Low-efficiency well negative pressure stimulation integrated device

Abstract

The present application relates to the technical field of oil exploitation, and particularly relates to a low-efficiency well negative pressure stimulation integrated device, which comprises an oil tree and an oil lifting machine, the oil tree is connected with a first negative pressure stimulation assembly, the first negative pressure stimulation assembly comprises a piston structure, a pressure stabilizing structure and a negative pressure structure; the input end of the piston structure is movably connected with a walking beam of the oil lifting machine, the pressure stabilizing structure is communicated with the output end of the piston structure and the negative pressure structure through one-way valves respectively, the negative pressure structure comprises a negative pressure pipe and a back pressure pipe, the negative pressure pipe is communicated with a wellhead through a one-way valve, and the back pressure pipe is communicated with the negative pressure structure through a one-way valve; the compression and release actions of the piston are used for buffering pressure fluctuation through the pressure stabilizing structure, and the negative pressure structure generates a pressure difference based on the piston movement to form a dynamic upward pressure boosting environment at the wellhead; the real-time regulation and control of the wellhead pressure are realized, a negative pressure environment is automatically generated, the resistance of wellbore fluid accumulation to gas-liquid flow is reduced, and thus the continuous flow of oil and gas from the formation to the wellhead is promoted.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of oil exploitation, in particular to a low-efficiency well negative pressure stimulation integrated device. BACKGROUND

[0002] In the exploitation process of a natural gas well, with the exploitation, liquids including free water in the formation, hydrocarbon condensate night deposit liquid and condensate water will enter the wellbore to form wellbore or gas well liquid loading, causing the pressure difference between the wellhead and the well bottom to drop sharply, so that the produced gas cannot flow to the wellhead, and the gas well production rapidly decreases. With the accumulation of liquid loading, the gas production gradually decreases until there is no production. In order to improve the gas production of the gas well, it is usually necessary to perform stimulation process on the low-efficiency well.

[0003] The stimulation process of an oil and gas well is a technical process for improving the production capacity of the oil and gas well, and usually adopts fracturing technology, perforation technology or multi-lateral drilling technology. The packer in the prior art cannot adapt to the pressure change in the oil well when performing the stimulation process, and thus cannot output crude oil under variable pressure. In addition, after the above stimulation process is performed, the productivity of the low-efficiency well is also limited by the pressure at the wellhead of the Christmas tree. Therefore, there is an urgent need for a low-efficiency well negative pressure stimulation integrated device. SUMMARY

[0004] The main purpose of the present application is to provide a low-efficiency well negative pressure stimulation integrated device, which aims to solve the problem that the low-efficiency well in the prior art cannot use the pressure change of the oil well to increase the stimulation process.

[0005] To achieve the above-mentioned purpose, the present application provides a low-efficiency well negative pressure stimulation integrated device, comprising a Christmas tree and an oil pumping machine arranged at the wellhead of a low-efficiency well, wherein the Christmas tree is connected with a first negative pressure stimulation assembly, and the first negative pressure stimulation assembly comprises a piston structure, a pressure stabilizing structure and a negative pressure structure.

[0006] The input end of the piston structure is movably connected with the walking beam of the oil pumping machine, the pressure stabilizing structure is in communication with the input end of the piston structure and the negative pressure structure through a one-way valve respectively, the negative pressure structure comprises a negative pressure pipe and a back pressure pipe, the negative pressure pipe is in communication with the wellhead through a one-way valve, and the back pressure pipe is in communication with the negative pressure structure through a one-way valve.

[0007] During the operation of the oil pumping machine, the reciprocating motion of the piston structure can be realized through the swinging of the walking beam, and the pressure increase of the wellhead by the negative pressure structure can be realized through the reciprocating motion of the piston structure.

[0008] Optionally, the negative pressure structure further comprises a negative pressure cylinder, a plug rod is slidably arranged in the negative pressure cylinder, an elastic member is arranged on one side of the negative pressure cylinder close to the wellhead, the negative pressure pipe is in communication with one side of the negative pressure cylinder close to the wellhead, the back pressure pipe is in communication with one side of the negative pressure cylinder away from the wellhead, the plug rod comprises a plug head, and the pressure stabilizing structure is in communication with one side of the negative pressure cylinder close to the plug head.

[0009] Optionally, the pressure stabilizing structure comprises a pressure stabilizing tank, wherein a pressure stabilizing component is arranged in the pressure stabilizing tank, and two ends of the pressure stabilizing tank are respectively communicated with the negative pressure cylinder and the piston structure.

[0010] Optionally, the pressure stabilizing structure is connected with a secondary negative pressure yield increasing assembly, wherein the secondary negative pressure yield increasing assembly comprises a pressure increasing tank, the pressure increasing tank is communicated with the negative pressure cylinder away from the plug through a one-way valve, and nitrogen is introduced into the pressure increasing tank.

[0011] Optionally, the secondary negative pressure yield increasing assembly further comprises a pressure increasing component, two ends of the pressure increasing component are respectively communicated with the pressure increasing tank and the pressure stabilizing structure through one-way valves.

[0012] Optionally, the pressure increasing component comprises a hollow pressure increasing seat, the pressure increasing seat comprises a negative pressure area and a pressure increasing area, a rotating shaft is arranged in the pressure increasing seat, a pressure increasing turbine and a negative pressure turbine are respectively arranged on two sides of the rotating shaft, the pressure increasing turbine is arranged in the pressure increasing area, the negative pressure turbine is arranged in the negative pressure area, an air outlet of the pressure increasing area is communicated with the pressure increasing tank, and an air inlet of the negative pressure area is communicated with the pressure stabilizing structure.

[0013] Optionally, the pressure stabilizing component is internally provided with a plurality of flow channels.

[0014] Optionally, the integrated device further comprises a packer, the packer comprises a pressure sensitive bellows and a hydraulic assembly, the hydraulic assembly is arranged in the packer and is used for controlling pressure changes of different packer segments.

[0015] Optionally, the air inlet of the piston structure, the air inlet of the pressure increasing component and the air inlet of the pressure increasing area are all introduced with nitrogen.

[0016] Optionally, the negative pressure pipe and the plurality of flow channels in the pressure stabilizing component are all Venturi tubes with spiral flow channels, and the throat diameter ratio is 1:8.

[0017] The low-efficiency well negative pressure stimulation integrated device provided by the embodiment of the present application, by innovatively combining mechanical linkage, pressure dynamic regulation and negative pressure generation technology, systematically solves the technical problem that the existing low-efficiency well stimulation process cannot effectively utilize the pressure change of the oil well to realize continuous stimulation, and significantly improves the adaptability and energy efficiency of the device. Specifically, during operation, the periodic swing of the oil pumping machine is converted into mechanical reciprocating motion of the piston structure, the compression and release actions of the piston are buffered by the pressure stabilizing structure to reduce pressure fluctuation, and the negative pressure structure generates a pressure difference based on the piston motion to form a dynamic upward pressure boosting environment at the wellhead; the negative pressure pipe introduces wellhead liquid or gas into the negative pressure structure through the one-way valve, and the back pressure pipe maintains the stability of the system through reverse pressure balance; this linkage mechanism realizes real-time regulation and control of the wellhead pressure, generates a negative pressure environment, reduces the resistance of the wellbore liquid to gas and liquid flow, and promotes the continuous flow of oil and gas from the formation to the wellhead. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 is a structural schematic diagram of the present application;

[0019] Figure 2 is a structural schematic diagram of the first-stage negative pressure stimulation assembly and the second-stage negative pressure stimulation assembly of the present application;

[0020] Figure 3 is a structural schematic diagram of the internal structure of the negative pressure cylinder of the present application;

[0021] Figure 4 is a structural schematic diagram of the pressure boosting piece of the present application;

[0022] Figure 5 is a structural schematic diagram of the internal structure of the pressure boosting piece of the present application;

[0023] Figure 6 is a structural schematic diagram of the packer of the present application.

[0024] Reference signs:

[0025] 1 - oil pumping machine, 2 - Christmas tree, 3 - wellhead, 4 - first-stage negative pressure stimulation assembly, 6 - second-stage negative pressure stimulation assembly, 7 - packer;

[0026] 11 - walking beam;

[0027] 41 - piston structure, 42 - pressure stabilizing structure, 43 - negative pressure structure;

[0028] 421 - pressure stabilizing tank;

[0029] 431 - negative pressure pipe, 432 - back pressure pipe, 433 - negative pressure cylinder, 434 - plug rod, 435 - elastic piece, 436 - plug head;

[0030] 61 - pressure boosting piece, 62 - pressure boosting tank;

[0031] 611 - plenum seat, 612 - negative pressure zone, 613 - plenum zone, 614 - rotating shaft, 615 - plenum turbine

[0032] 71 - pressure sensitive bellows, 72 - hydraulic assembly

[0033] The purposes, functional characteristics and advantages of the present application will be further described with reference to the embodiments and the accompanying drawings. DETAILED DESCRIPTION

[0034] The technical solutions in the embodiments of the present application will be clearly and completely described with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without creative efforts fall within the protection scope of the present application.

[0035] It should be noted that all the directionality indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present application are only used to explain the relative position relationship, movement condition, etc. between the components in a certain specific posture (as shown in the drawings). If the specific posture changes, the directionality indications also change accordingly.

[0036] In the present application, unless otherwise explicitly specified and limited, the terms "connection", "fixation", etc. should be understood in a broad sense. For example, "fixation" can be fixed connection, or detachable connection, or integral; can be mechanical connection, or electrical connection; can be direct connection, or indirect connection through an intermediate medium; can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise explicitly limited. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0037] In addition, if the present application has descriptions involving "first", "second", etc., the descriptions of "first", "second", etc. are only for the purpose of description, and cannot be understood as indicating or implying the relative importance of the indicated technical features or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first" and "second" can explicitly or implicitly include at least one of the features. In addition, the meaning of "and / or" appearing throughout the text includes three parallel solutions. Taking "A and / or B" as an example, it includes A solution, or B solution, or A and B solutions. In addition, the technical solutions of each embodiment can be combined with each other, but it must be based on the fact that a person skilled in the art can realize it. When the combination of technical solutions appears contradictory or unachievable, it should be considered that the combination of technical solutions does not exist, and is not within the protection scope of the present application. Embodiment

[0038] Reference is made to the accompanying drawings Figures 1 to 6 In this embodiment, a low-efficiency well negative pressure stimulation integrated device is provided, which comprises an oil tree 2 and an oil pumping machine 1 arranged at the wellhead 3 of the low-efficiency well. The oil tree 2 is connected with a first negative pressure stimulation assembly 4. The first negative pressure stimulation assembly 4 comprises a piston structure 41, a pressure stabilizing structure 42 and a negative pressure structure 43.

[0039] The input end of the piston structure 41 is movably connected with the walking beam 11 of the oil pumping machine 1. The pressure stabilizing structure 42 is in communication with the input end of the piston structure 41 and the negative pressure structure 43 through one-way valves, respectively. The negative pressure structure 43 comprises a negative pressure pipe 431 and a back pressure pipe 432. The negative pressure pipe 431 is in communication with the wellhead 3 through a one-way valve. The back pressure pipe 432 is in communication with the negative pressure structure 43 through a one-way valve.

[0040] During the operation of the oil pumping machine 1, the reciprocating motion of the piston structure 41 can be achieved by the swinging of the walking beam 11, and the pressure increase of the wellhead 3 by the negative pressure structure 43 can be achieved by the reciprocating motion of the piston structure 41.

[0041] It can be understood that in the prior art, the stimulation process of the low-efficiency well (such as fracturing and perforation) mainly relies on external energy input (such as high-pressure pumping), which not only has high cost, but also is difficult to adapt to the complex and variable pressure environment in the well. Especially when the wellbore fluid accumulation leads to a sharp drop in the pressure difference between the wellhead 3 and the well bottom, the traditional process cannot effectively utilize the pressure fluctuation in the well to restore the production capacity. In addition, the existing packer 7 and other devices are prone to sealing failure or response lag in the pressure dynamic change scene, which further limits the stimulation effect.

[0042] Based on the above problems, a low-efficiency well negative pressure stimulation integrated device is proposed in this embodiment. By innovatively combining mechanical linkage, pressure dynamic regulation and negative pressure generation technology, the technical problem that the existing low-efficiency well stimulation process cannot effectively utilize the pressure change of the oil well itself to achieve continuous stimulation is systematically solved, and the adaptability and energy efficiency of the device are significantly improved. Specifically, during the operation, the periodic swinging of the oil pumping machine 1 is converted into the mechanical reciprocating motion of the piston structure 41. The compression and release actions of the piston buffer the pressure fluctuation through the pressure stabilizing structure 42. At the same time, the negative pressure structure 43 generates a pressure difference based on the piston motion, forming a dynamic upward pressure increase environment at the wellhead 3. The negative pressure pipe 431 introduces the wellhead 3 fluid or gas into the negative pressure structure 43 through the one-way valve, and the back pressure pipe 432 maintains the stability of the system through the reverse pressure balance. This linkage mechanism realizes the real-time regulation and control of the pressure of the wellhead 3, generates a negative pressure environment, reduces the resistance of the wellbore fluid to the gas-liquid flow, and promotes the continuous flow of oil and gas from the formation to the wellhead 3.

[0043] It can be understood that the walking beam 11 of the oil extractor 1 swings regularly during the oil extraction process, and the swing is transmitted to the input end of the piston structure 41 through a mechanical connection to drive the piston to reciprocate in the cylinder. The compression stroke (moving towards the wellhead 3) of the piston compresses the gas or fluid in the cylinder, and the return stroke (moving away from the wellhead 3) forms a local vacuum in the cylinder, generates suction, and further converts the negative pressure in the negative pressure structure 43 into a pressurization process of the wellhead 3.

[0044] It can also be understood that the input end of the piston structure 41 is in communication with the pressure stabilizing structure 42 through a one-way valve. The pressure stabilizing structure 42 mainly comprises a pressure stabilizing tank 421 and an internal pressure stabilizing component. When the piston is compressed, high-pressure gas enters the pressure stabilizing tank 421 through the one-way valve, and the internal pressure stabilizing component in the tank slows down the high-speed gas flow through a spiral flow channel design and disperses the pressure to avoid the impact of pressure peaks on the downstream system; when the piston returns, the gas in the pressure stabilizing tank 421 flows back to the piston structure 41 through another one-way valve to supplement the vacuum area in the cylinder and maintain the pressure balance of the system.

[0045] Finally, during the piston return stroke, the negative pressure formed in the cylinder is transmitted to the wellhead 3 through the negative pressure pipe 431, and the gas in the wellbore is sucked into the negative pressure pipe 431 and enters the negative pressure cylinder 433. The plug rod 434 slidingly arranged in the negative pressure cylinder 433 cooperates with the elastic member 435, and when the negative pressure pipe 431 sucks the fluid of the wellhead 3, the plug rod 434 is pushed away from the wellhead 3 and moves away from the wellhead 3, compressing the elastic member 435 in the negative pressure cylinder 433. At this time, the back pressure pipe 432 communicates with the side of the negative pressure cylinder 433 away from the wellhead 3 through a one-way valve, releases the excess pressure to the pressure stabilizing structure 42 or the secondary pressure boosting assembly, and avoids the accumulation of pressure in the cylinder.

[0046] The negative pressure pipe 431 and the back pressure pipe 432 are both provided with one-way valves to ensure that the fluid only flows in the designed direction. Specifically, the negative pressure pipe 431 is only opened during the piston return stroke to allow the fluid of the wellhead 3 to enter the negative pressure cylinder 433; the back pressure pipe 432 is opened when the piston is compressed or the pressure in the negative pressure cylinder 433 is too high to guide the pressure to the pressure stabilizing tank 421 or the external environment.

[0047] In some embodiments, the input end of the piston structure 41 is filled with high-pressure nitrogen.

[0048] In some embodiments, the elastic member 435 is preferably a high-pressure spring.

[0049] In the embodiment, the negative pressure structure 43 further comprises a negative pressure cylinder 433, a plug rod 434 is slidably arranged in the negative pressure cylinder 433, an elastic element 435 is arranged on one side of the negative pressure cylinder 433 close to the wellhead 3, the negative pressure pipe 431 is in communication with one side of the negative pressure cylinder 433 close to the wellhead 3, the back pressure pipe 432 is in communication with the other side of the negative pressure cylinder 433 away from the wellhead 3, the plug rod 434 comprises a plug head 436, and the pressure stabilizing structure 42 is in communication with one side of the negative pressure cylinder 433 close to the plug head 436.

[0050] It should be noted that by introducing the cooperative design of the negative pressure cylinder 433, the plug rod 434 and the elastic element 435, the technical problem of pressure imbalance of the wellhead 3 and blocked oil and gas flow caused by wellbore fluid accumulation in the process of increasing production of low-efficiency wells is systematically solved. Specifically, the negative pressure cylinder 433 serves as a core pressure regulating unit, one side of which is in communication with the wellhead 3 through the negative pressure pipe 431, and the other side is connected with the pressure stabilizing structure 42 or the secondary pressure boosting assembly through the back pressure pipe 432. The plug rod 434 is slidably arranged in the negative pressure cylinder 433, one end of which is provided with the plug head 436, and the other end is dynamically connected with the inner wall of the negative pressure cylinder 433 through the elastic element 435. When the walking beam 11 of the oil pumping machine 1 drives the piston structure 41 to reciprocate, a negative pressure is formed in the cylinder during the piston return stroke, and the wellhead 3 fluid or gas is sucked into the negative pressure cylinder 433 through the negative pressure pipe 431. At this time, the wellhead 3 fluid pushes the plug rod 434 to move away from the wellhead 3, compresses the elastic element 435, and forms a controllable negative pressure space in the negative pressure cylinder 433, thereby avoiding the problem of crack plugging caused by long-time pressurization, etc. Not only is the pressure of the wellhead 3 actively reduced, but also the energy storage characteristics of the elastic element 435 buffer the pressure fluctuation, avoiding the influence of instantaneous pressure impact on the stability of the system. At the same time, the back pressure pipe 432 guides the excess pressure to the pressure stabilizing structure 42 or the outside through the one-way valve when the pressure in the negative pressure cylinder 433 is too high, further maintaining the pressure balance.

[0051] It should be further noted that the periodic swing of the oil pumping machine 1 is converted into the reciprocating motion of the plug rod 434 in the negative pressure cylinder 433 through mechanical linkage, and the pressure regulation is directly realized by using the power of the oil well itself without relying on external high-pressure equipment, thereby significantly reducing energy consumption and cost. Secondly, the introduction of the elastic element 435 realizes dynamic pressure compensation, smooths the pressure change during the piston compression and release process, and solves the problem of easy failure of the traditional packer 7 in the dynamic pressure environment. In addition, the partition design of the negative pressure cylinder 433 combined with the directional control of the one-way valve ensures that the fluid only flows along the preset path, not only avoiding backflow interference, but also preventing system overload through the pressure release mechanism of the back pressure pipe 432. This design also enables the wellhead 3 pressure to respond to the piston motion state in real time, forming a dynamic pressurization environment, continuously promoting the flow of oil and gas from the formation to the wellhead 3, and effectively overcoming the resistance of wellbore fluid accumulation to gas-liquid flow.

[0052] In the embodiment, the pressure stabilizing structure 42 comprises a pressure stabilizing tank 421, in which a pressure stabilizing component is arranged, and two ends of the pressure stabilizing tank 421 are respectively communicated with the negative pressure cylinder 433 and the piston structure 41.

[0053] In some embodiments, one end of the pressure stabilizing tank 421 is communicated with the input end of the piston structure 41, and the other end is connected with the negative pressure cylinder 433, forming a two-way channel for pressure transmission and buffering. The pressure stabilizing component arranged in the pressure stabilizing tank 421 can slow down, disperse and equalize the high-pressure airflow generated in the compression stage of the piston through a multi-channel structure, so as to avoid the direct impact of the pressure peak on the negative pressure cylinder 433 and downstream components, thereby preventing sealing failure or equipment damage.

[0054] In the piston return stage, the stable pressure stored in the pressure stabilizing tank 421 is returned to the piston structure 41 through a one-way valve, so as to supplement the pressure difference caused by the cylinder vacuum and maintain the dynamic balance of the system pressure. Not only the active buffering of pressure fluctuation is realized, but also the airflow control efficiency is improved through the flow channel optimization of the pressure stabilizing component, so as to ensure the continuity and stability of pressure transmission.

[0055] It can be understood that the conventional low-efficiency well stimulation device is prone to cause sealing failure of the packer 7 or pressure imbalance of the wellhead 3 due to pressure mutation in the reciprocating motion of the piston. The introduction of the pressure stabilizing tank 421 can convert the transient high pressure into controllable steady pressure output through the way of physical storage and staged release, thereby significantly reducing the sensitivity of the system to dynamic pressure change.

[0056] It can also be understood that the multi-channel design in the pressure stabilizing component can accelerate the local airflow and form a low-pressure area through the Venturi effect, thereby further optimizing the pressure distribution and solving the problem of uneven pressure dispersion caused by the single flow channel of the traditional pressure stabilizing device, so as to improve the adaptability to complex pressure environment. In addition, the linkage design of the pressure stabilizing tank 421 with the piston structure 41 and the negative pressure cylinder 433 enables the system to automatically adjust the pressure by using the mechanical energy of the piston motion, thereby reducing the dependence on additional pressure boosting equipment (such as an external high-pressure pump) and reducing energy consumption and operating cost.

[0057] In the embodiment, the pressure stabilizing structure 42 is connected with a two-stage negative pressure stimulation assembly 6, which comprises a pressure boosting tank 62, the pressure boosting tank 62 is communicated with the side of the negative pressure cylinder 433 away from the plug 436 through a one-way valve, and nitrogen is introduced into the pressure boosting tank 62.

[0058] Nitrogen gas is introduced into the booster tank 62 as a pressurizing medium, which avoids the problems of oxidation corrosion, icing or flow channel blockage caused by oxygen and moisture in traditional air medium, and the high stability and compressibility of nitrogen gas significantly improve the accuracy and response speed of pressure regulation. Through the synergistic effect of nitrogen gas and the booster turbine 615, the system can realize stable gas compression and storage in a high-pressure environment, and dynamically adjust the output pressure through the one-way valve to ensure the continuous stability of the wellhead 3 under negative pressure environment.

[0059] In this embodiment, the secondary negative pressure stimulation assembly 6 further comprises a booster 61, both ends of which are communicated with the booster tank 62 and the pressure stabilizing structure 42 through one-way valves respectively.

[0060] In some embodiments, the booster 61 comprises an internally hollow booster seat 611, which comprises a negative pressure area 612 and a booster area 613 respectively, and a rotating shaft 614 is arranged in the booster seat 611, both sides of the rotating shaft 614 are provided with a booster turbine 615 and a negative pressure turbine respectively, the booster turbine 615 is arranged in the booster area 613, and the negative pressure turbine is arranged in the negative pressure area 612, the gas outlet of the booster area 613 is communicated with the booster tank 62, and the gas inlet of the negative pressure area 612 is communicated with the pressure stabilizing structure 42.

[0061] The booster 61 is the core unit of the secondary negative pressure stimulation assembly 6, both ends of which are communicated with the booster tank 62 and the pressure stabilizing structure 42 through one-way valves to form a closed-loop pressure regulation system. The booster 61 is internally designed with a hollow booster seat 611, which is divided into a negative pressure area 612 and a booster area 613, and a booster turbine 615 and a negative pressure turbine are linked through a rotating shaft 614. When the gas flow from the pressure stabilizing structure 42 enters the negative pressure area 612, the negative pressure turbine is driven to rotate by the fluid kinetic energy, accelerates the gas flow rate and further reduces the local pressure, forming a more significant negative pressure gradient; at the same time, the booster turbine 615 rotates in the booster area 613 to compress the gas, which is then delivered to the booster tank 62 after its pressure is increased. This process not only realizes efficient energy conversion and reuse, but also dynamically balances the pressure difference through the synergistic effect of the double turbines to ensure stable operation of the system under complex pressure environment. The configuration of the one-way valve strictly limits the direction of the gas flow, avoids backflow interference, and maintains the one-way nature and continuity of the booster and negative pressure processes.

[0062] It can be understood that the double-turbine cooperative working mechanism significantly improves the supercharging efficiency. Through the active decompression of the negative pressure area 612 and the accurate pressurization of the supercharging area 613, a dynamic and stable pressure difference environment is formed, which effectively promotes the discharge of wellbore accumulation and the continuous flow of oil and gas. Secondly, the optimization of the energy conversion path greatly reduces the system energy consumption. The supercharging turbine 615 is driven by fluid kinetic energy, without the need for external power or hydraulic support, which not only reduces operating costs, but also enhances the applicability of the device in remote well sites. Thirdly, the closed-loop pressure regulation system, through the cooperation of the one-way valve and the supercharging tank 62, realizes the active absorption and redistribution of pressure fluctuations, avoiding equipment wear or seal failure caused by sudden pressure changes, and prolonging the service life of key components. Fourthly, the modular design of the supercharging part 61 can be seamlessly integrated with the primary negative pressure component. By filling nitrogen into the supercharging tank 62, the pressure control flexibility is further improved, making the device adaptable to complex conditions of different well depths, accumulation amounts, and formation permeability.

[0063] In some embodiments, the inside of the pressure stabilizer is provided with a plurality of flow channels.

[0064] It can be understood that the throat design of the Venturi tube causes the flow rate of nitrogen to increase sharply when it passes through this area. According to Bernoulli's principle, the increase in flow rate leads to a significant decrease in local pressure, forming a low-pressure area, thereby efficiently absorbing nitrogen during the piston compression stage. In the expansion section, the flow rate slows down and the pressure gradually recovers. Combined with the flow guiding effect of the spiral flow channel, nitrogen forms a rotating flow in the flow channel, reducing turbulent energy loss and achieving a smooth pressure recovery. This process balances the relationship between flow rate and pressure change through precise control of the throat diameter ratio, avoiding excessive flow resistance caused by a too narrow throat, and ensuring the continuity of pressure recovery in the expansion section, thereby maintaining a stable pressure gradient under the dynamic condition of intermittent nitrogen injection.

[0065] When the piston is compressed, nitrogen is pushed into the converging section of the Venturi tube at high speed, and the low-pressure area formed by the sudden increase in flow rate effectively absorbs the accumulation or gas in the wellbore. At the same time, the spiral flow channel enhances the gas-liquid mixing efficiency by guiding fluid rotation, reducing pressure fluctuations caused by local vortex. When the piston returns, the pressure recovery mechanism of the expansion section and the inertial effect of the spiral flow channel work together to make the nitrogen pressure rise smoothly into the pressure stabilizing tank 421, avoiding the impact of sudden pressure changes on downstream components.

[0066] In this embodiment, the integrated device further includes a packer 7, which includes a pressure-sensitive bellows 71 and a hydraulic component 72. The hydraulic component 72 is arranged in the packer 7 and is used to control the pressure change of different sealing sections of the packer 7.

[0067] The traditional packer 7 usually adopts rigid sealing rings or passive elastomers, which are difficult to adapt to the non-uniform pressure distribution in the well, especially in the horizontal well or multi-layer segmented exploitation scene, and are prone to sealing failure or casing damage due to pressure difference. The active deformation capability of the pressure-sensitive bellows 71 combined with the precise regulation of the hydraulic assembly 72 realizes independent pressure management of each packer section, solving the limitations of the traditional "one-size-fits-all" sealing. Secondly, the closed-loop control system of the hydraulic assembly 72 breaks through the technical bottleneck of slow response speed and low regulation precision of the traditional packer 7 through real-time pressure feedback and dynamic adjustment.

[0068] Under the impact of gas-liquid two-phase flow, the system can adjust the deformation amount of the bellows within milliseconds to balance the instantaneous pressure fluctuation and avoid the generation of sealing gaps. In addition, the multi-layer structure design of the pressure-sensitive bellows 71 enhances the anti-creep and anti-fatigue performance, and can still maintain stable deformation response in a long-term high-pressure environment, significantly prolonging the service life of the packer 7.

[0069] In some embodiments, the nitrogen gas inlet of the piston structure 41, the nitrogen gas inlet of the booster 61, and the nitrogen gas inlet of the booster area 613 are connected.

[0070] In this embodiment, the negative pressure pipe 431 and the flow channels inside the pressure stabilizer are all Venturi tubes with spiral flow channels, and the throat diameter ratio is 1:8.

[0071] It can be understood that the spiral flow channel forces the fluid to flow in a rotational manner along the axis through the internal spiral groove or guide vane. This rotational motion generates centrifugal force, causing the fluid to flow close to the pipe wall, significantly reducing boundary layer separation and turbulence generation. At the same time, the spiral flow extends the fluid's path in the flow channel, enhancing the conversion efficiency of kinetic energy and static pressure energy. For example, during the suction stage of the negative pressure pipe 431, the spiral flow channel guides the wellbore fluid to form a vortex flow, accelerating gas-liquid separation and reducing flow resistance; while during the pressure recovery stage of the pressure stabilizer, the inertial effect of the spiral flow channel helps to smoothly release kinetic energy, avoiding sudden pressure changes.

[0072] Design of the contraction section: The sharp contraction of the throat cross-sectional area (the diameter is reduced to 1 / 8 of the inlet) greatly increases the fluid velocity. According to Bernoulli's principle, the increase in flow velocity leads to a significant decrease in local static pressure, forming an efficient negative pressure suction environment, especially suitable for rapid discharge of wellbore fluid.

[0073] Design of the expansion section: The expansion section after the throat realizes a smooth conversion of kinetic energy to static pressure energy with a gradual change in cross-sectional area (gradually restored to the original diameter in proportion). The 1:8 throat diameter ratio controls the expansion angle to avoid flow separation and energy loss caused by rapid expansion, ensuring the continuity of the pressure recovery process.

[0074] The above merely describes the preferred embodiments of the present application, and is not intended to limit the patent scope of the present application, and any equivalent structure or equivalent process conversion, or direct or indirect application in other related technical fields, which are made by using the content of the present application specification and drawings, are also included in the patent protection scope of the present application.

Claims

1. A low-efficiency well negative pressure stimulation integrated device, comprising a Christmas tree and an oil lifting machine arranged at a wellhead of a low-efficiency well, characterized in that, The oil tree is connected with a first-stage negative pressure stimulation assembly, which comprises a piston structure, a pressure stabilizing structure and a negative pressure structure; The input end of the piston structure is movably connected with a walking beam of a pumping unit, the pressure stabilizing structure is communicated with the input end of the piston structure and the negative pressure structure through one-way valves respectively, and the negative pressure structure comprises a negative pressure pipe and a back pressure pipe, the negative pressure pipe is communicated with a well head through a one-way valve, and the back pressure pipe is communicated with the negative pressure structure through a one-way valve; The negative pressure structure further comprises a negative pressure cylinder, a plug rod is slidably arranged in the negative pressure cylinder, an elastic member is arranged on one side of the negative pressure cylinder close to the well head, the negative pressure pipe is communicated with the side of the negative pressure cylinder close to the well head, the back pressure pipe is communicated with the side of the negative pressure cylinder away from the well head, the plug rod comprises a plug head, and the pressure stabilizing structure is communicated with the side of the negative pressure cylinder close to the plug head; the pressure stabilizing structure comprises a pressure stabilizing tank, a pressure stabilizing member is arranged in the pressure stabilizing tank, and the two ends of the pressure stabilizing tank are communicated with the negative pressure cylinder and the piston structure respectively; The inside of the pressure stabilizing member is provided with a plurality of flow channels, the negative pressure pipe and the plurality of flow channels in the pressure stabilizing member are all Venturi pipes with spiral flow channels, and the throat diameter ratio is 1:8; During the working process of the pumping unit, the reciprocating motion of the piston structure can be realized through the swinging of the walking beam, and a vacuum is formed in the piston structure during the return stroke, so as to convert the negative pressure in the negative pressure structure into the pressure increase of the well head; Then the gas flow enters the pressure stabilizing tank through the piston structure and the one-way valve, and the pressure stabilizing member slows down and disperses the pressure of the gas flow through the spiral flow channels, so as to realize the pressure increase of the well head by the negative pressure structure; The pressure stabilizing structure is connected with a second-stage negative pressure stimulation assembly, the second-stage negative pressure stimulation assembly comprises a pressure increasing tank, the pressure increasing tank is communicated with the side of the negative pressure cylinder away from the plug head through a one-way valve, and nitrogen is introduced into the pressure increasing tank; The second-stage negative pressure stimulation assembly further comprises a pressure increasing member, the two ends of the pressure increasing member are communicated with the pressure increasing tank and the pressure stabilizing structure through one-way valves respectively.

2. The low-efficiency well negative pressure stimulation integrated device according to claim 1, characterized in that, The pressure increasing member comprises a hollow pressure increasing seat, the pressure increasing seat comprises a negative pressure area and a pressure increasing area respectively, a rotating shaft is rotatably arranged in the pressure increasing seat, a pressure increasing turbine and a negative pressure turbine are arranged on the two sides of the rotating shaft respectively, the pressure increasing turbine is arranged in the pressure increasing area, the negative pressure turbine is arranged in the negative pressure area, the gas outlet of the pressure increasing area is communicated with the pressure increasing tank, and the gas inlet of the negative pressure area is communicated with the pressure stabilizing structure.

3. The low-efficiency well negative pressure stimulation integrated device according to claim 1, characterized in that, The integrated device further comprises a packer, the packer comprises a pressure sensitive bellows and a hydraulic assembly, and the hydraulic assembly is arranged in the packer and used to control the pressure change of different sealing sections of the packer.

4. The low-efficiency well negative pressure stimulation integrated device according to claim 2, characterized in that, Nitrogen is introduced into the gas inlet of the piston structure, the gas inlet of the pressure increasing member and the gas inlet of the pressure increasing area.

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