Temporary plugging ball, ball throwing device and steam injection temporary plugging device and method

Abstract

The invention relates to a temporary plugging ball. The temporary plugging ball comprises a hollow alloy ball, the hollow alloy ball is made of magnesium-aluminum alloy, and the magnesium-aluminum alloy is prepared from the following components in percentage by mass: 2.5 to 3.5 percent of Al, 0.6 to 1.4 percent of Zn, 0.2 to 1 percent of Mn, 0 to 0.08 percent of Si, 0 to 0.01 percent of Cu, 0 to 0.001 percent of Ni, 0.2 to 2.00 percent of rare earth (gadolinium and yttrium) and the balance of Mg. The polytetrafluoroethylene coating is arranged on the surface of the hollow alloy ball, so that corrosive chemical substances can be effectively isolated, and the temperature resistance of the temporary plugging ball is improved.

Description

Technical Field

[0001] The present invention relates to the petroleum industry, and more particularly to a temporary plugging process. Background Art

[0002] Some oilfields, including Liaohe Oilfield, mainly use heavy oil steam huff and puff development as the main means to maintain stable production. As heavy oil enters the middle and late stages of development, affected by factors such as reservoir heterogeneity, the vertical production of the oil layer is uneven and the contradiction of steam channeling is prominent after multiple rounds of huff and puff. Heavy oil separation and injection is a key technology in steam huff and puff, and an effective means to solve the uneven vertical production of the oil layer. However, as heavy oil development deepens, affected by factors such as thermal stress and geostress, the deformation and damage of oil well casings are becoming more and more serious, with an annual casing loss rate of up to 4.7%, and the intact rate of oil well casings is only 32%. Due to poor wellbore integrity, the implementation of separation and injection technology is restricted, the contradiction of uneven oil layer production and steam channeling is aggravated, which seriously restricts the production capacity of oil wells. At present, conventional ball injection technology has been widely used in steam huff and puff, which has the advantages of simple process and low cost. However, the current temporary plugging ball temperature resistance is ≤150℃, which is not suitable for high temperature and high pressure conditions of heavy oil steam huff and puff. Summary of the invention

[0003] The embodiments of the present application provide a temporary blocking ball, a ball throwing device, a steam injection temporary blocking device and a method to solve the current technical problem of poor temperature resistance of temporary blocking balls.

[0004] In a first aspect, an embodiment of the present application provides a temporary blocking ball, the temporary blocking ball comprising:

[0005] Hollow alloy sphere;

[0006] A polytetrafluoroethylene coating is provided on the surface of the hollow alloy ball,

[0007] Wherein, the material of the hollow alloy ball is a magnesium-aluminum alloy, which is composed of the following components in terms of mass percentage of the magnesium-aluminum alloy: 2.5% to 3.5% Al, 0.6% to 1.4% Zn, 0.2% to 1% Mn, 0 to 0.08% Si, 0 to 0.01% Cu, 0 to 0.001% Ni, 0.2 to 2.00% rare earth elements, and the balance is Mg, wherein the rare earth element is selected from at least one of gadolinium and yttrium.

[0008] In some embodiments of the present application, the density of the temporary blocking ball is not greater than 1.0 g / cm 3 .

[0009] In some embodiments of the present application, the temporary blocking ball includes at least one of a small blocking ball and a large blocking ball, wherein the diameter of the small blocking ball is 8 to 12 mm, and the diameter of the large blocking ball is 20 to 22 mm.

[0010] In some embodiments of the present application, the wall thickness of the hollow alloy ball is 1 to 1.5 mm.

[0011] In some embodiments of the present application, the thickness of the polytetrafluoroethylene coating is 0.05 to 0.2 mm.

[0012] In some embodiments of the present application, the hollow alloy sphere includes two half hollow spheres.

[0013] The two semi-hollow balls are connected by welding to form the hollow alloy ball.

[0014] or,

[0015] The semi-hollow balls are connected by threaded connection to form the hollow alloy ball.

[0016] In some embodiments of the present application, the temporary blocking ball further includes polyurethane foam, and the polyurethane foam is filled inside the hollow alloy ball.

[0017] In a second aspect, an embodiment of the present application provides a ball pitching device, the ball pitching device comprising:

[0018] A ball pitching cylinder, wherein the cylinder wall of the ball pitching cylinder has a hollow interlayer, and a hot melt plate is arranged at the lower end of the hollow interlayer to isolate the hollow interlayer from the outside, and the melting temperature of the hot melt plate is 200-250°C;

[0019] The temporary blocking ball is the temporary blocking ball described in any embodiment of the first aspect, and the temporary blocking ball is stored in the hollow interlayer.

[0020] In some embodiments of the present application, the material of the hot melt plate is resin.

[0021] In a third aspect, an embodiment of the present application provides a steam injection temporary plugging device, the steam injection temporary plugging device comprising:

[0022] Steam injection pipeline;

[0023] a packer connected to the lower end of the steam injection pipeline;

[0024] A ball throwing device is arranged at the lower end of the steam injection pipeline, wherein the ball throwing device is the ball throwing device according to claim 7 or 8, and the ball throwing cylinder is connected to the steam injection pipeline.

[0025] In a fourth aspect, an embodiment of the present application provides a steam injection temporary plugging method, the steam injection temporary plugging method comprising the following steps:

[0026] Providing the steam injection temporary plugging device as described in any embodiment of the third aspect, installing the steam injection temporary plugging device in the casing of the oil well and lowering it to the high permeability layer;

[0027] Inject steam into the oil well casing through the steam injection pipeline to set the packer;

[0028] After the hot melt plate is melted, the temporary plugging ball moves with the steam flow and temporarily plugs the blasthole at the high permeability layer.

[0029] The above technical solution provided by the embodiment of the present application has the following advantages compared with the prior art:

[0030] The temporary plugging ball provided in the embodiment of the present application can effectively isolate corrosive chemicals and increase the temperature resistance of the temporary plugging ball by providing a polytetrafluoroethylene coating on the surface of the hollow alloy ball. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0032] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0033] Figure 1 A schematic diagram of the structure of a temporary blocking ball provided in an embodiment of the present application;

[0034] Figure 2 A schematic structural diagram of a steam injection temporary plugging device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0035] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0036] Unless otherwise specified, the terms used herein should be understood as commonly used in the art. Therefore, unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art to which this application belongs. In the event of a conflict, this specification takes precedence.

[0037] Unless otherwise specified, various raw materials, reagents, instruments and equipment used in this application can be purchased from the market or prepared by existing methods.

[0038] At present, temporary blocking balls have the technical problem of poor temperature resistance.

[0039] The technical solution provided by the embodiments of the present application is to solve the above technical problems, and the overall idea is as follows:

[0040] In the first aspect, the present application embodiment provides a temporary blocking ball 1, please refer to Figure 1 , the temporary blocking ball 1 comprises:

[0041] Hollow alloy ball 11;

[0042] The polytetrafluoroethylene coating 12 is provided on the surface of the hollow alloy ball 11.

[0043] Among them, the material of the hollow alloy ball 11 is a magnesium-aluminum alloy, which is composed of the following components in terms of mass percentage of the magnesium-aluminum alloy: 2.5% to 3.5% Al, 0.6% to 1.4% Zn, 0.2% to 1% Mn, 0 to 0.08% Si, 0 to 0.01% Cu, 0 to 0.001% Ni, 0.2 to 2.00% rare earth elements, and the balance is Mg, wherein the rare earth element is selected from at least one of gadolinium and yttrium.

[0044] The beneficial effect of using magnesium-aluminum alloy as the material of the hollow alloy ball 11 is that magnesium-aluminum alloy has good properties such as high strength, high toughness, and corrosion resistance.

[0045] In the magnesium-aluminum alloy, Zn has good corrosion resistance and can effectively slow down metal oxidation corrosion. The function of Mn is to increase the strength of the hollow alloy ball 11. Si, Cu, and Ni are inevitable impurities, and the lower their content, the better.

[0046] Temporary plugging ball 1 is used in oil layer. The chemical environment in oil layer is generally complex, and there are often ions such as sulfur ions and chloride ions that are corrosive to metals, as well as some organic compounds that are corrosive to metals. For example, in a specific steam injection operation, it was found through chemical analysis that the chloride ion content of steam injection boiler water was as high as 319.14mg / l.

[0047] For the present application, as an example, under the catalysis of chloride ions, water and magnesium can react as follows:

[0048]

[0049] The existing temporary plugging ball 1 is often difficult to adapt to the physical environment of high temperature and high pressure in such a complex chemical environment, and its tolerance temperature usually does not exceed 150° C. In the steam stimulation process applied to heavy oil, the oil layer often has a physical environment of high temperature and high pressure, which makes the existing temporary plugging ball 1 unsuitable for the steam stimulation process of heavy oil.

[0050] Therefore, the present application provides a polytetrafluoroethylene coating 12 on the surface of the hollow alloy ball 11 , which can effectively isolate corrosive chemicals and increase the temperature resistance of the temporary plugging ball 1 .

[0051] As an example, the temporary blocking ball 1 described in the present application can be prepared in the following manner:

[0052] Preparation of hollow alloy ball 11: The alloy is melted in a vacuum alloying melting furnace. After melting, it is cast into a bar. Then, the bar is cut into thin bars by a wire cutting machine, and then a vertical machining center is used to process the hemispherical parts according to the designed size structure. The two hemispheres are connected by threads to form a global structure, or the hemispheres are welded into a global structure by tungsten inert gas welding (TIG welding) process.

[0053] Preparation of temporary plugging ball 1: Clean the hollow alloy ball 11 to remove surface oil stains, and then perform sandblasting. Finally, spray polytetrafluoroethylene coating on the surface of the hollow alloy ball 11. In order to prevent the ball from flying during spraying, it is necessary to design a fixture clamp, and the clamping part needs to be sprayed twice.

[0054] In some embodiments of the present application, the density of the temporary blocking ball 1 is not greater than 1.0 g / cm 3 .

[0055] The density of the existing temporary plugging ball 1 is usually greater than 1.0g / cm 3 The density of the temporary plugging ball 1 described in this application is not greater than 1.0 g / cm 3 The beneficial effect is that the temporary plugging ball 1 can float on the liquid. Since the high permeability layer has a strong vapor absorption capacity and the liquid flow will flow to the high permeability layer blasthole, the temporary plugging ball 1 can block the high permeability layer blasthole along with the liquid flow.

[0056] In some embodiments of the present application, the temporary blocking ball 1 includes at least one of a small blocking ball and a large blocking ball, wherein the diameter of the small blocking ball is 8-12 mm, and the diameter of the large blocking ball is 20-22 mm.

[0057] As an example, the diameter of the small blocking ball may be 8 mm, 9 mm, 10 mm, 11 mm, or 12 mm.

[0058] As an example, the diameter of the large blocking ball may be 20 mm, 21 mm, or 22 mm.

[0059] The diameters of 8-12mm and 20-22mm correspond to two temporary plugging solutions.

[0060] Small plugging balls of 8 to 12 mm are mainly used to adjust the plane production status. The temporary plugging balls 1 of 8 to 12 mm have a small diameter and can enter the blastholes of the high permeability layer of the oil field, thereby filling the perforation channel, and then can regulate the plane steam absorption and injection speed, adjust the plane production status, inhibit the single-layer unidirectional advance of steam, and alleviate the contradiction of steam channeling.

[0061] The 20-22mm large plugging ball is mainly used to improve the vertical steam absorption condition of the oil layer. The 20-22mm temporary plugging ball 1 has a larger diameter and can directly block the blastholes of the high permeability layer of the oil field, thereby forcing the steam to enter the low-production layer, adjust the steam absorption profile, and improve the vertical steam absorption condition of the oil layer.

[0062] Large blocking balls and small blocking balls can also be used in combination to further achieve refined steam injection.

[0063] In some embodiments of the present application, the wall thickness of the hollow alloy ball 11 is 1 to 1.5 mm.

[0064] As an example, the wall thickness of the hollow alloy ball 11 may be 1 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, or 1.5 mm.

[0065] The wall thickness of the hollow alloy ball 11 is reasonably adjusted within the above range according to the actual operating pressure and density.

[0066] In some embodiments of the present application, the thickness of the polytetrafluoroethylene coating 12 is 0.05-0.2 mm.

[0067] As an example, the thickness of the polytetrafluoroethylene coating 12 may be 0.05 mm, 0.07 mm, 0.1 mm, 0.13 mm, 0.16 mm, or 0.2 mm.

[0068] The thickness of the polytetrafluoroethylene coating 12 can adjust the temperature resistance of the temporary blocking ball 1 .

[0069] Specifically, in a physical environment of high temperature and high pressure, the temporary plugging ball 1 will expand and contract due to heat and cold, resulting in deformation, which will cause stress inside the polytetrafluoroethylene coating 12. When the temperature of the oil layer rises high enough, the polytetrafluoroethylene coating 12 cannot resist the internal stress and will rupture, causing the hollow alloy ball 11 inside to come into contact with the corrosive chemicals in the oil layer, thereby causing the temporary plugging ball 1 to be melted. When the thickness of the polytetrafluoroethylene coating 12 is relatively thin and its ability to resist stress is weak, the temporary plugging ball 1 will be dissolved when the temperature of the oil layer is relatively low. When the thickness of the polytetrafluoroethylene coating 12 is relatively thick, the temporary plugging ball 1 will only be melted when the temperature of the oil layer is relatively high. The specific thickness of the polytetrafluoroethylene coating 12 mainly depends on the feedback from the actual production conditions.

[0070] In some embodiments of the present application, the hollow alloy ball 11 includes two half hollow balls 111.

[0071] The two semi-hollow balls 111 are connected by welding to form the hollow alloy ball 11.

[0072] or,

[0073] The semi-hollow balls 111 are connected by threaded connection to form the hollow alloy ball 11 .

[0074] The hollow alloy ball 11 is generally prepared by a mold, and the mold cannot directly prepare an integral hollow ball, and can only prepare two half hollow balls 111 first and then connect the two half hollow balls 111 to form the hollow alloy ball 11. Welding or threaded connection is a conventional connection method.

[0075] In some embodiments of the present application, the temporary blocking ball further includes polyurethane foam 13, and the polyurethane foam 13 is filled inside the hollow alloy ball.

[0076] The polyurethane foam 13 can play a supporting role and further improve the compressive strength of the soluble ball.

[0077] In the second aspect, the present application embodiment provides a pitching device, please refer to Figure 2 ,

[0078] The pitching device comprises:

[0079] A ball throwing cylinder 4, wherein the cylinder wall of the ball throwing cylinder 4 has a hollow interlayer, and a hot melt plate 41 is provided at the lower end of the hollow interlayer to isolate the hollow interlayer from the outside, and the melting temperature of the hot melt plate 41 is 200-250°C;

[0080] The temporary blocking ball 1 is the temporary blocking ball 1 described in any embodiment of the first aspect, and the temporary blocking ball 1 is stored in the hollow interlayer.

[0081] In some embodiments of the present application, the material of the hot melt plate 41 is resin.

[0082] In a third aspect, an embodiment of the present application provides a steam injection temporary plugging device, the steam injection temporary plugging device comprising:

[0083] Steam injection pipeline 2;

[0084] A packer 3 connected to the lower end of the steam injection pipeline 2;

[0085] A ball throwing device is arranged at the lower end of the steam injection pipeline 2, and the ball throwing device is the ball throwing device described in any embodiment of the second aspect, and the ball throwing cylinder is connected to the steam injection pipeline 2.

[0086] Those skilled in the art can understand that the packer 3 is a conventional device in the art.

[0087] It is easy to understand that when the steam injection operation begins, the temperature in the oil layer continues to rise, which will cause the hot melt plate 41 to melt, and the temporary plugging ball 1 to be released and float in the liquid; since the high permeability layer has a strong steam absorption capacity and the liquid flow will flow to the high permeability layer blasthole, the temporary plugging ball 1 can block the high permeability layer blasthole along with the liquid flow.

[0088] When the ball throwing device is in use, it is placed in the oil well casing 6 , and the temporary plugging ball 1 moves with the steam flow and temporarily plugs the blasthole 711 at the high permeability layer 7 .

[0089] In some embodiments of the present application, the steam injection temporary blocking device also includes a bell mouth 5, the end of the bell mouth 5 with a smaller diameter is connected to the lower end of the ball delivering working cylinder 4, and the inner diameter of the end of the bell mouth 5 with a smaller diameter is not less than the outer diameter of the lower end of the ball delivering working cylinder 4.

[0090] The bell mouth 5 is a conventional device in the art. Those skilled in the art can implement the bell mouth 5 according to the common knowledge in the art. The function of the bell mouth 5 is to allow steam to be injected into the oil well casing 6 more evenly.

[0091] In a fourth aspect, an embodiment of the present application provides a steam injection temporary plugging method, the steam injection temporary plugging method comprising the following steps:

[0092] Providing the steam injection temporary plugging device as described in any embodiment of the third aspect, the steam injection temporary plugging device is installed in the oil well casing 6 and lowered to the high permeability layer 7;

[0093] Inject steam into the oil well casing 6 through the steam injection pipeline 2, and set the packer 3;

[0094] After the hot melt plate 41 is melted, the temporary plugging ball 1 moves with the steam flow and temporarily plugs the blast hole 711 at the high permeability layer 7 .

[0095] It is easy to understand that the ball throwing device is set in the oil well casing 6 and lowered to the high permeability layer 7. This can be implemented according to the general method in the field. Specifically, according to the well conditions of the oil well, the ball throwing device should be lowered as close to the high permeability layer 7 as possible. If the well conditions are poor, it can also be lowered to a position above the high permeability layer 7.

[0096] It is easy to understand that when the hot melt plate 41 melts, the temporary plugging ball 1 falls under the action of gravity, and is ejected to the inner wall of the oil well casing 6 under the action of the steam flow. When the diameter of the temporary plugging ball 1 is 20-22 mm, it directly blocks the blast hole 711; when the diameter of the temporary plugging ball 1 is 8-12 mm, it fills the perforation channel 71.

[0097] After the hot melt plate 41 melts, the temporary plugging ball 1 is released, moves with the steam flow and temporarily plugs the blasthole at the high permeability layer 7. The steam is forced to enter the low-use layer to adjust the steam absorption profile. The steam injection time is about 5-7 days. Because the temporary plugging ball 1 has good corrosion resistance, temperature resistance, high strength and other properties, the plugging ball can effectively block the blasthole during the steam injection process. After the steam injection is completed, the temporary plugging ball 1 dissolves by itself under the action of the steam injection boiler water, and does not need to be dissolved by injecting a solution.

[0098] The present application will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are intended only to illustrate the present application and are not intended to limit the scope of the present application. The experimental methods for which specific conditions are not specified in the following examples are usually measured according to industry standards. If there is no corresponding industry standard, then the conditions recommended by the manufacturer are followed.

[0099] Example 1

[0100] This embodiment provides a temporary blocking ball, which includes:

[0101] Hollow alloy sphere;

[0102] A polytetrafluoroethylene coating is provided on the surface of the hollow alloy ball,

[0103] The hollow alloy ball is made of a magnesium-aluminum alloy, which consists of the following components in percentage by mass: 2.5% Al, 1.4% Zn, 0.2% Mn, 0.06% Si, 0.001% Cu, 0.001% Ni, and the remainder is Mg.

[0104] The density of the temporary blocking ball is 0.94g / cm 3 .

[0105] The diameter of the temporary blocking ball is 22 mm.

[0106] The wall thickness of the hollow alloy ball is 1.2 mm.

[0107] The thickness of the polytetrafluoroethylene coating is 0.07 mm.

[0108] The temporary blocking ball provided in Example 1 was used to carry out a blocking ball blocking experiment. The experimental conditions are shown in Table 1:

[0109] Steam temperature 300℃ Steam injection pressure 4MPa Number of blastholes 2 Exhaust speed 15L / min Number of blocked balls 3

[0110] Table 1

[0111] The experimental results show that the plugging ball blocks the blasthole and remains stable when it falls, and the plugging is successful. After plugging, its longitudinal mobilization degree can be increased by about 15%, and the air intake profile is significantly adjusted.

[0112] Example 2

[0113] This embodiment provides a ball pitching device, which includes:

[0114] A ball pitching cylinder, wherein the cylinder wall of the ball pitching cylinder has a hollow interlayer, and a hot melt plate is arranged at the lower end of the hollow interlayer to isolate the hollow interlayer from the outside, and the melting temperature of the hot melt plate is 200-250°C;

[0115] The temporary blocking ball is the temporary blocking ball described in any embodiment of the first aspect, and the temporary blocking ball is stored in the hollow interlayer.

[0116] The material of the hot melt plate is resin.

[0117] This embodiment also provides a steam injection temporary plugging device, the steam injection temporary plugging device comprising:

[0118] Steam injection pipeline;

[0119] a packer connected to the lower end of the steam injection pipeline;

[0120] The above-mentioned ball throwing device is arranged at the lower end of the steam injection pipeline, and the ball throwing tube is connected to the steam injection pipeline.

[0121] This embodiment also provides a steam injection temporary plugging method, which comprises the following steps:

[0122] Providing the above-mentioned steam injection temporary plugging device, installing the steam injection temporary plugging device in the casing of the oil well, and lowering it to the high permeability layer;

[0123] Inject steam into the oil well casing through the steam injection pipeline to set the packer;

[0124] After the hot melt plate is melted, the temporary plugging ball moves with the steam flow and temporarily plugs the blasthole at the high permeability layer.

[0125] The steam injection temporary plugging method described in this embodiment was implemented in the Du 212-33-K299 well of Shuguang Oil Production Plant, Liaohe Oilfield, PetroChina. Before the implementation of the method, the steam injection pressure of the well was 11.43MPa, with more steam absorption in the upper layer, accounting for 81.2%; less steam absorption in the lower layer, accounting for 18.8%. After the implementation of the method, the steam injection pressure was 15.46MPa, an increase of 4.03MPa. The proportion of steam absorption in the upper layer decreased to 65.5%; the proportion of steam absorption in the lower layer increased to 34.5%. The steam absorption profile was also significantly improved, and the vertical utilization degree increased by 15.7%.

[0126] Various embodiments of the present application may be presented in the form of a range; it should be understood that the description in the form of a range is only for convenience and brevity, and should not be understood as a rigid limitation on the scope of the present application; therefore, the range description should be considered to have specifically disclosed all possible sub-ranges and single numerical values ​​within the range. For example, the range description from 1 to 6 should be considered to have specifically disclosed sub-ranges, such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., as well as single numbers within the range, such as 1, 2, 3, 4, 5 and 6, which apply regardless of the range. In addition, whenever a numerical range is indicated herein, it is meant to include any cited number (fractional or integer) within the indicated range.

[0127] In the present application, in the absence of any contrary description, the directional words used, such as "upper" and "lower", are specifically the directions of the drawings in the accompanying drawings. In addition, in the description of the present application specification, the terms "including", "comprising", etc. refer to "including but not limited to". Moreover, the terms "including", "comprising" or any other variants thereof are intended to cover non-exclusive inclusion, so that the process, method, article or equipment including a series of elements not only includes those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or equipment. In the absence of further restrictions, the elements defined by the sentence "including..." do not exclude the existence of other identical elements in the process, method, article or equipment including the elements. In this article, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that there is any such actual relationship or order between these entities or operations. In this article, "and / or" describes the association relationship of associated objects, indicating that there can be three relationships, for example, A and / or B, which can represent: A exists alone, A and B exist at the same time, and B exists alone. For the association relationship of more than three associated objects described by "and / or", it means that any one of these three associated objects can exist alone, or any at least two of them exist at the same time. For example, for A, and / or B, and / or C, it can be represented that any one of A, B, and C exists alone, or any two of them exist at the same time, or three of them exist at the same time. In this article, "at least one" refers to one or more, and "multiple" refers to two or more. "At least one", "the following at least one (individual)" or similar expressions refer to any combination of these items, including any combination of single (individual) or plural (individual). For example, "at least one (individual) of a, b, or c", or "at least one (individual) of a, b, and c", can all represent: a, b, c, ab (i.e. a and b), ac, bc, or abc, wherein a, b, and c can be single or multiple, respectively.

[0128] The above description is only a specific implementation of the present application, so that those skilled in the art can understand or implement the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest range consistent with the principles and novel features applied for herein.

Claims

1. A temporary blocking ball, It is characterized in that The temporary blocking ball comprises: Hollow alloy sphere; A polytetrafluoroethylene coating is provided on the surface of the hollow alloy ball, Wherein, the material of the hollow alloy ball is a magnesium-aluminum alloy, which is composed of the following components in terms of mass percentage of the magnesium-aluminum alloy: 2.5% to 3.5% Al, 0.6% to 1.4% Zn, 0.2% to 1% Mn, 0 to 0.08% Si, 0 to 0.01% Cu, 0 to 0.001% Ni, 0.2 to 2.00% rare earth elements, and the balance is Mg, wherein the rare earth element is selected from at least one of gadolinium and yttrium.

2. The temporary blocking ball according to claim 1, It is characterized in that The density of the temporary plugging ball is not more than 1.0g / cm 3 .

3. The temporary blocking ball according to claim 1, It is characterized in that The temporary blocking ball includes at least one of a small blocking ball and a large blocking ball, wherein the diameter of the small blocking ball is 8-12 mm, and the diameter of the large blocking ball is 20-22 mm.

4. The temporary blocking ball according to claim 1, It is characterized in that The wall thickness of the hollow alloy ball is 1 to 1.5 mm; and / or, The thickness of the polytetrafluoroethylene coating is 0.05-0.2 mm.

5. The temporary blocking ball according to claim 1, It is characterized in that The hollow alloy ball comprises two half hollow balls, wherein: The two semi-hollow balls are connected by welding to form the hollow alloy ball. or, The semi-hollow balls are connected by threaded connection to form the hollow alloy ball.

6. The temporary blocking ball according to claim 1, It is characterized in that The temporary blocking ball also includes polyurethane foam, and the polyurethane foam is filled in the interior of the hollow alloy ball.

7. A pitching device, It is characterized in that The pitching device comprises: A ball pitching cylinder, wherein the cylinder wall of the ball pitching cylinder has a hollow interlayer, and a hot melt plate is arranged at the lower end of the hollow interlayer to isolate the hollow interlayer from the outside, and the melting temperature of the hot melt plate is 200-250°C; A temporary blocking ball, wherein the temporary blocking ball is the temporary blocking ball according to any one of claims 1 to 6, and the temporary blocking ball is stored in the hollow interlayer.

8. The pitching device according to claim 7, It is characterized in that The material of the hot melt plate is resin.

9. A steam injection temporary plugging device, It is characterized in that The steam injection temporary blocking device comprises: Steam injection pipeline; a packer connected to the lower end of the steam injection pipeline; A ball throwing device is arranged at the lower end of the steam injection pipeline, wherein the ball throwing device is the ball throwing device according to claim 7 or 8, and the ball throwing cylinder is connected to the steam injection pipeline.

10. A steam injection temporary blocking method, It is characterized in that The steam injection temporary blocking method comprises the following steps: Providing the steam injection temporary plugging device according to claim 9, installing the steam injection temporary plugging device in the casing of the oil well and lowering it to the high permeability layer; Inject steam into the oil well casing through the steam injection pipeline to set the packer; After the hot melt plate is melted, the temporary plugging ball moves with the steam flow and temporarily plugs the blasthole at the high permeability layer.

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