Novel environment-friendly composite scale-dissolving blocking remover

Abstract

The invention is suitable for the technical field of oil field scale dissolving, and provides a novel environment-friendly composite scale dissolving blocking remover which comprises the following components in parts by mass: 21-33 parts of DTPAMA, 7-11 parts of EDTA disodium, 2-3 parts of a corrosion inhibitor, 0.6-1 part of a surfactant, 0.5-1.5 parts of a stabilizer, 70-100 parts of water, 10-15 parts of low alcohol, 3-5 parts of a plant extract, 1-3 parts of polyvinyl alcohol and 1.5-4.5 parts of an amino acid complexing agent. Preferably, the mass ratio of the DTPAMA to the disodium EDTA is 3: 1. Through mutual cooperation of the components, solubilization, permeation, dispersion and chelation are combined together, the functions of reservoir protection, scale removal and plug removal are achieved, the scale removal rate is high, and the good cost-reducing and efficiency-improving performance is achieved; in addition, according to the scheme, operation is easy, construction is convenient, the operation period is greatly shortened, operation cost is saved, the safety coefficient of a well site is increased, risks are reduced, and construction conditions are improved.

Description

Technical Field

[0001] The invention relates to the technical field of oilfield scale dissolving, in particular to a novel environment-friendly composite scale dissolving and plugging remover. Background Art

[0002] The oil field is in the stage of development with extremely high water content, with an average water content of more than 92%. After long-term water injection development, due to changes in reservoir pressure and temperature or mixing of incompatible water phases, the problem of solid phase blockage in the formation and wellbore has become increasingly prominent, affecting crude oil production. The main types of composite solid phase blockage in oil fields are sulfates (calcium sulfate, barium sulfate, strontium sulfate), carbonates (calcium carbonate, carbonates), mud (calcium silicate), iron (corrosion products FeS, etc.), and organic matter (colloids, asphaltene, wax).

[0003] In addition, in order to increase the productivity of a single well, most oil fields currently use acidizing measures during production. However, excessive use of acidizing measures has the following drawbacks:

[0004] ① The acid-rock reaction speed is fast and the blockage removal radius is limited;

[0005] ②, destroy the rock skeleton and make it easy to collapse;

[0006] ③. It can form secondary pollution such as calcium fluoride and fluorosilicate;

[0007] ④. Construction requires moving the pipe column, which is highly corrosive to the pipe column and has high construction risks;

[0008] ⑤. Residual acid needs to be discharged, which is difficult to handle and has high cost;

[0009] ⑥. Not suitable for acid-sensitive reservoirs.

[0010] Based on the above defects of acidizing technology, the scale dissolution technology without moving tubing is the development direction of oil and water well production enhancement technology.

[0011] Disscaling technology is a common measure to remove blockages in near-well formations and restore and improve reservoir permeability. Oilfield disscaling refers to the use of chemical agents or other technical means to remove minerals or organic substances (scale) deposited in oil well equipment, pipelines, reservoirs and other facilities during oilfield production to restore production efficiency or ensure the normal operation of equipment. These scales are generally formed by the deposition of minerals in water, such as metal salts such as calcium, magnesium, and iron, and are prone to form scales, especially after water is injected into aquifers. The purpose of oilfield disscaling is usually to reduce equipment wear, increase production capacity, improve oil and gas production, and prevent problems such as blockage and corrosion caused by scale accumulation.

[0012] Scale dissolving technology is generally achieved through scale dissolving agents. However, most of the existing scale dissolving agents have a single component and a single function, which is only chelation. There are technical bottlenecks in practical applications. It is necessary to explore new scale removal and unblocking mechanisms to improve treatment efficiency and quality and ensure that the residual liquid after the reaction does not flow back directly into the ground system. Summary of the invention

[0013] The purpose of the present invention is to provide a novel environmentally friendly composite scale dissolving and plugging removing agent to solve the technical bottleneck problem that most scale dissolving agents in the prior art have a single component and a single function, namely, chelation, in practical applications.

[0014] To achieve the above object, the present invention provides the following technical solution: a novel environmentally friendly composite scale dissolving and plugging remover, the environmentally friendly composite scale dissolving and plugging remover comprising the following components and mass fractions:

[0015] 21-33 parts of DTPAMA, 7-11 parts of disodium EDTA, 2-3 parts of corrosion inhibitor, 0.6-1 parts of surfactant, 0.5-1.5 parts of stabilizer, 70-100 parts of water, 10-15 parts of lower alcohol, 3-5 parts of plant extract, 1-3 parts of polyvinyl alcohol, 1.5-4.5 parts of amino acid chelating agent.

[0016] Preferably, the environmentally friendly composite scale dissolving and blocking removing agent further comprises saponins, and the mass fraction of the saponins is 2 to 7 parts.

[0017] Preferably, the environmentally friendly composite scale dissolving and plugging removing agent further comprises polyacrylic acid and polyvinyl ether, and the mass ratio of polyvinyl alcohol, polyacrylic acid and polyvinyl ether is 2:1:3.

[0018] Preferably, the mass ratio of DTPAMA to disodium EDTA is 3:1.

[0019] Preferably, the corrosion inhibitor comprises one or more of triethanolamine, pyridine and tea polyphenols.

[0020] Preferably, the surfactant is one or more of sodium lauryl sulfate, cocamidopropyl betaine, and tetramethylammonium chloride.

[0021] Preferably, the stabilizer is one or more of sodium sulfite, sodium bisulfite, and sodium acetate.

[0022] Preferably, the lower alcohol is one or more of ethylene glycol, propylene glycol, glycerol and ethanol.

[0023] Preferably, the plant extract is one or more of seaweed extract, lemon extract and orange peel extract.

[0024] Preferably, the amino acid complexing agent is one or more of glycine, glutamic acid, and cysteine.

[0025] The present invention has at least the following beneficial effects:

[0026] (1) The novel environmentally friendly composite scale dissolving and plugging removing agent provided by the present invention combines solubilization, penetration, dispersion and chelation together through the synergy of various components, has the functions of reservoir protection, scale removal and plugging removal, has a high descaling rate, and has good cost reduction and efficiency improvement performance;

[0027] (2) The novel environmentally friendly composite scale dissolving and plugging removing agent provided by the present invention is simple to operate and convenient to construct, which greatly shortens the operation cycle and saves operation costs. Moreover, it also improves the safety factor of the well site, reduces risks, and improves construction conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a sample diagram of iron-calcium scale used for testing the product obtained in Example 1 of the present invention;

[0029] Figure 2 This is the scale dissolution diagram of the iron-calcium scale sample tested by the product obtained in Example 1 of the present invention after 60 hours;

[0030] Figure 3 This is a sample diagram of barium strontium sulfate scale used for testing the product obtained in Example 2 of the present invention;

[0031] Figure 4 This is the scale dissolution diagram of the barium strontium sulfate scale sample tested by the product obtained in Example 2 of the present invention after 60 hours;

[0032] Figure 5 The new environmentally friendly composite scale dissolving and plugging removing agent prepared in Example 3 of the present invention is used in the No. 1 test oil well, and the performance diagram before treatment;

[0033] Figure 6 The new environmentally friendly composite scale dissolving and plugging removing agent prepared in Example 3 of the present invention is used in the No. 1 test oil well, and the performance diagram after treatment;

[0034] Figure 7 The new environmentally friendly composite scale dissolving and plugging removing agent prepared in Example 3 of the present invention is used in the No. 2 test oil well, and the performance diagram before treatment;

[0035] Figure 8 The new environmentally friendly composite scale dissolving and plugging removing agent prepared in Example 3 of the present invention is used in the No. 2 test oil well, and the performance diagram after treatment;

[0036] Fig. 9 The new environmentally friendly composite scale dissolving and plugging removing agent prepared in Example 4 of the present invention is used in the No. 3 test oil well, and the performance diagram before treatment;

[0037] Fig.10 The new environmentally friendly composite scale dissolving and plugging removing agent prepared in Example 4 of the present invention is used in the No. 3 test oil well, and the performance diagram after treatment;

[0038] Fig.11 The new environmentally friendly composite scale dissolving and plugging remover prepared in Example 6 of the present invention was used in the No. 4 test oil well, and the daily oil production and water content before and after the construction were compared. DETAILED DESCRIPTION

[0039] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0040] The present invention provides a novel environmentally friendly composite scale dissolving and plugging removing agent, comprising the following components and mass fractions:

[0041] 21-33 parts of DTPAMA, 7-11 parts of disodium EDTA, 2-3 parts of corrosion inhibitor, 0.6-1 parts of surfactant, 0.5-1.5 parts of stabilizer, 70-100 parts of water, 10-15 parts of lower alcohol, 3-5 parts of plant extract, 1-3 parts of polyvinyl alcohol, 1.5-4.5 parts of amino acid chelating agent.

[0042] Furthermore, the environmentally friendly composite scale dissolving and blocking removing agent also includes saponins, and the mass fraction of saponins is 2 to 7 parts.

[0043] Furthermore, the environmentally friendly composite scale dissolving and plugging removing agent also includes polyacrylic acid and polyvinyl ether, and the mass ratio of polyvinyl alcohol, polyacrylic acid and polyvinyl ether is 2:1:3.

[0044] Furthermore, the mass ratio of DTPAMA to disodium EDTA is 3:1.

[0045] Furthermore, the corrosion inhibitor comprises one or more of triethanolamine, pyridine and tea polyphenols.

[0046] Furthermore, the surfactant is one or more of sodium lauryl sulfate, cocamidopropyl betaine, and tetramethylammonium chloride.

[0047] Furthermore, the stabilizer is one or more of sodium sulfite, sodium bisulfite, and sodium acetate.

[0048] Furthermore, the lower alcohol is one or more of ethylene glycol, propylene glycol, glycerol, and ethanol.

[0049] Furthermore, the plant extract is one or more of seaweed extract, lemon extract, and orange peel extract.

[0050] Furthermore, the amino acid complexing agent is one or more of glycine, glutamic acid, and cysteine.

[0051] Based on the above technical solutions, this patent provides the following partial embodiments:

[0052] Example 1

[0053] This embodiment provides a novel environmentally friendly composite scale dissolving and plugging removing agent, including the following components and mass fractions:

[0054] 33 parts of DTPAMA, 11 parts of disodium EDTA, 3 parts of corrosion inhibitor, 1 part of surfactant, 1.5 parts of stabilizer, 100 parts of water, 15 parts of lower alcohol, 5 parts of plant extract, 3 parts of polyvinyl alcohol, and 4.5 parts of amino acid chelating agent.

[0055] Among them, the mass ratio of DTPAMA and disodium EDTA is 3:1.

[0056] Among them, the corrosion inhibitor is pyridine; the surfactant is cocamidopropyl betaine; and the stabilizer is sodium bisulfite.

[0057] The lower alcohol is propylene glycol; the plant extract includes lemon extract; and the amino acid chelating agent is glutamic acid.

[0058] Example 2

[0059] This embodiment provides a novel environmentally friendly composite scale dissolving and plugging removing agent, including the following components and mass fractions:

[0060] 21 parts of DTPAMA, 7 parts of disodium EDTA, 2 parts of corrosion inhibitor, 0.6 parts of surfactant, 0.5 parts of stabilizer, 70 parts of water, 10 parts of lower alcohol, 3 parts of plant extract, 1 part of polyvinyl alcohol, and 1.5 parts of amino acid chelating agent.

[0061] Among them, the mass ratio of DTPAMA and disodium EDTA is 3:1.

[0062] Among them, the corrosion inhibitor is triethanolamine; the surfactant is sodium dodecyl sulfate; and the stabilizer is sodium sulfite.

[0063] The lower alcohol is ethylene glycol; the plant extract includes seaweed extract; and the amino acid chelating agent is glycine.

[0064] Example 3

[0065] This embodiment provides a novel environmentally friendly composite scale dissolving and plugging removing agent, including the following components and mass fractions:

[0066] 27 parts of DTPAMA, 9 parts of disodium EDTA, 2.5 parts of corrosion inhibitor, 0.8 parts of surfactant, 1.2 parts of stabilizer, 90 parts of water, 14 parts of lower alcohol, 4 parts of plant extract, 2 parts of polyvinyl alcohol, and 3.5 parts of amino acid complexing agent.

[0067] Among them, the mass ratio of DTPAMA and disodium EDTA is 3:1.

[0068] The corrosion inhibitor is tea polyphenols; the surfactant is tetramethylammonium chloride; and the stabilizer is sodium acetate.

[0069] The lower alcohol is glycerol; the plant extract includes one or more of orange peel extracts; and the amino acid complexing agent is cysteine.

[0070] Example 4

[0071] This embodiment provides a novel environmentally friendly composite scale dissolving and plugging removing agent, including the following components and mass fractions:

[0072] 24 parts of DTPAMA, 8 parts of disodium EDTA, 2.2 parts of corrosion inhibitor, 0.9 parts of surfactant, 0.8 parts of stabilizer, 75 parts of water, 11 parts of lower alcohol, 3.5 parts of plant extract, 1.8 parts of polyvinyl alcohol, 2 parts of amino acid chelating agent, and 2 parts of saponin.

[0073] Among them, the mass ratio of DTPAMA and disodium EDTA is 3:1.

[0074] Among them, the corrosion inhibitor is a mixture of triethanolamine and pyridine, and the mixing mass ratio of triethanolamine and pyridine is 1:3; the surfactant is a mixture of sodium dodecyl sulfate and tetramethylammonium chloride, and the mixing mass ratio is 2:1; the stabilizer is a mixture of sodium sulfite and sodium bisulfite, and the mixing mass ratio is 1:1.5.

[0075] Among them, the lower alcohol is ethanol; the plant extract includes a mixture of seaweed extract and lemon extract, and the mixing mass ratio is 2:1; the amino acid chelating agent is a mixture of glycine and glutamic acid, and the mixing mass ratio is 1:1.

[0076] Example 5

[0077] This embodiment provides a novel environmentally friendly composite scale dissolving and plugging removing agent, including the following components and mass fractions:

[0078] 30 parts of DTPAMA, 10 parts of disodium EDTA, 2.4 parts of corrosion inhibitor, 0.8 parts of surfactant, 1.1 parts of stabilizer, 85 parts of water, 13 parts of lower alcohol, 4.5 parts of plant extract, 2.7 parts of polyvinyl alcohol, 3.9 parts of amino acid chelating agent, and 7 parts of saponin.

[0079] Among them, the mass ratio of DTPAMA and disodium EDTA is 3:1.

[0080] Among them, the corrosion inhibitor is a mixture of pyridine and tea polyphenols, and the mixing mass ratio is 1:1; the surfactant is a mixture of sodium dodecyl sulfate and cocamidopropyl betaine, and the mixing mass ratio is 1:1.5; the stabilizer is a mixture of sodium bisulfite and sodium acetate, and the mixing mass ratio is 1:2.5.

[0081] Among them, the lower alcohol is a mixture of ethylene glycol and glycerol, and the mixing mass ratio is 2:1; the plant extract is a mixture of lemon extract and orange peel extract, and the mixing mass ratio is 1:1; the amino acid chelating agent is a mixture of glycine and cysteine, and the mixing mass ratio is 1:3.

[0082] Example 6

[0083] This embodiment provides a novel environmentally friendly composite scale dissolving and plugging removing agent, including the following components and mass fractions:

[0084] 21 parts of DTPAMA, 7 parts of disodium EDTA, 2 parts of corrosion inhibitor, 0.6 parts of surfactant, 0.5 parts of stabilizer, 70 parts of water, 10 parts of lower alcohol, 3 parts of plant extract, 1 part of polyvinyl alcohol, and 1.5 parts of amino acid chelating agent.

[0085] In addition, polyacrylic acid and polyvinyl ether are also included, and the mass ratio of polyvinyl alcohol, polyacrylic acid and polyvinyl ether is 2:1:3.

[0086] Among them, the mass ratio of DTPAMA and disodium EDTA is 3:1.

[0087] The corrosion inhibitor is pyridine; the surfactant is sodium dodecyl sulfate; and the stabilizer is sodium acetate.

[0088] The lower alcohol is ethylene glycol; the plant extract is seaweed extract; and the amino acid chelating agent is cysteine.

[0089] Comparative Example 1

[0090] This comparative example provides a scale dissolving agent, comprising the following components and weight fractions:

[0091] 33 parts DTPAMA, 11 parts disodium EDTA, 100 parts water.

[0092] Comparative Example 2

[0093] This comparative example provides a scale dissolving agent, comprising the following components and weight fractions:

[0094] 21 parts DTPAMA, 7 parts disodium EDTA, 70 parts water.

[0095] Comparative Example 3

[0096] This comparative example provides a scale dissolving agent, comprising the following components and weight fractions:

[0097] 27 parts DTPAMA, 9 parts disodium EDTA, 90 parts water.

[0098] The novel environmentally friendly composite scale dissolving and plugging removing agent provided by the present invention is different from the single chelating effect of the prior art. Through the mutual cooperation of various components, solubilization, penetration, dispersion and chelation are combined together, and the following technical effects are achieved:

[0099] ①. Clean the solid surface, peel off the surface oil film, and dissolve the organic components;

[0100] ②, Penetrate into the interior of the scale along the surface pores to accelerate scale dissolution;

[0101] ③. Multi-point complexation and dispersion to promote the decomposition of scale from lumps to small particles;

[0102] ④. Chelate the scale ions on the surface of inorganic scale and promote the dissolution of scale.

[0103] The scale dissolving and plugging removing performance of the products provided in the above examples and comparative examples was tested, and the results are shown in the following table:

[0104]

[0105] As can be seen from the above table, the present invention provides a new type of environmentally friendly composite scale dissolving and plugging remover, which has a strong scale dissolving and plugging removal effect on a variety of scale types, is widely used, and has significantly better scale dissolving performance than traditional scale dissolving and plugging removers. From the test results, it can be seen that the scale dissolving rates of Examples 1 to 6 are all higher than 90%, among which the scale dissolving rate of Example 5 when treating ferrous sulfide scale reaches 97.1%, showing the best scale dissolving effect. In contrast, the scale dissolving rates of Comparative Examples 1 to 3 are all lower than 80%, which shows that the composite scale dissolving and plugging remover of the present invention has significant advantages in practical applications.

[0106] In addition, the novel environmentally friendly composite scale dissolving and plugging removing agent provided by the present invention has good environmental performance, and its composition and reaction process meet environmental protection requirements and will not cause secondary pollution to the environment.

[0107] Figure 1-Figure 2 The product obtained in Example 1 of the present invention is used for the comparison of the iron-calcium scale dissolving effect of the test; Figure 3-Figure 4 The product obtained in Example 2 of the present invention is used for the comparison of the barium strontium sulfate scale dissolving effect in the test.

[0108] The construction method of a novel environmentally friendly composite scale dissolving and blocking agent provided by the present invention is as follows:

[0109] 1. There are two construction schemes for descaling and pump jam removal of oil well fixed pipes, as follows:

[0110] Solution 1:

[0111] Injection: Use a pump tanker to inject water into the wellbore through the casing, and the formation water is displaced to the predetermined position;

[0112] Soaking: Soak for 24-48 hours.

[0113] Option 2:

[0114] Injection: Added into the wellbore through casing;

[0115] Circulation: Connect the tubing and casing valves, start pumping, and allow the agent to circulate in the tubing and casing annulus.

[0116] 2. Process for removing formation blockage without moving the pipe string in oil wells:

[0117] Injection method: inject into the casing annulus without moving the tubing string;

[0118] Displacement: 0.1-0.5m3 / min;

[0119] Well shut-in response time: more than 48 hours.

[0120] Among them, the oil well fixed tubing descaling and pump jam removal process and the oil well fixed tubing unblocking formation blockage removal process are both downhole operations carried out in oil and gas wells to solve the problems of production interruption or production decline caused by different problems in the wellbore or oil and gas layer. Both processes belong to fixed tubing operations, but the applicable scenarios and technical means are different:

[0121] ①、Oil well stationary tubing descaling and pump jam removal process:

[0122] Objective: To resolve production stagnation or pump equipment failure caused by oil well pump sticking, scale deposition, oil well pump sticking and other problems, and ensure the normal operation of downhole pumps.

[0123] Applicable situations: The oil well pump is stuck or jammed, resulting in abnormal operation; there is too much scale and sediment in the pump body or pump pipe, resulting in the inability to smoothly extract the fluid; the internal and external equipment of the pump is blocked, seriously affecting the oil production efficiency.

[0124] ②. Technology for removing formation blockage without moving the oil well pipe string:

[0125] Objective: To eliminate blockage problems caused by sediments, minerals, hydrates, waxes and other substances in the formation and restore normal production of oil and gas wells.

[0126] Applicable situations: Formation blockage leading to obstruction of oil and gas flow; production decline and difficulty in fluid transportation; blockage problems in bad wells, low permeability oil layers, deep wells and other environments.

[0127] The application effect of a new type of environmentally friendly composite scale dissolving and plugging remover provided by the present invention was tested, and the results are as follows:

[0128] (1) Scale dissolution of the stationary tubing to resolve pump jams:

[0129] Injection: Inject 3-5 cubic meters of fluid into the wellbore through the casing by gravity;

[0130] Filling: Fill the casing with about 12 cubic meters of liquid;

[0131] Drawer: Use the drawer to allow the deblocking liquid to soak the oil pump. After 24 hours, resume production.

[0132] The injection process is simple and convenient, does not move the pipe column, and saves construction time.

[0133] Figure 5-Figure 6 The new environmentally friendly composite scale dissolving and plugging removing agent prepared in Example 3 of the present invention was used in the No. 1 test oil well. The performance chart before and after treatment was compared, and the performance chart showed that it had returned to normal. The production before treatment was 3.1 / 0.3 / 91.5%; after treatment, the production was 11.5 / 1.3 / 88.8%.

[0134] Figure 7-Figure 8 The new environmentally friendly composite scale dissolving and plugging removing agent prepared in Example 3 of the present invention was used in the No. 2 test oil well. The performance chart before and after treatment was compared, and the performance chart showed that it had returned to normal. The production before treatment was 4.3 / 0.5 / 88.4%; after treatment, the production was 5.4 / 0.8 / 85.8%.

[0135] Figure 9-10 The new environmentally friendly composite scale dissolving and plugging removing agent prepared in Example 4 of the present invention was used in the No. 3 test oil well, and the effect before and after treatment was compared. After treatment: the fluid supply was restored, normal production was achieved, and the operating cost was saved by 70,000 yuan.

[0136] (2) Remove formation blockage without moving the pipe string:

[0137] Fig.11 The new environmentally friendly composite scale dissolving and plugging remover prepared in Example 6 of the present invention was used in the No. 4 test oil well, and the daily oil production and water content before and after the construction were compared. The daily oil production increased by 1 ton, the water content decreased by 20%, and the blockage near the well was removed, the operation cycle was shortened by 3-5 days, and the operation cost of a single well was saved by 150,000 to 200,000 yuan.

[0138] In summary, the novel environmentally friendly composite scale dissolving and plugging remover provided by the present invention has the functions of reservoir protection, scale removal and plugging removal, has a high descaling rate, and has good cost reduction and efficiency improvement performance; the unblocking measures for oil and water wells without moving the tubing string can shorten the operation cycle by 3-5 days, and save 150,000 to 200,000 yuan in operating costs for a single well; the maintenance measures for oil and water wells without moving the tubing string are simple to operate and convenient to construct, and save 60,000 to 100,000 yuan in operating costs for a single well; in addition, the novel environmentally friendly composite scale dissolving and plugging remover provided by the present invention also improves the safety factor of the well site, reduces the operating risks of employees, and improves the construction conditions.

[0139] The above shows and describes the basic principles, main features and advantages of the present invention. It is obvious to those skilled in the art that the present invention is not limited to the details of the above exemplary embodiments, and that the present invention can be implemented in other specific forms without departing from the spirit or basic features of the present invention. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims are included in the present invention.

[0140] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A new type of environmentally friendly composite scale dissolving and plugging agent, characterized in that: The environmentally friendly composite scale dissolving and plugging removing agent includes the following components and mass fractions: 21-33 parts of DTPAMA, 7-11 parts of disodium EDTA, 2-3 parts of corrosion inhibitor, 0.6-1 parts of surfactant, 0.5-1.5 parts of stabilizer, 70-100 parts of water, 10-15 parts of lower alcohol, 3-5 parts of plant extract, 1-3 parts of polyvinyl alcohol, 1.5-4.5 parts of amino acid chelating agent.

2. A novel environmentally friendly composite scale dissolving and plugging removing agent according to claim 1, characterized in that: The environmentally friendly composite scale dissolving and blocking removing agent also includes saponins, and the mass fraction of the saponins is 2 to 7 parts.

3. The novel environmentally friendly composite scale dissolving and plugging removing agent according to claim 1 is characterized by: The environmentally friendly composite scale dissolving and plugging removing agent also includes polyacrylic acid and polyvinyl ether, and the mass ratio of polyvinyl alcohol, polyacrylic acid and polyvinyl ether is 2:1:

3.

4. The novel environmentally friendly composite scale dissolving and plugging removing agent according to claim 1 is characterized by: The mass ratio of the DTPAMA to disodium EDTA is 3:

1.

5. The novel environmentally friendly composite scale dissolving and plugging removing agent according to claim 1 is characterized by: The corrosion inhibitor comprises one or more components of triethanolamine, pyridine and tea polyphenols.

6. The novel environmentally friendly composite scale dissolving and plugging removing agent according to claim 1 is characterized by: The surfactant is one or more of sodium lauryl sulfate, cocamidopropyl betaine, and tetramethyl ammonium chloride.

7. The novel environmentally friendly composite scale dissolving and plugging removing agent according to claim 1 is characterized by: The stabilizer is one or more of sodium sulfite, sodium bisulfite and sodium acetate.

8. The novel environmentally friendly composite scale dissolving and plugging removing agent according to claim 1 is characterized by: The lower alcohol is one or more of ethylene glycol, propylene glycol, glycerol and ethanol.

9. The novel environmentally friendly composite scale dissolving and plugging removing agent according to claim 1 is characterized by: The plant extract is one or more of seaweed extract, lemon extract and orange peel extract.

10. The novel environmentally friendly composite scale dissolving and plugging removing agent according to claim 1 is characterized by: The amino acid complexing agent is one or more of glycine, glutamic acid and cysteine.

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