CN104178663B - For preparing aluminum-based alloy material of disintegrate pressure break ball and preparation method thereof - Google Patents

Abstract

The invention discloses an aluminum-based alloy material for preparing disintegrating fracturing balls and a preparation method thereof. The alloy is composed of 70wt.% to 96wt.% of Al, 1wt.% to 15wt.% of low melting point metal and 1wt. %～20wt.% element composition of strengthened Al alloy; low melting point metals are Ga, In, Sn and Bi, among which Ga is an essential element in the alloy, and the alloy can be added with one of other low melting point metals In, Sn and Bi or more; the element strengthening the Al alloy is one or more of Ti, Cu, Fe, Mg, Zn, Mn, Si. The best combination of low melting point metals is Ga, In and Sn, and the weight ratio is: Ga:In:Sn=(1~90):(0.1~60):(0.1~60). The alloy mainly contains two phases of Al solid solution and In3Sn. The fracturing ball prepared by the alloy of the invention has sufficient strength and can decompose by itself in the high-temperature and high-pressure water environment. Its price is low, pollution-free, and the preparation process is simple, which can effectively avoid the problems encountered by ordinary steel balls in engineering use.

Description

Aluminum-based alloy material for preparing disintegrating fracturing balls and preparation method thereof

technical field

The invention belongs to the fields of aluminum alloy material preparation and oil exploitation, and in particular provides an aluminum-based alloy material for preparing disintegrating fracturing balls and a preparation method thereof. The disintegrating fracturing balls involved are mainly used for pressure-guiding sandblasting of oil drilling The seal of the packer is used to separately fracture multiple formations where oil and gas are located to increase the single well productivity of oil.

Background technique

Since most of the oil is distributed in different formations, using multi-layer fracturing technology to exploit oil in multiple formations at the same time can not only increase the production capacity of a single well of oil, but also effectively prevent oil layer pollution, reduce operation and construction time, and reduce costs ^{[ 1, 2]} . Therefore, multi-layer fracturing technology is of great significance to the development of oil and gas fields, and is widely used in oil and gas exploitation at home and abroad. The basic technological process of multi-layer fracturing technology is as follows: firstly, the construction string of multi-layer fracturing is lowered, ordinary low-density steel balls are thrown, and when the balls fall to the setting ball seat, the packer is pressurized and set. Check the seal of the packer, and inject fracturing fluid through the oil pipe to construct the working layer after the seal inspection. After the construction of the first layer is completed, steel balls are thrown to open the sandblasting sliding sleeve of the second layer. After the sandblasting sliding sleeve core and steel balls fall on the ball seat to seal the packer, the fracturing fluid is then injected to Construction is carried out on the penultimate working layer. According to this method, it is constructed layer by layer, and finally the tubing is opened to implement mixed layer drainage. During the liquid flowback process, it is difficult for ordinary low-density steel balls to be taken out of the oil pipe by the liquid, which has a certain impact on oil production. Therefore, the project has certain restrictions on the density of steel balls, generally less than 2.4gcm ^-3 . If the steel ball is stuck on the setting ball seat during construction, it will waste a lot of time to take it out, increasing the construction cost. If the fracturing ball can be decomposed by itself, it will undoubtedly solve the problems caused by ordinary low-density steel balls. Currently the frac balls that can achieve this purpose are mainly made of organic materials ^[3] . Since the water pressure in the tubing is close to 60MPa and the temperature can reach 170°C during fracturing, in order to increase the strength of the fracturing ball, some people make the fracturing ball into a composite material composed of organic materials and fibers. Since the composite fracturing ball can only be decomposed in a special corrosive solution, the price of the fracturing ball and the related corrosive solution is very high, which significantly increases the construction cost.

references:

[1]. Zhang Wei, Zhang Huali, Li Shengfang, Zhou Jidong, Research and Application of Mechanical Layered Fracturing Technology in Jiangsu Oilfield, Drilling and Production Technology, Vol. 3l, No. 2, p. 48.

[2]. Diao Su, Zhu Liping, Huang Yuzhong, Liu Lin, Wang Xingwen, Yu Yi, Application of Layered Fracturing Technology with Non-moving Strings in Low Permeability Gas Fields, Natural Gas Technology and Economics, 2011, Vol. 5, No. 2 Issue, 34 pages.

[3].M.H.Naedler,P.L.Prosser,T.A.Goedrich,W.J.Costello,Patent,Disintegrating Ball For Sealing Frac Plug Seat,Pub.No.:US2012/0181032A1.

Contents of the invention

In order to overcome the disadvantages that ordinary low-density steel balls cannot be decomposed by themselves and organic composite fracturing balls are expensive, the invention provides an aluminum-based alloy material for preparing disintegrating fracturing balls and a preparation method thereof. The aluminum-based alloy can react with water, and the produced fracturing balls can be decomposed in water without a special corrosive solution, effectively avoiding the problems encountered by ordinary low-density steel balls in engineering use, while reducing construction costs and Improve oil production efficiency.

The present invention specifically provides an aluminum-based alloy for preparing disintegrating fracturing balls, which is characterized in that: the alloy consists of 70wt.% to 96wt.% of Al, 1wt.% to 15wt.% of low-melting point metals and 1wt.% .%～20wt.% element composition of strengthened Al alloy;

The low-melting point metals are Ga, In, Sn and Bi, among which Ga is an essential element in the alloy, and the alloy can be added with one or more of other low-melting point metals In, Sn and Bi; the elements to strengthen the Al alloy are Ti, Cu , Fe, Mg, Zn, Mn, Si one or more.

In the technical solution provided by the present invention, the low melting point metal is added to prevent the formation of an oxide film on the surface of Al crystal grains and ensure the continuous reaction between Al and water. The purpose of adding strengthening metal elements is to solid-solution strengthen the Al alloy and improve the fracture strength of the alloy. Adjusting the content of low-melting point metals and strengthening metals in the alloy can control the reaction speed of Al and water to meet the construction requirements of different working conditions.

The aluminum-based alloy used to prepare disintegrating fracturing balls according to the present invention is characterized in that: the most preferred combination of the low melting point metals is Ga, In and Sn, and its weight ratio is: Ga:In:Sn=(1～ 90): (0.1-60): (0.1-30), preferably Ga:In:Sn=(50-90): (30-60): (20-40).

The aluminum-based alloy used to prepare disintegrating fracturing balls according to the present invention is characterized in that: the composition ratio of the aluminum-based alloy is preferably the weight ratio Al:Ga:In:Sn:Mg:Si:Zn=(75～ 94):(2～8):(1～4):(1～4):(1～10):(0.1～0.5):(0.1～0.5).

The aluminum-based alloy for preparing disintegrating fracturing balls according to the present invention is characterized in that: the aluminum-based alloy mainly includes two phases of Al solid solution and In ₃ Sn.

The present invention also provides the preparation method of the aluminum-based alloy used to prepare the disintegrating fracturing ball, which is characterized in that it includes the following steps:

(a) Preparation of master alloy Al _x R _1-x : Weigh the alloy according to the alloy composition, where x=20wt.%～70wt.%, R is a low melting point metal; the alloy is melted in a vacuum induction furnace, and the induction furnace is vacuum The melting temperature is 1×10 ^-3 ~4×10 ^-3 Pa, the melting temperature is 750~900°C, and the melting time is not less than 30 minutes each time; the liquid alloy is stirred by electromagnetic stirring technology during the melting process, and the alloy is melted for 10 minutes. After ~30 minutes, under the protective atmosphere of inert gas, the liquid alloy is cast into a water-cooled copper mold to solidify;

(b) Preparation of multi-element Al alloys: Weigh the prepared master alloy, Al and Al-strengthening alloying elements according to the alloy composition. The melting time is not less than 30 minutes. Before melting, the surface of the alloy is covered with a salt covering agent (preferably NaCl or KCl). After the alloy is completely melted for 10 to 30 minutes, the liquid alloy is cast into a water-cooled copper mold to solidify.

The aluminum-based alloy described in the present invention can be used to prepare disintegrating fracturing balls, which have sufficient strength and can decompose by themselves in high-temperature and high-pressure water environments. After the fracturing operation of a certain formation is completed, the ball shatters and decomposes into powder, which loses its sealing effect, thus facilitating the continuation of the project.

The aluminum-based alloy provided by the invention has low price, no pollution, and simple preparation process, and the fracturing ball made of the alloy can effectively avoid the problems encountered by ordinary steel balls in engineering use.

Description of drawings

Figure 1 shows the aluminum water reaction curves of rich aluminum alloys Al _92.5 (Ga _3.6 In _1.8 Sn _0.6 ) ₆ Zn _1.5 and Al _87.8 (Ga _3.6 In _1.8 Sn _0.6 ) ₆ Zn ₆ Si _0.2 at a water temperature of 50°C;

Fig. 2 Aluminum water reaction curves of rich aluminum alloys Al _85.5 (Ga ₃ In ₃ Sn ₂ ) ₈ Mg ₆ Cu _0.5 and Al ₈₄ (Ga ₃ In ₃ Sn ₂ ) ₈ Mg ₇ Cu ₁ at a water temperature of 50°C.

detailed description

Example 1

Accurately weigh each metal according to the mass ratio of the alloy Al ₄₀ (Ga ₃₆ In ₁₈ Sn ₆ ) ₆₀ , use a 25 kg vacuum induction furnace to melt the alloy, the vacuum degree is 4×10 ^-3 Pa, the melting temperature is 800°C, each melting The time is 30 minutes. Stir the liquid alloy for 10 minutes using electromagnetic stirring technique. Under an argon protective atmosphere, the liquid alloy is cast into a water-cooled copper mold to solidify. The alloy is prepared according to the mass ratio of the alloy Al _92.5 (Ga _3.6 In _1.8 Sn _0.6 ) ₆ Zn _1.5 , the alloy is smelted in a normal pressure resistance furnace, and the surface of the alloy is covered with a covering agent NaCl before smelting. The smelting temperature is 750° C., and the smelting time is 30 minutes each time. After 10 minutes of complete melting of the alloy, the liquid alloy was cast into a water-cooled copper mold.

Measure the reaction rate of the alloy and water by the drainage method: Weigh 0.5g of the alloy sample, put it into tap water with a water temperature of 50°C for reaction, control the water temperature with a water bath, and measure the volume of hydrogen gas generated (see Figure 1 for test results). Because hydrogen is the result of the reaction of Al-water, in order to compare the speed of the reaction between the alloy and water, the measurement results were converted into the hydrogen volume per unit weight and time under normal pressure at 20°C, that is, the hydrogen production rate of the alloy. The results are shown in the table 1.

Yield strength at room temperature: Cut a cuboid sample with a size of 20mm×20×mm30mm for testing the mechanical properties of the alloy. The room temperature yield strength of the alloy was measured with a mechanical testing machine (Table 1).

Example 2

Repeat the process of Example 1, first accurately weigh each metal to prepare an intermediate alloy according to the mass ratio of the alloy Al ₄₀ (Ga ₃₆ In ₁₈ Sn ₆ ) ₆₀ , then weigh Al ₈₀ Si ₂₀ alloy to prepare Al _87.8 (Ga _3.6 In _1.8 Sn _0.6 ) ₆ Zn ₆ Si _0.2 alloy. Measure the reaction speed of the alloy and water at a water temperature of 50°C (Figure-1) and the yield strength of the alloy (see Table 1). Compared with the alloy in Example 1, the reaction speed of this alloy is slower, but the yield strength is significantly increased.

Example 3

Repeat the process of Example 1, first accurately weigh each metal to prepare an intermediate alloy according to the mass ratio of the alloy Al ₄₀ (Ga ₃₆ In ₁₈ Sn ₆ ) ₆₀ , then weigh Al ₈₀ Si ₂₀ alloy to prepare Al ₈₅ (Ga _3.6 In _1.8 Sn _0.6 ) ₆ Zn ₈ Si ₁ alloy. Measure the reaction speed of the alloy and water and the yield strength of the alloy when the water temperature is 50°C (see Table 1). As the content of strengthening alloying elements increases, the reaction speed of the alloy and water further slows down, and the yield strength also increases to a certain extent.

Example 4

Accurately weigh each metal according to the mass ratio of the alloy Al ₃₀ (Ga ₃₀ In ₃₀ Sn ₂₀ ) ₇₀ , use a 25Kg vacuum induction furnace to melt the alloy, the vacuum degree is 1×10 ^-3 Pa, the melting temperature is 900°C, and each melting time for 30 minutes. Stir the liquid alloy for ten minutes using electromagnetic stirring technology. Under an argon protective atmosphere, the liquid alloy is cast into a water-cooled copper mold to solidify. The alloy is formulated according to the mass ratio of the alloy Al _85.5 (Ga ₃ In ₃ Sn ₂ ) ₈ Mg ₆ Cu _0.5 , where Cu is added through the intermediate alloy Al ₉₀ Cu ₁₀ . The alloy is smelted in a normal-voltage resistance furnace, and the surface of the alloy is covered with a covering agent NaCl before smelting. The smelting temperature is 800° C., and the smelting time is 30 minutes each time. After the alloy was completely melted for 10 minutes, the liquid alloy was cast into a water-cooled copper mold for solidification, and an Al _85.5 (Ga ₃ In ₃ Sn ₂ ) ₈ Mg ₆ Cu _0.5 alloy was prepared. Measure the reaction speed of the alloy and water when the water temperature is 50°C (Figure-2) and the yield strength of the alloy (see Table 1). The alloy reacts slowly with water and has a high yield strength.

Example 5

Repeat the process of Example 4, first accurately weigh each metal according to the mass ratio of the alloy Al ₆₀ (Ga ₁₅ In ₁₅ Sn ₁₀ ) ₄₀ to prepare an intermediate alloy, and then prepare Al ₈₄ (Ga ₃ In ₃ Sn ₂ ) ₈ Mg ₇ Cu ₁ alloy. The reaction rate (Figure-2) and yield strength of the alloy and water were measured when the water temperature was 50°C. The results are shown in Table 1. The reaction speed of the alloy and water slows down rapidly, and the yield strength also increases to a certain extent.

Example 6

Repeat the process of Example 1, first accurately weigh each metal according to the mass ratio of the alloy Al ₃₀ (Ga ₃₅ In ₂₁ Sn ₁₄ ) ₇₀ to prepare an intermediate alloy, and then prepare Al _81.5 (Ga ₅ In ₃ Sn ₂ ) ₁₀ Mg ₈ Si _0.3 Mn _0.2 alloy. The reaction speed and yield strength of the alloy and water were measured when the water temperature was 50°C. The results are shown in Table 1. The increase of low-melting point metal content in the alloy accelerates the reaction speed of the alloy and water, while the yield strength increases slightly.

Example 7

Repeat the process of Example 1, first accurately weigh each metal according to the mass ratio of the alloy Al ₆₀ (Ga ₂₀ In ₁₀ Sn ₅ Bi ₅ ) ₄₀ to prepare a master alloy, and then prepare Al _91.5 (Ga ₂ In ₁ Sn _0.5 Bi _0.5 ) ₄ Mg ₅ Zn ₂ Si _0.3 Fe _0.2 alloy. The reaction speed and yield strength of the alloy and water were measured when the water temperature was 50°C. The results are shown in Table 1. The content of low-melting point metals in the alloy is reduced and elements such as Si and Fe are added, the reaction speed of the alloy and water becomes slower, and the yield strength of the alloy is higher.

Example 8

Repeat the process of Example 1, first accurately weigh each metal according to the mass ratio of the alloy Al ₄₀ (Ga ₄₀ In ₁₀ Sn ₁₀ ) ₆₀ to prepare an intermediate alloy, and then prepare Al _90.5 (Ga ₂ In _0.5 Sn _0.5 ) ₃ Zn ₇ Fe _0.2 Ti _0.1 Si _0.2 alloy. The reaction speed and yield strength of the alloy and water were measured when the water temperature was 50°C. The results are shown in Table 1. The reduction of low-melting-point metal content in the alloy and the addition of Si, Ti, Fe and other elements make the reaction speed of the alloy and water slower than that of the alloy in Example 7, while the yield strength is slightly reduced.

Example 9

Repeat the process of Example 1, first accurately weigh each metal according to the mass ratio of the alloy Al ₅₀ (Ga ₃₀ In ₁₀ Sn ₁₀ ) ₅₀ to prepare an intermediate alloy, and then prepare Al _91.5 (Ga ₃ In ₁ Sn ₁ ) ₅ Mg ₄ Zn ₁ Si _0.3 Fe _0.2 Cu _0.1 . The reaction speed and yield strength of the alloy and water were measured when the water temperature was 50°C. The results are shown in Table 1. The reaction rate of the alloy with water is slightly faster than that of the alloy in Example 7, and the yield strength is slightly lower.

Comparative example 1

Repeat the process of Example 1 to prepare Al ₈₅ Zn ₁₅ alloy. The reaction speed of the alloy and water was measured when the water temperature was 50°C, and the results are shown in Table 1. Since Ga and In and Sn are not added, the alloy does not react with water.

Comparative example 2

Repeat the process of Example 1 to prepare Al ₈₅ In ₁₅ . The reaction speed of the alloy and water was measured when the water temperature was 50°C, and the results are shown in Table 1. Since Ga and Sn are not added, the alloy does not react with water.

Comparative example 3

Repeat the process of Example 1 to prepare an Al ₈₀ In ₁₀ Sn ₁₀ alloy. The reaction speed of the alloy and water was measured when the water temperature was 50°C, and the results are shown in Table 1. Since no Ga is added, the alloy does not react with water.

Comparative example 4

Repeat the process of Example 1 to prepare an Al ₇₅ In ₁₀ Bi ₁₀ alloy. The reaction speed of the alloy and water was measured when the water temperature was 50°C, and the results are shown in Table 1. Since no Ga is added, the alloy does not react with water.

Comparative example 5

Repeating the process of Example 1, first accurately weigh each metal according to the mass ratio of the alloy Al ₇₀ (Ga ₂₀ In ₅ Sn ₁₀ ) ₅ to prepare a master alloy, and then prepare an Al ₆₄ (Ga ₂₀ In ₅ Sn ₅ ) ₃₀ Zn ₆ alloy. The reaction speed and yield strength of the alloy and water were measured when the water temperature was 50°C. The results are shown in Table 1. Due to the high content of low melting point metals in the alloy, the reaction between the alloy and water is accelerated. However, the Al content is too low, and the yield strength of the alloy is low.

Comparative example 6

Repeat the process of Example 1, first accurately weigh each metal according to the mass ratio of the alloy Al ₈₀ (Ga ₁₀ In ₆ Sn ₄ ) ₂₀ to prepare an intermediate alloy, and then prepare Al ₉₇ (Ga ₁ In _0.6 Sn _0.4 ) ₂ Mg _0.9 Ti _0.1 alloy. The reaction speed and yield strength of the alloy and water were measured when the water temperature was 50°C. The results are shown in Table 1. Due to the low melting point metal content in the alloy, the reaction between the alloy and water becomes slower, and the yield strength of the alloy becomes higher.

The invention provides alloys with different hydrogen production rates and yield strengths, which can be made into fracturing balls according to the needs of different production conditions, so as to be widely applicable to actual production needs.

Table 1 alloy performance test results

The above-mentioned embodiments are only to illustrate the technical concept and characteristics of the present invention, and the purpose is to enable those skilled in the art to understand the content of the present invention and implement it accordingly, and not to limit the protection scope of the present invention. All equivalent changes or modifications made according to the spirit of the present invention shall fall within the protection scope of the present invention.

Claims (7)

1. An aluminum-based alloy for preparing disintegrating fracturing balls, characterized in that: the alloy consists of 70wt.% to 96wt.% of Al, 1wt.% to 15wt.% of low-melting metals and 1wt.% to 20wt.% elemental composition of strengthening Al alloy; The low-melting point metals are Ga, In and Sn, and the weight ratio is: Ga:In:Sn=(1~90):(0.1~60):(0.1~30); the elements to strengthen the Al alloy are Ti, Cu, Fe, One or more of Mg, Zn, Mn, Si. 2. The aluminum-based alloy for preparing disintegrating fracturing balls according to claim 1, wherein the weight ratio of Ga, In and Sn is: Ga:In:Sn=(50～90):(30～60 ): (20~30). 3. The aluminum-based alloy for preparing disintegrating fracturing balls according to claim 1, characterized in that: the composition ratio of the aluminum-based alloy is the weight ratio Al:Ga:In:Sn:Mg:Si:Zn= (75～94):(2～8):(1～4):(1～4):(1～10):(0.1～0.5):(0.1～0.5). 4. The aluminum-based alloy for preparing disintegrating fracturing balls according to claim 1, wherein the aluminum-based alloy mainly comprises two phases of Al solid solution and In ₃ Sn. 5. A method for preparing an aluminum-based alloy for disintegrating fracturing balls as claimed in claim 1, comprising the following steps: (a) Preparation of master alloy Al _x R _1-x : Weigh the alloy according to the alloy composition, where x=20wt.%～70wt.%, R is a low melting point metal; the alloy is melted in a vacuum induction furnace, and the induction furnace is vacuum The melting temperature is 1×10 ^-3 ~4×10 ^-3 Pa, the melting temperature is 750~900°C, and the melting time is not less than 30 minutes each time; the liquid alloy is stirred by electromagnetic stirring technology during the melting process, and the alloy is melted for 10 minutes. After ~30 minutes, under the protective atmosphere of inert gas, the liquid alloy is cast into a water-cooled copper mold to solidify; (b) Preparation of multi-element Al alloy: Weigh the prepared master alloy, Al and Al-strengthening alloy elements according to the alloy composition. The melting time is not less than 30 minutes. Before melting, the surface of the alloy is covered with a salt covering agent. After the alloy is completely melted for 10 to 30 minutes, the liquid alloy is cast into a water-cooled copper mold to solidify. 6. The method for preparing an aluminum-based alloy for disintegrating fracturing balls according to claim 5, wherein the salt covering agent is NaCl or KCl. 7. A fracturing ball made of an aluminum-based alloy for preparing a disintegrating fracturing ball as claimed in claim 1.