection pump 1 is controlled by a 6SE6440-2UD33-0EB1 frequency converter from Siemens, Germany. The power supply of the frequency converter is controlled by the normally open contact of AC contactor KM1. The coil of AC contactor KM1 is controlled by the DQa module of the PLC controller. The speed regulation mode of the frequency converter is sent by the PLC controller through the RS485 communication interface.

[0037] like Figure 6 , Figure 8 As shown, the servo motor of the hydraulic pump station is driven by the Senchuang MS0100E / 80CB100C-500015 servo driver. The power input terminal is controlled by the normally open contact of AC contactor KM2. The coil of AC contactor KM2 is controlled by the DQa module of the PLC controller. The control signal of the servo driver is sent by the PLC controller through the RS485 communication interface.

[0038] Ground control cabinet 7 monitors the liquid level in storage tank 4 via a liquid level sensor and the outlet pressure of water injection pump 1 and the pressure in hydraulic control line 14 via a pressure transmitter. The PLC control system performs PID calculations and outputs control signals to the water injection pump frequency converter and hydraulic pump station servo drive. The frequency converter automatically adjusts the speed of water injection pump 1, while the servo drive, solenoid valves YV1 and YV2 control the pressure in hydraulic control line 14, thereby controlling the opening of multi-stage flow control valve 11 and achieving balanced system operation. The human-machine interface monitors the liquid level and pressure. The PLC module accurately calculates and processes the input data from the AI ​​module through its internal CPU, and the DQ module provides logic control with zero-delay signal output control.

[0039] The same-well intelligent gas production and reinjection method of the present invention includes the following steps: Step S1: The water injection pump 1 injects high-pressure power fluid into the power pipe 8 through the water injection pipeline 2. The negative pressure is generated by the nozzle of the hydraulic jet pump 12 to draw the liquid-gas mixture from the gas production layer 17. Step S2: The mixed fluid rises along the annulus between the oil pipe 9 and the power pipe 8. Part of it is reinjected back to the water injection layer 16 through the multi-stage flow control valve 11, and the rest enters the liquid-gas separator 3 through the return liquid line 6 for gas-liquid separation. Step S3: The separated liquid enters the storage tank 4 and is pumped out by the water pump 1 for recycling; Step S4: The ground control cabinet 7 monitors system parameters through sensors and automatically adjusts the speed of the water injection pump 1 and the opening of the multi-stage flow control valve 11 to achieve balanced system operation.

[0040] This invention achieves integrated operation of gas production, drainage, and reinjection through intelligent control and downhole structure optimization, effectively improving gas well production efficiency and environmental performance.

[0041] The above description is merely a preferred embodiment of the present invention, showing and describing the basic principles, main features, and advantages of the present invention. It is not intended to limit the scope of patent protection of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. In addition to the above embodiments, the present invention may have other implementations without departing from the spirit and scope of the invention. Various changes and modifications to the present invention are possible, and all technical solutions formed by equivalent substitutions or equivalent transformations fall within the scope of protection claimed by the present invention. The scope of protection of the present invention is defined by the appended claims and their equivalents. Technical features not described in the present invention can be implemented by or using existing technology, and will not be elaborated here.

Claims

1. A smart integrated gas production and reinjection system for the same well, comprising a downhole tubing string, characterized in that: The downhole tubing string includes tubing (9), a power pipe (8) installed inside the tubing (9), two cross-penetrating packers (10) connected in series on the tubing (9), a multi-stage flow control valve (11) installed between the two cross-penetrating packers (10), and a hydraulic jet pump (12) connected to the lower end of the power pipe (8). Among them, the two permeable isolation packers (10) are used to isolate the water injection layer (16), and the lower permeable isolation packer (10) corresponds to the gas production layer (17). The hydraulic jet pump (12) is equipped with a liquid production port (13) for pumping liquid-gas mixture from the gas-producing layer (17); The passable isolation packer (10) is provided with a gas sampling channel hole (19). The gas sampling channel holes (19) of the two passable isolation packers (10) are connected by a gas sampling channel pipe (15) to guide the gas across the packer section.

2. The integrated intelligent gas production and reinjection system according to claim 1, characterized in that: The wellhead surface is equipped with a water injection pump (1), a liquid-gas separator (3), a liquid storage tank (4), and a surface control cabinet (7). The inlet of the water injection pump (1) is connected to the outlet of the liquid storage tank (4), and the outlet of the water injection pump (1) is connected to the upper end of the power pipe (8) through the water injection pipeline (2). The upper end of the annulus between the oil pipe (9) and the power pipe (8) is connected to the inlet of the liquid-gas separator (3) through the return liquid pipeline (6), and the liquid outlet of the liquid-gas separator (3) is connected to the liquid storage tank (4).

3. The integrated intelligent gas production and reinjection system according to claim 1, characterized in that: The ground control cabinet (7) is connected to the ground end of the hydraulic control line (14). The hydraulic control line (14) passes through the through hole (18) on the permeable isolation packer (10) and is connected to the multi-stage flow control valve (11) to adjust the opening of the multi-stage flow control valve (11).

4. The integrated intelligent gas production and reinjection system according to claim 1, characterized in that: The hydraulic jet pump (12) generates negative pressure at the nozzle by injecting high-speed fluid into the power pipe (8), and draws the liquid-gas mixture from the gas production layer (17). The mixed fluid enters the annulus between the oil pipe (9) and the power pipe (8).

5. The integrated intelligent gas production and reinjection system according to claim 1, characterized in that: The multi-stage flow control valve (11) is directly opposite the water injection layer (16) and receives control signals from the ground control cabinet (7) through the liquid control pipeline (14) to automatically adjust the proportion of reinjected water.

6. The integrated intelligent gas production and reinjection system according to claim 1, characterized in that: A liquid level sensor is installed in the liquid storage tank (4), and the liquid level sensor is connected to the ground control cabinet (7) via a signal cable (5).

7. The integrated intelligent gas production and reinjection system according to claim 1, characterized in that: The ground control cabinet (7) includes a PLC control system, which outputs control signals to the water injection pump frequency converter control system and the hydraulic pump servo drive control system through PID calculation based on the liquid level and pressure signals, and automatically adjusts the speed of the water injection pump (1) and the opening degree of the multi-stage flow control valve (11).

8. The integrated intelligent gas production and reinjection system according to claim 1, characterized in that, The passable isolation packer (10) adopts a three-channel structure, providing a power fluid channel, a return fluid channel and a gas extraction channel.

9. The integrated intelligent gas production and reinjection system according to claim 1, characterized in that, The system is suitable for high water-cut gas wells, enabling the produced water to be directly reinjected into the injection layer within the wellbore (16).

10. A method for intelligent gas production and reinjection from the same well based on the system described in any one of claims 1-9, characterized in that, Includes the following steps: Step S1: The water injection pump (1) injects high-pressure power fluid into the power pipe (8) through the water injection pipeline (2), and generates negative pressure through the nozzle of the hydraulic jet pump (12) to draw the liquid-gas mixture of the gas-producing layer (17); Step S2: The mixed fluid rises along the annulus between the oil pipe (9) and the power pipe (8), part of which is reinjected into the water injection layer (16) through the multi-stage flow control valve (11), and the rest enters the liquid-gas separator (3) through the return liquid line (6) for gas-liquid separation; Step S3: The separated liquid enters the storage tank (4) and is pumped out by the water pump (1) for recycling; Step S4: The ground control cabinet (7) monitors system parameters through sensors and automatically adjusts the speed of the water injection pump (1) and the opening of the multi-stage flow control valve (11) to achieve balanced operation of the system.

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