A controllable-dissolution aluminum alloy downhole completion tool and a preparation method thereof
By using precise proportions and optimized manufacturing processes, aluminum alloy downhole cementing and completion tools have solved the problem of balancing mechanical properties and controllable dissolution performance, achieving high strength stability and precise dissolution in downhole operations and ensuring wellbore safety.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- XI'AN PETROLEUM UNIVERSITY
- Filing Date
- 2026-03-24
- Publication Date
- 2026-05-29
AI Technical Summary
Existing aluminum alloy downhole cementing and completion tools struggle to balance mechanical properties with controllable dissolution performance, leading to easy failure or incomplete dissolution in high-pressure, high-temperature, and highly corrosive environments, which affects wellbore safety and subsequent operations.
By precisely proportioning Mg, Cu, Ti, Ga, In, and Sn elements, and combining processes such as high-temperature smelting, ultrasonic coupling homogenization, and low-pressure pulsed vacuum heat treatment, aluminum alloy downhole cementing and completion tools are prepared, achieving synergistic optimization of mechanical properties and controllable dissolution properties.
The tool maintains its structural integrity under high pressure, possesses high strength and stability, and can be precisely dissolved after the operation is completed, avoiding wellbore blockage and reducing operating costs.
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Abstract
Description
Technical Field
[0001] This invention relates to the field of oil and gas field completion tool materials technology, and more specifically, to a controllable dissolution aluminum alloy downhole cementing completion tool and its preparation method. Background Technology
[0002] In downhole cementing and completion operations during oil and gas field exploration and development, downhole cementing and completion tools, as core supporting components, need to serve in complex wellbore environments with high pressure, high temperature, and strong corrosion for extended periods. They must not only meet the mechanical performance requirements of high strength and high stability during operations to ensure the smooth implementation of cementing and completion construction, but also achieve rapid and controllable dissolution after the operation is completed to avoid tool residues causing wellbore blockage and affecting subsequent oil and gas extraction operations. At the same time, they should reduce the high costs and high risks associated with traditional fishing operations.
[0003] Currently, most downhole cementing and completion tools used in the oil and gas field are made of traditional aluminum alloys, steel, or soluble resins. Among them, traditional aluminum alloys have become the mainstream choice due to their low density and good machinability. However, existing aluminum alloy completion tools generally suffer from the technical bottleneck of not being able to balance mechanical properties and controllable dissolution performance. Some aluminum alloy tools have been modified to improve mechanical properties by adjusting the composition ratio to strengthen the matrix structure, but this has led to a significant reduction in the dissolution rate. As a result, they cannot dissolve quickly after the operation is completed, leaving residues in the wellbore. Some aluminum alloy tools have been modified to achieve solubility by adding a large number of corrosion-regulating elements, but this has sacrificed the mechanical strength of the matrix. Under complex loads such as downhole pressure, impact, and tension, they are prone to deformation, fracture, and other failures, and cannot meet the stringent service requirements.
[0004] Existing processes for preparing soluble aluminum alloys also have many shortcomings. Traditional smelting and heat treatment processes easily lead to uneven distribution of alloying elements, porosity, and internal stress within the castings. This not only causes fluctuations in mechanical properties but also triggers imbalances in localized corrosion rates, resulting in localized excessive dissolution and localized areas of poor dissolution control. Furthermore, current technologies rely on limited methods for controlling the dissolution rate of aluminum alloys, often simply adding corrosive elements. This fails to achieve precise control for "low loss during service and high dissolution after operation," making it difficult to meet the core operational requirements of cementing and completion operations.
[0005] In summary, developing an aluminum alloy downhole cementing and completion tool with excellent mechanical properties, a precise and controllable dissolution process, and the ability to meet the requirements of the entire process of downhole cementing and completion operations in oil and gas fields, while also providing a suitable manufacturing process to ensure its stable performance, has become an urgent technical problem to be solved in the field of oil and gas field completion tool materials. Summary of the Invention
[0006] The purpose of this invention is to provide a controllable dissolution aluminum alloy downhole cementing and completion tool and its preparation method.
[0007] To achieve the above objectives, the present invention provides the following technical solution: One of the technical solutions of this invention: A controllable dissolution aluminum alloy downhole cementing and completion tool, composed of the following elements by mass percentage: Mg 5.5%–7.5%, Cu 1.5%–2.5%, Ti 0.4%–0.7%, Ga 1%–2%, In 0.3%–0.5%, Sn 0.7%–1.3%, balance Al.
[0008] The second technical solution of this invention: The above-mentioned method for preparing a controllable dissolution aluminum alloy downhole cementing and completion tool includes the following steps: 1) Weigh out the high-purity metal or intermediate alloy according to the element mass percentage; 2) Mix the high-purity metals and intermediate alloys weighed in step 1), melt them at high temperature, and homogenize them by ultrasonic coupling to obtain an aluminum alloy melt; 3) Refine the aluminum alloy melt obtained in step 2), let it stand, and skim off the slag to obtain a pure aluminum alloy melt; 4) Pour the pure aluminum alloy melt obtained in step 3) into a mold, cool it in a furnace, and obtain an aluminum alloy casting; 5) Perform low-pressure pulse vacuum heat treatment on the aluminum alloy casting obtained in step 4) to obtain vacuum heat-treated aluminum alloy casting; 6) Perform solution treatment and aging treatment on the vacuum heat-treated aluminum alloy casting obtained in step 5) to obtain the controllable dissolution aluminum alloy downhole cementing and completion tool.
[0009] Further, in step 2), the high-temperature melting specifically refers to melting at 720–760°C for 20–30 minutes under argon protection.
[0010] Further, in step 2), the ultrasonic coupling homogenization specifically involves maintaining the temperature at 720–760°C, controlling the stirring speed at 350–450 r / min, the ultrasonic power at 200–300 W, the ultrasonic frequency at 20–25 kHz, and performing ultrasonic treatment for 15–25 min.
[0011] Further, in step 3), the refining specifically involves adding 0.2 wt.% of sodium-free refining agent to the aluminum alloy melt, and refining it by rotary jetting argon gas at 690–710°C while controlling the argon pressure at 0.2 MPa.
[0012] Further, in step 4), the casting specifically involves: first preheating the mold to 200-240°C, then controlling the casting temperature at 680-700°C under a pressure of 0.03-0.05 MPa, casting the pure aluminum alloy melt into the mold, and holding the pressure for 3-5 minutes.
[0013] Further, in step 4), the furnace cooling specifically refers to cooling the furnace to 280-320°C.
[0014] Further, in step 5), the low-pressure pulsed vacuum heat treatment specifically involves: first, at 450℃~550℃, evacuating the heat treatment furnace to a pressure of 5×10⁻⁶. -2 Hold the pressure at 80-100 kPa for 3-5 minutes, then use argon as the refill gas to refill the heat treatment furnace to a pressure of 80-100 kPa, hold the pressure for 8-12 minutes, and complete one cycle. Repeat this cycle 3-5 times in total.
[0015] Further, in step 6), the solution treatment specifically involves: holding the aluminum alloy casting at 500℃~520℃ for 1.5~2.5h, then transferring the casting to quench it in circulating cooling water at 20℃, and air-cooling it to room temperature.
[0016] Further, in step 6), the aging treatment specifically involves maintaining the temperature at 150℃~170℃ for 7~9 hours.
[0017] Compared with the prior art, the beneficial effects of the present invention are as follows: The present invention provides a controllable dissolution aluminum alloy downhole cementing and completion tool with a room temperature tensile strength of up to 332 MPa, a high temperature tensile strength of up to 302 MPa at 120℃, a Vickers hardness of up to 116, and a compressive strength of up to 685 MPa, exhibiting excellent mechanical properties.
[0018] The aluminum alloy downhole cementing and completion tool provided by this invention exhibits a controllable dissolution performance. In an oily cement slurry medium at 90°C, the mass loss rate is only 3.7% after 72 hours, and it can be completely dissolved in 161 hours. In a clean water medium at 90°C, the mass loss rate is only 4.9% after 72 hours, and it can be completely dissolved in 130 hours.
[0019] This invention provides a controllable dissolution aluminum alloy downhole cementing and completion tool. Through the precise proportioning of alloy components and the innovative collaborative design of the manufacturing process, it achieves dual optimization of mechanical properties and controllable dissolution performance. It perfectly meets the core working condition requirements of "high strength and stability during service and precise and controllable dissolution after operation" in oil and gas field downhole cementing and completion operations. It effectively solves the technical problems of insufficient mechanical properties, uncontrollable dissolution rate, and difficulty in balancing service and dissolution performance of traditional aluminum alloy completion tools.
[0020] The present invention provides a controllable dissolution aluminum alloy downhole cementing and completion tool. In terms of mechanical properties, it can ensure that the tool maintains structural integrity throughout the process under complex load environments such as downhole high pressure, impact, and tension, without deformation, fracture, or other failure problems. It provides reliable structural support for the smooth implementation of cementing and completion operations and meets the stringent service strength requirements downhole.
[0021] This invention provides a controllable dissolution aluminum alloy downhole cementing and completion tool. In terms of controllable dissolution performance, it exhibits precise and controllable characteristics of low loss in the early stage and high dissolution in the later stage in typical downhole 90℃ oily cement slurry and water media. This ensures that the tool is not excessively corroded before completing the cementing and completion operation. After the operation is completed, it can be quickly and completely dissolved in the downhole environment without the need for subsequent retrieval, which greatly reduces the cost of downhole operations and avoids subsequent technical problems such as wellbore blockage caused by tool residue.
[0022] The performance advantages of the controllable dissolution aluminum alloy downhole cementing and completion tool provided by this invention stem from the dual scientific design of alloy composition and preparation process. The two are coupled and work synergistically to achieve precise control of mechanical properties and dissolution properties at the microstructure and phase structure level. In the alloy composition design, Al is used as the matrix, and Mg, Cu, and Ti are precisely matched as mechanical strengthening elements. Mg and Al form Mg2Al3 precipitate strengthening phase, Cu and Al and Mg form Al-Cu-Mg multi-metallic intermetallic compounds to further refine the precipitate phase, and Ti forms TiAl3 nucleation core to refine the cast grains. The three work together to achieve precipitation strengthening and grain refinement of the alloy, which greatly improves the room temperature and high temperature mechanical properties of the alloy. At the same time, Ga, In, and Sn are added as dissolution control elements. These three types of low potential elements form a micro-galvanic corrosion cell with the Al matrix. Al acts as the anode and undergoes oxidation and dissolution, while the low potential elements act as the cathode to accelerate the corrosion reaction. By precisely controlling the addition ratio of elements, the corrosion rate can be controlled and adjusted to avoid dissolution that is too fast or too slow. At the same time, it ensures that the micro-galvanic corrosion reaction is slow in the early stage and accelerates exponentially in the later stage as the corrosion pit expands and connects, forming a dissolution characteristic of low loss in the early stage and high dissolution in the later stage. The proportions of mechanical strengthening elements and dissolution-regulating elements are designed to be mutually compatible. The strengthening phase only improves the matrix strength without damaging the micro-galvanic corrosion system, while the dissolution-regulating elements only gradually exert their effects after the process is completed without affecting the structural stability during service, thus achieving a performance balance between strengthening and dissolution. In terms of the preparation process design, each step of this invention synergistically regulates the microstructure of the aluminum alloy, ensuring that the design advantages of the alloy composition are fully utilized. High-temperature melting combined with ultrasonic coupling homogenization treatment effectively breaks up element agglomerates, achieving a uniform distribution of each alloying element in the Al matrix and avoiding fluctuations in mechanical properties and imbalances in dissolution rates caused by uneven local element concentrations. Low-pressure pulsed vacuum heat treatment is used to fully eliminate internal stress in the casting, close internal micropores, and promote uniform element diffusion. Compared with traditional constant-temperature vacuum or atmospheric pressure heat treatment, this significantly improves the uniformity and density of the alloy structure. Each preparation process step is progressive and mutually coordinated, achieving excellent results in both mechanical properties and controllable dissolution performance. Detailed Implementation
[0023] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention. It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the present invention.
[0024] Furthermore, regarding the numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Every smaller range between any stated value or intermediate value within a stated range, and any other stated value or intermediate value within said range, is also included within this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.
[0025] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.
[0026] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be apparent to those skilled in the art. This specification and embodiments are merely exemplary.
[0027] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.
[0028] In the following examples and comparative examples, the high-purity metals and intermediate alloys are commercially available or pre-cast alloys, and are not specifically limited, as long as they can achieve the mass percentages defined in this invention.
[0029] The following embodiments illustrate a method for preparing a controllably dissolved aluminum alloy downhole cementing and completion tool, comprising the following steps: 1) Weigh the high-purity metal or master alloy according to the following mass percentages: Mg 5.5%–7.5%, Cu 1.5%–2.5%, Ti 0.4%–0.7%, Ga 1%–2%, In 0.3%–0.5%, Sn 0.7%–1.3%, balance Al; 2) Mix the high-purity metals and intermediate alloys weighed in step 1), melt them at high temperature, and homogenize them by ultrasonic coupling to obtain an aluminum alloy melt; Specifically, the high-temperature melting refers to melting at 720–760°C for 20–30 minutes under argon protection. Specifically, the ultrasonic coupling homogenization involves maintaining a temperature of 720–760°C, controlling the stirring speed to be 350–450 r / min, the ultrasonic power to be 200–300 W, the ultrasonic frequency to be 20–25 kHz, and the ultrasonic treatment to be 15–25 min. 3) Refine the aluminum alloy melt obtained in step 2), let it stand, and skim off the slag to obtain a pure aluminum alloy melt; Specifically, the refining process involves adding 0.2 wt.% of a sodium-free refining agent to the aluminum alloy melt and refining it by rotary jetting argon gas at a temperature of 690–710°C and an argon pressure of 0.2 MPa. 4) Pour the pure aluminum alloy melt obtained in step 3) into a mold, cool it in a furnace, and obtain an aluminum alloy casting; Specifically, the casting process involves: first, preheating the mold to 200-240°C, then controlling the casting temperature at 680-700°C under a pressure of 0.03-0.05 MPa, and casting the pure aluminum alloy melt into the mold, holding the pressure for 3-5 minutes. Specifically, the furnace cooling refers to cooling the furnace to 280–320°C. 5) Perform low-pressure pulse vacuum heat treatment on the aluminum alloy casting obtained in step 4) to obtain vacuum heat-treated aluminum alloy casting; Specifically, the low-pressure pulsed vacuum heat treatment involves first evacuating the heat treatment furnace to a pressure of 5 × 10⁻⁶ at 450℃~550℃. -2 Pa, hold pressure for 3-5 minutes, then use argon as the refill gas to refill the heat treatment furnace to a pressure of 80-100 kPa, hold pressure for 8-12 minutes, complete one cycle, and repeat 3-5 cycles in total; 6) Perform solution treatment and aging treatment on the vacuum heat-treated aluminum alloy casting obtained in step 5) to obtain the controllable dissolution aluminum alloy downhole cementing and completion tool. The solution treatment specifically involves holding the aluminum alloy casting at 500℃~520℃ for 1.5~2.5h, then transferring the casting to a circulating cooling water at 20℃ for quenching, and finally air-cooling it to room temperature. Specifically, the aging process involves maintaining the temperature at 150℃ to 170℃ for 7 to 9 hours.
[0030] Example 1 A controllable dissolution aluminum alloy downhole cementing and completion tool 1) Weigh the high-purity metal or master alloy according to the following mass percentages: Mg 6.5%, Cu 2%, Ti 0.6%, Ga 1.52%, In 0.4%, Sn 1%, balance Al; 2) Mix the high-purity metals and intermediate alloys weighed in step 1), melt them at high temperature, and homogenize them by ultrasonic coupling to obtain an aluminum alloy melt; Specifically, the high-temperature melting process involves melting at 740°C for 25 minutes under argon protection. Specifically, the ultrasonic coupling homogenization involves maintaining a temperature of 740℃, controlling the stirring speed at 400r / min, the ultrasonic power at 250W, the ultrasonic frequency at 25kHz, and performing ultrasonic treatment for 20min. 3) Refine the aluminum alloy melt obtained in step 2), let it stand, and skim off the slag to obtain a pure aluminum alloy melt; Specifically, the refining process involves adding 0.2 wt.% of a sodium-free refining agent to the aluminum alloy melt and refining it by rotary jetting argon gas at 700°C while controlling the argon pressure at 0.2 MPa. 4) Pour the pure aluminum alloy melt obtained in step 3) into a mold, cool it in a furnace, and obtain an aluminum alloy casting; Specifically, the casting process involves: first, preheating the mold to 220°C, then controlling the casting temperature at 690°C under a pressure of 0.04 MPa, casting the pure aluminum alloy melt into the mold, and holding the pressure for 4 minutes. Specifically, the furnace cooling refers to cooling the furnace to 300°C. 5) Perform low-pressure pulse vacuum heat treatment on the aluminum alloy casting obtained in step 4) to obtain vacuum heat-treated aluminum alloy casting; Specifically, the low-pressure pulsed vacuum heat treatment involves first evacuating the heat treatment furnace to a pressure of 5 × 10⁻⁶ at 500°C. -2 Pa, hold pressure for 4 min, then use argon as the refill gas to refill the heat treatment furnace to a pressure of 90 kPa, hold pressure for 10 min, complete one cycle, and repeat 5 cycles in total; 6) Perform solution treatment and aging treatment on the vacuum heat-treated aluminum alloy casting obtained in step 5) to obtain the controllable dissolution aluminum alloy downhole cementing and completion tool. Specifically, the solution treatment involves holding the aluminum alloy casting at 510°C for 2 hours, then transferring it to a circulating cooling water at 20°C for quenching, and finally air-cooling it to room temperature. Specifically, the aging process involves maintaining the temperature at 160°C for 8 hours.
[0031] Example 2 A controllable dissolution aluminum alloy downhole cementing and completion tool 1) Weigh the high-purity metal or master alloy according to the following mass percentages: Mg 5.5%, Cu 1.5%, Ti 0.4%, Ga 1%, In 0.3%, Sn 0.7%, balance Al; 2) Mix the high-purity metals and intermediate alloys weighed in step 1), melt them at high temperature, and homogenize them by ultrasonic coupling to obtain an aluminum alloy melt; Specifically, the high-temperature melting process involves melting at 720°C for 20 minutes under argon protection. Specifically, the ultrasonic coupling homogenization involves maintaining a temperature of 720℃, controlling the stirring speed at 350r / min, the ultrasonic power at 200W, the ultrasonic frequency at 20kHz, and performing ultrasonic treatment for 15min. 3) Refine the aluminum alloy melt obtained in step 2), let it stand, and skim off the slag to obtain a pure aluminum alloy melt; Specifically, the refining process involves adding 0.2 wt.% of a sodium-free refining agent to the aluminum alloy melt and refining it by rotary jetting argon gas at 690°C while controlling the argon pressure at 0.2 MPa. 4) Pour the pure aluminum alloy melt obtained in step 3) into a mold, cool it in a furnace, and obtain an aluminum alloy casting; Specifically, the casting process involves: first, preheating the mold to 200°C, then controlling the casting temperature at 680°C under a pressure of 0.03 MPa, casting the pure aluminum alloy melt into the mold, and holding the pressure for 3 minutes. Specifically, the furnace cooling refers to cooling the furnace to 280°C. 5) Perform low-pressure pulse vacuum heat treatment on the aluminum alloy casting obtained in step 4) to obtain vacuum heat-treated aluminum alloy casting; Specifically, the low-pressure pulsed vacuum heat treatment involves first evacuating the heat treatment furnace to a pressure of 5 × 10⁻⁶ at 450°C. -2 Pa, hold pressure for 3 minutes, then use argon as the refill gas to refill the heat treatment furnace to a pressure of 80 kPa, hold pressure for 8 minutes, complete one cycle, and repeat 3 cycles in total; 6) Perform solution treatment and aging treatment on the vacuum heat-treated aluminum alloy casting obtained in step 5) to obtain the controllable dissolution aluminum alloy downhole cementing and completion tool. Specifically, the solution treatment involves holding the aluminum alloy casting at 500℃ for 1.5 hours, then transferring it to a circulating cooling water at 20℃ for quenching, and finally air-cooling it to room temperature. Specifically, the aging process involves maintaining the temperature at 150℃ for 7 hours.
[0032] Example 3 A controllable dissolution aluminum alloy downhole cementing and completion tool 1) Weigh the high-purity metal or master alloy according to the following mass percentages: Mg 7.5%, Cu 2.5%, Ti 0.7%, Ga 2%, In 0.5%, Sn 1.3%, balance Al; 2) Mix the high-purity metals and intermediate alloys weighed in step 1), melt them at high temperature, and homogenize them by ultrasonic coupling to obtain an aluminum alloy melt; Specifically, the high-temperature melting process involves melting at 760°C for 30 minutes under argon protection. Specifically, the ultrasonic coupling homogenization involves maintaining a temperature of 760℃, controlling the stirring speed at 450r / min, the ultrasonic power at 300W, the ultrasonic frequency at 25kHz, and performing ultrasonic treatment for 25min. 3) Refine the aluminum alloy melt obtained in step 2), let it stand, and skim off the slag to obtain a pure aluminum alloy melt; Specifically, the refining process involves adding 0.2 wt.% of a sodium-free refining agent to the aluminum alloy melt and refining it by rotary jetting argon gas at 710°C while controlling the argon pressure at 0.2 MPa. 4) Pour the pure aluminum alloy melt obtained in step 3) into a mold, cool it in a furnace, and obtain an aluminum alloy casting; Specifically, the casting process involves: first, preheating the mold to 240°C, then controlling the casting temperature at 700°C under 0.05MPa, casting the pure aluminum alloy melt into the mold, and holding the pressure for 5 minutes. Specifically, the furnace cooling refers to cooling the furnace to 320°C. 5) Perform low-pressure pulse vacuum heat treatment on the aluminum alloy casting obtained in step 4) to obtain vacuum heat-treated aluminum alloy casting; Specifically, the low-pressure pulsed vacuum heat treatment involves first evacuating the heat treatment furnace to a pressure of 5 × 10⁻⁶ at 550°C. -2 Pa, hold pressure for 5 min, then use argon as the refill gas to refill the heat treatment furnace to a pressure of 100 kPa, hold pressure for 12 min, complete one cycle, and repeat 5 cycles in total; 6) Perform solution treatment and aging treatment on the vacuum heat-treated aluminum alloy casting obtained in step 5) to obtain the controllable dissolution aluminum alloy downhole cementing and completion tool. Specifically, the solution treatment involves holding the aluminum alloy casting at 520°C for 2.5 hours, then transferring it to a circulating cooling water at 20°C for quenching, and finally air-cooling it to room temperature. Specifically, the aging process involves maintaining the temperature at 170°C for 9 hours.
[0033] Comparative Example 1 An aluminum alloy downhole cementing and completion tool Same as Example 1, except that step 1) is: Weigh out the high-purity metal or master alloy according to the following mass percentages: Mg 6.5%, Cu 2%, Ti 0.6%, balance Al.
[0034] Comparative Example 2 An aluminum alloy downhole cementing and completion tool Same as Example 1, except that step 1) is: Weigh out the high-purity metal or master alloy according to the following mass percentages: Mg 6.5%, Cu 2%, Ti 0.6%, Ga 0.8%, In 0.2%, Sn 0.5%, balance Al.
[0035] Comparative Example 3 An aluminum alloy downhole cementing and completion tool Same as Example 1, except that step 1) is: Weigh out the high-purity metal or master alloy according to the following mass percentages: Mg 6.5%, Ti 0.6%, Ga 1.52%, In 0.4%, Sn 1%, balance Al.
[0036] Comparative Example 4 An aluminum alloy downhole cementing and completion tool Same as Example 1, except that step 1) is: Weigh out the high-purity metal or master alloy according to the following mass percentages: Mg 6.5%, Cu 2%, Ga 1.52%, In 0.4%, Sn 1%, balance Al.
[0037] Comparative Example 5 An aluminum alloy downhole cementing and completion tool Same as Example 1, except that step 2) is: Mix the high-purity metals and intermediate alloys weighed in step 1), and melt them at high temperature to obtain an aluminum alloy melt; Specifically, the high-temperature melting process involves melting at 740°C for 25 minutes under argon protection.
[0038] Comparative Example 6 An aluminum alloy downhole cementing and completion tool Same as Example 1, except that step 5) is: The aluminum alloy casting obtained in step 4) is subjected to constant temperature vacuum heat treatment to obtain vacuum heat-treated aluminum alloy casting. Specifically, the constant temperature vacuum heat treatment involves heating at 500℃ for 5 × 10⁻⁶ hours. -2 Keep warm at Pa for 70 minutes.
[0039] Comparative Example 7 An aluminum alloy downhole cementing and completion tool Same as Example 1, except that step 5) is: The aluminum alloy casting obtained in step 4) is subjected to isothermal and atmospheric pressure heat treatment to obtain atmospheric pressure heat-treated aluminum alloy casting. Specifically, the constant temperature and normal pressure heat treatment is performed at 500℃ and 90kPa for 70 minutes.
[0040] Effect verification I. Mechanical Properties The mechanical properties of the aluminum alloy downhole cementing and completion tools prepared in Examples 1-3 and Comparative Examples 1-7 were tested, and the results of the mechanical property tests are shown in Table 1. Table 1 Mechanical property test results
[0041] As shown in Table 1, the aluminum alloy downhole cementing and completion tool with controllable dissolution provided by the present invention has a room temperature tensile strength of up to 332 MPa, a high temperature tensile strength of up to 302 MPa at 120℃, a Vickers hardness of up to 116, and a compressive strength of up to 685 MPa, exhibiting excellent mechanical properties.
[0042] II. Controllable solubility The controlled dissolution performance of the aluminum alloy downhole cementing and completion tools prepared in Examples 1-3 and Comparative Examples 1-7 was tested. The results of the controlled dissolution performance test are shown in Tables 2 and 3. Table 2. Test results of controllable solubility of oily cement slurry at 90℃
[0043] Table 3. Test results of controllable solubility in water at 90℃
[0044] As shown in Tables 2 and 3, the aluminum alloy downhole cementing and completion tool with controllable dissolution provided by this invention has a mass loss rate of only 3.7% in 90°C oily cement slurry medium after 72 hours and can be completely dissolved in 161 hours. In 90°C clean water medium, the mass loss rate is only 4.9% in 72 hours and can be completely dissolved in 130 hours, demonstrating good controllable dissolution performance.
[0045] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.
Claims
1. A controllable dissolution aluminum alloy downhole cementing and completion tool, characterized in that, It consists of the following elements by mass percentage: Mg 5.5%–7.5%, Cu 1.5%–2.5%, Ti 0.4%–0.7%, Ga 1%–2%, In 0.3%–0.5%, Sn 0.7%–1.3%, balance Al.
2. A method for preparing a controllable dissolution aluminum alloy downhole cementing and completion tool as described in claim 1, characterized in that, Includes the following steps: 1) Weigh out the high-purity metal or intermediate alloy according to the element mass percentage; 2) Mix the high-purity metals and intermediate alloys weighed in step 1), melt them at high temperature, and homogenize them by ultrasonic coupling to obtain an aluminum alloy melt; 3) Refine the aluminum alloy melt obtained in step 2), let it stand, and skim off the slag to obtain a pure aluminum alloy melt; 4) Pour the pure aluminum alloy melt obtained in step 3) into a mold, cool it in a furnace, and obtain an aluminum alloy casting; 5) Perform low-pressure pulse vacuum heat treatment on the aluminum alloy casting obtained in step 4) to obtain vacuum heat-treated aluminum alloy casting; 6) Perform solution treatment and aging treatment on the vacuum heat-treated aluminum alloy casting obtained in step 5) to obtain the controllable dissolution aluminum alloy downhole cementing and completion tool.
3. The method for preparing the controllable dissolution aluminum alloy downhole cementing and completion tool according to claim 2, characterized in that, In step 2), the high-temperature melting specifically refers to melting at 720-760°C for 20-30 minutes under argon protection.
4. The method for preparing the controllable dissolution aluminum alloy downhole cementing and completion tool according to claim 2, characterized in that, In step 2), the ultrasonic coupling homogenization specifically involves maintaining the temperature at 720–760°C, controlling the stirring speed at 350–450 r / min, the ultrasonic power at 200–300 W, the ultrasonic frequency at 20–25 kHz, and performing ultrasonic treatment for 15–25 min.
5. The method for preparing the controllable dissolution aluminum alloy downhole cementing and completion tool according to claim 2, characterized in that, In step 3), the refining specifically involves adding 0.2 wt.% of sodium-free refining agent to the aluminum alloy melt and refining it by rotating and blowing argon gas at 690–710°C while controlling the argon pressure at 0.2 MPa.
6. The method for preparing the controllable dissolution aluminum alloy downhole cementing and completion tool according to claim 2, characterized in that, In step 4), the casting process specifically involves: first, preheating the mold to 200-240°C, then controlling the casting temperature at 680-700°C under a pressure of 0.03-0.05 MPa, casting the pure aluminum alloy melt into the mold, and holding the pressure for 3-5 minutes.
7. The method for preparing the controllable dissolution aluminum alloy downhole cementing and completion tool according to claim 2, characterized in that, In step 4), the furnace cooling specifically refers to cooling the furnace to 280-320°C.
8. The method for preparing the controllable dissolution aluminum alloy downhole cementing and completion tool according to claim 2, characterized in that, In step 5), the low-pressure pulsed vacuum heat treatment specifically involves: first, at 450℃~550℃, evacuating the heat treatment furnace to a pressure of 5×10⁻⁶. -2 Hold the pressure at 80-100 kPa for 3-5 minutes, then use argon as the refill gas to refill the heat treatment furnace to a pressure of 80-100 kPa, hold the pressure for 8-12 minutes, and complete one cycle. Repeat this cycle 3-5 times in total.
9. The method for preparing the controllable dissolution aluminum alloy downhole cementing and completion tool according to claim 2, characterized in that, Further, in step 6), the solution treatment specifically involves: holding the aluminum alloy casting at 500℃~520℃ for 1.5~2.5h, then transferring the casting to quench it in circulating cooling water at 20℃, and air-cooling it to room temperature.
10. The method for preparing the controllable dissolution aluminum alloy downhole cementing and completion tool according to claim 2, characterized in that, Further, in step 6), the aging process specifically involves maintaining the temperature at 150℃~170℃ for 7~9 hours.