Sealing ring body manufacturing method based on self-expanding material and packer

Abstract

The invention relates to the technical field of underground packers, and particularly discloses a sealing ring body manufacturing method based on a self-expanding material, which comprises the following steps of: performing mould pressing on a hydrated expanding metal material to form a sealing ring body mould pressing part capable of hydrating and expanding, and forming a threading channel in the sealing ring body mould pressing part; sintering the plurality of sealing ring body molded parts to form an integrated sealing ring body fusion part; vulcanizing the rubber material on the surface of the sealing ring body fusion piece to form an elastic protection layer; an electrode is implanted into the sealing ring body molded part or the sealing ring body fusion part, and the expansion metal material can react with well fluid to form a primary battery through the electrode. The method overcomes the defects that a traditional packer is poor in machinability, complex in process, high in cost, poor in adaptability and the like, solves the problem that the setting condition is inconvenient to detect due to the fact that underground electric equipment is inconvenient to connect with electricity, and improves the energy utilization rate of the self-expanding material.

Description

Technical Field

[0001] This invention relates to the field of downhole packer technology, specifically a method for manufacturing a sealing ring based on a self-expanding material and a packer. Background Technology

[0002] The harsh downhole environment places high demands on the pressure and temperature resistance of downhole tools and materials, especially critical components such as rubber seals or sleeves of packers. Mechanical downhole packers include compression, expansion, and self-expanding packers, with elastomeric rubber materials primarily including nitrile butadiene rubber (NBR), hydrogenated NBR, polytetrafluoroethylene (PTFE), and fluororubber. Currently, tools and materials with temperature resistance below 150°C have been widely adopted, while tools based on downhole sealing materials with temperature resistance above 200°C are not widely used due to their high cost. In recent years, some packer tools based on special materials (such as water-swellable alloys) have begun to enter the field, offering advantages such as good high-temperature resistance (200-300°C, comparable to high-temperature cement), compact structure, high reliability, and low operational risk, thus providing a beneficial supplement to existing sleeve-type packers. Currently, the processing of sealing rings based on water-swellable alloy materials still uses solution casting. The alloy material needs to be preheated to a high-temperature liquid state, and the molds and supporting tooling are relatively complex. After casting, machining is still required to become the final part. The method is complicated, with poor economic indicators such as time and cost, and it does not support pre-installed cables and special modules, resulting in poor adaptability. Summary of the Invention

[0003] The purpose of this invention is to provide a method for manufacturing a sealing ring based on a self-expanding material, overcoming the drawbacks of traditional packers such as poor machinability, complex processes, high costs, and poor adaptability, solving the problem that it is inconvenient to connect downhole electrical equipment to power, which makes it difficult to detect the setting status, and improving the energy utilization rate of the self-expanding material.

[0004] The objective of this invention can be achieved through the following technical solutions:

[0005] A method for manufacturing a sealing ring based on a self-expanding material includes:

[0006] Molding a hydrating and expanding metal material to form a hydrating and expanding sealing ring molded part, and forming a wire passage inside the sealing ring molded part;

[0007] Multiple sealing ring molded parts are sintered to form an integral sealing ring fusion part; an elastic protective layer is formed on the surface of the sealing ring fusion part by vulcanizing rubber.

[0008] An electrode is implanted in the molded part or fused part of the sealing ring body, and the electrode enables the expanded metal material to form a galvanic cell when it reacts with the well fluid.

[0009] In a further embodiment, the hydrated expandable metal material comprises expandable metal and a binder, wherein the expandable metal is bonded by the binder and forms a condensed expandable substance upon contact with water.

[0010] In a further embodiment, the expanded metal comprises a composition selected from magnesium-calcium-aluminum or formed by any combination of magnesium-calcium-aluminum, and the binder comprises polyacrylamide-sodium silicate or a polyacrylamide-sodium silicate composition.

[0011] In a further embodiment, the method for molding hydrated and expanding metallic materials includes:

[0012] The hydrated and expanding metal material is compacted by a stamping die to form a sealing ring with a threading channel in one step.

[0013] In a further embodiment, the stamping die includes a pressing die and a bottom die. The bottom die has a first groove for forming the sealing ring body, and a cable core is provided in the first groove. The pressing die has a sealing ring body core corresponding to the first groove and a second groove corresponding to the cable core. When the pressing die and the bottom die are engaged, the sealing ring body core is inserted into the first groove to form the molded sealing ring body, and the cable core is inserted into the second groove to form a wire passage in the molded sealing ring body.

[0014] Based on the same inventive concept described above, the present invention provides a packer comprising a sealing ring body manufactured by any of the above-described methods for manufacturing a sealing ring body based on a self-expanding material.

[0015] A further embodiment also includes an electrode connecting piece, which is connected to an electrode inside the sealing ring.

[0016] In a further embodiment, the two ends of the sealing ring are connected to limit rings, and the electrode connecting piece is disposed inside the limit rings. The limit rings are used to limit the position of the sealing ring on the sleeve.

[0017] In a further embodiment, a sensor is installed inside the limiting ring, and the sensor is powered through the electrode connecting piece. The sensor is a temperature sensor-pressure sensor or an ion sensor.

[0018] In a further embodiment, a signal modem and a discharge controller are also provided inside the limiting ring. Both the signal modem and the discharge controller are electrically connected to the electrode connecting piece. The signal modem is used to digitize the sensor signal and transmit it to the ground through the cable. The discharge controller is used to control the discharge of the galvanic cell.

[0019] The beneficial effects of this invention are:

[0020] This invention applies hydrated, expandable metal materials to packers, and after molding, sintering, and vulcanization, forms a sealing ring with an elastic protective layer. This ensures the protection of the sealing ring's interior during downhole operation, preventing problems such as cracking due to wall collisions. By embedding electrodes within the sealing ring, a battery can be formed to power low-power devices, meeting the power requirements of sensors and other devices. When used in packers, the sealing ring produced by this method offers excellent sealing performance, simple processing, and, due to its galvanic cell, can be used for downhole power supply, resulting in enhanced functionality and high energy utilization.

[0021] Hydrated and expandable metal materials of various raw material types, such as powders, granules, and blocks, can be formed by molding. Through sintering, fusion can be achieved. Compared with solid solution casting, the internal structure of the sealing ring prepared by powder sintering is dense and uniform, which can better meet the harsh requirements of high-temperature downhole tools. The biodegradable protective layer of overall sulfidation ensures that the sealing ring is safe to use when going downhole. The new pre-installed cable method avoids internal defects such as cracks and cavities that may be caused by traditional methods.

[0022] This invention utilizes the hydration reaction of the expanded alloy to make part of the packer structure a well fluid battery. The battery output power is sufficient to drive low-power electrical equipment such as sensors and controllers. The overall system structure is simple and compact, with high reliability. It avoids the need for a separate expensive downhole lithium battery, thus reducing tool costs.

[0023] Sensors enable effective monitoring of downhole tools and dynamics: they can effectively monitor the setting status of self-expanding packers, and after oil and gas wells are put into production, they can effectively sample and transmit downhole production dynamic data, providing important basis for future automated and intelligent production. Attached Figure Description

[0024] 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 some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a schematic diagram of the installation and connection of the sealing ring body in an embodiment of the present invention;

[0026] Figure 2 This is a schematic diagram of a stamping equipment assembly for manufacturing the sealing ring body according to an embodiment of the present invention;

[0027] Figure 3 This is a schematic diagram of a molding and vulcanizing mold used to manufacture the sealing ring body in an embodiment of the present invention;

[0028] Figure 4 This is a schematic diagram of a packer according to an embodiment of the present invention;

[0029] In the diagram: 1-Sleeve; 2-Sealing ring body; 3-Limiting ring; 4-Oil pipe coupling; 5-Elastic protective layer; 6-Pipeline; 7-Fastener; 8-Stamping base; 9-Stamping table; 10-Top support frame; 11-Top hydraulic cylinder; 12-Pressure die; 120-First groove; 121-Sealing ring body core; 122-Second groove; 13-Pneumatic clamp; 14-Stamping assembly fastener; 15-Template vibratory source; 16-Bottom template; 17-Stamping head; 18-Bottom hydraulic cylinder; 19-Pipeline core; 20-Top mold frame; 21-Elastomer material; 22-Bottom mold frame. Detailed Implementation

[0030] 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 some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] Hydrated expandable metal materials mainly include expandable metals such as Mg-Ca and elements-based binders such as sodium silicate-PAM. Expandable metals undergo a metal hydration reaction in salt water, expanding to form metal oxides or metal hydroxides. The volume of the resulting product is greater than the original alloy material. For example, magnesium (Mg) → Mg(OH)₂ expands by approximately 85%; calcium (Ca) → Ca(OH)₂ expands by approximately 32%; and aluminum (Al) → Al(OH)₃ expands by approximately 160%. Among binders, sodium silicate (water glass) has strong adhesion, high strength, and good acid and heat resistance. Magnesium and calcium ions in the solution react rapidly with sodium silicate to form silicate gel and a very strong calcium silicate-magnesium silicate gel. The chemical reaction formula is as follows:

[0032] Na2O·nSiO2+CaC l2=2NaC l+CaO·nSiO2↓

[0033] Na2O·nSiO2+MgC l2=2NaC l+MgO·nSiO2↓

[0034] The products of this reaction have properties similar to those of cement-rock materials, resulting in a tighter bond between the sealing ring 2 and the wellbore after expansion and sealing. At room temperature, the volume expansion rate of the hydrated expansion alloy system reaches 3-5 times, while at high temperatures, the expansion rate is even faster and more stable, which is beneficial for improving downhole sealing performance.

[0035] A specific implementation method for molding a hydrating and expanding metal material to form a hydrating and expanding sealing ring molded part, wherein a wire passage is formed within the sealing ring molded part, can be described as follows:

[0036] In practice, a molding machine can be used as the carrier, the structure of which is shown in the attached figure. Figure 2 As shown, the main components are a stamping base 8, a stamping table 9, a top support frame 10, a top hydraulic cylinder 11, a die 12, a pneumatic clamp 13, a stamping assembly fastener 14, a template vibrator 15, a bottom template 16, a stamping head 17, a bottom hydraulic cylinder 18, and a cable core 19. The stamping head 17 is slidably connected to a third groove within the bottom template 16, forming a first groove 120 between itself and the bottom template 16. The die 12 has a sealing ring core 121 corresponding to the first groove 120 and a second groove 122 corresponding to the cable core 19. When the die and bottom mold are engaged, the sealing ring core 121 inserts into the first groove 120 to form a molded sealing ring, while the cable core inserts into the second groove to form a threading channel within the molded sealing ring. The top hydraulic cylinder 11 and the bottom hydraulic cylinder 18 provide linear power for the stamping process. After the die 12, bottom template 16, and stamping head 17 are assembled, their internal cavities form the 3D outline of the sealing ring body 2. The diameter of the upper cylinder of the stamping head 17 is the inner diameter of the annular cylinder of the sealing ring body 2, and the inner diameter of the bottom template 16 is the outer diameter of the annular cylinder of the sealing ring body 2. The dimensions of the cable core 19 are the dimensions of the pre-placed cable 6 and match the second groove of the die 12. After the die is closed, under the load of the hydraulic cylinder, the powder or granular raw material is compacted into a whole. The stamping head 17 also functions as a stamping part, ejecting the formed stamping part. The ejected stamping part contains a pre-formed deep hole space for the cable to pass through. The dimensions of the bottom template 16 and the stamping head 17 can be adjusted according to different processing objects to meet the customization requirements of the sealing ring body 2. The pneumatic clamp 13 employs a miniature pneumatic cylinder design. Before placing the bottom template 16, the pneumatic clamp 13 is in a retracted state. After the bottom template 16 is placed on the stamping table, the pneumatic clamp 13 extends to position and fix the bottom template 16. The top hydraulic cylinder 11 adopts a dual-cylinder synchronous action mode to ensure that the mold 12 can normally close and open during its up-and-down movement. The dual hydraulic cylinders replace the existing directional guide rod structure. The template vibrator 15 is placed inside the stamping table 9, with its upper part closely attached to the lower surface of the flange of the bottom template 16. This vibrator is based on piezoelectric ceramics, has an adjustable frequency, and mainly adopts existing technology. During the stamping process of the seal, after filling the inner cavity of the bottom template 16 with raw material, the template vibrator 15 is activated to ensure that the raw material is effectively filled into all cavities. The top support frame 10 provides support for the mold 12 and the top hydraulic cylinder 11.

[0037] Multiple sealing ring molded parts are sintered to form a fused sealing ring assemblies; an elastic protective layer is formed on the surface of the fused sealing ring assemblies by vulcanizing rubber; the specific implementation method is as follows:

[0038] After the sealing ring body is stamped, it is removed and transferred to a sintering device for sintering. The sintering method and supporting equipment are existing mature technologies, and are not limited to vacuum sintering, micro-pressure sintering, SPS sintering, microwave sintering, etc. If the length of the sealing ring body 2 to be processed is long, it can be divided into multiple independent units, stamped and formed separately, and then connected in series to form a single whole after sintering.

[0039] See Figure 3 As shown, after the sealing ring body 2, formed by powder metallurgy and stamping, is processed, an elastic protective layer 5 will be coated on its outer surface, which will be completed by vulcanization equipment. The elastic protective layer 5 can be a high-temperature resistant non-degradable elastomer material, such as hydrogenated nitrile-fluororubber, or a degradable elastomer material, such as an elastomer material based on polyglycolic acid (PGA) or polylactic acid (PLA).

[0040] The vulcanization mold is composed of a top mold frame 20, a bottom mold frame 21, and various positioning components and fasteners. In the compression molding vulcanization of the elastomer protective layer, the first step is material preparation, including raw rubber, vulcanization accelerators, and other additives. The stamped sealing ring 2 is fitted into the sleeve 1 and then into the AP I oil pipe / sleeve. The designated pre-installed cable 6 is then inserted and placed inside the sealing ring 2. The assembled packer prototype is placed into the mold composed of the top mold frame 20 and the bottom mold frame 21, and the prepared raw rubber and additive system is filled into the gaps inside the mold. After closing the mold and installing the fasteners, it is transferred to a flat vulcanizing machine for vulcanization. The compression molding vulcanization process is carried out according to relevant standards and specifications. After the compression molding vulcanization is completed, the mold is opened, the packer prototype is removed, and transferred to relevant machining equipment for shaping and finishing of the sealing ring 2 and the vulcanized elastic protective layer 5. (See reference...) Figure 1 As shown, the limiting ring 3 is installed at both ends of the sealing ring body 2, the pre-installed cable 6 passes through the limiting ring 3 and is fixed by crimping and fasteners. Finally, the pre-installed cable 6 is subjected to pipeline pressure test and circuit electrical test to verify the status of the pre-installed cable 6.

[0041] The types of pre-installed cables 6 include hydraulic lines, electrical cables, optical cables, flat cables, and other commonly used cables in oil and gas wells. The assembled units are placed together into a molding die. The elastic protective layer on the outer surface of the molded and vulcanized sealing ring assembly has many protrusions and burrs, and its shape accuracy does not meet the requirements for field deployment. It must be shaped by machining. Limiting rings 3 are installed at both ends using crimping and fastener connection methods. Finally, the pre-installed cables undergo factory testing. After passing the test, matching components, such as pipe fittings and electrical connectors, are installed.

[0042] Molded hydrated expandable metal materials support various raw material types such as powders, granules, and blocks. By adjusting the sintering method parameters, sealing rings with different mechanical properties and different sealing performance can be prepared. They can be processed as a whole or processed into different units and then combined into a whole sealing ring, offering good flexibility and higher efficiency: For pre-installed cables, the sealing ring processing and cable pre-installation cavity processing can be completed in one step with the help of matching molding equipment, balancing processing quality and timeliness, and reducing processing costs; Higher processing quality: Compared with the solution casting method, the internal structure of the sealing ring prepared by powder sintering is dense and uniform, which can better meet the harsh requirements of high-temperature downhole tools. The biodegradable protective layer of overall vulcanization ensures that the sealing ring is safe for use in the well. The new pre-installed cable method avoids internal defects such as cracks and cavities that may be caused by traditional methods.

[0043] This invention patent overcomes the shortcomings of traditional packers, such as poor processability, high cost, and poor adaptability, and has the advantages of good process adaptability, high efficiency, and good processing quality, which can meet the processing requirements of high temperature hydration expansion packers.

[0044] Specific methods for embedding electrodes in expanded metal materials, inserting electrodes into molded parts formed after molding, or embedding electrodes into sintered sealing ring fusion parts, so that the electrodes can form a galvanic cell when the expanded metal material reacts with the well fluid in the sealing ring, include: placing the electrodes into the hydrated expanded metal material before molding and then molding them together; or molding the electrode mounting groove first, then inserting the electrode sheet and then bonding or sintering it for fixation; the manufacturing of electrodes can be referenced from existing battery electrode sheets.

[0045] An expandable alloy-well fluid battery is integrated into the self-expanding packer. This battery is a primary battery, generally non-rechargeable, and adopts an open structure. The cathode, made of graphite, is placed into a side-mounted limiting ring via electrode connecting pieces. The anode, an expandable magnesium alloy system within the packer's sealing ring, is also placed into the limiting ring after being connected via electrode connecting pieces. Mineralized well fluid serves as the electrolyte. The specific battery structure can be referenced from existing magnesium-seawater fuel cells. A discharge controller is incorporated into this side-mounted limiting ring; this module regulates and protects the energy release process of the expandable alloy-well fluid battery. A pressure sensor is also incorporated into this side-mounted limiting ring. The battery's chemical reaction principle is as follows:

[0046] Anodic reaction: Mg → Mg 2+ +2e

[0047] Cathode reaction: O2 + 2H2O + 4e → 4OH- -

[0048] On the other side, a limiting ring houses a pressure sensor, an ion sensor, and a signal modulator / demodulator. The pressure sensor measures the downhole annular pressure on both sides of the packer, enabling dynamic monitoring during fracturing operations and production. The ion sensor monitors the hydration reaction process of the sealing ring and, in conjunction with the pressure sensor, can be used for pressure testing of the self-expanding packer to determine its setting status and packing effectiveness. The signal modulator / demodulator digitizes the signals from each sensor and transmits them to the surface via pipeline, enabling real-time transmission and monitoring of data such as the self-expanding packer's operating status and downhole production dynamics. Each pressure sensor, ion sensor, and signal modulator / demodulator is powered by an electrode connection piece within the expansion alloy-well fluid battery. Additional sensors, such as temperature and flow sensors, can be added to the self-expanding packer as needed on-site.

[0049] The scheme has the following characteristics: (1) Integrated high-efficiency structure: The hydration reaction of the expansion alloy makes the packer part of the structure become a well fluid battery. The output power of the battery is sufficient to drive low-power electrical equipment such as sensors and control modules. The overall structure of the system is simple and compact, and the reliability is high; (2) Realize effective monitoring of downhole tools and dynamics: It can effectively monitor the setting and sealing status of the self-expanding packer. After the oil and gas well is put into production, it can effectively sample and transmit downhole production dynamic data, providing an important basis for future automated and intelligent production; (3) Controllable cost: It avoids the separate equipment of expensive downhole lithium batteries and reduces tool costs.

[0050] When this sealing ring is used for sealing purposes, it can be implemented as follows: (See [reference]) Figure 4 As shown, the limiting ring 3 and the sealing ring body 2 are fixedly connected by matching fasteners 7. The inner surface of the limiting ring 3 has a pre-made crimping groove, and the outer surface of the sleeve 1 also has a corresponding crimping groove. During assembly, a hydraulic crimping machine is used to fix the limiting ring 3 to the sleeve 1 by crimping. The crimped joint surface has a certain sealing capability to prevent external high-pressure fluid from entering the packer through the joint surface. The limiting ring 3 is milled with a platform structure for cable passage and is connected in series with the existing oil pipe through the oil pipe coupling 4.

[0051] It should be noted that the terms "first," "second," etc., used in this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate for the embodiments of this application described herein.

[0052] In the description of this specification, references to terms such as "an embodiment," "an example," and "a specific example" indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0053] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed invention.

Claims

1. A method for manufacturing a sealing ring based on a self-expanding material, characterized in that, include: Molding a hydrating and expanding metal material to form a hydrating and expanding sealing ring molded part, and forming a wire passage inside the sealing ring molded part; Multiple sealing ring molded parts are sintered to form an integral sealing ring fusion part; an elastic protective layer is formed on the surface of the sealing ring fusion part by vulcanizing rubber. An electrode is implanted in the molded part or fused part of the sealing ring body, and the electrode enables the expanded metal material to form a galvanic cell when it reacts with the well fluid.

2. The method for manufacturing a sealing ring based on a self-expanding material according to claim 1, characterized in that, The hydrated expandable metal material includes expandable metal and a binder. The expandable metal is bonded by the binder and forms a solidified expandable substance when it comes into contact with water.

3. The method for manufacturing a sealing ring based on a self-expanding material according to claim 2, characterized in that, The expanded metal comprises a composition selected from magnesium-calcium-aluminum or formed by any combination of magnesium-calcium-aluminum, and the binder comprises polyacrylamide-sodium silicate or a polyacrylamide-sodium silicate composition.

4. The method for manufacturing a sealing ring based on a self-expanding material according to claim 1, characterized in that, The method for molding hydrated and expanded metallic materials includes: The hydrated and expanding metal material is compacted by a stamping die to form a sealing ring with a wire passage in one step (2).

5. A method for manufacturing a sealing ring based on a self-expanding material according to claim 4, characterized in that, The stamping die includes a pressing die (12) and a bottom die. The bottom die has a first groove (120) for forming the sealing ring body (2). The first groove has a cable core (19). The pressing die (12) has a sealing ring body core (121) corresponding to the first groove (120) and a second groove (122) corresponding to the cable core (19). When the pressing die (12) and the bottom die are engaged, the sealing ring body core (121) is inserted into the first groove (120) to form the sealing ring body molded part, and the cable core (19) is inserted into the second groove (122) to form a wire passage in the sealing ring body molded part.

6. A packer, characterized in that, Including a sealing ring body manufactured using any one of the sealing ring body manufacturing methods based on self-expanding materials according to claims 1 to 5 (2) 。 7. A packer according to claim 6, characterized in that, It also includes an electrode connecting piece, which is connected to the electrode inside the sealing ring body (2).

8. A packer according to claim 7, characterized in that, The sealing ring body (2) is connected to two ends of a limiting ring (3), and the electrode connecting piece is disposed inside the limiting ring. The limiting ring (3) is used to limit the position of the sealing ring body (2) on the sleeve (1).

9. A packer according to claim 8, wherein a sensor is installed inside the limiting ring (3), the sensor is powered through the electrode connecting piece, and the sensor is a temperature sensor, a pressure sensor and / or an ion sensor.

10. A packer according to claim 9, characterized in that, The limiting ring (3) is also equipped with a signal modem and a discharge controller. The signal modem and the discharge controller are both electrically connected to the electrode connecting piece. The signal modem is used to digitize the sensor signal and transmit it to the ground through the pipeline. The discharge controller is used to control the discharge of the galvanic cell.

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