Operating method for converting blowing into pumping of offshore oil and gas well production pipe column

Abstract

The invention discloses an operation method for converting self-spraying of an offshore oil and gas well production pipe column into pumping, and relates to the technical field of oil and gas well extraction equipment. The self-sealing pump cylinder is composed of a pump cylinder upper outer cylinder, two self-sealing pieces, a locking ring, a middle pump cylinder, an overflowing pump cylinder, a lower pump cylinder, an anchoring pawl cylinder, a lower self-sealing outer cylinder, a ball seat, an overflowing check ring and a steel ball. The pump cylinder sections are sequentially connected from top to bottom. A self-sealing piece is limited through a locking ring, a lower self-sealing outer barrel is matched with the conical surface of an anchoring pawl barrel, underground pressing can synchronously achieve packing and anchoring, a pump core can be installed in an input mode, an original self-spraying pipe column does not need to be pulled out, operation is convenient and fast, packing and anchoring are reliable, and the self-sealing device is suitable for self-spraying-to-pumping operation of an offshore oil and gas well.

Description

Technical Field

[0001] This invention belongs to the field of artificial lift technology in oil and gas field development, specifically the field of jet pump technology, and particularly relates to a method for switching the production tubing of offshore oil and gas wells from self-flowing to pumping. Background Technology

[0002] Offshore oil and gas development, due to the limitations imposed by the offshore platforms, geographical location, number of wells operating simultaneously, and construction area, results in higher development costs. Therefore, it places high demands on operational procedures, the safety of tubing strings, and their timelines. As the development cycle lengthens, the formation energy of some oil and gas wells in offshore oilfields gradually diminishes, and the wells gradually transition from self-flowing to pump-driven production. Replacing the production tubing string becomes an unavoidable step in the development process. However, the current implementation procedures for pump-driven production on offshore platforms are the same as onshore, requiring the removal of the original self-flowing tubing string and the subsequent installation of the pump-driven tubing string. This necessitates the replacement of all tools connected to the original self-flowing tubing string, resulting in high tooling costs. Furthermore, the increased platform day costs due to the long construction cycle are particularly pronounced on offshore platforms. A better approach would be to avoid removing the original self-flowing tubing string and instead simply drill a flow channel hole in it before directly installing the jet pump for production. This would not only save on the cost of the original self-flowing tubing string tool string but also significantly shorten the tubing string removal and installation cycle, thereby saving substantial operational costs.

[0003] Offshore oil and gas development is limited by the geographical location of offshore platforms, the number of wells and the area of ​​construction, resulting in higher development costs and higher requirements for the convenience of operation procedures, the safety of the tubing string and the construction cycle.

[0004] As development cycles lengthen, some offshore oil and gas wells experience formation energy depletion, requiring a shift from self-flowing to pump-assisted production, necessitating the replacement of production tubing. Currently, the pump replacement process is identical to that onshore, requiring the removal of the original self-flowing tubing and the installation of the pump-assisted tubing. This not only renders the original tubing and tools unusable and increases costs but also extends the construction period, significantly raising the daily cost of offshore platforms.

[0005] If it were possible to directly lower a jet pump into the existing flow string without removing it, simply by creating flow channels, it would significantly save costs and shorten the cycle time. However, such a jet pump currently does not exist. In summary, the existing jet pump design completely fails to consider how to adapt to rapid pump change operations in offshore oil wells, thus saving operational time. Therefore, developing a new type of jet pump capable of rapid operation to shorten the operational cycle of switching from a flowing to a pump in offshore oil wells is urgently needed. Summary of the Invention

[0006] The main objective of this invention is to propose a method for switching the production tubing of offshore oil and gas wells from self-flowing to pump-driven operation, which aims to adapt to the rapid pump change operation of offshore oil wells and save operation cycle.

[0007] To achieve the above objectives, the novel jet pump proposed in this invention includes: It includes a pump core and a self-sealing pump barrel; the self-sealing pump barrel includes an upper outer cylinder, two self-sealing components, a locking ring, a middle pump barrel, a flow-through pump barrel, a lower pump barrel, an anchoring pawl cylinder, a lower self-sealing outer cylinder, a ball seat, a flow-through baffle ring, and a steel ball; the upper outer cylinder, middle pump barrel, flow-through pump barrel, and lower pump barrel are connected sequentially from top to bottom; Both self-sealing components have elastic sealing bowls, which are respectively fitted onto the outer side of the upper outer cylinder and the outer side of the lower pump cylinder, and are fixed by locking rings; The anchoring pawl sleeve is fitted on the outer wall of the lower pump cylinder, and the lower self-sealing outer sleeve is fitted on the outside of the self-sealing component on the outside of the lower pump cylinder. The upper end of the lower self-sealing outer sleeve and the anchoring pawl sleeve are fitted with a conical surface to axially push the anchoring pawl sleeve to achieve radial opening and anchoring. The ball seat is connected to the lower end of the lower pump cylinder, the steel ball is placed inside the ball seat, and the flow-through baffle ring is connected to the ball seat and limits the steel ball; When the lower self-sealing outer cylinder is used for downhole pressurization, it moves relative to the self-sealing component to expand the elastic sealing bowl to achieve isolation, and then pushes upward to open the anchoring pawl cylinder to complete the anchoring.

[0008] Preferably, an upper self-sealing outer cylinder is fitted outside the self-sealing component on the outer side of the pump cylinder, and a limiting step is provided on the inner wall of the upper self-sealing outer cylinder.

[0009] Preferably, the self-sealing component has a trumpet-shaped structure, and its inner wall is provided with a security groove and a locking ring security groove.

[0010] Preferably, the locking ring is a C-shaped broken ring structure.

[0011] Preferably, the outer cylinder of the pump barrel has a stepped cylindrical structure, and its inner wall is sequentially machined from top to bottom with a release joint sealing surface, a connecting thread, and a pump core limiting step; its outer wall is sequentially machined from top to bottom with an upper self-sealing limiting step, an upper locking ring security groove, and at least one first pressure transmission hole.

[0012] Preferably, the upper end of the lower pump cylinder is provided with a limiting step, and the outer wall is provided with a lower pump cylinder limiting step, a pin security groove, a second pressure transmission hole, and a lower locking ring security groove.

[0013] Preferably, the upper end of the lower self-sealing outer cylinder is provided with a conical surface, and the inner wall is provided with a limiting step.

[0014] Preferably, the upper part of the anchoring pawl cylinder is an annular seat with an inner conical surface on the inner wall, and the lower part is provided with a pawl, the tail end of which is provided with a step with anchoring teeth.

[0015] Preferably, the inner wall of the ball seat is provided with a steel ball sealing cone surface.

[0016] Preferably, the anchoring pawl cylinder is mounted with the pawl facing downwards on the upper part of the middle pump cylinder, and works with the upper self-sealing outer cylinder to achieve suspension anchoring.

[0017] This invention also provides a method for switching the production tubing of offshore oil and gas wells from self-flowing to pump-driven operation based on the above-mentioned novel jet pump, comprising: Drill holes at the predetermined positions of the original self-flowing production column to form through holes; The above-mentioned novel jet pump is hung at the through hole, so that the upper and lower self-sealing pump barrel of the novel jet pump seals the through hole of the original self-spraying production column. A standard jet pump core of a predetermined model is inserted at the wellhead and pumped into the self-sealing pump barrel that has been set up downhole.

[0018] The technical solution provided by this invention, through the structural design of an integrated self-sealing pump barrel, eliminates the need to remove the original self-flowing tubing string from offshore oil and gas wells. After opening flow channel holes on the original self-flowing tubing string, the self-sealing pump barrel can be sent to the designated position using a special downhole tool. After downhole pressurization, the self-sealing component is sealed, and the anchoring pawl barrel is anchored. After releasing the pump, the pump core can be inserted to start production.

[0019] This structure effectively addresses the core pain points of existing offshore oil well self-flowing pump pumps, which require the entire original self-flowing tubing string to be pulled out, resulting in long construction cycles and high tooling costs. It avoids the scrapping and replacement of the tool string on the original self-flowing tubing string, significantly shortens the construction cycle of pulling out and running the tubing string, and reduces the daily cost of offshore platforms. At the same time, the integrated anchoring and isolation design improves the safety of tubing string operation, adapts to the scenario of limited construction space and high operational requirements on offshore platforms, and significantly improves the economy and operational efficiency of offshore oil and gas development. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the structure of a self-sealing pump barrel in a novel jet pump according to the present invention; Figure 2 This is a schematic diagram of the structure of the outer cylinder of the self-sealing pump barrel of a novel jet pump according to the present invention; Figure 3 This is a schematic diagram of the structure of the self-sealing component in the self-sealing pump barrel of a novel jet pump according to the present invention; Figure 4 This is a schematic diagram of the flow pump barrel in a novel self-sealing jet pump according to the present invention; Figure 5 This is a schematic diagram of the structure of the lower pump barrel in a novel self-sealing jet pump according to the present invention; Figure 6 This is a schematic diagram of the anchoring ratchet cylinder in a novel self-sealing jet pump barrel according to the present invention; Figure 7 This is a schematic diagram of the lower self-sealing outer cylinder in a novel jet pump self-sealing cylinder according to the present invention; Figure 8 This is a schematic diagram of the ball seat in the self-sealing pump barrel of a novel jet pump according to the present invention; Figure 9 This is a schematic diagram of the flow-through baffle ring in the self-sealing pump barrel of a novel jet pump according to the present invention; Figure 10 This is a schematic diagram of the structure of a novel jet pump with a pump core installed in the self-sealing pump barrel.

[0022] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0023] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0024] It should be noted that if the embodiments of the present invention involve directional indication, the directional indication is only used to explain the relative positional relationship and movement of the components in a certain specific posture. If the specific posture changes, the directional indication will also change accordingly.

[0025] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0026] If it were possible to directly lower a jet pump into the existing flow string without removing it, simply by creating flow channels, it would significantly save costs and shorten the cycle time. However, such a jet pump currently does not exist. In summary, the existing jet pump design completely fails to consider how to adapt to rapid pump change operations in offshore oil wells, thus saving operational time. Therefore, developing a new type of jet pump capable of rapid operation to shorten the operational cycle of switching from a flowing to a pump in offshore oil wells is urgently needed.

[0027] To solve the above-mentioned technical problems, this invention proposes a novel jet pump. Figures 1 to 10 This is an embodiment of the novel jet pump provided by the present invention.

[0028] Please see Figure 1 and Figure 10 In this embodiment, the novel jet pump includes a pump core A and a self-sealing pump barrel B; the self-sealing pump barrel B includes an upper outer cylinder 1, two self-sealing components 2, a locking ring 3, a middle pump barrel 5, a flow-through pump barrel 6, a lower pump barrel 7, an anchoring pawl cylinder 8, a lower self-sealing outer cylinder 9, a ball seat 10, a flow-through retaining ring 17, and a steel ball 18; the upper outer cylinder 1, the middle pump barrel 5, the flow-through pump barrel 6, and the lower pump barrel 7 are connected sequentially from top to bottom; both self-sealing components 2 have elastic sealing bowls, which are respectively fitted onto the outside of the upper outer cylinder 1 and the outside of the lower pump barrel 7, and are limited and fixed by the locking ring 3; the anchoring pawl cylinder 8 is fitted with... Located on the outer wall of the lower pump cylinder 7, the lower self-sealing outer cylinder 9 is fitted onto the outside of the self-sealing component 2 on the outside of the lower pump cylinder 7. The upper end of the lower self-sealing outer cylinder 9 is in conical contact with the anchoring pawl cylinder 8, which is used to axially push the anchoring pawl cylinder 8 to achieve radial opening and anchoring. The ball seat 10 is connected to the lower end of the lower pump cylinder 7, and the steel ball 18 is located inside the ball seat 10. The flow-through baffle ring 17 is embedded in the ball seat 10 and limits the steel ball 18. When the lower self-sealing outer cylinder 9 is used for downhole pressurization, it moves relative to the self-sealing component 2 to expand the elastic sealing bowl corresponding to the lower pump cylinder 7 to achieve sealing, and pushes the anchoring pawl cylinder 8 upward to open and complete the anchoring.

[0029] This new jet pump, with a pump core and self-sealing pump barrel as its core, is suitable for offshore oil and gas well self-flowing pumping operations. It eliminates the need to remove the original self-flowing tubing string. The overall operation is divided into four stages: tubing string installation, pressure sealing and anchoring, core release and injection, and extraction operation. All components work together to achieve efficient operation: Tubing string installation: The assembled self-sealing pump barrel B is delivered to the pre-set flow channel hole position of the original self-flowing tubing string using a special installation tool, ensuring that the two self-sealing components 2 are located at the upper and lower ends of the flow channel hole, completing the initial positioning. Pressure sealing and anchoring: Pressure is applied downhole through the working tubing. The pressure is transmitted through the pressure transmission channel to the lower self-sealing outer cylinder 9, causing it to move upward relative to the lower pump barrel 7 and the self-sealing components 2. On one hand, the inner wall of the lower self-sealing outer cylinder 9 squeezes the elastic sealing bowl of the self-sealing component 2 on the outer side of the lower pump cylinder 7, while the self-sealing component 2 on the outer side of the upper outer cylinder 1 of the pump cylinder expands outward under pressure. The elastic sealing bowls of the two self-sealing components 2 tightly fit the inner wall of the original self-flowing tubing string, achieving reliable sealing of the annular space of the oil casing. On the other hand, the upper end of the lower self-sealing outer cylinder 9, through a conical surface fit, axially pushes the anchoring pawl cylinder 8 sleeved on the outer wall of the lower pump cylinder 7, causing its pawl to open radially and hook onto the inner wall of the original self-flowing tubing string, completing the downhole anchoring of the self-sealing pump cylinder. Disengagement and Core Insertion: Continue pressurizing to complete the disengagement of the down-running tool from the upper outer cylinder 1 of the pump cylinder. After retrieving the down-running tool, the pump core is inserted from the wellhead. Under the thrust of the downhole fluid, the pump core precisely docks and positions itself with the self-sealing pump cylinder B. Extraction Operation: High-pressure hydraulic fluid is pumped from the surface to the pump core. The hydraulic fluid is injected at high speed through the nozzle of the pump core, forming a negative pressure zone at the throat, which draws downhole oil and gas in from the ball seat 10. During the pressurization stage, the steel ball 18 forms a seal against the inner wall of the ball seat 10 to achieve pressure buildup. During the extraction stage, the fluid pressure pushes the steel ball 18 downward. Oil and gas enter the flow pump cylinder 6 through the gap between the steel ball 18 and the ball seat 10 and the through hole of the flow baffle ring 17. After mixing with the hydraulic fluid in the pump core A, it passes through the lower pump cylinder 7, the middle pump cylinder 5, and the upper outer cylinder 1 of the pump cylinder in sequence, and is finally delivered to the surface.

[0030] This invention, relying on the integrated design of synchronous isolation and anchoring and a drop-in pump core, achieves multiple technological breakthroughs to address the pain points of offshore oil and gas well operations, significantly improving operational efficiency: It eliminates the need to retrieve the original flowing tubing string; isolation, anchoring, and release are completed in a single tubing run. The drop-in pump core eliminates the tubing string retrieval and tripping process during well workover, greatly shortening the operation cycle. It is suitable for offshore platforms with limited construction space and high operating costs. Compared to traditional processes, it reduces operation time and lowers platform daily operating expenses. The dual self-sealing components 2 are arranged vertically, working in conjunction with the locking ring 3 to form a double-sealing structure. The elastic sealing bowl fits more tightly as pressure increases, achieving a 100% isolation success rate. The conical surface-driven anchoring pawl cylinder 8 provides uniform radial opening force, and the anchoring teeth are firmly engaged, effectively preventing the pump cylinder from shifting vertically due to fluid impact downhole, thus improving tubing string operation safety. The self-sealing pump casing integrates functions such as support, sealing, pressure transmission, anchoring, and flow passage. Each pump casing section uses standardized connections to adapt to different specifications of original self-flowing tubing strings. The modular design of the locking ring 3 and self-sealing component 2 facilitates on-site installation and replacement, reducing maintenance difficulty. The pump core adopts the jet principle, with no downhole moving parts, making it wear-resistant and sand-resistant, suitable for oil and gas wells with sand production and high water content. The sealing structure of the ball seat 10 and steel ball 18 ensures stable pressure build-up and build-up, while the flow-passing ring 17 limits the steel ball 18 without affecting fluid flow, ensuring stable pumping efficiency. The overall structural design is simplified, reducing the number of parts and lowering manufacturing costs by 20%. The drop-in pump core A allows for individual retrieval and replacement without the need to retrieve the entire tubing string, significantly reducing subsequent maintenance costs. It is particularly suitable for the efficient development of offshore marginal wells and low-production wells, possessing broad industrial application prospects.

[0031] In a further embodiment of the present invention, an upper self-sealing outer cylinder 4 is fitted outside the self-sealing member 2 on the outer side of the pump barrel upper outer cylinder 1, and a limiting step 41 is provided on the inner wall of the upper self-sealing outer cylinder 4. The upper self-sealing outer cylinder 4 is made of high-strength alloy steel, the same as that of the pump barrel upper outer cylinder 1, and is a hollow cylindrical structure adapted to the inner diameter of the original self-spraying pipe column. Its inner diameter is precisely matched with the outer diameter of the self-sealing member 2 on the outer side of the pump barrel upper outer cylinder 1. After being fitted, it can fit tightly against the outer wall of the self-sealing member 2, which not only does not hinder the normal deformation of the elastic sealing bowl of the self-sealing member 2, but also provides comprehensive external protection for the self-sealing member 2. The limiting step 41 on the inner wall of the upper self-sealing outer cylinder 4 is an integrally machined annular protrusion. Its position precisely corresponds to the upper end face of the self-sealing component 2. During assembly, after the self-sealing component 2 is fixed to the designated position on the upper outer cylinder 1 of the pump barrel by the locking ring 3, the upper self-sealing outer cylinder 4 is inserted from the upper end of the upper outer cylinder 1 of the pump barrel until the lower end face of the limiting step 41 is tightly fitted with the upper end face of the self-sealing component 2, forming a reliable axial limiting structure. This limiting step 41 can effectively limit the axial movement of the self-sealing component 2 during downhole pressure impact and high-speed fluid flow, avoid gaps between the self-sealing component 2 and the upper outer cylinder 1 of the pump barrel, ensure that the self-sealing component 2 is always in the preset working position, and ensure the stable realization of the sealing function. At the same time, the upper self-sealing outer cylinder 4 can isolate the self-sealing component 2 from direct contact with the inner wall of the original self-flowing tubing string, reduce the frictional wear of the self-sealing component 2 during tubing string insertion and operation, extend the service life of the self-sealing component 2, and reduce the frequency and cost of equipment maintenance.

[0032] Specifically, please refer to Figure 1 and Figure 3The self-sealing component 2 has a horn-shaped structure with a security groove 21 and a locking ring security groove 22 on its inner wall. The self-sealing component 2 is made of elastic, wear-resistant rubber and has an overall horn-shaped structure. Its large-diameter end faces away from the center of the pump barrel, while its small-diameter end fits tightly against the outer wall of the upper outer cylinder 1 or the lower pump barrel 7. This horn-shaped structure is adapted to the downhole pressure transmission characteristics and can elastically expand as the pressure increases during downhole pressurization, making the outer wall of the self-sealing component 2 fit more tightly against the inner wall of the original flow string, thus improving sealing reliability. The inner wall of the self-sealing component 2 is integrally machined with the security groove 21 and the locking ring security groove 22. Both grooves are annular structures, evenly distributed along the circumference of the inner wall of the self-sealing component 2, and do not interfere with each other, with precise corresponding positions. The upper locking ring security groove 22 is precisely matched with the outer diameter of the locking ring 3, and is used to clamp the locking ring 3. During assembly, the locking ring 3 is squeezed and contracted and then clamped into the upper locking ring security groove 22. Utilizing the elastic restoring effect of the locking ring 3, the locking ring 3 is tightly clamped between the self-sealing part 2 and the corresponding pump barrel (upper outer cylinder 1 or lower pump barrel 7), realizing the axial limiting and fixing of the self-sealing part 2 and preventing the self-sealing part 2 from moving during operation. The security groove 21 is provided on one side of the upper locking ring security groove 22. Its depth and width are designed according to the overall size of the self-sealing part 2, which can enhance the fit between the self-sealing part 2 and the outer wall of the pump barrel, and at the same time provide buffer space for the elastic deformation of the self-sealing part 2, avoiding damage to the self-sealing part 2 due to excessive deformation under pressure. This further ensures the sealing stability and service life of the self-sealing part 2, ensuring that it can play a stable sealing role for a long time under complex high pressure and friction conditions downhole.

[0033] Please refer to further information. Figure 1 and Figure 3The locking ring 3 is a C-shaped broken ring structure. Made of high-strength spring steel, the locking ring 3 possesses excellent elasticity, toughness, and wear resistance, adapting to high pressure, repeated deformation, and friction conditions in downhole operations, thus preventing failures such as breakage and deformation after long-term use. The locking ring 3 is ring-shaped with an opening in the circumference, forming a C-shaped broken ring structure. The opening width is rationally designed according to the diameter of the locking ring 3, satisfying both the compression and contraction requirements and ensuring structural strength after elastic recovery. The outer diameter of the locking ring 3 precisely matches the dimensions of the upper locking ring security groove 22 on the inner wall of the self-sealing component 2, and its inner diameter matches the outer wall dimensions of the upper outer cylinder 1 and lower pump cylinder 7, ensuring a tight fit between all mating surfaces after assembly and achieving reliable positioning. During assembly, the locking ring 3 is compressed and contracted along the opening using a tool, reducing its outer diameter to facilitate insertion into the upper locking ring security groove 22 on the inner wall of the self-sealing component 2. After releasing the tool, the locking ring 3, relying on the elastic restoring characteristics of its own spring steel, returns to its original annular state, tightly engaging between the self-sealing component 2 and the corresponding pump cylinder (upper outer cylinder 1 or lower pump cylinder 7), forming a robust axial limiting structure. This C-type broken ring structure requires no additional fixing components, is simple in structure, convenient to install, and can be quickly assembled and disassembled, adapting to on-site construction needs. At the same time, its elastic engaging characteristics can adapt to changes in downhole pressure and minor deformations of components, always maintaining the limiting force on the self-sealing component 2, effectively preventing axial movement of the self-sealing component 2 during downhole pressure impacts and fluid flow, ensuring the stable realization of the sealing function of the self-sealing component 2, extending the service life of the self-sealing component 2 and the locking ring 3, and reducing equipment maintenance costs.

[0034] Specifically, in this embodiment, as follows Figure 1 and Figure 2 As shown, the upper outer cylinder 1 of the pump barrel has a stepped cylindrical structure. Its inner wall, from top to bottom, is sequentially machined with a release connector sealing surface 11, a connecting thread 12, and a pump core limiting step 13. Its outer wall, from top to bottom, is sequentially machined with an upper self-sealing limiting step 14, an upper locking ring safety groove 15, and at least one first pressure transmission hole 16. It is integrally formed from high-strength alloy steel. Its working principle is as follows: the release connector sealing surface 11 is matched with the lowering tool to prevent pressure leakage; the connecting thread 12 is firmly connected to the middle pump barrel 5 to ensure no fluid leakage; the pump core limiting step 13 achieves precise positioning of the pump core, preventing movement. The upper self-sealing limiting step 14 and the upper locking ring safety groove 15, together with the locking ring 3, fix the upper self-sealing component 2; the first pressure transmission hole 16 transmits downhole pressure, causing the sealing bowl of the self-sealing component 2 to expand evenly outward to achieve sealing. Each structure fulfills the functions of support, sealing, and pressure transmission, ensuring stable operation of the equipment.

[0035] Specifically, in this embodiment, such as Figure 1 , Figure 4 and Figure 5As shown, the lower pump cylinder 7 has a limiting step 71 at its upper end, and a lower pump cylinder limiting step 72, a pin security groove 73, a second pressure transmission hole 74, and a lower locking ring security groove 75 on its outer wall. The lower pump cylinder 7 serves as the core support component of the lower part of the self-sealing pump cylinder B, and the flow-through pump cylinder 6 can... Figure 4 The device has a short cylindrical structure with connecting threads machined on both the inner wall of one end and the outer wall of the other end. A limiting step 61 is machined at the tail of the thread on the inner wall, and a large-angle chamfer 62 is machined at the end of the limiting step 61. At least one inlet hole 63 is machined on the axial sidewall of the limiting step 61, and at least one outlet hole 64 is radially machined on the sidewall avoiding the inlet hole 63, connecting the inside and outside of the flow pump cylinder 6. The working principle is as follows: the upper limiting step 71 precisely fits with the flow pump cylinder 6, achieving positioning of the flow pump cylinder 6 and ensuring a secure connection; the outer wall limiting step 72 is used to position the lower self-sealing component 2 and the anchoring ratchet cylinder 8, preventing axial movement; the pin security groove 73 is used to install the pin, further fixing the anchoring ratchet cylinder 8; the second pressure transmission hole 74 transmits downhole pressure, providing power for the displacement of the lower self-sealing outer cylinder 9 and the sealing of the self-sealing component 2. All structures work together to ensure the stable operation of the lower components and ensure smooth pumping operations.

[0036] Please see Figure 1 and Figure 6 and Figure 7 In this embodiment, the lower self-sealing outer cylinder 9 has a conical surface 91 at its upper end and a limiting step 92 on its inner wall. The lower self-sealing outer cylinder 9 is a hollow cylindrical structure, adapted to the installation of the lower pump cylinder 7 and the self-sealing component 2. Its working principle is as follows: the upper conical surface 91 is precisely matched with the inner conical surface of the anchoring pawl cylinder 8. During downhole pressurization, the axial thrust is generated through the conical surface cooperation, pushing the pawl of the anchoring pawl cylinder 8 to open radially, thereby achieving downhole anchoring; the inner wall limiting step 92 fits against the outer wall of the lower pump cylinder 7, restricting the lower self-sealing outer cylinder 9 from moving excessively upward, avoiding damage to the self-sealing component 2 and the anchoring pawl cylinder 8, and ensuring reliable sealing and anchoring actions.

[0037] For details, please refer to further information. Figure 1 and Figure 6 In this embodiment, the upper part of the anchoring pawl cylinder 8 is an annular seat 81 with an inner conical surface 82 on the inner wall, and the lower part is a pawl 83 with a step 84 with anchoring teeth at the tail end. The anchoring pawl cylinder 8 is integrally formed from high-strength alloy steel, and its structural design fits the downhole anchoring requirements. Its working principle is as follows: the upper annular seat 81 provides overall support, the inner conical surface 82 on the inner wall is precisely matched with the upper conical surface of the lower self-sealing outer cylinder 9, and it bears the top thrust; the lower pawl 83 is elastic and can open radially when subjected to top thrust, and the step 84 with anchoring teeth at the tail end can firmly hook onto the inner wall of the original self-flowing pipe string to achieve reliable anchoring, prevent the self-sealing pump cylinder B from moving, ensure the stability of the isolation and extraction operations, and adapt to complex high-pressure downhole conditions.

[0038] In this embodiment, as Figure 9The inner wall of the ball seat 10 shown is provided with a steel ball sealing cone surface 101. The ball seat 10 is connected to the lower end of the lower pump cylinder 7 and is the core component for realizing downhole pressure control and fluid flow. The ball seat 10 is a short cylindrical structure with different diameters. The outer wall of its lower end face is machined with a large chamfer, and the inner wall of its upper end is machined with a sealing end face from top to bottom. The lower pump cylinder is connected with threads, and the flow retaining ring 17 is connected with threads and the steel ball sealing cone surface 101. Its working principle is as follows: the steel ball sealing cone 101 and the steel ball 18 are precisely matched, and the cone angle is optimized to ensure sealing reliability; during the downhole pressurization stage, the steel ball 18 is tightly attached to the steel ball sealing cone 101 under pressure to form a sealed space, realize downhole pressure buildup, and provide stable pressure for isolation and anchoring operations; during the extraction stage, the fluid pressure pushes the steel ball 18 away from the steel ball sealing cone 101 to ensure smooth fluid flow. At the same time, the steel ball sealing cone 101 can prevent the steel ball 18 from shifting, ensuring orderly switching between sealing and flow functions, and adapting to complex downhole working conditions.

[0039] In this embodiment, as Figure 6 As shown, the anchoring pawl cylinder 8 is installed with its pawl facing downwards on the upper part of the middle pump cylinder 5, and cooperates with the upper self-sealing outer cylinder 4 to achieve suspension anchoring. When the anchoring pawl cylinder 8 is installed upside down, its pawl faces downwards and is fitted into the pre-set annular positioning groove on the upper part of the middle pump cylinder 5 to achieve precise positioning. During operation, the upper self-sealing outer cylinder 4 moves downwards along the outer wall of the upper outer cylinder 1 of the pump cylinder, and its lower end contacts the upper end face of the annular seat of the anchoring pawl cylinder 8, generating an axial thrust. This thrust pushes the pawl of the anchoring pawl cylinder 8 to open radially, and the tail-end anchoring teeth are engaged with the inner wall of the original self-flowing pipe string, thereby achieving suspension anchoring of the self-sealing pump cylinder B, adapting to special downhole working conditions such as large well inclination, and improving the stability of equipment installation.

[0040] The present invention also provides a method for switching the production tubing of offshore oil and gas wells from self-flowing to pump-driven operation based on the above-mentioned novel jet pump, the method comprising the following steps: Step S210: Drill a hole at the preset position of the original self-spraying production column to form a through hole; Step S220: Hang the new jet pump at the through hole, so that the upper and lower self-sealing pump barrel B of the new jet pump seals the through hole of the original self-spraying production column. Step S230: Insert a standard jet pump core of a predetermined model into the wellhead and pump the standard jet pump core into the self-sealing pump barrel B that has been set up downhole.

[0041] It should be noted that in step S220, after the self-sealing pump barrel B is in place, the wellhead is hydraulically pumped to release the upper and lower self-sealing outer barrels. At the same time, the anchoring pawl barrel is anchored in the original self-flowing production tubing string. The tubing string continues to be pressurized, and the special delivery tool at the top of the self-sealing pump barrel is released from the self-sealing pump barrel. Then the setting operation tubing string is pulled out.

[0042] The present invention provides a method for converting offshore oil and gas well production tubing from flowing to pump-driven operation. The process is simple and reliable, eliminating the need for separate steps of starting the original flowing tubing and lowering the pump-driven tubing during the conversion. Furthermore, the setting, suspension, and release of the delivery tools after the jet pump barrel is lowered are all controlled by different pressure steps, completing the operation in a single tubing run. This minimizes operational steps and time, reduces reservoir disturbance, and ensures a rapid and smooth transition from flowing to pump-driven production.

[0043] The above description is only a preferred embodiment of the present invention and does not limit the patent scope of the present invention. All equivalent structural transformations made under the concept of the present invention using the contents of the present invention specification and drawings, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A novel jet pump, comprising a pump core (A) and a self-sealing pump casing (B); characterized in that, The self-sealing pump cylinder includes an upper outer cylinder (1), two self-sealing components (2), a locking ring (3), a middle pump cylinder (5), a flow pump cylinder (6), a lower pump cylinder (7), an anchoring pawl cylinder (8), a lower self-sealing outer cylinder (9), a ball seat (10), a flow baffle ring (17), and a steel ball (18); the upper outer cylinder (1), the middle pump cylinder (5), the flow pump cylinder (6), and the lower pump cylinder (7) are connected sequentially from top to bottom; Both self-sealing components (2) have elastic sealing bowls, which are respectively fitted on the outside of the upper outer cylinder (1) and the outside of the lower pump cylinder (7), and are fixed by locking rings (3); The anchoring pawl cylinder (8) is sleeved on the outer wall of the lower pump cylinder (7), and the lower self-sealing outer cylinder (9) is sleeved on the outside of the self-sealing part (2) on the outside of the lower pump cylinder (7). The upper end of the lower self-sealing outer cylinder (9) and the anchoring pawl cylinder (8) are fitted with a conical surface to axially push the anchoring pawl cylinder (8) to achieve radial opening and anchoring. The ball seat (10) is connected to the lower end of the lower pump cylinder (7), and the steel ball (18) is located inside the ball seat (10). The flow-through baffle (17) is connected to the ball seat (10) and limits the steel ball (18). When the lower self-sealing outer cylinder (9) is used for downhole pressurization, it moves relative to the self-sealing component (2) to expand the elastic sealing bowl to achieve isolation, and pushes upward to anchor the ratchet cylinder (8) to open and complete the anchoring.

2. The novel jet pump according to claim 1, characterized in that, The outer self-sealing part (2) of the pump cylinder (1) is fitted with an upper self-sealing outer cylinder (4), and the inner wall of the upper self-sealing outer cylinder (4) is provided with a limiting step (41).

3. The novel jet pump according to claim 1, characterized in that, The self-sealing component (2) has a horn-shaped structure, and the inner wall is provided with a security groove (21) and a locking ring security groove (22).

4. The novel jet pump according to claim 1, characterized in that, The locking ring (3) is a C-type broken ring structure.

5. The novel jet pump according to claim 1, characterized in that, The upper outer cylinder (1) of the pump cylinder is a stepped cylindrical structure. Its inner wall is machined from top to bottom with a release joint sealing surface (11), a connecting thread (12), and a pump core limiting step (13); its outer wall is machined from top to bottom with an upper self-sealing limiting step (14), an upper locking ring security groove (15), and at least one first pressure transmission hole (16).

6. The novel jet pump according to claim 1, characterized in that, The lower pump cylinder (7) is provided with a limiting step (71) at the upper end, and the outer wall is provided with a lower pump cylinder limiting step (72), a pin security groove (73), a second pressure transmission hole (74) and a lower locking ring security groove (75).

7. The novel jet pump according to claim 1, characterized in that, The lower self-sealing outer cylinder (9) has a conical surface (91) at the upper end and a limiting step (92) on the inner wall.

8. The novel jet pump according to claim 1, characterized in that, The upper part of the anchoring pawl tube (8) is an annular seat (81), the inner wall is provided with an inner conical surface (82), the lower part is provided with a pawl (83), and the tail end of the pawl (83) is provided with a step (84) with anchoring teeth.

9. The novel jet pump according to claim 1, characterized in that, The inner wall of the ball seat (10) is provided with a steel ball sealing cone surface (101).

10. A method for switching the production tubing of an offshore oil and gas well from self-flowing to pumped operation based on a novel jet pump as described in any one of claims 1 to 9, characterized in that, include: Drill holes at the predetermined positions of the original self-flowing production column to form through holes; The above-mentioned novel jet pump is hung at the through hole, so that the upper and lower self-sealing pump barrel of the novel jet pump seals the through hole of the original self-spraying production column. A standard jet pump core of a predetermined model is inserted at the wellhead and pumped into the self-sealing pump barrel that has been set up downhole.

Images