Self-sealing type steam injection tubular column pitch changing equipment

Abstract

The invention discloses self-sealing type variable pitch equipment for a steam injection tubular column. The device comprises a sliding variable-pitch device, a self-sealing variable-pitch pipe assembly, a steam injection fluid pushing system and a steam inlet end pressure cavity. The steam injection fluid pushing system pushes gas through a Tesla valve pipe, the flow during steam injection is larger than the reverse flow when steam injection is stopped, and after steam injection is stopped, residual steam in the pressure cavity keeps the temperature in the device within a certain time so as to reduce stress drastic change caused by drastic change of the temperature. The negative pressure generated by the negative pressure generating device located near the steam outlet port of the sliding variable-pitch device is used for sealing the steam outlet port, effective connection of the outer pipe is kept when steam injection is stopped, and forced connection of the inner pipe is quitted, so that the stress of the pipe orifice is reduced, and damage to the pipe orifice caused by sudden increase of the stress of the pipe orifice is avoided. The steam injection pipe column solves the technical problem that a steam injection pipe column in the prior art is prone to damage.

Description

Technical Field

[0001] The present application relates to the technical field of oil production equipment, and in particular to a self-sealing steam injection pipe column variable pitch equipment. Background Art

[0002] This section is intended to provide a background or context to what is stated in the claims or specification, and no admission is made that what is described herein is prior art by inclusion in this section.

[0003] Heavy oil resources are a potential successor for increasing reserves and production and achieving sustainable development in the future. Heavy oil reservoirs have high viscosity and are not easy to flow. How to pump them from the formation into the wellbore and then lift them to the ground from the wellbore is a relatively difficult problem. Injecting steam into the oil layer to reduce its viscosity is currently the most commonly used and most effective method.

[0004] During the steam injection process in heavy oil blocks, heavy oil wells frequently experience failures such as failure of steam injection pipe sealing and connection, and failure to recover the steam injection pipe column, which are difficult to repair. The shortcomings of the current existing technology are as follows:

[0005] 1) The existing steam injection expansion pipe is of the normally open type and is fully opened after entering the well. It has no effect when used in conjunction with the thermal packer (i.e., when the steam injection string shrinks due to cold after the steam injection is stopped, it is fully opened and cannot compensate for the length of the steam injection string shrinkage).

[0006] 2) The seal of the existing steam injection expansion pipe is a rigid seal. In order to prevent the failure of the seal and connection, manual installation is usually adopted, which is labor-intensive and has prominent safety issues. After the manual installation is completed, the sealing state is irrelevant to whether the steam injection is stopped, and manual intervention is required to complete the unsealing.

[0007] 3) After the steam injection is stopped, the temperature drops from the wellhead from top to bottom, the insulation pipe string cools down and shrinks, and the thermosensitive packer is not released synchronously, which increases the stress of the steam injection pipe string and causes damage to the steam injection pipe string.

[0008] 4) The steam injection expansion pipe is often used to compensate for the thermal expansion and contraction of the pipe string during the steam injection process through the relative sliding between the inner and outer concentric pipes. Therefore, the difference in dynamic sealing performance (self-sealing performance) and variable distance thermal insulation performance between the inner and outer pipes of the expansion pipe affects the service life and production efficiency of the steam injection pipe string.

[0009] 5) The existing technology has a low degree of automation, and the sealing effect is positively correlated with the proficiency and technical level of the installer, which results in extremely unstable working conditions in actual use.

[0010] 6) During the long-term steam injection process, the inner and outer walls of the steam injection expansion pipe are prone to scaling, causing wear of the seals, thereby weakening the dynamic sealing effect of the expansion pipe, resulting in a significant shortening of the effective service life of the expansion pipe, serious waste, and increased costs.

[0011] To address the above-mentioned problems, no effective solution has been proposed yet. Summary of the invention

[0012] The embodiment of the present application provides a self-sealing steam injection pipe column pitch-changing device to at least solve the technical problem in the related art that the steam injection pipe column is easily damaged.

[0013] According to one aspect of an embodiment of the present application, a self-sealing steam injection pipe column pitch changing device is provided, comprising: a sliding pitch changing device, a self-sealing pitch changing pipe assembly, a steam injection fluid driving system and a steam inlet end pressure chamber; the steam injection fluid driving system drives the gas through a Tesla valve tube, and the flow rate during steam injection is greater than the reverse flow rate when the steam injection is stopped. After the steam injection is stopped, the remaining steam in the pressure chamber maintains the temperature in the device for a certain period of time to reduce the stress drastic changes caused by the rapid temperature changes; the negative pressure generated by the negative pressure generating device located near the steam outlet port of the sliding pitch changing device is used to seal the steam outlet port and keep the outer tube effectively connected and the inner tube withdrawn from the strong connection when the steam injection is stopped, thereby reducing the pipe mouth stress and avoiding the pipe mouth damage caused by the sudden increase in stress.

[0014] Optionally, the sliding pitch changing device includes: a heat-insulating sliding sleeve, a distance ring, a front end seal, a steam outlet port, a baffle, a self-cleaning ring and an outer sleeve.

[0015] Optionally, the self-sealing variable pitch pipe assembly includes: steam inlet and outlet pipes, a sliding sleeve, a negative pressure pipe, a negative pressure pipe port, a variable diameter pressure regulating ring, a pressure regulating ring and a pressure control ring.

[0016] Optionally, the steam injection fluid propulsion system includes: a steam inlet duct, a thrust slider, a negative pressure spoiler chamber, a spacer ring, a thrust ring, a thrust ring, a Tesla tube, a connecting pipe and a steam inlet pipe positioning inner cone.

[0017] Optionally, the steam injection fluid driving system includes: a rear end of the pressure chamber, a steam inlet end of the pressure chamber, a diaphragm, a spring, a first O-ring, a second O-ring, a third O-ring and a pressure chamber regulating push rod.

[0018] Optionally, the steam injection pipe column is docked with the rear end of the pressure chamber of the pressure chamber body at the steam inlet end, and is guided and fixed by means of conical surfaces and grooves; after being connected with the steam inlet pipe positioning inner cone and the steam inlet and outlet pipes, the pressure chamber regulating push rod is pushed open by the steam injection pipe column; the steam inlet pipe positioning inner cone at the rear end of the pressure chamber and the conical surfaces on the steam inlet and outlet pipes form a complete internal and external sealed closed loop, and the spring under the pressure chamber regulating push rod provides kinetic energy for reset in the normally closed state; the first O-ring, the second O-ring, and the third O-ring are used to ensure the sealing condition of the pressure chamber regulating push rod when it slides.

[0019] Optionally, steam enters the steam injection fluid propulsion system from the steam inlet and outlet pipes, forming pressure and temperature inside the cavity; the internal pressure of the cavity pushes the thrust slider, thrust ring, and thrust ring to slide limitedly in three grooves set on the steam inlet and outlet pipes, pushing the steam inlet duct to perform secondary docking inside the device; after the steam inlet duct is docked with the Tesla tube and the connecting pipe, steam begins to be transported through the Tesla tube.

[0020] Optionally, after the steam enters the steam inlet end pressure cavity from the steam inlet and outlet pipes to form the internal pressure and temperature of the cavity, the internal pressure of the cavity pushes the variable diameter pressure regulating ring, the pressure regulating ring, and the pressure control ring to move within a limited range, and pushes the self-cleaning ring and the sliding sleeve to move within the control range of the fixed distance ring, thereby completing the unidirectional variable distance function.

[0021] Optionally, after the steam passes through the Tesla tube, it enters the sliding pitch-changing device connected to the lower end. The steam flow forms a pressure difference under the action of the negative pressure tube, the negative pressure pipe mouth, and the negative pressure turbulence chamber, which pushes the self-cleaning ring to reciprocate. Since the multiple self-cleaning rings are in different positions, different pressure differences can be formed, which push the self-cleaning ring and the sliding sleeve to reciprocate in the insulating sliding sleeve, thereby completing the one-way pitch-changing function and the self-cleaning function.

[0022] Optionally, a self-sealing steam injection pipe column variable pitch device is connected to another self-sealing steam injection pipe column variable pitch device through the steam inlet and outlet pipes and the steam outlet port to complete the transmission and injection of steam.

[0023] In an embodiment of the present application, a self-sealing steam injection pipe column pitch change equipment includes: a sliding pitch change device, a self-sealing pitch change pipe assembly, a steam injection fluid driving system and a steam inlet end pressure chamber; the steam injection fluid driving system drives the gas through a Tesla valve tube, and the flow rate during steam injection is greater than the reverse flow rate when the steam injection is stopped. After the steam injection is stopped, the residual steam in the pressure chamber maintains the temperature in the device for a certain period of time to reduce the stress drastic changes caused by the rapid temperature changes; the negative pressure generated by the negative pressure generating device located near the steam outlet port of the sliding pitch change device is used to seal the steam outlet port and keep the outer tube effectively connected and the inner tube withdraw from the strong connection when the steam injection is stopped, thereby reducing the pipe mouth stress and avoiding the pipe mouth damage caused by the sudden increase in stress, thereby solving the technical problem of easy damage to the steam injection pipe column in the related technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0025] Figure 1 is a schematic diagram of an optional self-sealing steam injection column pitch-changing device according to an embodiment of the present application;

[0026] Figure 2 is a schematic diagram of an optional self-sealing steam injection column pitch-changing device according to an embodiment of the present application;

[0027] Figure 3 is a schematic diagram of an optional self-sealing steam injection column pitch-changing device according to an embodiment of the present application;

[0028] Figure 4 is a schematic diagram of an optional self-sealing steam injection column pitch-changing device according to an embodiment of the present application;

[0029] Figure 5 is a schematic diagram of an optional sliding pitch-changing device according to an embodiment of the present application;

[0030] Figure 6 is a schematic diagram of an optional self-sealing variable pitch tube assembly according to an embodiment of the present application;

[0031] Figure 7 is a schematic diagram of an optional steam injection fluid propulsion system according to an embodiment of the present application;

[0032] Figure 8 is a schematic diagram of an optional steam injection fluid propulsion system according to an embodiment of the present application;

[0033] Fig. 9 It is a schematic diagram of an optional self-sealing steam injection pipe column variable pitch device according to an embodiment of the present application. DETAILED DESCRIPTION

[0034] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present application.

[0035] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0036] It should be noted that the full name of the steam injection string described in this application is the steam injection insulation string, which is a commonly used vulnerable standard part in oil production (especially heavy oil production), mass-produced by relevant enterprises, and has standard parameter specifications. The steam injection packer is an important component of the steam injection string, which is very important for reducing wellbore heat loss, improving steam injection dryness, and improving steam injection effect. Commonly used steam injection packers are mechanically set and thermal expansion types. The mechanically set type is similar to the conventional packer, but the seal is high temperature resistant to meet the needs of high-temperature steam injection. The working principle of the thermal expansion packer is to rely on the pressure and temperature of the steam injection to expand the packer, seal the oil casing annulus, and play a sealing role. It is usually composed of a coupling, an insulating bushing, a sealing ring, an outer pipe, an insulating material, an inner pipe, etc.

[0037] The present application provides a self-sealing steam injection pipe column pitch-changing device, which mainly relates to the sealing and pitch-changing of a "pipe joint" to solve the problems existing in the prior art.

[0038] like Figures 1 to 4 As shown in the figure, the self-sealing steam injection pipe column pitch changing equipment is mainly composed of four modules: sliding pitch changing device, self-sealing pitch changing pipe assembly, steam injection fluid driving system, and steam inlet pressure chamber. Each module is composed of about 6-8 parts to achieve different functions. The four modules of sliding pitch changing device, self-sealing pitch changing pipe assembly, steam injection fluid driving system, and steam inlet pressure chamber correspond to one grayscale respectively.

[0039] In order to solve the technical problem that the steam injection pipe column is easily damaged in the related technology, the present invention changes the normally open mode of the steam injection telescopic pipe in the prior art and adopts a Tesla valve pipe structure, so that the flow rate during steam injection is much larger than the reverse flow rate when the steam injection is stopped. When the steam injection is stopped, the residual steam in the pressure chamber can maintain the temperature in the device for a short time, reducing the stress fusion caused by the rapid temperature change; a negative pressure generating device is provided near the steam outlet port, and the generated negative pressure can ensure the effective sealing of the steam outlet port while keeping the outer pipe effectively connected and the inner pipe withdrawn from the strong connection when the steam injection is stopped, so as to reduce the pipe mouth stress and effectively protect the pipe mouth from damage caused by the sharp increase in stress.

[0040] See also Figures 5 to 8 The sliding pitch-changing device comprises: a heat-insulating sliding sleeve 1, a distance ring 2, a front seal 3, a steam outlet port 4, a baffle 5, a self-cleaning ring 6 and an outer sleeve 7. The self-sealing pitch-changing pipe assembly comprises: a steam inlet and outlet pipe 8, a sliding sleeve 9, a negative pressure pipe 10, a negative pressure pipe port 11, a variable-diameter pressure regulating ring 12, a pressure regulating ring 13 and a pressure control ring 14. The steam injection fluid driving system comprises: a steam inlet duct 15, a thrust slider 16, a negative pressure spoiler chamber 17, a spacer ring 18, a thrust ring 19, a thrust ring 20, a Tesla tube 21, a connecting pipe 22 and a steam inlet pipe positioning inner cone 23. The steam injection fluid driving system comprises: a pressure chamber rear end 24, a pressure chamber steam inlet end 25, a spacer 26, a spring 27, a first O-type sealing ring 28, a second O-type sealing ring 29, a third O-type sealing ring 30 and a pressure chamber regulating push rod 31.

[0041] The seal of the present invention is a flexible seal, which relies on the pressure of the injected steam to form positive and negative pressure and variable distance to complete its self-sealing working condition, does not require manual installation, and solves the problems of labor intensity and construction safety. The sealing state is released under the condition of stopping steam injection, and it is completed without manual intervention.

[0042] In order to facilitate a deeper understanding of the technical solution of the present application, the technical solution of the present application is further described in detail below in conjunction with specific implementation methods:

[0043] The steam injection column is connected to the pressure chamber steam inlet end 25 on the "steam inlet end pressure chamber" module, and is guided and fixed by the conical surface and groove; after being connected to the steam inlet pipe positioning inner cone 23 and the steam inlet and outlet pipe 8, the pressure chamber regulating push rod 31 (the spring provides constant force) is pushed open by the steam injection column; the pressure chamber steam inlet end 25, the steam inlet pipe positioning inner cone 23, and the conical surface on the steam inlet and outlet pipe 8 form a complete internal and external sealed closed loop, and the spring 27 under the pressure chamber regulating push rod 31 provides the kinetic energy for reset in the normally closed state. The three sealing rings of O-ring I28, O-ring II29, and O-ring III30 ensure the sealing condition of the pressure chamber regulating push rod 31 during sliding displacement (opening and closing).

[0044] At this time, steam enters the "steam injection fluid propulsion system" module from the steam inlet and outlet pipes 8, forming pressure and temperature inside the cavity; the pressure inside the cavity pushes the thrust slider 16, thrust ring 19, and thrust ring 20 to slide in limited displacement in three grooves on the steam inlet and outlet pipes 8, pushing the steam inlet duct 15 to perform secondary docking inside the device; after the steam inlet duct 15 is docked with the Tesla tube 21 and the connecting pipe 22, steam begins to be transported through the Tesla tube 21. At the same time as the previous action, steam enters the "steam inlet end pressure cavity" module from the steam inlet and outlet pipes 8, forming pressure and temperature inside the cavity; the pressure inside the cavity pushes the variable diameter pressure regulating ring 12, the pressure regulating ring 13, and the pressure control ring 14 to move within a limited range, pushing the self-cleaning ring 6 and the sliding sleeve 9 to move within the control range of the 2. fixed distance ring to complete the unidirectional (elongation) variable distance function.

[0045] After the steam passes through the Tesla tube 21, it enters the "sliding pitch device" module connected at the lower end. The steam flow forms a pressure difference under the action of the negative pressure pipe 10, the negative pressure pipe port 11, and the negative pressure turbulent cavity 17, which drives the self-cleaning ring 6 to reciprocate. Due to the different positions of the three self-cleaning rings 6 (see Fig. 9 ), forming different pressure differences, pushing the self-cleaning ring 6 and the sliding sleeve 9 to move back and forth within the range of the heat-insulating sliding sleeve 1, completing another one-way variable pitch function and self-cleaning function without the need for other kinetic energy.

[0046] The self-sealing steam injection pipe column pitch-changing device is connected to the next steam injection pipe column through the steam inlet and outlet pipes 8 and the steam outlet port 4 to complete the transmission and injection of steam.

[0047] When the steam injection is stopped, the upper pressure chamber regulating push rod 31 is reset under the push of the spring 27, and the thrust slider 16, thrust ring 19, and thrust ring 20 are reset under the action of the residual steam in the "steam inlet pressure chamber". After the residual steam pressure is unloaded, the Tesla tube 21 controls the reflux of steam under its one-way transmission characteristics. At this time, the steam in the heat-insulating sliding sleeve 1 pushes the steam injection column through the pressure regulating exhaust port on the steam inlet and outlet pipe 8 to ensure that the device and the steam injection column are smoothly disconnected.

[0048] The beneficial effects of the present invention are as follows: the self-sealing steam injection pipe column pitch-changing equipment, through the use of the cavity compression sleeve in conjunction with the sealing cavity, the use of the sealing ring, the thrust sleeve and the sealing sleeve in conjunction with each other, and then through the internal operation of the variable-diameter pressure regulating ring 12, the pressure regulating ring 13 and the pressure control ring 14, the self-cleaning ring 6 and the sliding sleeve 9 move to achieve the purpose of flexible self-sealing and automatic pitch adjustment, enhance the self-sealing performance of the overall device, greatly reduce the risk of manual use and safety, and reduce the damage and service life of the steam injection pipe.

[0049] 1) The present invention changes the original elastic seal compensation mode into a pressure flexible seal compensation mode, introduces high-pressure steam as the kinetic energy for seal compensation, and can generate a corresponding pressure-varying pressing force on the seal through the action of a variable distance compensation body, thereby changing and compensating the loss of the seal to ensure the sealing effect.

[0050] 2) A self-cleaning device is added to the structure. During the expansion and contraction process, the self-cleaning device can automatically remove scale and other impurities on the outer wall of the inner tube as the inner tube slides to reduce the wear of the seal.

[0051] 3) The design of the heat-insulating outer pipe can ensure that the heat loss of the expansion pipe part during long-term steam injection is minimized, thereby ensuring the overall insulation effect of the steam injection pipe column.

[0052] 4) The self-sealing steam injection pipe column pitch changing equipment is mainly composed of four parts: "sliding pitch changing device", "self-sealing pitch changing pipe assembly", "steam injection fluid driving system" and "steam inlet end pressure chamber".

[0053] 5) The structure adopts multi-cavity plus metal seal, and the variable-diameter pressure regulating ring 12, pressure regulating ring 13, and pressure control ring 14 can move at any time under high temperature and pressure to push the steam inlet and outlet pipe 8 to ensure its self-sealing performance. The variable distance device improves the sealing effect and service life of the long-term self-sealing performance.

[0054] 6) The Tesla tube is used to reduce heat loss by the difference in steam flow in the forward and reverse directions, while improving the insulation and temperature resistance of the entire steam injection pipe column, and allowing the internal pressure of the device to continue to complete the disconnection action when the steam injection is stopped.

[0055] 7) The present invention adopts negative pressure compensation type to push the variable distance telescopic tube. The telescopic tube can automatically remove scale, change the elastic sealing mode to steam injection pressure flexible seal, and the heat insulation type outer tube design improves the movable sealing performance and service life of the telescopic tube.

[0056] It should be noted that, for the aforementioned method embodiments, for the sake of simplicity, they are all expressed as a series of action combinations, but those skilled in the art should be aware that the present application is not limited by the described order of actions, because according to the present application, certain steps can be performed in other orders or simultaneously. Secondly, those skilled in the art should also be aware that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily required by the present application.

[0057] Through the description of the above implementation methods, those skilled in the art can clearly understand that the method according to the above embodiment can be implemented by means of software plus a necessary general hardware platform, and of course by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art, can be embodied in the form of a software product, which is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk), and includes a number of instructions for a terminal device (which can be a mobile phone, computer, server, or network device, etc.) to execute the methods described in each embodiment of the present application.

[0058] The serial numbers of the above-mentioned embodiments of the present application are for description only and do not represent the advantages or disadvantages of the embodiments.

[0059] If the integrated units in the above embodiments are implemented in the form of software functional units and sold or used as independent products, they can be stored in the above computer-readable storage medium. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product, which is stored in a storage medium and includes several instructions for enabling one or more computer devices (which may be personal computers, servers, or network devices, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present application.

[0060] In the above embodiments of the present application, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, please refer to the relevant description of other embodiments.

[0061] In the several embodiments provided in the present application, it should be understood that the disclosed client can be implemented in other ways. Among them, the device embodiments described above are only schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of units or modules, which can be electrical or other forms.

[0062] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0063] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0064] The above is only a preferred implementation of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present application. These improvements and modifications should also be regarded as the scope of protection of the present application.

Claims

1. A self-sealing steam injection pipe column pitch changing device, characterized in that: include: Sliding pitch change device, self-sealing pitch change tube assembly, steam injection fluid propulsion system and steam inlet end pressure chamber; The steam injection fluid driving system drives the gas through the Tesla valve tube, and the flow rate during steam injection is greater than the reverse flow rate when the steam injection is stopped. After the steam injection is stopped, the residual steam in the pressure chamber at the steam inlet end maintains the temperature in the device for a certain period of time to reduce the stress drastic change caused by the rapid temperature change; The negative pressure generated by the negative pressure generating device located near the steam outlet port of the sliding pitch changing device is used to seal the steam outlet port and keep the outer pipe effectively connected and the inner pipe withdrawn from the strong connection when the steam injection is stopped, thereby reducing the pipe mouth stress and avoiding the pipe mouth damage caused by the sudden increase of stress.

2. The self-sealing steam injection pipe column pitch changing device according to claim 1, characterized in that: The sliding pitch changing device comprises: Insulating sliding sleeve, distance ring, front end seal, steam outlet port, baffle, self-cleaning ring and outer sleeve.

3. The self-sealing steam injection pipe column pitch changing device according to claim 2, characterized in that: The self-sealing variable pitch tube assembly comprises: Inlet and outlet steam pipes, sliding sleeves, negative pressure pipes, negative pressure pipe openings, variable-diameter pressure regulating rings, pressure regulating rings and pressure control rings.

4. The self-sealing steam injection pipe column pitch changing device according to claim 3, characterized in that: The steam injection fluid propulsion system comprises: Steam inlet duct, thrust slider, negative pressure spoiler cavity, spacer ring, thrust ring, thrust ring, Tesla tube, connecting pipe and steam inlet pipe positioning inner cone.

5. The self-sealing steam injection pipe column pitch changing device according to claim 4, characterized in that: The steam injection fluid propulsion system comprises: The rear end of the pressure chamber, the steam inlet end of the pressure chamber, the spacer, the spring, the first O-type sealing ring, the second O-type sealing ring, the third O-type sealing ring and the pressure chamber regulating push rod.

6. The self-sealing steam injection pipe column pitch changing device according to claim 5, characterized in that: The steam injection pipe column is initially docked with the rear end of the pressure chamber of the steam inlet end pressure chamber, and is guided and fixed by the conical surface and the groove; after being connected with the steam inlet pipe positioning inner cone and the inlet and outlet steam pipes, the pressure chamber regulating push rod is pushed open by the steam injection pipe column; the rear end of the pressure chamber, the steam inlet pipe positioning inner cone, and the conical surface on the inlet and outlet steam pipes form a complete internal and external sealing closed loop, and the spring under the pressure chamber regulating push rod provides the kinetic energy for reset in the normally closed state; the first O-ring, the second O-ring, and the third O-ring are used to ensure the sealing condition of the pressure chamber regulating push rod when it slides.

7. The self-sealing steam injection pipe column pitch changing device according to claim 6, characterized in that: Steam enters the steam injection fluid propulsion system from the steam inlet and outlet pipes, forming pressure and temperature inside the cavity; the internal pressure of the cavity pushes the thrust slider, thrust ring, and thrust ring to slide limitedly in the three grooves set on the steam inlet and outlet pipes, pushing the steam inlet duct to perform secondary docking inside the device; after the steam inlet duct is docked with the Tesla tube and the connecting pipe, steam begins to be transported through the Tesla tube.

8. The self-sealing steam injection pipe column pitch changing device according to claim 7, characterized in that: After the steam enters the pressure cavity at the steam inlet end from the steam inlet and outlet pipes to form the internal pressure and temperature of the cavity, the internal pressure of the cavity pushes the variable diameter pressure regulating ring, the pressure regulating ring, and the pressure control ring to move within a limited range, and pushes the self-cleaning ring and the sliding sleeve to move within the control range of the fixed distance ring, thereby completing the one-way variable distance function.

9. The self-sealing steam injection pipe column pitch changing device according to claim 8, characterized in that: After the steam passes through the Tesla tube, it enters the sliding pitch-changing device connected at the lower end. The steam flow forms a pressure difference under the action of the negative pressure pipe, the negative pressure pipe mouth, and the negative pressure turbulence cavity, which pushes the self-cleaning ring to reciprocate. Because multiple self-cleaning rings are in different positions, different pressure differences can be formed, which push the self-cleaning ring and the sliding sleeve to reciprocate in the insulating sliding sleeve, completing the one-way pitch-changing function and the self-cleaning function.

10. The self-sealing steam injection pipe column pitch changing device according to any one of claims 1 to 9, characterized in that: A self-sealing steam injection pipe column variable pitch device is connected to another self-sealing steam injection pipe column variable pitch device through the steam inlet and outlet pipes and the steam outlet port to complete the transmission and injection of steam.

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