Wellhead casing annulus dosing device and method and related application

Abstract

The invention discloses a wellhead casing annulus dosing device, a wellhead casing annulus dosing method and related application. The device comprises an outer shell, a sealing cover, a medicament container, a supporting body and a Venturi tube assembly, wherein the sealing cover, the medicament container, the supporting body and the Venturi tube assembly are arranged in the outer shell from top to bottom; a Venturi tube structure is formed in the Venturi tube assembly, an inlet of the Venturi tube structure is communicated with an air source, an outlet of the Venturi tube structure is communicated with one end of an output tube, and the other end of the output tube is communicated with an oil jacket annulus; an inner hole of the support body is communicated with the medicament container and the Venturi tube structure; an electromagnetic push-pull module is arranged in the supporting body and comprises an electromagnetic coil, an armature arranged in the electromagnetic coil, a gate plate connected with the armature and a reset spring arranged between the inner wall of the supporting body and the armature. The armatures are used for driving the flashboards corresponding to the armatures to move towards the ends close to the outer shell and compressing the reset springs so that the flashboards can be opened to block the inner holes of the supporting bodies, and the flashboards are driven to reset under the action of restoring force of the reset springs. And automatic dosing of the casing annulus can be realized.

Description

Technical Field

[0001] This invention relates to the field of oilfield oil and gas production technology, and in particular to a wellhead casing annulus chemical dosing device, method and related applications. Background Technology

[0002] In actual oilfield production, various chemical agents need to be added to wells to achieve corrosion inhibition, wax prevention, and viscosity reduction, thereby reducing accidents such as sticking, blockage, and breakage of sucker rods, tubing, and pumps. In existing technologies, when adding chemicals to the wellhead for the first time, the chemicals are generally added to the protective fluid and introduced into the well along with the casing. As time passes, the chemicals are gradually consumed, requiring re-addition to the casing annulus. Currently, this re-addition is typically done manually at the wellhead periodically. Summary of the Invention

[0003] The inventors of this application discovered that, in the prior art, manual deployment to a well requires disassembling the wellhead, referring to... Figure 1 As shown, since the annulus of the gas production well is not completely filled with protective fluid, the top section is often empty. This empty section typically contains a large amount of natural gas and has a certain pressure. If improper handling occurs when adding chemical agents into the annulus during wellhead disassembly, resulting in poor wellhead sealing, natural gas leakage accidents can easily occur. Furthermore, manual, periodic addition is labor-intensive, complex, and inefficient, and requires the mobilization of personnel and vehicles, increasing costs. Therefore, developing a device for adding chemical agents is an urgent problem to solve.

[0004] In view of the above problems, the present invention is proposed to provide a wellhead casing annulus chemical dosing device, method and related applications that overcome or at least partially solve the above problems.

[0005] The wellhead casing annulus chemical dosing device provided in this embodiment of the invention includes: an outer shell, a sealing cap disposed inside the outer shell from top to bottom, a chemical container, a support body, and a venturi tube assembly;

[0006] The Venturi tube assembly has a Venturi tube structure, the inlet of which is used to connect to the gas source, and the outlet is connected to one end of the output pipe, the other end of which is used to connect to the oil jacket annulus.

[0007] The upper end of the inner hole of the support body is connected to the drug container, and the lower end is connected to the Venturi tube structure.

[0008] The support body is provided with multiple mounting holes distributed vertically, and an electromagnetic push-pull module is correspondingly installed in each mounting hole;

[0009] The electromagnetic push-pull module includes: an electromagnetic coil, an armature disposed within the electromagnetic coil, a gate connected to one end of the armature via a connecting rod, and a return spring disposed between the inner wall of the support body and the armature.

[0010] The gate is disposed in the inner hole of the support body and is used to control the sealing and opening of the inner hole of the support body;

[0011] The armature is used to drive the corresponding gate plate to move towards one end closer to the outer casing when the electromagnetic coil is energized, and to compress the reset spring to open the gate plate's seal on the inner hole of the support body, and to drive the gate plate to reset under the restoring force of the reset spring after the electromagnetic coil is de-energized.

[0012] In an optional embodiment, the venturi assembly includes: a nozzle and a throat body;

[0013] The nozzle’s inner bore, the channel formed between the nozzle’s outer wall and the throat body’s inner wall, and the inner bore of the throat body form a Venturi tube structure.

[0014] Accordingly, the inner hole of the nozzle is used to connect to the air source, one end of the output pipe is connected to the inner hole of the throat body, and the lower end of the inner hole of the support body is connected to the channel formed between the outer wall of the nozzle and the inner wall of the throat body.

[0015] In an optional embodiment, the pharmaceutical container includes a cylindrical section and a conical section;

[0016] The cylindrical segment is connected to the larger diameter end of the conical segment, and the smaller diameter end of the conical segment is the end closer to the support body. A support block is provided between the outer wall of the conical segment and the upper surface of the support body.

[0017] In an optional embodiment, a buffer pad is provided inside the electromagnetic coil near one end of the outer casing;

[0018] Accordingly, the reset spring is disposed between the buffer pad and the armature.

[0019] In an optional embodiment, a heating and insulation layer is further provided on the outside of the outer casing;

[0020] The heating and insulation layer is provided with an electric heating resistance wire and insulation material.

[0021] The outer wall of the heating and insulation layer is provided with an electric heating electrode plug for connecting the electric heating resistance wire to an external power source.

[0022] In an optional embodiment, a temperature sensor is also provided inside the heating and insulation layer;

[0023] The temperature sensor is used to detect the temperature of the medicine and transmit the temperature to an external controller so that the controller can control the electric heating resistance wire to heat the medicine based on the temperature.

[0024] In an optional embodiment, the pharmaceutical container is further provided with a squeezing plate that can slide relative to the inner wall of the pharmaceutical container;

[0025] When the medicine is contained in the medicine container, the extrusion plate is disposed at the upper end of the medicine;

[0026] A compression spring is provided between the sealing cap and the extrusion plate.

[0027] In an optional embodiment, the inner bore of the support body is provided with an inner liner tube;

[0028] Accordingly, the upper end of the inner hole of the inner liner tube is connected to the medicine container, and the lower end is connected to the Venturi tube structure. The gate is disposed in the central hole of the inner liner tube and is used to control the sealing and opening of the inner hole of the support body.

[0029] In an optional embodiment, the inner liner is a polytetrafluoroethylene (PTFE) tube or a plastic tube.

[0030] In an optional embodiment, the wellhead casing annulus chemical dosing device provided in this embodiment of the invention further includes: a bottom support plate;

[0031] The upper end of the bottom support plate is disposed within the outer shell;

[0032] A sealing element is provided between the outer shell, the sealing cover, and the bottom support plate.

[0033] In an optional embodiment, the wellhead casing annulus chemical dosing device provided in this embodiment of the invention further includes: a controller;

[0034] The controller is used to control the energization or de-energization of the electromagnetic coil.

[0035] In an optional embodiment, the wellhead casing annulus chemical dosing device provided in this embodiment of the invention has a connector on the sealing cap for connecting to an external gas source.

[0036] A check valve is installed on the connecting pipeline between the gas source and the inlet of the Venturi tube structure.

[0037] The outer casing is also provided with a wire seal and an electrical plug. The wire of the electromagnetic coil passes through the wire seal and is connected to the electrical plug, which is used to connect to an external power source.

[0038] Based on the same inventive concept, embodiments of the present invention also provide a wellhead casing annulus chemical dosing method based on the above-mentioned wellhead casing annulus chemical dosing device, comprising:

[0039] The electromagnetic coil of the uppermost electromagnetic push-pull module is energized, and the armature of the electromagnetic push-pull module drives the corresponding gate to move towards the end closer to the outer shell, compressing the reset spring to open the gate's seal on the inner hole of the support body, allowing the medicine to fall onto the gate of the lower electromagnetic push-pull module. Then, the electromagnetic coil of the electromagnetic push-pull module is de-energized, and the armature, under the restoring force of the reset spring, drives the gate to reset.

[0040] The electromagnetic coils of the control electromagnetic push-pull module are energized and de-energized sequentially from top to bottom until the agent enters the Venturi tube structure under the negative pressure and mixes with the gas entering from the inlet of the Venturi tube structure. The agent is then output to the output pipe and transported to the annulus through the output pipeline connected to the output pipe to complete one dosing process.

[0041] The dosing process is repeated cyclically based on a preset number of dosing cycles until the current round of dosing is completed.

[0042] Based on the same inventive concept, this invention also provides an application of the above-mentioned wellhead casing annulus chemical dosing device in the field of oilfield oil and gas production technology.

[0043] The beneficial effects of the above-described technical solutions provided in the embodiments of the present invention include at least the following:

[0044] The wellhead casing annulus chemical dosing device provided in this embodiment of the invention is equipped with vertically distributed electromagnetic push-pull modules. By controlling the energization of the electromagnetic coils in the electromagnetic push-pull modules, the sealing and opening of the inner hole of the support body can be controlled, thereby controlling the chemical dosing process. The chemical in the chemical container gradually falls into the Venturi tube structure and is then transported to the tubing annulus. This device is suitable for dispensing both solid and liquid chemicals. Furthermore, through the cooperation of the vertically distributed electromagnetic push-pull modules, the amount of chemical dispensed can be precisely controlled. Specifically, in application, the energization and de-energization of the electromagnetic coils of the electromagnetic push-pull modules are controlled sequentially from top to bottom. First, the electromagnetic coil of the uppermost electromagnetic push-pull module is energized. The armature of this module drives the corresponding gate plate to move towards the end closer to the outer casing, compressing the spring to open the gate plate's seal on the inner hole of the support body. This allows the chemical to fall onto the gate plate of the lower electromagnetic push-pull module. Subsequently, the electromagnetic coil of the lower electromagnetic push-pull module is controlled... When power is cut off, the armature, under the restoring force of the spring, drives the gate to reset. At this time, the dosage between the uppermost gate and its adjacent gate is the dosage in one dosing process. Based on the preset number of dosing cycles, the dosing process can be cyclically repeated to achieve precise control of the dosage, ensure optimal use of the chemicals, avoid overdosing and waste, and be applicable to different working conditions. Furthermore, the structural design of this embodiment enables efficient and automated dosing operations in the annulus of the oil casing. Compared with the existing manual dosing method, the dosing device of this embodiment does not require disassembling the wellhead, which can improve the efficiency and safety of oil and gas extraction operations.

[0045] Furthermore, the wellhead casing annulus chemical dosing device of this embodiment is equipped with a heating and insulation layer on its outer shell, which can keep the chemical in the chemical container warm and heated. At low temperatures, the liquid chemical may become viscous, causing it to become unable to flow or even solidify, resulting in accidents where chemical dosing cannot be performed. The heating and insulation layer on the outer shell increases the applicability of the device, improves its reliability, and ensures its use in cold regions and during cold seasons.

[0046] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the written description, claims, and drawings.

[0047] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0048] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:

[0049] Figure 1 This is a schematic diagram of the wellbore structure in the existing technology;

[0050] Figure 2 This is a schematic diagram of the wellhead casing annulus chemical dosing device in an embodiment of the present invention;

[0051] Figure 3 As described in the embodiments of the present invention Figure 2 Enlarged structural diagram at point A;

[0052] Figure 4 This is a schematic diagram of the uppermost electromagnetic push-pull module in the open state in an embodiment of the present invention.

[0053] Figure 5 This is a schematic diagram of the structure of the medicine being placed between the gates of the two electromagnetic push-pull modules in an embodiment of the present invention;

[0054] Figure 6 This is a schematic diagram of the electromagnetic push-pull module at the lower end in the open state in an embodiment of the present invention;

[0055] Figure 7 This is a schematic diagram of the wellhead casing annulus chemical dosing device after one dosing cycle in an embodiment of the present invention.

[0056] Explanation of reference numerals in the attached figures:

[0057] 1. Connector; 2. Sealing cap; 3. Heating and insulation layer; 4. Outer shell; 5. Compression spring; 6. Extrusion plate; 7. Medicine container; 8. Support block; 9. Support body; 10. Cable seal; 11. Electrical plug; 12. Electromagnetic coil; 13. Throat body; 14. Output pipe; 15. Seal; 16. Bottom support plate; 17. Electric heating electrode plug; 18. Wire; 19. Armature; 20. Buffer pad; 21. Return spring; 22. Connecting rod; 23. Gate; 24. One-way valve; 25. Nozzle;

[0058] 251. The inner hole of the nozzle; 131. The channel formed between the outer wall of the larynx and the inner wall of the larynx; 132. The inner hole of the larynx. Detailed Implementation

[0059] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0060] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0061] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0062] To address the problems of high labor intensity, complex operation, and low work efficiency in the existing technology of manual periodic chemical dosing, embodiments of the present invention provide a wellhead casing annulus chemical dosing device, method, and related applications.

[0063] The wellhead casing annulus chemical dosing device provided in this embodiment of the invention refers to... Figure 2 and Figure 3 As shown, it includes: an outer shell 4, a sealing cap 2 disposed inside the outer shell 4 from top to bottom, a medicine container 7, a support 9, and a venturi tube assembly;

[0064] The Venturi tube assembly has a Venturi tube structure. The inlet of the Venturi tube structure is used to connect to the gas source, and the outlet is connected to one end of the output pipe 14. The other end of the output pipe 14 is used to connect to the oil jacket annulus.

[0065] The upper end of the inner hole of the support body 9 is connected to the medicine container 7, and the lower end is connected to the Venturi tube structure;

[0066] The support body 9 is provided with multiple mounting holes distributed vertically, and an electromagnetic push-pull module is installed in each mounting hole.

[0067] The electromagnetic push-pull module includes: an electromagnetic coil 12, an armature 19 disposed in the electromagnetic coil 12, a gate 23 connected to one end of the armature 19 via a connecting rod 22, and a return spring 21 disposed between the inner wall of the support body 9 and the armature 19.

[0068] The gate 23 is disposed in the inner hole of the support body 9 and is used to control the sealing and opening of the inner hole of the support body 9;

[0069] The armature 19 is used to drive the corresponding gate 23 to move closer to the outer casing 4 when the electromagnetic coil 12 is energized, and to compress the reset spring 21 to open the gate 23 from the inner hole of the support body 9, and to drive the gate 23 to reset under the restoring force of the reset spring 21 after the electromagnetic coil 12 is de-energized.

[0070] The wellhead casing annulus chemical dosing device provided in this embodiment of the invention, during chemical dosing, firstly, controls the electromagnetic coil 12 of the uppermost electromagnetic push-pull module to be energized. The armature 19 of this electromagnetic push-pull module drives the corresponding gate 23 to move towards the end closer to the outer casing 4, compressing the return spring 21 to open the seal of the gate 23 on the inner hole of the support body 9. The chemical agent falls onto the gate 23 of the lower electromagnetic push-pull module under gravity. Subsequently, the electromagnetic push-pull... When the electromagnetic coil 12 of the module is de-energized, the armature 19, under the action of the spring restoring force, drives the gate 23 to reset. Subsequently, the operation of energizing and de-energizing the electromagnetic coil 12 of the control electromagnetic push-pull module is performed sequentially from top to bottom until the agent enters the Venturi tube structure under the negative pressure of the Venturi tube structure and mixes with the gas entering from the inlet of the Venturi tube structure. The agent is then output to the output pipe 14 and transported to the annulus through the output pipe 14 line connected to the output pipe 14 to complete one dosing process.

[0071] This wellhead casing annulus chemical dosing device is suitable for the dosing of both solid and liquid chemicals. Through the cooperation of upper and lower distributed electromagnetic push-pull modules, the device can precisely control the amount of chemicals dispensed, ensuring optimal use of chemicals and avoiding waste caused by overdosing. It is applicable to different working conditions to achieve efficient and automated chemical dosing operation in the oil casing annulus, with high reliability.

[0072] In this embodiment of the invention, the specific number, location, and distribution distance of the electromagnetic push-pull modules are not specifically limited, and can be selected according to actual needs; for example, they can be set on the same side of the support body 9 or on different sides of the support body 9, as shown in the reference. Figure 1The diagram shows the structure of the electromagnetic push-pull module when it is installed on different sides of the support body 9. It should be noted that the electromagnetic push-pull module in this embodiment can be multiple, specifically two or more. When there are two or more electromagnetic push-pull modules, in practical applications, any two modules can be used to control the dosage in a single dosing process, while the electromagnetic coils 12 of the remaining modules can be energized so that the gate of the module is not blocking the support body 9. That is, in the wellhead casing annulus dosing device of this embodiment, when there are two or more electromagnetic push-pull modules, the device can also achieve different control accuracies by controlling the on / off state of the electromagnetic coils 12, thus increasing the applicability of the device.

[0073] In one embodiment, refer to Figure 2 As shown, the venturi assembly includes: a nozzle 25 and a throat body 13;

[0074] A Venturi tube structure is formed between the nozzle's inner hole 251, the channel 131 formed between the outer wall of the larynx and the inner wall of the larynx, and the inner hole 132 of the larynx.

[0075] Correspondingly, the inner hole 251 of the nozzle is used to connect to the air source, and one end of the output pipe 14 is connected to the inner hole 132 of the throat body;

[0076] The lower end of the inner hole of the support body 9 is connected to the channel 131 formed between the outer wall of the nozzle and the inner wall of the throat body.

[0077] In an optional embodiment, refer to Figure 2 As shown, the wellhead casing annulus chemical dosing device of this embodiment of the invention further includes: a bottom support plate 16;

[0078] The upper end of the bottom support plate 16 is disposed inside the outer shell 4 to support the wellhead casing annulus chemical dosing device provided in this embodiment of the invention, so that the device is in an upright state and can operate stably.

[0079] A sealing element 15 is provided between the outer shell 4, the sealing cover 2, and the bottom support plate 16.

[0080] Specifically, the armature 19 and the connecting rod 22, the connecting rod 22 and the gate 23, the sealing cover 2 and the outer shell 4, and the support 9 and the outer shell 4 can all be threaded connections; among them, the sealing cover 2 plays the role of bearing pressure and sealing.

[0081] In an optional embodiment, refer to Figure 2As shown, the wellhead casing annulus chemical dosing device of this embodiment of the invention has a connector 1 on its sealing cap 2 for connecting to an external gas source. Specifically, the connector 1 and the sealing cap 2 are connected by threads, and the connector 1 serves to connect to the external pipeline and provide a seal. In practical applications, gas is introduced into the wellhead casing annulus chemical dosing device through the connector 1 to create a higher internal pressure, thereby balancing the pressure inside the device with that inside the casing annulus and facilitating the delivery of chemicals into the casing annulus. Optionally, in practical applications, the connector 1 can be directly connected to the casing annulus through an external pipeline to introduce casing gas into the wellhead casing annulus chemical dosing device.

[0082] Furthermore, a check valve 7 is installed on the connecting pipeline between the gas source and the inlet of the venturi tube structure. This check valve only allows gas to enter the wellhead casing annulus chemical dosing device from the outside. Specifically, the check valve 7 is located between the gas source and the inner hole of the nozzle 25. In actual application, the gas source can be the casing annulus, that is, the gas introduced into the wellhead casing annulus chemical dosing device through the check valve 7 can be casing gas.

[0083] The outer casing 4 is also provided with a wire seal and an electrical plug 11. The wire 18 of the electromagnetic coil 12 passes through the wire seal and is connected to the electrical plug 11. The electrical plug 11 is used to connect to an external power source. The electrical plug 11 is a quick-connect plug for electrical appliances, which can transmit electrical energy stably and reliably. The function of the wire seal is to seal the internal and external pressure and prevent air or liquid leakage at the electrical plug 11.

[0084] In one embodiment, refer to Figure 2 As shown, the pharmaceutical container 7 includes a cylindrical section and a conical section;

[0085] The cylindrical section is connected to the larger diameter end of the conical section, and the smaller diameter end of the conical section is the end closest to the support body 9. A support block 8 is provided between the outer wall of the conical section and the upper end face of the support body 9 to provide a certain support force to the drug container 7 and prevent the conical section of the drug container 7 from being damaged under the pressure of the drug.

[0086] In one embodiment, refer to Figure 2 As shown, a buffer pad 20 is provided at one end of the electromagnetic coil 12 near the outer casing 4;

[0087] Correspondingly, the return spring 21 is disposed between the buffer pad 20 and the armature 19. The buffer pad 20 can buffer the force when the armature 19 moves towards the end of the housing, avoiding damage to the housing 4 when the spring directly contacts the inner wall of the housing 4. On the other hand, it also facilitates subsequent maintenance. If the buffer pad 20 is damaged when the attractive force generated by the electromagnetic coil 12 is large, only the buffer pad 20 needs to be replaced during equipment maintenance, reducing the cost of equipment maintenance.

[0088] In one embodiment, the wellhead casing annulus chemical dosing device of this embodiment may also be provided with a heating and insulation layer 3 on the outside of the outer shell 4;

[0089] The heating and insulation layer 3 contains an electric heating resistance wire and insulation material; and the outer wall of the heating and insulation layer 3 is equipped with an electric heating electrode plug 17 for connecting the electric heating resistance wire to an external power source. The external heating and insulation layer 3 serves to insulate and heat the medicine inside the medicine container 7. At low temperatures, liquid medicines may become viscous, causing them to become stagnant or even solidify, preventing the addition of medicine. The external heating and insulation layer 3 expands the applicability of the device, improves its reliability, and ensures its usability in cold regions and during cold seasons.

[0090] Furthermore, a temperature sensor can also be installed inside the heating insulation layer 3;

[0091] A temperature sensor is used to detect the temperature of the medicine and transmit the temperature to an external controller. The controller then controls the electric heating resistance wire to heat the medicine based on the temperature. Specifically, the external controller can control the electric heating resistance wire to heat when the temperature transmitted by the temperature sensor is lower than a first preset temperature threshold, and control the electric heating resistance wire to stop heating when the temperature transmitted by the temperature sensor is higher than a second preset temperature threshold, so that the temperature of the medicine is always within a suitable temperature range. That is, the annular dosing device of this embodiment also has an electric heating and heat preservation function and a temperature monitoring function. It can remotely control the heating of the device and the medicine, so that the medicine is in a good flow state and will not cause accidents that prevent the dosing of medicine in winter.

[0092] In one embodiment, refer to Figure 2 As shown, the medicine container 7 is also provided with a squeezing plate 6 that can slide relative to the inner wall of the medicine container 7;

[0093] When the medicine container 7 contains medicine, the extrusion plate 6 is positioned at the top of the medicine.

[0094] A compression spring 5 is provided between the sealing cover 2 and the extrusion plate 6.

[0095] Specifically, in practical applications, the compression spring 5 provides a downward thrust to the extrusion plate 6, which in turn provides a downward thrust for the medicine in the medicine container 7, thus preventing the medicine, especially solid medicine, from failing to fall under the action of gravity and causing dispensing failure. At the same time, when the extrusion plate 6 moves downward under the elastic force of the compression spring 5, it can clean the residual medicine on the inner wall of the medicine container 7, thereby reducing the residue of medicine, especially solid medicine, on the inner wall of the medicine container 7.

[0096] In one embodiment, the wellhead casing annulus chemical dosing device of this embodiment has an inner liner pipe provided in the inner hole of the support body 9;

[0097] Accordingly, the upper end of the inner hole of the inner liner tube is connected to the drug container 7, and the lower end is connected to the Venturi tube structure. The gate is located in the central hole of the inner liner tube and is used to control the sealing and opening of the inner hole of the support body 9. The structure with the inner liner tube avoids direct contact between the drug and the support body 9, thus preventing damage to the support body 9. It also facilitates subsequent maintenance work; when the drug flows through the support tube, it mainly contacts the inner liner tube. Even if the drug has a corrosive or destructive effect, it will only damage the inner liner tube. During maintenance, only the inner liner tube needs to be replaced, further reducing maintenance costs. Furthermore, the material of the inner liner tube can be selected according to actual needs; for example, the inner liner tube can be a polytetrafluoroethylene (PTFE) tube or a plastic tube.

[0098] In one embodiment, the wellhead casing annulus chemical dosing device of the present invention may further include: a controller (not shown in the figure), which is used to control the energization or de-energization of the electromagnetic coil 12. Specifically, the controller may be configured with a corresponding control program according to actual needs to complete the relevant sequence control of the energization and de-energization of the electromagnetic coil 12. Simultaneously, when the wellhead casing annulus chemical dosing device is equipped with a heating and insulation layer 3, the controller can also be used to receive the temperature from a temperature sensor and control the heating of the electric heating resistance wire based on that temperature.

[0099] In one embodiment, refer to Figure 2 As shown, taking the wellhead casing annulus chemical dosing device, which includes two electromagnetic push-pull modules distributed vertically, as an example, the dosing process of the wellhead casing annulus chemical dosing device provided in this embodiment of the invention is illustrated below:

[0100] 1. Add the desired chemical to the chemical container 7 of the wellhead casing annulus chemical dosing device. This chemical can be either a solid powder or a liquid. After the chemical is added, it tends to move downwards under its own weight and the spring clamping force. An external control program energizes the upper electromagnetic coil 12, generating an attractive force. The upper gate 23 moves from right to left under the pulling force of the armature 19, opening the seal of the gate 23 on the inner hole of the inner liner. Under the pressure, the chemical falls onto the lower gate 23. Blocked by the lower gate 23, the chemical cannot descend further. (See the schematic diagram of the wellhead casing annulus chemical dosing device for further details.) Figure 4 As shown.

[0101] 2. By de-energizing the upper electromagnetic coil 12 through an external control program, the armature 19, under the force of the return spring 21, re-seals the inner hole of the inner liner tube with the upper gate 23. At this time, the medicine is located between the gates 23 of the upper and lower electromagnetic push-pull modules. (See the schematic diagram for details.) Figure 5 As shown.

[0102] 3. Subsequently, the lower electromagnetic coil 12 is energized through an external control program. Under the pulling force of the armature 19, the lower gate 23 moves from left to right to open the seal of the inner hole of the inner liner tube. The reagent falls to the vicinity of the lower nozzle 25 under its own weight. At this time, refer to the structural schematic diagram of the wellhead casing annulus dosing device. Figure 6 As shown.

[0103] 4. External casing gas enters the device through check valve 24. Utilizing the Bernoulli effect, the casing gas can quickly draw in the reagent, mix it with the casing gas, and then rapidly output the reagent to output pipe 14. Refer to the schematic diagram of the wellhead casing annulus chemical dosing device at this point. Figure 7 As shown.

[0104] 5. The control program de-energizes the lower electromagnetic coil 12, and under the force of the reset spring 21, the lower gate 23 re-seals the inner hole of the inner liner tube.

[0105] 6. At this point, the device has completed one drug delivery cycle. In each cycle, the amount of drug delivered is a fixed volume V1 ml. If the total amount of drug to be delivered in this round is V ml, then the number of deliveries N = V / V1.

[0106] 7. Under the control of an external program, continue to drop the product, for a total of N drops.

[0107] 8. This round of drug administration is now complete.

[0108] This invention relates to a wellhead casing annulus chemical injection device, which is a highly efficient and automated chemical injection system designed to improve the efficiency and safety of oil and gas extraction operations. The device achieves precise control of the chemical injection volume by controlling the on / off state of an electromagnetic coil, ensuring normal production and maintenance of oil and gas wells. Specifically, the device offers the following advantages in application:

[0109] (1) Wide range of applications and high reliability: This device is suitable for dispensing various solid and liquid agents and is suitable for all-weather seasonal temperatures in winter and summer; at the same time, the device adopts electromagnetic control for dosing and has a heat preservation function to ensure the use of the device in cold regions; and the device can withstand pressure up to 50Mpa, which can be widely used for dosing operations in casing pressurized wells, ensuring the use of the device in high-pressure areas.

[0110] (2) Automated operation is simple and improves efficiency: The device adopts electromagnetic control for dosing, which makes automated operation simple; and the automation function reduces manual intervention, reduces labor intensity, shortens operation time, improves the efficiency of oil and gas production, and reduces costs.

[0111] (3) Precise control and convenient measurement: The device is equipped with multiple electromagnetic push-pull modules, which can be controlled by the program to quantitatively dispense and deliver the medicine. The injection rate of the medicine can be adjusted according to actual needs through the external electrical control system to ensure the optimal use of the medicine and avoid waste caused by over-dosing. It is suitable for different working conditions.

[0112] (4) The device has a simple and reliable structure, and each component is basically a mechanical part with a long service life. It is also very easy to maintain. When a component is damaged and needs to be repaired, the component can be removed and replaced.

[0113] In summary, the wellhead casing annulus chemical dosing device of this invention is an indispensable piece of equipment in oil and gas extraction. Through precise and automated chemical injection, it provides strong support for the stable and efficient production of oil and gas wells. It also enhances its adaptability to different operating environments, bringing significant economic and environmental benefits to the oil and gas extraction industry.

[0114] Based on the same inventive concept, embodiments of the present invention also provide a method for chemical dosing in the wellhead casing annulus based on the above-mentioned wellhead casing annulus pressurization device, comprising:

[0115] The electromagnetic coil of the uppermost electromagnetic push-pull module is energized, which drives the corresponding gate plate of the electromagnetic push-pull module to move towards the end closer to the outer shell through the armature of the electromagnetic push-pull module, and compresses the return spring to open the gate plate's seal on the inner hole of the support body, so that the medicine falls into the gate plate of the lower electromagnetic push-pull module. Then, the electromagnetic coil of the electromagnetic push-pull module is de-energized, and the armature drives the gate plate to return to its original position under the restoring force of the return spring.

[0116] The electromagnetic coils of the control electromagnetic push-pull module are energized and de-energized sequentially from top to bottom until the agent enters the Venturi tube structure under the negative pressure of the Venturi tube structure and mixes with the gas entering from the inlet of the Venturi tube structure. The agent is then output to the output pipe and transported to the oil sleeve annulus through the output pipeline connected to the output pipe to complete one dosing process.

[0117] The dosing process is repeated cyclically based on a preset number of dosing cycles until the current round of dosing is completed.

[0118] The preset number of dosing cycles can be calculated based on the total amount of medicine needed in this round and the amount of medicine added in one dosing cycle.

[0119] It should be noted that the specific process of the wellhead casing annulus chemical injection method in the above embodiments has been described in detail in the embodiments related to the wellhead casing annulus pressurization device, and will not be elaborated here.

[0120] Based on the same inventive concept, this invention also provides an application of the above-mentioned wellhead casing annulus chemical dosing device in the field of oilfield oil and gas production technology.

[0121] It should be understood that the specific order or hierarchy of steps in the disclosed process is an example of an exemplary method. Based on design preferences, it should be understood that the specific order or hierarchy of steps in the process may be rearranged without departing from the scope of this disclosure. The appended method claims provide elements of various steps in an exemplary order and are not intended to limit the scope to the specific order or hierarchy described.

[0122] In the detailed description above, various features are combined together in a single embodiment to simplify this disclosure. This approach to disclosure should not be construed as reflecting an intention that embodiments of the claimed subject matter require more features than are explicitly stated in each claim. Rather, as reflected in the appended claims, the invention is presented with fewer features than all of the features in a single disclosed embodiment. Therefore, the appended claims are hereby explicitly incorporated into the detailed description, with each claim representing a separate preferred embodiment of the invention.

[0123] The foregoing description includes examples of one or more embodiments. It is certainly impossible to describe all possible combinations of components or methods in order to describe the above embodiments, but those skilled in the art will recognize that further combinations and arrangements of the various embodiments are possible. Therefore, the embodiments described herein are intended to cover all such changes, modifications, and variations that fall within the scope of the appended claims. Furthermore, the term "comprising" as used in the specification or claims is interpreted in a manner similar to the term "including," as interpreted when used as a conjunction in the claims. Additionally, the use of any term "or" in the specification of the claims is intended to mean "non-exclusive or."

Claims

1. A wellhead casing annulus chemical dosing device, characterized in that, include: The outer casing, a sealing cap disposed within the outer casing from top to bottom, a pharmaceutical container, a support body, and a venturi tube assembly; The Venturi tube assembly has a Venturi tube structure, the inlet of which is used to connect to the gas source, and the outlet is connected to one end of the output pipe, the other end of which is used to connect to the oil jacket annulus. The upper end of the inner hole of the support body is connected to the drug container, and the lower end is connected to the Venturi tube structure. The support body is provided with multiple mounting holes distributed vertically, and an electromagnetic push-pull module is correspondingly installed in each mounting hole; The electromagnetic push-pull module includes: an electromagnetic coil, an armature disposed within the electromagnetic coil, a gate connected to one end of the armature via a connecting rod, and a return spring disposed between the inner wall of the support body and the armature. The gate is disposed in the inner hole of the support body and is used to control the sealing and opening of the inner hole of the support body; The armature is used to drive the corresponding gate plate to move towards one end closer to the outer casing when the electromagnetic coil is energized, and to compress the reset spring to open the gate plate's seal on the inner hole of the support body, and to drive the gate plate to reset under the restoring force of the reset spring after the electromagnetic coil is de-energized.

2. The wellhead casing annulus chemical dosing device as described in claim 1, characterized in that, The Venturi tube assembly includes: a nozzle and a throat body; The nozzle’s inner bore, the channel formed between the nozzle’s outer wall and the throat body’s inner wall, and the inner bore of the throat body form a Venturi tube structure. Accordingly, the inner hole of the nozzle is used to connect to the air source, one end of the output pipe is connected to the inner hole of the throat body, and the lower end of the inner hole of the support body is connected to the channel formed between the outer wall of the nozzle and the inner wall of the throat body.

3. The wellhead casing annulus chemical dosing device as described in claim 1, characterized in that, The pharmaceutical container includes: a cylindrical section and a conical section; The cylindrical segment is connected to the larger diameter end of the conical segment, and the smaller diameter end of the conical segment is the end closer to the support body. A support block is provided between the outer wall of the conical segment and the upper surface of the support body.

4. The wellhead casing annulus chemical dosing device as described in claim 1, characterized in that, A buffer pad is provided inside the electromagnetic coil near the outer casing; Accordingly, the reset spring is disposed between the buffer pad and the armature.

5. The wellhead casing annulus chemical dosing device as described in claim 1, characterized in that, The outer shell is also provided with a heating and insulation layer; The heating and insulation layer is provided with an electric heating resistance wire and insulation material. The outer wall of the heating and insulation layer is provided with an electric heating electrode plug for connecting the electric heating resistance wire to an external power source.

6. The wellhead casing annulus chemical dosing device as described in claim 5, characterized in that, A temperature sensor is also installed inside the heating and insulation layer; The temperature sensor is used to detect the temperature of the medicine and transmit the temperature to an external controller so that the controller can control the electric heating resistance wire to heat the medicine based on the temperature.

7. The wellhead casing annulus chemical dosing device as described in claim 1, characterized in that, The medicine container is also equipped with a squeezing plate that can slide relative to the inner wall of the medicine container; When the medicine is contained in the medicine container, the extrusion plate is disposed at the upper end of the medicine; A compression spring is provided between the sealing cap and the extrusion plate.

8. The wellhead casing annulus chemical dosing device as described in claim 1, characterized in that, The inner hole of the support body is provided with an inner liner tube; Accordingly, the upper end of the inner hole of the inner liner tube is connected to the medicine container, and the lower end is connected to the Venturi tube structure. The gate is disposed in the central hole of the inner liner tube and is used to control the sealing and opening of the inner hole of the support body.

9. The wellhead casing annulus chemical dosing device as described in claim 8, characterized in that, The inner lining tube is a polytetrafluoroethylene tube or a plastic tube.

10. The wellhead casing annulus chemical dosing device as described in claim 1, characterized in that, Also includes: Bottom support plate; The upper end of the bottom support plate is disposed within the outer shell; A sealing element is provided between the outer shell, the sealing cover, and the bottom support plate.

11. The wellhead casing annulus chemical dosing device as described in claim 1, characterized in that, Also includes: Controller; The controller is used to control the energization or de-energization of the electromagnetic coil.

12. The wellhead casing annulus chemical dosing device as described in any one of claims 1-11, characterized in that, The sealing cover is provided with a connector for connecting to an external air source; A check valve is installed on the connecting pipeline between the gas source and the inlet of the Venturi tube structure. The outer casing is also provided with a wire seal and an electrical plug. The wire of the electromagnetic coil passes through the wire seal and is connected to the electrical plug, which is used to connect to an external power source.

13. A method for chemical dosing in the annulus of a wellhead casing, characterized in that, Based on the wellhead casing annulus chemical dosing device as described in any one of claims 1-12, including: The electromagnetic coil of the uppermost electromagnetic push-pull module is energized, and the armature of the electromagnetic push-pull module drives the corresponding gate to move towards the end closer to the outer shell, compressing the reset spring to open the gate's seal on the inner hole of the support body, allowing the medicine to fall onto the gate of the lower electromagnetic push-pull module. Then, the electromagnetic coil of the electromagnetic push-pull module is de-energized, and the armature, under the restoring force of the reset spring, drives the gate to reset. The electromagnetic coils of the control electromagnetic push-pull module are energized and de-energized sequentially from top to bottom until the agent enters the Venturi tube structure under the negative pressure and mixes with the gas entering from the inlet of the Venturi tube structure. The agent is then output to the output pipe and transported to the annulus through the output pipeline connected to the output pipe to complete one dosing process. The dosing process is repeated cyclically based on a preset number of dosing cycles until the current round of dosing is completed.

14. The application of a wellhead casing annulus chemical dosing device as described in any one of claims 1-13 in the field of oilfield oil and gas production technology.

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