A dual-component composite flocculant, a preparation method, a use method and an application thereof

Abstract

The present application belongs to the field of oilfield environmental protection technology, and relates to a two-component composite flocculant, a preparation method, a use method and application thereof. The preparation method of the two-component composite flocculant comprises the following steps: (1) dissolving a chlorinated metal salt in water to prepare a solution, adding acid to adjust the pH to be acidic, and drying to obtain a chlorinated composite metal salt flocculant A; (2) preparing a solution of a peroxide and an organic acid, adding a stabilizer, and drying to obtain a modified organic acid salt flocculant B. The two-component composite flocculant comprises the chlorinated composite metal salt flocculant A and the modified organic acid salt flocculant B. After the two flocculants are mixed, the effect of "oxidized species chain breaking and destabilization-organic network net trapping and flocculation" is generated, efficient solid-liquid separation of water-based drilling fluid waste is realized, and the two-component composite flocculant has the characteristics of simple operation, short treatment period, good treatment effect and small dosage.

Description

Technical Field

[0001] This invention belongs to the field of oilfield environmental protection technology, and relates to a two-component composite flocculant and its preparation method, usage method and application, especially a water-based drilling fluid waste sequential addition type two-component composite flocculant and its preparation method, usage method and application. Background Technology

[0002] my country is placing increasing emphasis on offshore oil exploration, with extraction efforts intensifying year by year. In recent years, water-based drilling fluids have become the most widely used drilling fluid in my country's offshore oil drilling due to their low cost and mature processing technology. However, this has also generated a large amount of water-based drilling fluid waste. Water-based drilling fluids are formulated with a large number of functional additives such as viscosity reducers, filtration reducers, lubricants, anti-collapse agents, leak plugging agents, shale inhibitors, and emulsifiers. The solid content of the waste drilling fluid can reach 35%–60%, and the organic matter content can reach 30g / L. -1 With a zeta potential as low as -40mV, the drilling fluid exhibits complex interactions between its organic polymers and inorganic drill cuttings, resulting in a highly stable, non-Newtonian fluid state. This makes solid-liquid separation difficult and severely restricts the recycling of water-based drilling fluids.

[0003] Compared to onshore oil fields, offshore drilling platforms are smaller in area, have more compact equipment, and require higher operational safety standards. The environmental friendliness and speed of waste drilling fluid treatment on offshore drilling platforms are also higher than those onshore. Therefore, drilling fluid solid-liquid separation treatment agents suitable for offshore drilling platforms must simultaneously consider safety, ease of operation, speed, and efficiency. They must avoid the use of hazardous chemicals, be easy to prepare, have short treatment times, and not introduce difficult-to-remove harmful components that could affect filtrate reuse.

[0004] Existing flocculation technologies are mainly used in water treatment, and there is still a lack of specific agents for flocculating waste water-based drilling fluids. For example, Chinese invention patent application number 201310352916.9 discloses a method for preparing polyaluminum ferric chloride-polyepoxychloropropane-ethylenediamine. This method includes: preparing a polyepoxychloropropane-ethylenediamine solution; preparing a polyaluminum ferric chloride solution; and placing the prepared polyepoxychloropropane-ethylenediamine solution and the polyaluminum ferric chloride solution in an ultrasonic generator at a weight ratio of 1:20 to 1:50 for ultrasonic vibration to prepare a polyaluminum ferric chloride-polyepoxychloropropane-ethylenediamine flocculant. The product prepared by this invention is a composite of polyaluminum ferric chloride and polyepoxychloropropane-ethylenediamine, mainly used for the decolorization treatment of dye wastewater.

[0005] Chinese invention patent application number 02117325.7 discloses a method for coagulation and dewatering waste drilling fluid. The method includes: adding an inorganic aluminum salt coagulant and an organic cationic polyelectrolyte flocculant solution to the waste drilling fluid, stirring thoroughly, and then allowing it to stand for coagulation for 10-15 minutes; after the waste drilling fluid has been completely chemically destabilized and dewatered, the agglomerated flocs and some of the flocculated water are centrifuged for dewatering; the inorganic aluminum salt coagulant is preferably aluminum trichloride, with a dosage of 2000-3500 mg / L; the organic cationic polyelectrolyte flocculant is an organic cationic polyelectrolyte with quaternary ammonium salt cationic functional groups. Under the synergistic effect of coagulation and flocculation by the inorganic aluminum salt coagulant and the organic cationic polyelectrolyte flocculant, suspended fine particles are agglomerated into large flocs, which are then centrifuged for dewatering, ultimately achieving solid-liquid separation of the waste drilling fluid. However, because aluminum ions are usually introduced into the flocculant, affecting the reuse of the filtrate, this method is not suitable for the flocculation treatment of offshore waste water-based drilling fluids.

[0006] Chinese invention patent CN1342505A discloses a method for solidifying waste water-based drilling fluid and its solidifying agent, which consists of waste water-based drilling fluid and a solidifying agent formulation. The formulation includes 1-6% inorganic iron salt coagulant, 0.1-0.6% clay adsorbent, 1-6% magnesia, and 1-10% cement binder. This formulation can solidify waste water-based drilling fluid into a solidified body with good water resistance and a certain strength after 3-6 days. The leachate from the solidified body has a pH ≤ 7.5, total Cr ≤ 1.5 mg / L, CODcr ≤ 200 mg / L, and petroleum hydrocarbons ≤ 10 mg / L. However, the ferric chloride used in the formulation is a hazardous chemical with corrosive and toxic properties, increasing operational safety hazards and resulting in a long treatment cycle and reduced overall treatment efficiency.

[0007] Traditional flocculants such as polyaluminum sulfate and polyferric sulfate introduce harmful components and produce filtrates with high levels of sulfate ions, significantly hindering filtrate reuse and making them unsuitable for treating drilling fluids on offshore drilling platforms. Polyacrylamide dissolves slowly, requires long preparation times, and is ineffective in polymer-based drilling fluid systems. Therefore, there is an urgent need to develop and screen targeted agents suitable for treating drilling fluids on offshore drilling platforms, avoiding the use of hazardous chemicals and the introduction of difficult-to-remove harmful components, to achieve efficient flocculation of drilling fluids and meet filtrate reuse requirements. Summary of the Invention

[0008] To address the aforementioned technical problems, this invention provides a two-component composite flocculant, its preparation method, usage method, and application.

[0009] Specifically, the present invention is achieved through the following technical solutions.

[0010] A method for preparing a two-component composite flocculant, comprising:

[0011] (1) Dissolve the metal chloride salt in water to prepare a solution, add acid to adjust the pH to acidic, and dry to obtain the chloride composite metal salt flocculant A;

[0012] (2) Prepare a solution by mixing peroxide and organic acid, add stabilizer, and dry to obtain modified organic acid salt flocculant B.

[0013] In the above-mentioned method for preparing a two-component composite flocculant, the chloride metal salt includes any one or more of ferrous chloride, ferric chloride, cerium trichloride, zirconium oxychloride, and copper chloride.

[0014] In the preparation method of the above-mentioned two-component composite flocculant, in step (1), the acid includes any one or more of hydrochloric acid, nitric acid, formic acid, and phosphoric acid.

[0015] In the above-mentioned method for preparing a two-component composite flocculant, the concentration of the solution prepared with the metal chloride salt is 0.005–800 g / L.

[0016] In the above-mentioned method for preparing a two-component composite flocculant, in step (1), the pH value of the solution after adding acid is ≤4.

[0017] In the above-mentioned method for preparing a two-component composite flocculant, the peroxide includes any one of sodium percarbonate, urea peroxide, and hydrogen peroxide with a concentration of 1-50%.

[0018] In the above-mentioned method for preparing a two-component composite flocculant, the organic acid includes any one or a mixture of several of citrate, oxalate, tartrate, acetate, lactate, pyruvate, and malate.

[0019] The above-mentioned method for preparing two-component composite flocculants uses a solution concentration of 0.002–1000 g / L prepared from peroxide and organic acid.

[0020] The stabilizer in the above-mentioned method for preparing the two-component composite flocculant includes any one or a mixture of several of the following: benzoic acid, salicylic acid, 8-hydroxyquinoline, EDTA, sodium pyrophosphate, sodium hexametaphosphate, and polyvinyl alcohol.

[0021] In the above-mentioned method for preparing a two-component composite flocculant, the weight ratio of the peroxide, the organic acid, and the stabilizer is (1-5):(1-5):(0.001-0.3), and more preferably (1-2):(1-2):(0.02-0.06).

[0022] In the above-mentioned method for preparing a two-component composite flocculant, the weight ratio of the chloride composite metal salt flocculant A to the modified organic acid salt flocculant B is (1-4):(1-4), and more preferably (1-2):(1-2).

[0023] A two-component composite flocculant is prepared using the above-mentioned method for preparing two-component composite flocculants.

[0024] A method for preparing a two-component composite flocculant and a method for using the prepared two-component composite flocculant, comprising:

[0025] The chlorinated composite metal salt flocculant A and the modified organic acid salt flocculant B are respectively added to the water-based drilling fluid waste, mixed thoroughly, and then separated into solid and liquid components; or...

[0026] Prepare a solution of chloride-based composite metal salt flocculant A and a solution of modified organic acid salt flocculant B, then add them separately to water-based drilling fluid waste, mix them thoroughly, and separate the solid and liquid components.

[0027] The above-mentioned method for preparing a two-component composite flocculant involves converting the chlorinated composite metal salt flocculant A and the modified organic acid salt flocculant B into solids, and then adding them to water-based drilling fluid waste at a dosage of 0.1 to 10 wt%.

[0028] The above-mentioned method for preparing a two-component composite flocculant and the method for using the two-component composite flocculant, wherein the water-based drilling fluid waste includes drilling and completion fluid returned during drilling, well washing fluid discharged during oil reservoir stimulation, fracturing fluid, and various types of wastewater generated during drilling and completion operations.

[0029] The application of the two-component composite flocculant prepared by the above-mentioned method in the treatment of water-based drilling fluid waste.

[0030] In the above applications, the water-based drilling fluid waste refers to the waste drilling fluid from offshore drilling platforms.

[0031] The technical solution of the present invention has the following beneficial effects:

[0032] (1) The two-component composite flocculant of the present invention includes chlorinated composite metal salt flocculant A and modified organic acid salt flocculant B. After the two flocculants are mixed, they produce the effect of "oxide chain destabilization - organic network capture and flocculation", which realizes efficient solid-liquid separation of water-based drilling fluid waste. It has the characteristics of simple operation, short treatment cycle, good treatment effect and low dosage.

[0033] (2) The dehydration rate of drilling fluid waste treated with the two-component composite flocculant of the present invention reaches more than 70%, the solid phase water content is less than 35%, the flocculation effect is good, and no ions that affect reuse are introduced. Detailed Implementation

[0034] To fully understand the purpose, features, and effects of this invention, the following detailed embodiments are provided. Except as described below, the process methods of this invention employ conventional methods or apparatus in the art. Unless otherwise specified, the terms and expressions used below have the meanings commonly understood by those skilled in the art.

[0035] When a range of values ​​is disclosed herein, the range is considered continuous and includes the minimum and maximum values ​​of the range, as well as every value between the minimum and maximum values. Furthermore, when the range refers to integers, it includes every integer between the minimum and maximum values ​​of the range. Additionally, when multiple ranges are provided to describe a feature or characteristic, the ranges may be combined. In other words, unless otherwise specified, all ranges disclosed herein should be understood to include any and all subranges to which they are incorporated.

[0036] Specifically, in a first aspect, the present invention provides a method for preparing a two-component composite flocculant, comprising:

[0037] (1) Dissolve the metal chloride salt in water to prepare a solution, add acid to adjust the pH to acidic, and dry to obtain the chloride composite metal salt flocculant A;

[0038] (2) Prepare a solution by mixing peroxide and organic acid, add stabilizer, and dry to obtain modified organic acid salt flocculant B.

[0039] This invention combines chlorinated composite metal salt flocculant A and modified organic acid salt flocculant B. By using oxidizing active species to destroy the long-chain structure of polymers in drilling fluid, thereby destabilizing them, and combined with the entrapment effect of a three-dimensional organic network, it achieves the effect of "oxide species chain breaking and destabilization - organic network entrapment and flocculation", thus achieving a highly efficient solid-liquid separation effect.

[0040] In some preferred embodiments, the metal salts in the chlorinated composite metal salt flocculant A can be flexibly selected, including any one or more of ferrous chloride, ferric chloride, cerium trichloride, zirconium oxychloride, and copper chloride, which enhances the applicability of the flocculant.

[0041] In some preferred embodiments, in step (1), the acid includes any one or more of hydrochloric acid, nitric acid, formic acid, and phosphoric acid, and the pH value of the solution after adding the acid is ≤4. Adjusting the pH of the metal chloride salt solution can effectively ensure the stability and efficiency of the flocculant.

[0042] In some preferred embodiments, the concentration of the solution prepared using the metal chloride salt is 0.005–800 g / L, more preferably 300–600 g / L.

[0043] In some preferred embodiments, the peroxide includes any one of sodium percarbonate, urea peroxide, and hydrogen peroxide at a concentration of 1% to 50% (preferably 5% to 30%); the organic acid includes any one or a mixture of several of citrate, oxalate, tartrate, acetate, lactate, pyruvate, and malate.

[0044] The modified organic acid salt flocculant B of this invention combines various small molecule organic acids with peroxides, which not only ensures efficient flocculation but also meets the needs of different drilling waste characteristics.

[0045] In some preferred embodiments, the concentration of the solution prepared by using peroxide and organic acid is 0.002 to 1000 g / L, and more preferably 300 to 600 g / L.

[0046] In some preferred embodiments, the stabilizer includes any one or a mixture of several of benzoic acid, salicylic acid, 8-hydroxyquinoline, EDTA, sodium pyrophosphate, sodium hexametaphosphate, and polyvinyl alcohol, thereby ensuring the stability and efficiency of the flocculant.

[0047] In some preferred embodiments, the weight ratio of the peroxide, the organic acid, and the stabilizer is (1-5):(1-5):(0.001-0.3), and more preferably (1-2):(1-2):(0.02-0.06).

[0048] In some preferred embodiments, the weight ratio of the chloride composite metal salt flocculant A to the modified organic acid salt flocculant B in the two-component composite flocculant is (1-4):(1-4), and more preferably (1-2):(1-2).

[0049] This invention ensures that the dehydration rate of the treated waste drilling fluid is higher than 70% and the solid phase water content is lower than 35% by adjusting the concentration and dosage ratio of the chloride composite metal salt flocculant A and the modified organic acid salt flocculant B, effectively achieving solid-liquid separation. This rapid and effective solid-liquid separation results in a short wastewater treatment cycle and saves operation time.

[0050] The drying methods for the chlorinated composite metal salt flocculant A and the modified organic acid salt flocculant B are flexible and diverse, including evaporation crystallization, natural air drying, freeze drying, etc., and the most suitable method can be selected according to the site conditions.

[0051] Secondly, the present invention also provides a two-component composite flocculant, which is prepared by the above-mentioned method for preparing two-component composite flocculants.

[0052] The working principle of this invention's sequentially added two-component composite flocculant is to achieve efficient destabilization and flocculation of water-based drilling fluid waste through the synergistic effect of chain-breaking destabilization by highly oxidizing active species and the entrapment and flocculation by a three-dimensional organic network. Specifically, after flocculant A and flocculant B are mixed, highly oxidizing active species ·OH and Fe(IV) are generated. These two highly oxidizing active species destroy the long-chain structure of high molecular weight polymers in the drilling fluid, achieving efficient destabilization of the drilling fluid. The mixture of flocculant A and flocculant B can also generate a three-dimensional organic network precipitate, which, through a entrapment and sweeping action, efficiently flocculates the drilling fluid, demonstrating significant innovation.

[0053] Thirdly, the present invention also provides a method for using the two-component composite flocculant, comprising:

[0054] The chlorinated composite metal salt flocculant A and the modified organic acid salt flocculant B are respectively added to the water-based drilling fluid waste, mixed thoroughly, and then separated into solid and liquid components; or...

[0055] Prepare a solution of chloride-based composite metal salt flocculant A and a solution of modified organic acid salt flocculant B, then add them separately to water-based drilling fluid waste, mix them thoroughly, and separate the solid and liquid components.

[0056] The two-component composite flocculant of this invention adopts a sequential addition method, where flocculants A and B can be added separately without a specific order and without the need for special mixing equipment, making operation simpler and more convenient. For the compact environment of offshore platforms, this significantly reduces operational difficulty and equipment requirements.

[0057] In some preferred embodiments, the chloride composite metal salt flocculant A and the modified organic acid salt flocculant B, after being converted to solids (i.e., dry weight), are added to water-based drilling fluid waste at a rate of 0.1 to 10 wt% (preferably 1 to 5 wt%).

[0058] The water-based drilling fluid waste refers to a complex emulsified or semi-emulsified system generated during oil drilling operations, consisting of seawater, rock cuttings, chemical additives, heavy metals, and other substances. It mainly includes drilling and completion fluids returned during drilling, as well as well-washing fluids, fracturing fluids, and various types of wastewater generated during oil reservoir stimulation.

[0059] The combined flocculant of this invention does not introduce harmful ions that affect filtrate reuse. After treating water-based drilling fluid waste, the solid-liquid separated filtrate can be directly recycled, meeting the requirements of environmental protection and sustainable development. This characteristic is particularly suitable for offshore drilling operations with high requirements for wastewater recycling.

[0060] In some preferred embodiments, the mixing method is one or a combination of stirring, shaking, and agitation.

[0061] In some preferred embodiments, the solid-liquid separation method includes one or more combinations of pressure filtration, centrifugation, and membrane filtration.

[0062] The two-component composite flocculant of this invention is suitable for various solid-liquid separation methods (pressure filtration, centrifugation, membrane filtration, etc.) and maintains good separation performance under different methods. This characteristic allows the flocculant to adapt to various equipment and process conditions, improving its applicability and flexibility in practical applications.

[0063] Fourthly, the present invention also provides the application of the above-mentioned two-component composite flocculant in the treatment of water-based drilling fluid waste.

[0064] In some preferred embodiments, the water-based drilling fluid waste is waste drilling fluid from offshore drilling platforms.

[0065] The two-component composite flocculant of the present invention avoids the use of high-valence metal ions or hazardous chemicals commonly used in the prior art, significantly reducing environmental risks, and is particularly suitable for application in scenarios with high environmental protection and safety requirements, such as offshore drilling platforms.

[0066] Example

[0067] The present invention is further illustrated below by way of embodiments, but the invention is not limited to the scope of the embodiments described herein. Experimental methods in the following embodiments, unless otherwise specified, were performed according to conventional methods and conditions. The raw materials used in the following embodiments were all commercially available.

[0068] Example 1

[0069] A 500 g / L solution was prepared by mixing ferrous chloride, cerium trichloride, and copper chloride in a mass ratio of 80:20:1, and then adjusting the pH to 3 with phosphoric acid. After evaporation and crystallization, the resulting solid was the chloride-containing composite metal salt flocculant A. A 300 g / L solution was prepared by mixing potassium citrate, sodium percarbonate, and the stabilizer EDTA in a mass ratio of 2:1:0.03, and then evaporating and crystallizing at room temperature. The resulting solid was the modified organic acid salt flocculant B.

[0070] Chlorinated composite metal salt flocculant A and modified organic acid salt flocculant B, with a mass ratio of 10:3, were added to 100 ml of water-based drilling fluid waste at a dosage of 2 wt%. The mixture was stirred evenly and then filtered under a pressure of 100 psi. The liquid removal rate after filtration was 71% and the solid water content was 34%.

[0071] Example 2

[0072] A solution of ferric chloride, copper chloride, and zirconium oxychloride in a mass ratio of 60:40:1 was prepared to a concentration of 750 g / L. Sulfuric acid was added to adjust the pH to 3.4. After evaporation and crystallization, the resulting solid was the chloride-containing composite metal salt flocculant A. A solution of potassium tartrate, urea peroxide, and benzoic acid as a stabilizer in a mass ratio of 1.5:1:0.04 was prepared to a concentration of 500 g / L. After evaporation and crystallization at room temperature, the resulting solid was the modified organic acid salt flocculant B.

[0073] Chlorinated composite metal salt flocculant A and modified organic acid salt flocculant B, with a mass ratio of 7:3, were added to 100 ml of water-based drilling fluid waste, with an addition amount of 2.5 wt%. The mixture was stirred evenly and then filtered under a pressure of 100 psi. The liquid removal rate after filtration was 73% and the solid water content was 33%.

[0074] Example 3

[0075] A solution of ferrous chloride, ferric chloride, and cerium trichloride in a mass ratio of 50:50:1 was prepared to a concentration of 950 g / L. Concentrated hydrochloric acid was added to adjust the pH to 3.7. After evaporation and crystallization, the resulting solid was the chloride-containing composite metal salt flocculant A. A solution of potassium oxalate, 30% hydrogen peroxide, and salicylic acid (as a stabilizer) in a mass ratio of 1:2:0.06 was prepared to a concentration of 600 g / L. This solution was then evaporated and crystallized at room temperature. The resulting solid was the modified organic acid salt flocculant B.

[0076] Chlorinated complex metal salt flocculant A was weighed and dissolved in 100 ml of deionized water to prepare a chlorinated complex metal salt flocculant A solution with an effective content of 40%. Modified organic acid salt flocculant B was weighed and dissolved in 100 ml of deionized water to prepare a modified organic acid salt flocculant B solution with an effective content of 35%. The chlorinated complex metal salt flocculant A solution and the modified organic acid salt flocculant B solution (dry weight ratio 1:1.5) were respectively added to 100 ml of water-based drilling fluid waste, stirred and mixed thoroughly. The dosage was 5 wt%. Filtration was performed at 100 psi pressure, and the liquid removal rate after filtration was determined to be 76%, and the solid water content was 31%.

[0077] Example 4

[0078] A 1000 g / L solution was prepared by mixing ferric chloride, zirconium oxychloride, and cerium trichloride in a mass ratio of 50:50:2, and nitric acid was added to adjust the pH to 3.9. After evaporation and crystallization, the resulting solid was the chlorinated composite metal salt flocculant A. A 500 g / L solution was prepared by mixing potassium lactate, 20% hydrogen peroxide, and the stabilizer 8-hydroxyquinoline in a mass ratio of 1:1.9:0.05, and evaporated and crystallized at room temperature. The resulting solid was the modified organic acid salt flocculant B.

[0079] Chlorinated composite metal salt flocculant A was weighed and dissolved in 100 ml of deionized water to prepare a chlorinated composite metal salt flocculant A solution with an effective content of 40%. Modified organic acid salt flocculant B was weighed and dissolved in 100 ml of deionized water to prepare a modified organic acid salt flocculant B solution with an effective content of 30%. The chlorinated composite metal salt flocculant A solution and the modified organic acid salt flocculant B solution (dry weight ratio 1:1.8) were respectively added to 100 ml of water-based drilling fluid waste, stirred and mixed thoroughly. The dosage was 3.8 wt%. Filtration was performed at 100 psi pressure, and the liquid removal rate after filtration was determined to be 72%, and the solid water content was 34%.

[0080] The present invention has been disclosed above with reference to preferred embodiments. However, those skilled in the art should understand that these embodiments are merely illustrative of the invention and should not be construed as limiting its scope. It should be noted that any variations and substitutions equivalent to these embodiments should be considered to be covered within the scope of the claims. Therefore, the scope of protection of the present invention should be determined by the scope defined in the claims.

Claims

1. A method for preparing a two-component composite flocculant, characterized in that, include: (1) Dissolve the metal chloride salt in water to prepare a solution, add acid to adjust the pH to acidic, and dry to obtain the chloride composite metal salt flocculant A; (2) Prepare a solution by mixing peroxide and organic acid salt, add a stabilizer, and dry to obtain modified organic acid salt flocculant B; The organic acid salts include any one or a mixture of several of citrate, oxalate, tartrate, acetate, lactate, pyruvate, and malate; the stabilizers include any one or a mixture of several of benzoic acid, salicylic acid, 8-hydroxyquinoline, EDTA, sodium pyrophosphate, sodium hexametaphosphate, and polyvinyl alcohol. The weight ratio of the peroxide, the organic acid salt, and the stabilizer is (1~5):(1~5):(0.001~0.3). The chloride metal salts include one or two of ferrous chloride and ferric chloride, and one or two of cerium trichloride and copper chloride.

2. The preparation method according to claim 1, characterized in that, In step (1), the acid includes any one or more of hydrochloric acid, nitric acid, formic acid, and phosphoric acid.

3. The preparation method according to claim 1, characterized in that, The concentration of the solution prepared using the aforementioned metal chloride salt is 0.005~800 g / L.

4. The preparation method according to claim 1, characterized in that, In step (1), the pH value of the solution after adding acid is ≤4.

5. The preparation method according to claim 1, characterized in that, The peroxides include any one of sodium percarbonate, urea peroxide, and hydrogen peroxide at a concentration of 1-50%.

6. The preparation method according to claim 1, characterized in that, The weight ratio of the peroxide, the organic acid salt, and the stabilizer is (1~2):(1~2):(0.02~0.06).

7. The preparation method according to claim 1, characterized in that, In the two-component composite flocculant, the weight ratio of the chloride composite metal salt flocculant A to the modified organic acid salt flocculant B is (1~4):(1~4).

8. The preparation method according to claim 7, characterized in that, In the two-component composite flocculant, the weight ratio of the chloride composite metal salt flocculant A to the modified organic acid salt flocculant B is (1~2):(1~2).

9. A two-component composite flocculant, characterized in that, It is prepared by the preparation method of the two-component composite flocculant according to any one of claims 1 to 8.

10. The method of using the two-component composite flocculant prepared by the preparation method of the two-component composite flocculant according to any one of claims 1 to 8, characterized in that, include: The chlorinated composite metal salt flocculant A and the modified organic acid salt flocculant B were respectively added to the water-based drilling fluid waste, mixed and homogenized, and then separated into solid and liquid components. or, Prepare a solution of chloride-based composite metal salt flocculant A and a solution of modified organic acid salt flocculant B, then add them separately to water-based drilling fluid waste, mix them thoroughly, and separate the solid and liquid components.

11. The method of use according to claim 10, characterized in that, After converting the chlorinated composite metal salt flocculant A and the modified organic acid salt flocculant B into solids, the dosage of the water-based drilling fluid waste is 0.1~10 wt%.

12. The method of use according to claim 10, characterized in that, The water-based drilling fluid waste includes drilling and completion fluids returned during drilling, well washing fluids discharged during reservoir stimulation, fracturing fluids, and various types of wastewater generated during drilling and completion operations.

13. The application of the two-component composite flocculant prepared by the preparation method of any one of claims 1 to 8 in the treatment of water-based drilling fluid waste.

14. The application according to claim 13, characterized in that, The water-based drilling fluid waste refers to the waste drilling fluid from offshore drilling platforms.