Blocking removal composition with barium and strontium scale dissolving function as well as preparation method and application of blocking removal composition

Abstract

The invention relates to the technical field of unblocking liquid, and discloses an unblocking composition with a barium and strontium scale dissolving function as well as a preparation method and application of the unblocking composition. Wherein the blocking removal composition contains polycyclic crown ether and an organic carboxylate complexing agent, and the mass ratio of the polycyclic crown ether to the organic carboxylate complexing agent is (5-15): (75-105). The blocking removal composition contains the polycyclic crown ether and the organic carboxylate complexing agent, the polycyclic crown ether has strong selectivity and complexing ability to metal ions due to the fact that a cave-shaped ligand of the polycyclic crown ether has a three-dimensional structure and a spherical cavity, and the organic carboxylate complexing agent, a phosphonic acid organic matter and the like are added at the same time, so that the purpose of synergistic descaling is achieved; the unblocking composition has a good descaling effect on barium and strontium sulfate scales, can effectively remove barium and strontium scales of gathering and transportation pipelines, and guarantees normal production of oil and gas fields.

Description

Technical Field

[0001] The present invention relates to the technical field of plugging removal fluids, and particularly relates to a plugging removal composition having the function of dissolving barium strontium scale, a preparation method thereof, and an application thereof. Background Art

[0002] With the continuous deepening of the development of major oil and gas fields, the comprehensive water cut is continuously rising, and the barium strontium content in the formation water of some blocks is relatively high, resulting in increasingly serious barium strontium sulfate scaling at gathering and transportation stations. The scaling cycle is short, the scale removal is frequent, equipment and instruments are damaged from time to time, and the daily maintenance workload of the station is large. For barium strontium sulfate scale, due to its low solubility product constant and insolubility in acids and bases, it is difficult to treat, seriously affecting normal production and the stable production foundation of oilfield gas.

[0003] At present, for the problem of barium strontium scale plugging, common scale removal technologies include mechanical scale removal, physical scale removal, and chemical scale removal. Mechanical scale removal is to remove the scale on the pipe wall by the rotation of a drill bit, milling or rail cone. This technology has a slow scale removal and cleaning speed, and will cause damage to the pipe body. Physical scale removal is to remove scale by using physical means such as sound, light, electricity, and magnetism and corresponding equipment. This technology has a narrow application range, high energy consumption, and unstable scale removal efficiency. Chemical scale removal refers to selecting different scale removers according to different types of scale to achieve the purpose of chemical conversion and dissolution scale removal. Chemical scale removal technology has a wide application range and high scale removal efficiency, so it is the main technology for plugging removal of barium strontium scale in oilfields.

[0004] For removing barium strontium scale by chemical technology, the common scale removers have poor scale removal effects and poor solubility in barium strontium. Therefore, it is urgent to develop a plugging removal fluid with good scale removal effect. Summary of the Invention

[0005] The purpose of the present invention is to overcome the problems of poor scale removal effect of existing scale removers and poor solubility in barium strontium, and to provide a plugging removal composition having the function of dissolving barium strontium scale, a preparation method thereof, and an application thereof.

[0006] To achieve the above purpose, in the first aspect of the present invention, a plugging removal composition having the function of dissolving barium strontium scale is provided. The plugging removal composition contains a polycyclic crown ether and an organic carboxylate complexing agent, and the mass ratio of the polycyclic crown ether to the organic carboxylate complexing agent is (5 - 15):(75 - 105).

[0007] In the second aspect of the present invention, a preparation method of a plugging removal composition is provided. The polycyclic crown ether, the organic carboxylate complexing agent, an optional phosphonic acid organic compound, an optional penetrant, an optional dispersant, an optional cosolvent, and an optional water are mixed to obtain the plugging removal composition.

[0008] In the third aspect of the present invention, an application of the plugging removal composition in removing barium strontium scale is provided.

[0009] Through the above technical solution, the present invention provides a plugging removal composition with the function of dissolving barium strontium scale, its preparation method and application. The plugging removal composition contains macrocyclic crown ether and organic carboxylate complexing agent. Due to the three-dimensional structure of its cavity ligand, the cavity of macrocyclic crown ether is spherical, and it has strong selectivity and complexing ability for metal ions. At the same time, adding organic carboxylate complexing agent and phosphonic acid organic matter, etc., to achieve the purpose of synergistic scale removal. The plugging removal composition has a good scale removal effect on barium strontium sulfate scale, can effectively remove barium strontium scale in gathering and transportation pipelines, and ensure the normal production of oil and gas fields. Specific Embodiments

[0010] In the ranges disclosed herein, the endpoints and any values are not limited to the exact ranges or values, and these ranges or values should be understood to include values close to these ranges or values. For numerical ranges, the endpoint values of each range, between the endpoint values of each range, between the endpoint value of each range and a single point value, and between single point values can be combined with each other to obtain one or more new numerical ranges, and these numerical ranges should be regarded as specifically disclosed herein.

[0011] In the first aspect of the present invention, a plugging removal composition with the function of dissolving barium strontium scale is provided. Among them, the plugging removal composition contains macrocyclic crown ether and organic carboxylate complexing agent, and the mass ratio of the macrocyclic crown ether to the organic carboxylate complexing agent is (5 - 15):(75 - 105).

[0012] In the present invention, a plugging removal composition with the function of dissolving barium strontium scale, its preparation method and application are provided. The plugging removal composition contains macrocyclic crown ether and organic carboxylate complexing agent. Due to the three-dimensional structure of its cavity ligand, the cavity of macrocyclic crown ether is spherical, and it has strong selectivity and complexing ability for metal ions. At the same time, adding organic carboxylate complexing agent and phosphonic acid organic matter, etc., to achieve the purpose of synergistic scale removal. The plugging removal composition has a good scale removal effect on barium strontium sulfate scale (composed of Ba 0.25 Sr 0.75 SO4), can effectively remove barium strontium scale in gathering and transportation pipelines, and ensure the normal production of oil and gas fields.

[0013] In some specific embodiments of the present invention, the mass ratio of the macrocyclic crown ether to the organic carboxylate complexing agent is (5 - 10):(85 - 100). When the mass ratio of the macrocyclic crown ether to the organic carboxylate complexing agent is within this range, the plugging removal composition has a good scale removal effect on barium strontium sulfate scale.

[0014] In some specific embodiments of the present invention, the macrocyclic crown ether is selected from one or more of cryptand [2,2,2], cryptand [1,1,1], cryptand [2,2,1], cryptand [3,2,2] and cryptand [3,3,3]. When preferably selected from cryptand [2,2,2], the plugging removal composition has a good scale removal effect on barium strontium sulfate scale.

[0015] The organic carboxylate complexing agent is selected from one or more of nitrogen-containing organic carboxylate complexing agents, preferably selected from sodium ethylenediaminetetraacetate and sodium cyclohexanediaminetetraacetate. When the organic carboxylate complexing agent is selected from sodium ethylenediaminetetraacetate and sodium cyclohexanediaminetetraacetate, the plugging removal composition has a good scale removal effect on barium strontium sulfate scale.

[0016] In some specific embodiments of the present invention, when the organic carboxylate complexing agent is selected from sodium ethylenediaminetetraacetate and sodium cyclohexanediaminetetraacetate, the mass ratio of the polycyclic crown ether, sodium ethylenediaminetetraacetate and sodium cyclohexanediaminetetraacetate is (5 - 15):(70 - 90):(5 - 15), preferably (5 - 10):(80 - 90):(5 - 10). When the mass ratio of the polycyclic crown ether, sodium ethylenediaminetetraacetate and sodium cyclohexanediaminetetraacetate is within this range, the plugging removal composition has a good scale removal effect on barium strontium sulfate scale.

[0017] In some specific embodiments of the present invention, the plugging removal composition further contains phosphonic acid organic compounds.

[0018] In some specific embodiments of the present invention, the phosphonic acid organic compounds are selected from pentasodium diethylenetriaminepenta(methylene phosphonate) and / or tetrasodium 2-phosphonobutane-1,2,4-tricarboxylate. Pentasodium diethylenetriaminepenta(methylene phosphonate) and / or tetrasodium 2-phosphonobutane-1,2,4-tricarboxylate have a very good synergistic effect on the polycyclic crown ether and the organic carboxylate complexing agent, and have a good scale removal effect on barium strontium sulfate scale.

[0019] In some specific embodiments of the present invention, the plugging removal composition further contains a penetrant, a dispersant, a cosolvent and water.

[0020] In some specific embodiments of the present invention, the penetrant is selected from one or more of fatty alcohol polyoxyethylene ether, isooctanol polyoxyethylene ether, sodium dioctyl sulfosuccinate and sodium polystyrene sulfonate, preferably isooctanol polyoxyethylene ether and / or sodium polystyrene sulfonate.

[0021] In some specific embodiments of the present invention, the dispersant is selected from sodium polyacrylate, and the number average molecular weight of sodium polyacrylate is 500 - 3000 g / mol, preferably 800 - 1200 g / mol.

[0022] In some specific embodiments of the present invention, the cosolvent is selected from C1 - C4 alcohols, preferably methanol and / or ethanol.

[0023] In some specific embodiments of the present invention, when the phosphonic acid organic compound is selected from pentasodium diethylenetriamine pentamethylenephosphonate and tetrasodium 2-phosphonobutane-1,2,4-tricarboxylate, the mass ratio of pentasodium diethylenetriamine pentamethylenephosphonate to tetrasodium 2-phosphonobutane-1,2,4-tricarboxylate is (50-75):(25-50), preferably (60-75):(25-40).

[0024] In some specific embodiments of the present invention, based on 100 parts by weight of the plugging removal composition, the plugging removal composition contains: 1-4 parts by weight of polycyclic crown ether, 16-39 parts by weight of organic carboxylate complexing agent, 5-10 parts by weight of phosphonic acid organic compound, 4-8 parts by weight of penetrant, 4-8 parts by weight of dispersant, 10-20 parts by weight of cosolvent, and the balance is water.

[0025] In some specific embodiments of the present invention, more preferably, based on 100 parts by weight of the plugging removal composition, the plugging removal composition contains: 2-3 parts by weight of cryptand [2,2,2], 20-26 parts by weight of sodium ethylenediaminetetraacetate, 1-5 parts by weight of sodium cyclohexanediaminetetraacetate, 2-5 parts by weight of pentasodium diethylenetriamine pentamethylenephosphonate, 1-3 parts by weight of tetrasodium 2-phosphonobutane-1,2,4-tricarboxylate, 4-6 parts by weight of penetrant, 4-6 parts by weight of dispersant, 10-18 parts by weight of cosolvent, and the balance is water.

[0026] The plugging removal composition of the present invention can be in the form of liquid, solid or other compositions.

[0027] The second aspect of the present invention provides a method for preparing a plugging removal composition, wherein the cryptand, organic carboxylate complexing agent, optional phosphonic acid organic compound, optional penetrant, optional dispersant, optional cosolvent and optional water are mixed to obtain the plugging removal composition.

[0028] The third aspect of the present invention provides an application of the plugging removal composition in removing barium and strontium scale.

[0029] The present invention will be described in detail below through examples.

[0030] In the following examples and comparative examples, those not specified in specific conditions are carried out according to conventional conditions or conditions recommended by the manufacturer. Reagents or instruments not specified in the manufacturer are all conventional products that can be obtained through commercial channels.

[0031] Example 1

[0032] First, add a total of 3 g of cryptand [2,2,2], sodium ethylenediaminetetraacetate, and sodium cyclohexanediaminetetraacetate to a stirrer. Among them, the mass ratio of cryptand [2,2,2], sodium ethylenediaminetetraacetate, and sodium cyclohexanediaminetetraacetate is 10:80:10; then add a total of 0.5 g of pentasodium diethylenetriaminepenta(methylene phosphonic acid) and tetrasodium 2-phosphonobutane-1,2,4-tricarboxylic acid to the stirrer and stir for 15 min. Among them, the mass ratio of pentasodium diethylenetriaminepenta(methylene phosphonic acid) and tetrasodium 2-phosphonobutane-1,2,4-tricarboxylic acid is 75:25; then add 0.5 g of isooctyl polyoxyethylene ether and stir for 15 min; then add 0.5 g of sodium polyacrylate with a number average molecular weight of 1000 and stir for 15 min; finally, add 1.5 g of methanol and 4 g of water and stir for 60 min to prepare 10 g of barium-strontium scale removal solution.

[0033] Example 2

[0034] First, add a total of 4 g of cryptand [2,2,2], sodium ethylenediaminetetraacetate, and sodium cyclohexanediaminetetraacetate to a stirrer. Among them, the mass ratio of cryptand [2,2,2], sodium ethylenediaminetetraacetate, and sodium cyclohexanediaminetetraacetate is 10:75:10; then add a total of 0.5 g of pentasodium diethylenetriaminepenta(methylene phosphonic acid) and tetrasodium 2-phosphonobutane-1,2,4-tricarboxylic acid to the stirrer and stir for 15 min. Among them, the mass ratio of pentasodium diethylenetriaminepenta(methylene phosphonic acid) and tetrasodium 2-phosphonobutane-1,2,4-tricarboxylic acid is 75:25; then add 0.5 g of isooctyl polyoxyethylene ether and stir for 15 min; then add 0.5 g of sodium polyacrylate with a number average molecular weight of 1000 and stir for 15 min; finally, add 1.5 g of methanol and 3 g of water and stir for 60 min to prepare 10 g of barium-strontium scale removal solution.

[0035] Example 3

[0036] First, add a total of 2 g of cryptand [2,2,2], sodium ethylenediaminetetraacetate, and sodium cyclohexanediaminetetraacetate to a stirrer. Among them, the mass ratio of cryptand [2,2,2], sodium ethylenediaminetetraacetate, and sodium cyclohexanediaminetetraacetate is 5:80:5; then add a total of 0.5 g of pentasodium diethylenetriaminepenta(methylene phosphonic acid) and tetrasodium 2-phosphonobutane-1,2,4-tricarboxylic acid to the stirrer and stir for 15 min. Among them, the mass ratio of pentasodium diethylenetriaminepenta(methylene phosphonic acid) and tetrasodium 2-phosphonobutane-1,2,4-tricarboxylic acid is 75:25; then add 0.5 g of isooctyl polyoxyethylene ether and stir for 15 min; then add 0.5 g of sodium polyacrylate with a number average molecular weight of 1000 and stir for 15 min; finally, add 1.5 g of methanol and 5 g of water and stir for 60 min to prepare 10 g of barium-strontium scale removal solution.

[0037] Example 4

[0038] Prepare the barium-strontium scale removal and plugging removal fluid according to the method of Example 1. Among them, the difference is that cryptand [1,1,1] is used to replace cryptand [2,2,2], and other conditions are the same as those in Example 1.

[0039] Example 5

[0040] Prepare the barium-strontium scale removal and plugging removal fluid according to the method of Example 1. Among them, the difference is that cryptand [2,2,1] is used to replace cryptand [2,2,2], and other conditions are the same as those in Example 1.

[0041] Example 6

[0042] Prepare the barium-strontium scale removal and plugging removal fluid according to the method of Example 1. Among them, the difference is that cryptand [3,2,2] is used to replace cryptand [2,2,2], and other conditions are the same as those in Example 1.

[0043] Example 7

[0044] Prepare the barium-strontium scale removal and plugging removal fluid according to the method of Example 1. Among them, the difference is that the mass ratio of cryptand [2,2,2], sodium ethylenediaminetetraacetate and sodium cyclohexanediaminetetraacetate is set to 15:60:30, and other conditions are the same as those in Example 1.

[0045] Example 8

[0046] Prepare the barium-strontium scale removal and plugging removal fluid according to the method of Example 1. Among them, the difference is that the mass ratio of sodium diethylenetriaminepenta(methylene phosphonic acid) pentasodium salt and tetrasodium 2-phosphonobutane-1,2,4-tricarboxylate is set to 50:30, and other conditions are the same as those in Example 1.

[0047] Example 9

[0048] Prepare the barium-strontium scale removal and plugging removal fluid according to the method of Example 1. Among them, the difference is that there is only one kind of organic carboxylate complexing agent, which is sodium ethylenediaminetetraacetate. Among them, the mass ratio of cryptand [2,2,2] and sodium ethylenediaminetetraacetate is 10:90, and other conditions are the same as those in Example 1.

[0049] Example 10

[0050] Prepare the barium-strontium scale removal and plugging removal fluid according to the method of Example 1. Among them, the difference is that there is only one kind of phosphonic acid organic compound, which is sodium diethylenetriaminepenta(methylene phosphonic acid) pentasodium salt, and the amount of sodium diethylenetriaminepenta(methylene phosphonic acid) pentasodium salt is 0.5 g, and other conditions are the same as those in Example 1.

[0051] Example 11

[0052] Prepare the barium-strontium scale removal and plugging removal fluid according to the method of Example 1. Among them, the difference is that the phosphonic acid organic compound is not added, and other conditions are the same as those in Example 1.

[0053] Example 12

[0054] Prepare the barium-strontium scale removal fluid according to the method of Example 1. Among them, the difference is that dipotassium glutamate-N,N-diacetate is used to replace sodium cyclohexanediaminetetraacetate, and other conditions are the same as those in Example 1.

[0055] Example 13

[0056] Prepare the barium-strontium scale removal fluid according to the method of Example 1. Among them, the difference is that there is only one kind of phosphonic acid organic matter, which is ethylenediaminetetramethylenephosphonic acid, and the amount of ethylenediaminetetramethylenephosphonic acid is 0.5 g, and other conditions are the same as those in Example 1.

[0057] Example 14

[0058] Prepare the barium-strontium scale removal fluid according to the method of Example 1. Among them, the difference is that the phosphonic acid organic matter is replaced by l-hydroxyethylidene-1,1-diphosphonic acid and ethylenediaminetetramethylenephosphonic acid. Among them, the mass ratio of ethylenediaminetetramethylenephosphonic acid to l-hydroxyethylidene-1,1-diphosphonic acid is 75:25, and other conditions are the same as those in Example 1.

[0059] Example 15

[0060] Prepare the barium-strontium scale removal fluid according to the method of Example 1. Among them, the difference is that dipotassium glutamate-N,N-diacetate is used to replace sodium ethylenediaminetetraacetate, and dipotassium cyclohexanediaminetetraacetate is used to replace sodium cyclohexanediaminetetraacetate, and other conditions are the same as those in Example 1.

[0061] Comparative Example 1

[0062] First, add a total of 3 g of sodium ethylenediaminetetraacetate and sodium cyclohexanediaminetetraacetate to a stirrer, where the mass ratio of sodium ethylenediaminetetraacetate to sodium cyclohexanediaminetetraacetate is 80:10; then add 0.5 g of barium-strontium scale removal fluid additive and stir for 15 min. The mass ratio of pentasodium diethylenetriaminepenta(methylene phosphonic acid) and tetrasodium 2-phosphonobutane-1,2,4-tricarboxylic acid in the additive is 75:25; then add 0.5 g of isooctyl polyoxyethylene ether and stir for 15 min; then add 0.5 g of sodium polyacrylate with a number average molecular weight of 1000 and stir for 15 min; finally, add 1.5 g of methanol and 4 g of water and stir for 60 min to prepare 10 g of barium-strontium scale removal fluid.

[0063] Comparative Example 2

[0064] Prepare the barium-strontium scale removal fluid according to the method of Example 1. Among them, the difference is that 15-crown-5 is used to replace cryptand [2,2,2], and other conditions are the same as those in Example 1.

[0065] Performance test:

[0066] First, dilute the prepared barium-strontium scale removal composition above with clear water to a solution with a concentration of 40% by weight. Then, take 50 mL of the solution and place it in a 100 mL beaker. Next, add 1 g of the on-site massive barium-strontium scale sample (from the surface pipeline of an oilfield, with the composition of Ba 0.25 Sr 0.75 SO4), put in a magnetic stir bar, and finally stir at 100 r / min for 4 h at room temperature. Filter and dry the remaining barium-strontium scale, weigh the weight m0 of the remaining barium-strontium scale, and calculate the dynamic scale removal rate S. The calculation formula is:

[0067] S = (1 - m0) / 1;

[0068] Respectively test the dynamic scale removal performance of the barium-strontium scale removal liquid provided in the examples, and the results are shown in Table 1.

[0069] Table 1

[0070]

[0071]

[0072] It can be seen from the results in Table 1 that each component of the scale removal composition with the function of dissolving barium-strontium scale in the present invention is mutually coordinated. The dynamic scale removal rate of the barium-strontium scale removal liquid of the examples prepared has a good scale removal effect, can effectively remove the barium-strontium scale in the gathering and transportation pipeline, and has a significantly better effect compared with the comparative example.

[0073] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited thereto. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, including any other suitable combination of each technical feature. These simple modifications and combinations should also be regarded as the content disclosed by the present invention and fall within the protection scope of the present invention.

Claims

1. A plugging removal composition with the function of dissolving barium strontium scale, characterized in that, The plugging removal composition contains polycyclic crown ethers and organic carboxylate complexing agents, and the mass ratio of the polycyclic crown ethers to the organic carboxylate complexing agents is (5 - 15):(75 - 105).

2. The plugging removal composition according to claim 1, wherein, The mass ratio of the polycyclic crown ethers to the organic carboxylate complexing agents is (5 - 10):(85 - 100); Preferably, the polycyclic crown ethers are selected from one or more of cryptand[2,2,2], cryptand[1,1,1], cryptand[2,2,1], cryptand[3,2,2] and cryptand[3,3,3], preferably cryptand[2,2,2]; Preferably, the organic carboxylate complexing agents are selected from one or more of nitrogen-containing organic carboxylate complexing agents, preferably sodium ethylenediaminetetraacetate and / or sodium cyclohexanediaminetetraacetate; More preferably, when the organic carboxylate complexing agents are selected from sodium ethylenediaminetetraacetate and sodium cyclohexanediaminetetraacetate, the mass ratio of the polycyclic crown ethers, sodium ethylenediaminetetraacetate and sodium cyclohexanediaminetetraacetate is (5 - 15):(70 - 90):(5 - 15).

3. The plugging removal composition according to claim 1 or 2, wherein, The plugging removal composition further contains organophosphonic acid compounds, and the mass ratio of the polycyclic crown ethers to the organophosphonic acid compounds is 1:(1 - 2); Preferably, the organophosphonic acid compounds are selected from one or more of pentasodium diethylenetriaminepenta(methylene phosphonate) and / or tetrasodium 2-phosphonobutane-1,2,4-tricarboxylate; 4. The plugging removal composition according to any one of claims 1-3, wherein, The plugging removal composition further contains a penetrant, a dispersant, a cosolvent and water.

5. The plugging removal composition according to claim 4, wherein, The penetrant is selected from one or more of fatty alcohol polyoxyethylene ethers, isooctanol polyoxyethylene ethers, sodium dioctyl sulfosuccinate and sodium polystyrene sulfonate, preferably isooctanol polyoxyethylene ether and / or sodium polystyrene sulfonate; 6. The plugging removal composition according to claim 4 or 5, wherein The dispersant is selected from sodium polyacrylate, wherein the number-average molecular weight of sodium polyacrylate is 500 - 3000 g / mol, preferably 800 - 1200 g / mol; And / or, the cosolvent is selected from C1 - C4 alcohols, preferably methanol and / or ethanol.

7. The plugging removal composition according to claim 3, wherein, When the organophosphonic acid compounds are selected from pentasodium diethylenetriaminepenta(methylene phosphonate) and tetrasodium 2-phosphonobutane-1,2,4-tricarboxylate, the mass ratio of pentasodium diethylenetriaminepenta(methylene phosphonate) to tetrasodium 2-phosphonobutane-1,2,4-tricarboxylate is (50 - 75):(25 - 50), preferably (60 - 75):(25 - 40).

8. The plugging removal composition according to any one of claims 1-7, wherein, Based on 100 parts by weight of the plugging removal composition, the plugging removal composition contains: 1 - 4 parts by weight of polycyclic crown ethers, 16 - 39 parts by weight of organic carboxylate complexing agents, 5 - 10 parts by weight of organophosphonic acid compounds, 4 - 8 parts by weight of penetrants, 4 - 8 parts by weight of dispersants, 10 - 20 parts by weight of cosolvents, and the balance is water; More preferably, based on 100 parts by weight of the plugging removal composition, the plugging removal composition contains: cryptand [2,2,2] 2-3 parts by weight, sodium ethylenediaminetetraacetate 20-26 parts by weight, sodium cyclohexanediaminetetraacetate 1-5 parts by weight, sodium diethylenetriaminepenta(methylene phosphonic acid) 2-5 parts by weight, tetrasodium 2-phosphonobutane-1,2,4-tricarboxylate 1-3 parts by weight, penetrant 4-6 parts by weight, dispersant 4-6 parts by weight, cosolvent 10-18 parts by weight, and the balance is water.

9. A preparation method of a plugging removal composition, characterized in that, Mixing the polycyclic crown ether, organic carboxylate complexing agent, optional phosphonic acid organic compound, optional penetrant, optional dispersant, optional cosolvent and optional water described in any one of claims 1-8 to obtain the plugging removal composition.

10. Use of the plugging removal composition described in any one of claims 1-8 in removing barium and strontium scale.

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