Freely-combined multifunctional well sealing device

Abstract

A multifunctional well plugging device capable of being freely combined belongs to the technical field of oil field engineering operation and comprises a connecting flange, a rubber core leading-in cone, a hydraulic cylinder, a well plugging device outer wall, a rubber core and a rubber core fixing base, the well plugging device outer wall is connected with a well mouth through the connecting flange, the connecting flange is connected with the rubber core fixing base through the hydraulic cylinder, and the rubber core is arranged on the rubber core fixing base. The rubber core fixing base is provided with a first through hole for an oil pipe to penetrate through, the connecting flange is provided with a blowout preventer center hole for the oil pipe to penetrate through, the connecting flange is provided with a rubber core leading-in cone, the rubber core leading-in cone is provided with a taper hole for the oil pipe to penetrate through, and the taper hole, the first through hole and the blowout preventer center hole are located on the same straight line. According to the principle that a cone clamps a rubber core, sealing of high-pressure oil and water in an annular space is achieved, multiple functions are compatible through series connection of a plurality of well sealing devices, reliability and durability are improved in principle, normal operation is effectively achieved when high-pressure fluid exists in an oil-water well, and environmental pollution and high-pressure operation risks are avoided.

Description

Technical Field

[0001] This invention belongs to the field of oilfield engineering operation technology, specifically relating to a freely combinable multifunctional well sealing device. Background Technology

[0002] In the internal operations of PetroChina, there are various operation methods, including major repairs, minor repairs, live operations, gas well operations, and coiled tubing operations. The commonly used well sealing devices are gate blowout preventers (BOPs) or ball BOPs. Gate BOPs have a single function and cannot be used for tubing tripping operations when the gate is partially closed. Ball BOPs are expensive and have poor reliability. Although the rubber core can be used for tubing tripping operations in a closed state, the ball rubber core is easily damaged under the pressure inside the well during tubing tripping and tubing tripping. Usually, the rubber core needs to be replaced before the operation of a well is completed. The replacement process is cumbersome, and the replacement must be completed at the wellhead, which brings certain risks to the operation. Summary of the Invention

[0003] To address the aforementioned problems, this invention proposes a freely combinable multifunctional well sealing device, comprising a connecting flange, a rubber core inlet cone, a hydraulic cylinder, a well sealer outer wall, a rubber core, and a rubber core fixing base. The well sealer outer wall is connected to the wellhead via the connecting flange, and the connecting flange is connected to the rubber core fixing base via the hydraulic cylinder. A rubber core is mounted on the rubber core fixing base, and a first through hole for tubing to pass through is provided on the rubber core fixing base. The connecting flange has a well sealer central hole for tubing to pass through, and the connecting flange has a rubber core inlet cone. The rubber core inlet cone has a conical hole for tubing to pass through, and the conical hole, the first through hole, and the well sealer central hole are all on a straight line.

[0004] Furthermore, the connecting flange is provided with connecting holes for fixing.

[0005] Furthermore, the core is a solid truncated cone.

[0006] Furthermore, the rubber core is provided with a second through hole for the oil pipe to pass through.

[0007] Furthermore, the core-introducing cone is provided with a rounded chamfer.

[0008] Furthermore, the core-introducing cone is made of steel or lead.

[0009] Furthermore, the core is made of rubber.

[0010] Furthermore, the rubber core is an iron core with locking teeth.

[0011] The beneficial effects of this invention are as follows: This invention utilizes the principle of a conical clamping rubber core to achieve a sealed annular space for high-pressure oil and water. Simultaneously, by connecting multiple well-sealing devices in series and using different series connection methods, multiple functions are achieved. Compared with traditional similar functional devices, this invention improves reliability and durability from a fundamental perspective, achieving compatibility of multiple functions. It effectively enables normal operation when there is high-pressure fluid in the oil and water well, avoiding environmental pollution and the risks of high-pressure operations. Attached Figure Description

[0012] Figure 1 This is a longitudinal sectional view of the well sealing device of the present invention;

[0013] Figure 2 This is a diagram of the first assembly of the well sealing device of the present invention;

[0014] Figure 3 This is a diagram of the second assembly configuration of the well sealing device of the present invention;

[0015] Figure 4 This is a diagram of the third assembly configuration of the well sealing device of the present invention;

[0016] Figure 5 This is a diagram of the fourth assembly configuration of the well sealing device of the present invention;

[0017] Figure 6 This is a diagram of the fifth assembly configuration of the well sealing device of the present invention;

[0018] Figure 7 This is a diagram showing the sealing state of the rubber core in the fifth combination of the well sealing device of the present invention;

[0019] Figure 8 This is a schematic diagram of the solid rubber core structure of the present invention;

[0020] Figure 9 This is a schematic diagram of the through-hole rubber core structure of the present invention.

[0021] The attached figures are labeled as follows:

[0022] 1. Connecting hole; 2. Connecting flange; 3. Rubber core inlet cone; 31. Conical hole; 32. Rounded chamfer; 4. Hydraulic cylinder; 5. Outer wall of well sealer; 6. Rubber core; 61. Second through hole; 7. Rubber core fixing base; 71. First through hole; 8. Middle hole of well sealer. Detailed Implementation

[0023] To make the technical means and objectives of this invention easier to understand, the invention is further described below in conjunction with specific embodiments, including a freely combinable multifunctional well sealing device, such as... Figure 1As shown, the device includes a connecting flange 2, a rubber core inlet cone 3, a hydraulic cylinder 4, a well sealer outer wall 5, a rubber core 6, and a rubber core fixing base 7. The well sealer outer wall 5 is connected to the wellhead via the connecting flange 2. The connecting flange 2 is connected to the rubber core fixing base 7 via the hydraulic cylinder 4. The rubber core 6 is installed on the rubber core fixing base 7. The rubber core fixing base 7 has a first through hole 71 for tubing to pass through. The connecting flange 2 has a well sealer central hole 8 for tubing to pass through. The connecting flange 2 has a rubber core inlet cone 3. The rubber core inlet cone 3 has a cone hole 31 for tubing to pass through. The cone hole 31, the first through hole, and the well sealer central hole 8 are on a straight line.

[0024] The connecting flange 2 is provided with a connecting hole 1 for fixing.

[0025] Among them, such as Figure 8 As shown, the core 6 is a solid truncated cone.

[0026] Among them, such as Figure 9 As shown, the rubber core 6 is provided with a second through hole 61 for the oil pipe to pass through.

[0027] The core-introducing cone 3 is provided with a rounded chamfer 32.

[0028] The core-introducing cone 3 is made of steel or lead.

[0029] The core 6 is made of rubber.

[0030] The rubber core 6 is an iron core with locking teeth.

[0031] To address the various problems existing in well sealing devices during current operations, this design aims to fundamentally resolve the issues present in the two existing well sealing devices (gate type and ball type) and to develop a half-conical rubber core. ( (Or made of steel or lead), a conical rubber core enters the cone, and the cone compresses the conical rubber core. This compression of the half-core achieves a seal. The structure is simple, the seal is reliable, and it can achieve sealing with or without tubing. Multiple cones can be combined to achieve multi-functional well sealing, simultaneously providing zero-seal, half-seal, sliding seal, and tubing clamping functions. Furthermore, the stacking of multiple cones significantly increases the reliability and durability of a single well. The design is compact (total weight less than 70 kg), with universal upper and lower connections and no diameter change in the upper and lower flanges. When one of multiple series-connected conical well sealers malfunctions, replacing the rubber core is very troublesome; therefore, a new well sealer can be added directly without replacing the damaged core. Due to its light weight, disassembly and assembly are simpler and more convenient compared to traditional devices. This avoids the various drawbacks of current well sealers.

[0032] Its structural feature is that the device is installed at the wellhead or other suitable location through two connecting flanges. By shrinking the hydraulic cylinder, it reaches the appropriate position and pushes the rubber core into the cone. The cone clamps the rubber core, maintaining the pressure inside the well while allowing the tubing string to slide up and down or rotate.

[0033] The principles underlying the design:

[0034] 1. When the hydraulic cylinder of this device extends, the tubing can be pulled up or down even when there is no pressure inside the well;

[0035] 2. In complex high-pressure well conditions, the rubber core is pushed into the cone body by shrinking the hydraulic cylinder. The cone body clamps the rubber core, and the rubber core seals the pressure in the annular space of the tubing and casing. This ensures that when the pressure inside the well is high, the liquid inside the well will not spray out, pollute the surrounding environment, or cause operational risks, thus reducing the difficulty of construction.

[0036] 3. Designed as a structure that can be connected in series. 1-5 are simplified diagrams of different series connection methods. In well conditions with greater depth and pressure, the rubber core is damaged due to the lifting of multiple tubing. A single rubber core cannot guarantee stability and durability. However, multiple rubber cores connected in series can achieve higher sealing pressure, automatic clamping of the tubing string, self-sealing, improved durability, avoid pressure shock in the well when the tubing string is lowered, and seal the well when the wellbore is empty, among other functions.

[0037] 4. Design multiple rubber cores, which can be made of rubber to seal pressure. The rubber core can be replaced with an iron core of the same shape with toothed slips to clamp the tubing string. At the same time, multiple rubber core well sealers and iron core well sealers can be connected in series to seal excessive pressure in the well while clamping the tubing string that is pushed up under high pressure.

[0038] 5. The design allows for direct replacement of the rubber core from the side of the device, or direct replacement of damaged individual well sealers in series, making maintenance and repair simple, cost-effective, and highly reliable.

[0039] like Figure 2 , Figure 5 As shown, ① Combination methods 1 and 4, two methods of series-connected well sealers - mainly used for live pipe pulling operations;

[0040] like Figure 3 , Figure 4 As shown, ② Combination methods 2 and 3 are two types of well sealers connected in series - mainly used for live tubing installation operations;

[0041] like Figure 6 As shown, combination method 5, which involves multiple series connections, is used for pressurized pipe pulling operations in high-pressure wells and deep wells.

[0042] like Figure 7As shown, combination ④, method 5, can also use two types of rubber cores. The bottom rubber core (No. 4) with a smaller diameter can seal the tubing. The middle rubber cores (No. 2 and No. 3) with larger diameters can seal packers, water distributors, and other accessories. The top rubber core (No. 1) with a smaller diameter can seal the tubing. This allows for the following: when retrieving large-diameter accessories, rubber cores 1 and 4 can be opened, and rubber cores 2 and 3 can be used to seal the accessory. When the accessory passes through rubber core 4, rubber core 4 can be closed, sealing the tubing connected to the lower end of the accessory. When the accessory passes through rubber core 1, rubber core 1 can be closed, completing the accessory retrieval process. When the accessory is lowered into the well, the above switching sequence can be reversed. This combination and method of use effectively avoids damage to the rubber cores caused by the large diameter difference between the tubing and the accessories, improving sealing stability and durability.

[0043] ⑤ It can also be combined in multiple ways to achieve various functions.

[0044] This invention utilizes the principle of a conical clamping rubber core to achieve a sealed annular space for high-pressure oil and water. Simultaneously, by connecting multiple well-sealing devices in series with different series configurations, it achieves multiple functions. Compared to traditional similar devices, it fundamentally improves reliability and durability, achieving compatibility across multiple functions. It effectively enables normal operation even when high-pressure fluids are present in oil and water wells, avoiding environmental pollution and the risks of high-pressure operations.

[0045] The effect achieved:

[0046] 1. Through extensive field application of this invention, the service life of the rubber core is extended, one rubber core can be used in more than two wells, and the cost of the rubber core is low, only 50 RMB;

[0047] 2. Improved efficiency of pressurized well workover operations, long durability to avoid frequent replacements, reasonable structure, longer service life, and reduced delays caused by replacing rubber cores in a single well. The disassembly and assembly time for replacing rubber cores is generally one day.

[0048] 3. It has a wide range of applications, including general pressurized operations, pressurized overhaul operations, and temporary well shut-in during well repairs;

[0049] 4. Reduced operating costs. Both gate blowout preventers and ball blowout preventers have rubber cores costing over 10,000 yuan each. One rubber core is used per well. PetroChina performs live operations on 5,000 wells a year. The rubber core consumption alone saves nearly 49 million yuan annually. The time lost can be used for operations, allowing for more than 500 additional wells to be operated, generating an additional 50 million yuan in benefits. The overall benefit is nearly 100 million yuan.

[0050] This invention can be combined in various series.

[0051] 1. The oil pipe can be lifted and lowered while maintaining a sealed oil pipe during cylinder retraction;

[0052] 2. When multiple units are connected in series, a pressure seal of 35 MPa and above can be achieved;

[0053] 3. It can achieve well completion in 3000-5000 meters without replacing the rubber core in one go;

[0054] 4. Small size and low cost, enabling low-cost operation during pressurized work;

[0055] 5. Improve efficiency and avoid environmental pollution;

[0056] 6. Saves costs, increases workload, and creates significant economic benefits;

[0057] 7. Multiple units can be connected in series to solve the problem of high-pressure wells with large depths, allowing for the removal and removal of large-diameter accessories without damaging the rubber core;

[0058] 8. Alternatively, the rubber core can be replaced with an iron core, with the iron core inlaid with slips to achieve the function of clamping the oil pipe. It can also be replaced with a rubber core without an inner hole to achieve full sealing.

[0059] 9. The combined iron core and combined rubber core can be transformed into a tubing string holder and well sealer, or multiple units can be connected in series to achieve all the above functions;

[0060] 10. Multiple combinations of methods can achieve the best results in live-line operation management.

[0061] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A freely combinable multifunctional well sealing device, characterized in that, The device includes a connecting flange (2), a rubber core inlet cone (3), a hydraulic cylinder (4), a well sealer outer wall (5), a rubber core (6), and a rubber core fixing base (7). The well sealer outer wall (5) is connected to the wellhead via the connecting flange (2). The connecting flange (2) is connected to the rubber core fixing base (7) via the hydraulic cylinder (4). The rubber core (6) is installed on the rubber core fixing base (7). The rubber core fixing base (7) has a first through hole (71) for tubing to pass through. The connecting flange (2) has a well sealer central hole (8) for tubing to pass through. The connecting flange (2) has a rubber core inlet cone (3). The rubber core inlet cone (3) has a cone hole (31) for tubing to pass through. The cone hole (31), the first through hole (71), and the well sealer central hole (8) are on a straight line.

2. The freely combinable multifunctional well sealing device as described in claim 1, characterized in that, The connecting flange (2) is provided with a connecting hole (1) for fixing.

3. The freely combinable multifunctional well sealing device as described in claim 1, characterized in that, The core (6) is a solid truncated cone.

4. The freely combinable multifunctional well sealing device as described in claim 1, characterized in that, The rubber core (6) is provided with a second through hole (61) for the oil pipe to pass through.

5. The freely combinable multifunctional well sealing device as described in claim 1, characterized in that, The core-introducing cone (3) is provided with a rounded chamfer (32).

6. The freely combinable multifunctional well sealing device as described in claim 1, characterized in that, The core-introducing cone (3) is made of steel or lead.

7. The freely combinable multifunctional well sealing device as described in claim 1, characterized in that, The core (6) is made of rubber.

8. The freely combinable multifunctional well sealing device as described in claim 1, characterized in that, The rubber core (6) is an iron core with locking teeth.

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