Ga-containing sealed copper alloy, and preparation method and application thereof
By preparing a Ga-containing copper alloy, the problem of insufficient sealing performance of existing sealing materials under high temperature and high pressure environments has been solved, achieving a highly efficient sealing effect in oil drilling.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- CHINA NAT PETROLEUM CORP
- Filing Date
- 2022-09-08
- Publication Date
- 2026-07-03
AI Technical Summary
Existing rubber sealing materials cannot effectively seal in high-temperature environments, and metal sealing materials such as Ag and In alloys are not strong enough, while Cu alloys have insufficient sealing performance, which cannot meet the high-temperature and high-pressure requirements of deep well drilling.
It is made of Ga-containing copper alloy and prepared by vacuum centrifugal casting. The addition of Ga element improves the sealing performance and ensures that the alloy maintains good strength and toughness at 300℃, making it suitable for oil drilling seals.
The prepared Ga-containing copper alloy exhibits high tensile strength and low leakage rate at 300℃, meeting the long-term sealing performance requirements of downhole seals and solving the sealing problem under high temperature and high pressure environments.
Smart Images
Figure CN117701938B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of sealing materials technology, specifically relating to a Ga-containing sealing copper alloy, its preparation method, and its application. Background Technology
[0002] In the oil drilling industry, deep well casing typically requires leak repair within a certain range depending on the specific downhole conditions. A common repair method is using expansion tubing, where a rubber seal is applied between the expansion tubing and the original casing. Rubber seals are widely used in drilling due to their advantages such as good sealing performance, low expansion pressure, ease of operation, and high reliability. However, the maximum operating temperature of rubber materials is limited to ≤140℃ due to their heat resistance. With the continuous development of deep well drilling technology and the increasing drilling depth, the operating temperature that expansion tubing needs to withstand has reached 300℃, rendering existing rubber sealing materials unusable. Furthermore, the increasing design life (≥20 years) of deep well expansion tubing significantly exceeds the limits of existing rubber sealing materials.
[0003] Metal sealing materials, with their high operating temperature and long service life, are the most promising sealing materials to meet the above requirements. Currently available metal sealing materials include Cu, Ag, In, stainless steel, and high-temperature alloys. Among them, Ag and In alloys are relatively soft and have good sealing performance, but their strength is insufficient, their operating temperature is relatively low, and their cost is relatively high. Stainless steel and high-temperature alloys have higher operating temperatures and can meet high-temperature sealing requirements, but due to their hardness, their expansion pressure is relatively high, their sealing interference is small, and their sealing performance is relatively poor.
[0004] Copper alloys possess a certain strength and good plasticity and toughness, and are often used to make sealing gaskets. However, current copper alloy gaskets also have the following disadvantages: First, their plasticity and viscosity are insufficient, and their sealing performance is not as good as Ag and In alloys; second, the sealing temperature of current copper alloys is relatively low, below 300℃. Summary of the Invention
[0005] To address the aforementioned technical problems, the present invention aims to provide a Ga-containing sealing copper alloy, its preparation method, and its application. This Ga-containing sealing copper alloy has a sealing temperature of up to 300°C and superior sealing performance compared to existing copper gasket materials, thus meeting the requirements of downhole sealing components.
[0006] To achieve the above objectives, the present invention provides a Ga-containing sealing copper alloy, the composition of which, by mass percentage, comprises: Ga 3.0-12.0 wt%, Ag 0.04-0.09 wt%, Ni 0.6-4.7 wt%, and the balance being Cu.
[0007] This invention, while retaining the good strength and toughness of copper alloys, enhances the sealing performance of the alloy by adding Ga, developing a sealing copper alloy with a sealing temperature of up to 300℃ that can meet the requirements of downhole sealing components. This ensures the long-term sealing performance of sealing elements under high temperature and high pressure environments, solving the problem that rubber sealing element materials such as hangers and packers are prone to failure and aging, making it difficult to maintain good sealing performance in high temperature, high pressure and corrosive media environments in deep and ultra-deep wells.
[0008] The present invention also provides a method for preparing the above-mentioned Ga-containing sealing copper alloy, which includes the following steps:
[0009] The Ga, Ag, Ni and Cu metal raw materials were cleaned and weighed separately. All the metal raw materials were placed in a vacuum centrifugal casting furnace and induction melting and centrifugal casting were carried out in a vacuum environment to obtain the Ga-containing sealed copper alloy.
[0010] The present invention employs vacuum centrifugal casting, which enables the alloy material to have higher purity and more uniform composition, thereby giving the Ga-containing sealing copper alloy better mechanical properties and good deformation ability.
[0011] In the above-mentioned method for preparing Ga-containing sealed copper alloy, preferably, the melting temperature during induction melting is 1300-1500℃ and the melting time is 0.5-1h.
[0012] In the above-mentioned method for preparing Ga-containing sealed copper alloy, preferably, the heating rate to the melting temperature is 20-50℃ / s.
[0013] In the above-mentioned method for preparing Ga-containing sealed copper alloy, preferably, the vacuum degree during induction melting is 1×10⁻⁶. -1 -5×10 -3 Pa.
[0014] In the above-mentioned method for preparing Ga-containing sealed copper alloy, preferably, the centrifugal speed during centrifugal casting is 400-500 r / min.
[0015] In the above-mentioned method for preparing Ga-containing sealed copper alloy, preferably, the vacuum degree during centrifugal casting is 1×10⁻⁶. -1 -5×10 -3 Pa.
[0016] In the above-mentioned method for preparing Ga-containing sealed copper alloy, preferably, when the metal raw material is placed, Ga is located on the top layer of the metal raw material. Placing Ga on the top layer of the metal raw material can prevent Ga from adhering to the bottom and causing uneven melting.
[0017] In the above-mentioned method for preparing Ga-containing sealed copper alloy, preferably, the purity specifications of the metal raw materials are: Cu purity ≥ 99.95 wt%, Ga purity ≥ 99.99 wt%, Ag purity ≥ 99.9 wt%, and Ni purity ≥ 99.99 wt%.
[0018] In the above-mentioned method for preparing Ga-containing sealed copper alloy, preferably, the pretreatment of the metal raw materials includes steps such as cleaning, ultrasonication, and drying to remove impurities from the surface of the metal raw materials.
[0019] The above-mentioned method for preparing Ga-containing sealed copper alloy preferably includes the following steps:
[0020] (1) Selection of metal raw materials: ≥99.95wt% Cu, ≥99.99wt% Ga, ≥99.99wt% Ni, ≥99.9wt% Ag;
[0021] (2) Pretreatment and weighing of metal raw materials: Cut Cu blocks into 2-3 cm pieces, weigh the required weight, and then pickle them in a 5% dilute sulfuric acid solution. After pickling, the Cu blocks are ultrasonically cleaned with alcohol 3-4 times, dried, and sealed for storage. Similarly, weigh the Ni and Ag blocks separately, pickle them, ultrasonically clean them with alcohol, and then dry and seal for storage. The weighing of Ga is as follows: Place the Ga block in a plastic cup, then place the plastic cup in hot water to melt the Ga (melting in hot water). Use a dropper to draw the Ga and drop it into a petri dish to weigh the required weight. After weighing, place the dish in a freezer to solidify. Finally, weigh and batch the materials according to the mass fraction range of each alloying element.
[0022] (3) Alloy Vacuum Melting and Casting: The prepared metal raw materials are placed in a graphite crucible and then placed in a vacuum centrifugal casting furnace for vacuum induction melting, with the Ga block placed on top; the vacuum centrifugal casting furnace is evacuated, and when the vacuum degree reaches the required level, heating is started at a heating rate of 20-50℃ / s, heated to a temperature range of 1300-1500℃, and held for 0.5-1 hour for vacuum induction melting; after melting, casting is carried out by centrifugal casting, and the vacuum degree used in centrifugal casting is 1×10 -1 Pa-5×10 -3 Pa, centrifuge rotation speed of 400-500 r / min, followed by furnace cooling to room temperature, to obtain the Ga-containing sealing copper alloy.
[0023] The present invention also provides the application of the above-mentioned Ga-containing sealing copper alloy or the Ga-containing sealing copper alloy obtained by the above preparation method in oil drilling seals.
[0024] In the above applications, preferably, the Ga-containing sealing copper alloy is used as a sealing gasket.
[0025] In the above applications, preferably, the Ga-containing sealing copper alloy is used in a temperature environment of 25-300°C, more preferably in a temperature environment of 300°C.
[0026] The technical solution provided by this invention has the following beneficial effects:
[0027] The Ga-containing sealing copper alloy of the present invention retains the good strength and toughness of copper alloy, and enhances the sealing performance of the alloy by adding Ga element. The sealing temperature can reach 300°C, which can meet the sealing copper alloy requirements of downhole sealing components, thereby ensuring the long-term sealing performance of sealing elements under high temperature and high pressure environments. Attached Figure Description
[0028] Figure 1 This is a schematic diagram of the structure of the vacuum centrifugal casting furnace used in this invention;
[0029] Figure 2 The image shows the metallographic structure of the Ga-containing sealing copper alloy from Example 1.
[0030] Figure 3 This is a scanning electron microscope image of the Ga-containing sealed copper alloy of Example 1. Detailed Implementation
[0031] In order to provide a clearer understanding of the technical features, objectives and beneficial effects of the present invention, the technical solution of the present invention will now be described in detail below, but it should not be construed as limiting the scope of implementation of the present invention.
[0032] A schematic diagram of the vacuum centrifugal casting furnace used in this embodiment of the invention is shown below. Figure 1 As shown.
[0033] The purity specifications of the metal raw materials used in the embodiments of the present invention are as follows: Cu purity ≥ 99.95 wt%, Ga purity ≥ 99.99 wt%, Ag purity ≥ 99.9 wt%, and Ni purity ≥ 99.99 wt%.
[0034] In this embodiment of the invention, the tensile strength of the Ga-containing sealing copper alloy was tested using the high-temperature tensile test method for metallic materials specified in GB / T 4338-2006, and the sealing performance of the Ga-containing sealing copper alloy was tested using the leakage rate determination method for rubber and plastic hoses and hose assemblies specified in ISO 4080-2009.
[0035] Example 1
[0036] This embodiment provides a Ga-containing sealed copper alloy ingot with a total weight of 200g, which is composed of the following alloy composition by mass percentage: 3.0 wt.% Ga, 0.04 wt.% Ag, 0.6 wt.% Ni, and the remainder Cu.
[0037] The preparation method of the Ga-containing sealed copper alloy ingot in this embodiment is as follows:
[0038] Cut the Cu block into 2-3 cm pieces, weigh 192.72 g, then acid-wash it in a 5% dilute sulfuric acid solution. After acid washing, ultrasonically clean the Cu block with alcohol 3-4 times and then seal it for storage. Similarly, weigh 1.2 g of Ni block and 0.08 g of Ag, acid-wash them, ultrasonically clean them with alcohol, and then seal them for storage. The Ga block is weighed as follows: place the Ga block in a plastic cup, then place the plastic cup in hot water to melt the Ga (melting in a hot water bath). Use a dropper to draw 6 g of the Ga block and drop it into a petri dish. After weighing, freeze the dish to solidify.
[0039] Then, the weighed raw materials were placed in a graphite crucible and then placed in a vacuum centrifugal casting furnace. Cu, Ni, and Ag blocks were uniformly mixed and placed at the bottom, while Ga blocks were placed on top of the raw materials for melting. The vacuum centrifugal casting furnace was then evacuated to a vacuum level of 1×10⁻⁶. -1 Pa was heated to 1400℃ at a heating rate of 20℃ / s and held at that temperature for 0.5 hours for vacuum induction melting. Then, the vacuum level was kept constant and the furnace was cooled to room temperature to complete centrifugal casting. During casting, the centrifuge rotation speed was 400r / min, and the final product was a Ga-containing sealed copper alloy ingot.
[0040] Testing revealed that the Ga-containing sealing copper alloy exhibited a tensile strength of 183 MPa at 300°C and a leakage rate ≤10% in a helium environment. -3 Pa·m 3 / s. The metallographic structure and scanning electron microscope images of the Ga-containing sealed copper alloy ingot in this embodiment are respectively... Figure 2 and Figure 3 As shown.
[0041] Example 2
[0042] A Ga-containing sealed copper alloy ingot, with a total weight of 200g, is composed of the following alloy composition by mass percentage: 6.0 wt.% Ga, 0.04 wt.% Ag, 0.6 wt.% Ni, and the remainder Cu.
[0043] The preparation method of the Ga-containing sealed copper alloy ingot in this embodiment is as follows:
[0044] Cut the Cu block into 2-3cm pieces, weigh 186.72g, then acid-wash it in a 5% dilute sulfuric acid solution. After acid washing, ultrasonically clean the Cu block with alcohol 3-4 times and then seal it for storage. Similarly, weigh 1.2g of Ni block and 0.08g of Ag, acid-wash them, ultrasonically clean them with alcohol, and then seal them for storage. The Ga block is weighed as follows: place the Ga block in a plastic cup, then place the plastic cup in hot water to melt the Ga (melting in a hot water bath). Use a dropper to draw out 12g of the Ga block and drop it into a petri dish. After weighing, freeze the dish to solidify.
[0045] Then, the weighed raw materials were placed in a graphite crucible and then placed in a vacuum centrifugal casting furnace. Cu, Ni, and Ag blocks were uniformly mixed and placed at the bottom, while Ga blocks were placed on top of the raw materials for melting. The vacuum centrifugal casting furnace was then evacuated to a vacuum level of 1×10⁻⁶. -1 Pa was heated to 1400℃ at a heating rate of 20℃ / s and held at that temperature for 0.5 hours for vacuum induction melting. Then, the vacuum level was kept constant and the furnace was cooled to room temperature to complete centrifugal casting. During casting, the centrifuge rotation speed was 400r / min, and the final product was a Ga-containing sealed copper alloy ingot.
[0046] Testing revealed that the Ga-containing sealing copper alloy exhibited a tensile strength of 168 MPa at 300°C and a leakage rate ≤10% in a helium environment. -3 Pa·m 3 / s.
[0047] Example 3
[0048] A Ga-containing sealed copper alloy ingot, with a total weight of 200g, is composed of the following alloy composition by mass percentage: 9 wt.% Ga, 0.04 wt.% Ag, 0.6 wt.% Ni, and the remainder Cu.
[0049] The preparation method of the Ga-containing sealed copper alloy ingot in this embodiment is as follows:
[0050] Cut the Cu block into 2-3 cm pieces, weigh 180.72 g, then acid-wash it in a 5% dilute sulfuric acid solution. After acid washing, ultrasonically clean the Cu block with alcohol 3-4 times and then seal it for storage. Similarly, weigh 1.2 g of Ni block and 0.08 g of Ag, acid-wash them, ultrasonically clean them with alcohol, and then seal them for storage. The Ga block is weighed as follows: place the Ga block in a plastic cup, then place the plastic cup in hot water to melt the Ga (melting in a hot water bath). Use a dropper to draw out 18 g of the Ga block and drop it into a petri dish. After weighing, freeze the dish to solidify.
[0051] Then, the weighed raw materials were placed in a graphite crucible and then placed in a vacuum centrifugal casting furnace. Cu, Ni, and Ag blocks were uniformly mixed and placed at the bottom, while Ga blocks were placed on top of the raw materials for melting. The vacuum centrifugal casting furnace was then evacuated to a vacuum level of 5 × 10⁻⁶. -3 Pa was heated to 1400℃ at a heating rate of 50℃ / s and held at that temperature for 0.5 hours for vacuum induction melting. Then, the vacuum level was kept constant and the furnace was cooled to room temperature to complete centrifugal casting. During casting, the centrifuge rotation speed was 400r / min, and the final product was a Ga-containing sealed copper alloy ingot.
[0052] Testing revealed that the Ga-containing sealing copper alloy exhibited a tensile strength of 155 MPa at 300°C and a leakage rate ≤10% in a helium environment. -3 Pa·m 3 / s.
[0053] Example 4
[0054] A Ga-containing sealed copper alloy ingot, with a total weight of 200g, is composed of the following alloy composition by mass percentage: 9wt.% Ga, 0.09wt.% Ag, 3.0wt.% Ni, and the remainder Cu.
[0055] The preparation method of the Ga-containing sealed copper alloy ingot in this embodiment is as follows:
[0056] Cut the Cu block into 2-3cm pieces, weigh 175.82g, then acid-wash it in a 5% dilute sulfuric acid solution. After acid washing, ultrasonically clean the Cu block with alcohol 3-4 times and then seal it for storage. Similarly, weigh 6g of Ni block and 0.18g of Ag, acid-wash them, ultrasonically clean them with alcohol, and then seal them for storage. The Ga block is weighed as follows: place the Ga block in a plastic cup, then place the plastic cup in hot water to melt the Ga (melting in a hot water bath). Use a dropper to draw out 18g of the Ga block and drop it into a petri dish. After weighing, freeze the dish to solidify.
[0057] The weighed raw materials were then placed in a graphite crucible and placed in a vacuum centrifugal casting furnace. Cu, Ni, and Ag blocks were evenly mixed and placed at the bottom layer, followed by Ga blocks on top for melting. The vacuum centrifugal casting furnace was then evacuated to a vacuum level of 5 × 10⁻⁶. -3 Pa was heated to 1450℃ at a heating rate of 50℃ / s and held at that temperature for 0.5 hours for vacuum induction melting. Then, the vacuum level was kept constant and the furnace was cooled to room temperature to complete centrifugal casting. During casting, the centrifuge rotation speed was 500r / min, and the final product was a Ga-containing sealed copper alloy ingot.
[0058] Testing revealed that the Ga-containing sealing copper alloy exhibited a tensile strength of 205 MPa at 300°C and a leakage rate ≤10% in a helium environment.-3 Pa·m 3 / s.
[0059] Example 5
[0060] A Ga-containing sealed copper alloy ingot, the total weight of which is 200g, is composed of the following alloy composition by mass percentage: 12wt.% Ga, 0.09wt.% Ag, 4.7wt.% Ni, and the remainder being Cu.
[0061] The preparation method of the Ga-containing sealed copper alloy ingot in this embodiment is as follows:
[0062] Cut the Cu block into 2-3 cm pieces, weigh 166.42 g, then acid-wash it in a 5% dilute sulfuric acid solution. After acid washing, ultrasonically clean the Cu block with alcohol 3-4 times and then seal it for storage. Similarly, weigh 9.4 g of Ni block and 0.18 g of Ag, acid-wash them, ultrasonically clean them with alcohol, and then seal them for storage. The Ga block is weighed as follows: place the Ga block in a plastic cup, then place the plastic cup in hot water to melt the Ga (melting in a hot water bath). Use a dropper to draw the Ga block and drop it into a petri dish, weighing 24 g. After weighing, freeze the dish to solidify.
[0063] Then, the weighed raw materials were placed in a graphite crucible and then placed in a vacuum centrifugal casting furnace. Cu, Ni, and Ag blocks were evenly mixed and placed at the bottom, while Ga blocks were placed on top of the raw materials for melting. The vacuum centrifugal casting furnace was then evacuated to a vacuum level of 5 × 10⁻⁶. -3 Pa was heated to 1450℃ at a heating rate of 20℃ / s and held at that temperature for 0.5 hours for vacuum induction melting. Then, the vacuum level was kept constant and the furnace was cooled to room temperature to complete centrifugal casting. During casting, the centrifuge rotation speed was 500r / min, and the final product was a Ga-containing sealed copper alloy ingot.
[0064] Testing revealed that the Ga-containing sealing copper alloy exhibited a tensile strength of 213 MPa at 300°C and a leakage rate ≤10% in a helium environment. -3 Pa·m 3 / s.
[0065] As can be seen from the above embodiments, the Ga sealing copper alloy prepared in the embodiments of the present invention has a tensile strength of not less than 150 MPa at a high temperature of 300℃, and a leakage rate of ≤10% in a helium environment. -3 Pa·m 3 / s. Under the same testing conditions, the tensile strength of pure copper at 300℃ is only 108 MPa, and the leakage rate of the Cu-Ni alloy prepared under the same conditions is 5×10⁻⁶ under the same helium atmosphere. -2 Pa·m 3 / s, in comparison, the Ga-containing sealing copper alloy of the present invention has higher tensile strength and better sealing performance.
[0066] In summary, the Ga-containing sealing copper alloy of the present invention maintains good toughness, strength and sealing properties even at a sealing temperature of 300°C, which can guarantee its long-term sealing performance as a sealing element under high temperature and high pressure environments.
Claims
1. A Ga-containing sealing copper alloy, comprising, by weight percentage: Ga 3.0-12.0wt%, Ag 0.04-0.09wt%; Ni 0.6-4.7wt%, balance Cu; The preparation method of the Ga-containing sealed copper alloy includes the following steps: pre-treating and weighing Ga, Ag, Ni and Cu metal raw materials respectively, placing all metal raw materials into a vacuum centrifugal casting furnace, and performing induction melting and centrifugal casting in a vacuum environment.
2. A method for preparing the Ga-containing sealing copper alloy according to claim 1, comprising the following steps: Ga, Ag, Ni and Cu metal raw materials are pretreated and weighed separately. All metal raw materials are placed in a vacuum centrifugal casting furnace and induction melting and centrifugal casting are carried out in a vacuum environment to obtain the Ga-containing sealed copper alloy.
3. The method for preparing the Ga-containing sealing copper alloy according to claim 2, wherein, The melting temperature during induction melting is 1300-1500℃, and the melting time is 0.5-1h.
4. The method for preparing the Ga-containing sealing copper alloy according to claim 3, wherein, The heating rate to the melting temperature is 20-50℃ / s.
5. The method for preparing the Ga-containing sealing copper alloy according to claim 2, wherein, The vacuum degree during induction melting is 1×10 -1 -5×10 -3 Pa.
6. The method for preparing the Ga-containing sealing copper alloy according to claim 2, wherein, The centrifugal speed during centrifugal casting is 400-500 r / min.
7. The method for preparing the Ga-containing sealing copper alloy according to claim 3, wherein, The vacuum degree during centrifugal casting is 1×10 -1 -5×10 -3 Pa.
8. The method for preparing the Ga-containing sealing copper alloy according to claim 2, wherein, When metal raw materials are placed, Ga is located on the top layer of the metal raw materials.
9. The method for preparing the Ga-containing sealing copper alloy according to claim 2, wherein, The purity specifications of the metal raw materials are as follows: Cu purity ≥ 99.95wt%, Ga purity ≥ 99.99wt%, Ag purity ≥ 99.9wt%, and Ni purity ≥ 99.99wt%.
10. The application of the Ga-containing sealing copper alloy of claim 1 or the Ga-containing sealing copper alloy obtained by the preparation method of any one of claims 2-9 in oil drilling seals.
11. The application according to claim 10, wherein, The Ga-containing sealing copper alloy is used as a sealing gasket.
12. The application according to claim 10, wherein, The Ga-containing sealing copper alloy is used in environments ranging from 25 to 300°C.
13. The application according to claim 12, wherein, The Ga-containing sealing copper alloy is used in an environment of 300°C.