Method for preparing strong-inhibition drilling fluid by utilizing fracturing flow-back fluid and water-based drilling fluid

Abstract

The invention relates to a method for preparing a strong inhibitory drilling fluid by using a fracturing flow-back fluid and a water-based drilling fluid, and the method comprises the following steps: 1, adding clear water into a container, adding bentonite accounting for 5-10% of the mass of the clear water while stirring, and continuously stirring for 3-10 h, the clear water being weakly alkaline water, and the bentonite being a commercially available qualified product for oil field drilling fluids; 2, adding sodium carbonate into the container while stirring, measuring the pH value while adding, adjusting the pH value to 8.5-10, and continuously stirring for 5-6.5 hours; 3, adding a glue protecting agent accounting for 0.5-1.6% of the total mass into the mixed solution in the container while stirring, uniformly stirring, and continuously stirring for 6-9 hours; and 4, adding fracturing flow-back fluid which is 1.5-3 times of the volume of the glue solution prepared in the step 3 into the container at a constant speed while stirring, and continuously stirring for 2h-6h. The drilling fluid has protection and stabilization effects on colloid formed by bentonite, the inhibition of the drilling fluid is improved, and resource utilization of wastes is realized.

Description

Technical Field

[0001] The present invention relates to the technical field of waste resource utilization in oil and gas field development, and specifically to a method for preparing a highly inhibitory drilling fluid using fracturing flowback fluid. Background Art

[0002] Fracturing flowback fluid is a liquid containing a solid phase that is discharged after the fracturing operation in oil and gas fields. Its main components include guar gum, preservatives, degumming agents, petroleum and various other chemical additives. This type of liquid has the characteristics of "three highs" (high COD value, high stability, and high viscosity). If it is discharged directly without treatment, it will cause serious harm to the environment. In the development of oil and gas fields, fracturing has become the dominant technology for the development of low-permeability oil and gas fields, and the treatment of fracturing flowback fluid generated after the fracturing operation has always been an important problem faced by the oil and gas industry. Fracturing flowback fluid is difficult to treat and has high treatment costs. It contains a large amount of harmful suspended solids, difficult-to-degrade organic matter, petroleum and other pollutants. It has the characteristics of high viscosity, turbidity, and organic pollutants (with COD as the detection indicator) and strong stability.

[0003] If the fracturing flowback fluid is converted into drilling fluid that can be used for drilling operations through a specific formula and process, not only can the fracturing flowback fluid be efficiently treated and resourced, but also the strong inhibitory property of clay protective gelling agents (such as KCl, ammonium salts, etc.) in the flowback fluid can be used to prepare a highly inhibitory water-based drilling fluid. A highly inhibitory drilling fluid is a drilling fluid with water as a continuous phase. It has good inhibitory properties and stability, and can effectively prevent well wall collapse and formation contamination. By converting fracturing flowback fluid into a highly inhibitory drilling fluid, not only can the treatment problem of fracturing flowback fluid be solved, but also the drilling cost can be reduced and the drilling efficiency can be improved. This technology has broad application prospects and important environmental significance.

[0004] When preparing drilling fluid with clean water and bentonite, the bentonite particles hydrate, swell and disperse into smaller clay flakes, and the particle size is reduced from hundreds of microns to several microns. The dispersed clay flakes form a stable basic drilling fluid with a network structure in the water. However, since a large amount of KCl and other substances are added as clay protective agents during the preparation of fracturing fluid, the concentration of KCl in the flowback fluid is as high as more than 5%. Due to the strong inhibition of KCl, when the flowback fluid is directly prepared with bentonite to prepare the basic drilling fluid, the bentonite particles cannot swell and disperse into smaller particles, and cannot form a stable base slurry with a network structure in the water, that is, it is impossible to directly prepare water-based drilling fluid. In addition, if high-concentration brine is directly added to the basic drilling fluid prepared with clean water, the strong electrolyte will compress the diffuse double layer of the clay flakes, causing the network structure to collapse and produce flocculation, and the required water-based drilling fluid cannot be prepared. Summary of the invention

[0005] To this end, it is necessary to provide a new method for preparing a strong consistency drilling fluid using fracturing return fluid, which can utilize waste resources, save expenses, and improve the effective utilization rate of the product.

[0006] To achieve the above object, the inventor provides a method for preparing a strong inhibitory drilling fluid using fracturing flowback fluid, comprising the following steps:

[0007] The first step is to add clean water into a container, add 5%-10% of the mass of the clean water with bentonite while stirring, and continue stirring for 3h-10h, wherein the clean water is weakly alkaline water and the bentonite is a commercially available qualified product for oilfield drilling fluid;

[0008] The second step is to add sodium carbonate to the above container while stirring, measure the pH while adding, adjust the pH to 8.5-10, and continue stirring for 5-6.5 hours;

[0009] The third step is to add 0.5%-1.6% of the total weight of the protective agent to the mixed liquid in the container while stirring, stir evenly, and continue stirring for 6h-9h;

[0010] The fourth step is to uniformly add 1.5 to 3 times the volume of the fracturing flowback fluid prepared in the third step into the above container while stirring, and control the adding speed to 20% to 50% of the volume of the glue prepared in the third step per hour. After all the fracturing flowback fluid is added, continue stirring for 2h to 6h; the fracturing flowback fluid is a strongly inhibitory flowback fluid.

[0011] In one embodiment of the present application, the clean water is weakly alkaline water containing calcium ions, magnesium ions and potassium ions.

[0012] In one embodiment of the present application, the total content of calcium and magnesium ions is no more than 1000 mg / L, and the content of potassium ions is no more than 100 mg / L.

[0013] In one embodiment of the present application, the protective glue agent is industrial grade polyvinyl alcohol 1788.

[0014] In one embodiment of the present application, the protective glue agent is polyvinyl pyrrolidone.

[0015] In one embodiment of the present application, the adhesive protecting agent is industrial-grade partially hydrolyzed polyacrylamide with a hydrolysis degree of 50% and a molecular weight of 15 million, and a composition thereof.

[0016] In one embodiment of the present application, in the fourth step, a fracturing flowback fluid having a volume three times that of the glue prepared in the third step is added at a uniform speed, and the adding speed is 50% of the volume of the glue prepared in the third step per hour;

[0017] Or, control the uniform speed of adding fracturing flowback fluid of 1.5 times the volume of the glue prepared in the third step, and the adding speed is 20% of the volume of the glue prepared in the third step per hour.

[0018] In one embodiment of the present application, the fracturing flowback fluid is the flowback fluid after the construction of guar gum-based fracturing fluid used in oil and gas field fracturing fluid production operations is completed, or the flowback fluid after the construction of polymer-based fracturing fluid used in oil and gas field fracturing fluid production operations is completed, or the flowback fluid after the construction of viscoelastic surfactant fracturing fluid used in oil and gas field fracturing fluid production operations is completed.

[0019] In one embodiment of the present application, the fracturing flowback fluid is a fracturing flowback fluid containing KCl.

[0020] A water-based drilling fluid, wherein the water-based drilling fluid is prepared according to the method according to any one of claims 1-9.

[0021] The beneficial results of the present invention are as follows: since the present invention firstly prepares a bentonite slurry with a high concentration with clean water, the clay has been dispersed into smaller sheet structures, and the addition of a gel protector has a protective and stabilizing effect on the colloid formed by the bentonite, and has a certain shielding effect on potassium ions, the fracturing flowback fluid rich in potassium ions can be prepared so that the drilling fluid remains stable, the bentonite does not settle, and the KCl in the flowback fluid is used to improve the inhibition of the drilling fluid, the clay expansion rate is reduced by 30-50%, and the resource utilization of waste is realized at the same time. DETAILED DESCRIPTION

[0022] In order to explain the technical content, structural features, achieved objectives and effects of the technical solution in detail, the following is a detailed description in conjunction with specific embodiments.

[0023] In a specific embodiment, bentonite can be used for drilling grouting during drilling. The present application uses bentonite with weak acidic or alkaline properties and good slurry-forming properties. The alkaline bentonite can be sodium-based bentonite (alkaline soil), calcium-based bentonite (alkaline earth soil), etc. Bentonite has strong hygroscopicity and swelling properties, and can absorb 8 to 15 times its own volume of water, and its volume can expand by several times to 30 times; it can be dispersed into a gel and suspension in an aqueous medium, and this medium solution has certain viscosity, thixotropy and lubricity; it has a strong cation exchange capacity; it has a certain adsorption capacity for various gases, liquids, and organic substances, and the maximum adsorption capacity can reach 5 times its own weight; its mixture with water, mud or fine sand has plasticity and adhesion; the surface-active acidic bleaching earth (activated white clay, natural bleaching earth-acidic white clay) can adsorb colored ions.

[0024] Example 1

[0025] A method for preparing a strong inhibitory drilling fluid using fracturing flowback fluid comprises the following steps:

[0026] The first step is to add clean water to a container at room temperature, add bentonite accounting for 5% of the clean water mass while stirring, and continue stirring for 4.5 hours. The clean water is well water with a total calcium and magnesium ion content of 1000 mg / L and a potassium ion content of 100 mg / L. The bentonite is a commercially available qualified product for oil field drilling fluid;

[0027] The second step is to add sodium carbonate to the above container while stirring, measure the pH while adding, adjust the pH to 10, and continue stirring for 6 hours. The sodium carbonate is an industrial grade product;

[0028] The third step is to add 1.5% of the total mass of a protective glue agent to the mixed solution in the container while stirring, stir evenly, and continue stirring for 6 hours. The protective glue agent is industrial grade polyvinyl alcohol 1788;

[0029] The fourth step is to add the fracturing flowback fluid in an amount of 1.5 times the volume of the gel liquid prepared in the third step into the above container at a uniform speed while stirring, and control the adding speed to 50% of the volume of the gel liquid prepared in the third step per hour, and continue stirring for 3 hours. The fracturing flowback fluid is the flowback fluid after the construction of the guar gum-based fracturing fluid used in the fracturing fluid production operation of the oil and gas field is completed.

[0030] The beneficial results of the present invention are as follows: since the present invention firstly prepares a bentonite slurry with a high concentration with clean water, and adds a gel protector to protect and stabilize the colloid formed by the bentonite, when the fracturing flowback fluid rich in KCl is added, the drilling fluid remains stable and the bentonite does not settle. At the same time, the KCl in the flowback fluid can be used to improve the inhibition of the drilling fluid, the clay expansion rate is reduced by 48%, and the resource utilization of waste is realized.

[0031] Example 2

[0032] A method for preparing a strong inhibitory drilling fluid using fracturing flowback fluid comprises the following steps:

[0033] The first step is to add clean water to a container at room temperature, add bentonite accounting for 6% of the clean water mass while stirring, and continue stirring for 5 hours. The clean water is lake water with a total calcium and magnesium ion content of 900 mg / L and a potassium ion content of 50 mg / L. The bentonite is a commercially available qualified product for oil field drilling fluid;

[0034] The second step is to add sodium carbonate to the above container while stirring, measure the pH while adding, adjust the pH to 9, and continue stirring for 5 hours. The sodium carbonate is a chemically pure product;

[0035] The third step is to add 1% of the total mass of a protective glue agent to the mixed solution in the container while stirring, stir evenly, and continue stirring for 9 hours, wherein the protective glue agent is chemically pure polyvinyl pyrrolidone;

[0036] The fourth step is to add the fracturing flowback fluid twice the volume of the gel liquid prepared in the third step into the above container at a uniform speed while stirring, and control the adding speed to 40% of the volume of the gel liquid prepared in the third step per hour, and continue stirring for 3 hours. The fracturing flowback fluid is the flowback fluid after the construction of the polymer-based fracturing fluid used in the fracturing fluid production operation of the oil and gas field is completed.

[0037] The beneficial results of the present invention are as follows: since the present invention firstly prepares a bentonite slurry with a high concentration with clean water, and adds a gel protector to protect and stabilize the colloid formed by the bentonite, when the fracturing flowback fluid rich in KCl is added, the drilling fluid remains stable and the bentonite does not settle. At the same time, the KCl in the flowback fluid can be used to improve the inhibition of the drilling fluid, the clay expansion rate is reduced by 33%, and the resource utilization of waste is realized.

[0038] Example 3

[0039] A method for preparing a strong inhibitory drilling fluid using fracturing flowback fluid comprises the following steps:

[0040] The first step is to add clean water to a container at room temperature, add bentonite accounting for 8% of the clean water mass while stirring, and continue stirring for 10 hours. The clean water is river water with a total calcium and magnesium ion content of 700 mg / L and a potassium ion content of 50 mg / L. The bentonite is a commercially available qualified product for oilfield drilling fluid;

[0041] The second step is to add sodium carbonate to the above container while stirring, measure the pH while adding, adjust the pH to 8.5, and continue stirring for 6 hours. The sodium carbonate is an analytically pure product;

[0042] The third step is to add 0.5% of the total mass of the protective glue agent to the mixed solution in the container while stirring, stir evenly, and continue stirring for 6.5 hours. The protective glue agent is partially hydrolyzed polyacrylamide with an analytical pure hydrolysis degree of 30% and a molecular weight of 8.5 million;

[0043] The fourth step is to add 2.5 times the volume of the prepared glue liquid in the third step into the above container at a uniform speed while stirring, and control the adding speed to 20% of the volume of the prepared glue liquid in the third step per hour, and continue stirring for 6 hours. The fracturing flowback fluid is the flowback fluid after the construction of the viscoelastic surfactant fracturing fluid used in the fracturing fluid production operation of oil and gas fields is completed.

[0044] The beneficial results of the present invention are as follows: since the present invention firstly prepares a bentonite slurry with a high concentration with clean water, and adds a gel protector to protect and stabilize the colloid formed by the bentonite, when the fracturing flowback fluid rich in KCl is added, the drilling fluid remains stable and the bentonite does not settle. At the same time, the KCl in the flowback fluid can be used to improve the inhibition of the drilling fluid, the clay expansion rate is reduced by 48%, and the resource utilization of waste is realized.

[0045] Example 4

[0046] A method for preparing a strong inhibitory drilling fluid using fracturing flowback fluid comprises the following steps:

[0047] The first step is to add clean water to a container at room temperature, add bentonite accounting for 10% of the clean water mass while stirring, and continue stirring for 8 hours. The clean water is tap water with a total calcium and magnesium ion content of 500 mg / L and a potassium ion content of 20 mg / L. The bentonite is a commercially available qualified product for oilfield drilling fluid;

[0048] The second step is to add sodium carbonate to the above container while stirring, measure the pH while adding, adjust the pH to 8, and continue stirring for 6 hours. The sodium carbonate is an industrial grade product;

[0049] The third step is to add 1.5% of the total mass of a protective glue agent to the mixed solution in the container while stirring, stir evenly, and continue stirring for 8 hours. The protective glue agent is industrial grade polyvinyl alcohol 1788;

[0050] The fourth step is to add the fracturing flowback fluid of 3 times the volume of the gel liquid prepared in the third step into the above container at a uniform speed while stirring, and control the adding speed to 30% of the volume of the gel liquid prepared in the third step per hour, and continue stirring for 6 hours. The fracturing flowback fluid is the flowback fluid after the construction of the guar gum-based fracturing fluid used in the fracturing fluid production operation of the oil and gas field is completed.

[0051] The beneficial results of the present invention are as follows: since the present invention firstly prepares a bentonite slurry with a high concentration with clean water, and adds a gel protector, which has a protective and stabilizing effect on the colloid formed by the bentonite, when the fracturing flowback fluid rich in KCl is added, the drilling fluid remains stable and the bentonite does not settle. At the same time, the KCl in the flowback fluid can be used to improve the inhibition of the drilling fluid, the clay expansion rate is reduced by 36%, and the resource utilization of waste is realized.

[0052] Example 5

[0053] A method for preparing a strong inhibitory drilling fluid using fracturing flowback fluid comprises the following steps:

[0054] The first step is to add clean water to a container at room temperature, add bentonite accounting for 9% of the clean water mass while stirring, and continue stirring for 8 hours, wherein the clean water is river water with a total calcium and magnesium ion content of no more than 300 mg / L and a potassium ion content of no more than 10 mg / L, and the bentonite is a commercially available qualified product for oilfield drilling fluid;

[0055] The second step is to add sodium carbonate to the above container while stirring, measure the pH while adding, adjust the pH to 10, and continue stirring for 6 hours. The sodium carbonate is an industrial grade product;

[0056] The third step is to add 1.2% of the total mass of a protective glue agent to the mixed solution in the container while stirring, stir evenly, and continue stirring for 8 hours, wherein the protective glue agent is industrial grade polyvinyl pyrrolidone;

[0057] The fourth step is to add the fracturing flowback fluid twice the volume of the gel liquid prepared in the third step into the above container at a uniform speed while stirring, and control the adding speed to 25% of the volume of the gel liquid prepared in the third step per hour, and continue stirring for 6 hours. The fracturing flowback fluid is the flowback fluid after the construction of the polymer-based fracturing fluid used in the fracturing fluid production operation of the oil and gas field is completed.

[0058] The beneficial results of the present invention are as follows: since the present invention firstly prepares a bentonite slurry with a high concentration with clean water, and adds a gel protector to protect and stabilize the colloid formed by the bentonite, when the fracturing flowback fluid rich in KCl is added, the drilling fluid remains stable and the bentonite does not settle. At the same time, the KCl in the flowback fluid can be used to improve the inhibition of the drilling fluid, the clay expansion rate is reduced by 34%, and the resource utilization of waste is realized.

[0059] Example 6

[0060] A method for preparing a strong inhibitory drilling fluid using fracturing flowback fluid comprises the following steps:

[0061] The first step is to add clean water to a container at room temperature, add bentonite accounting for 6% of the clean water mass while stirring, and continue stirring for 5 hours. The clean water is lake water with a total calcium and magnesium ion content of no more than 800 mg / L and a potassium ion content of no more than 10 mg / L. The bentonite is a commercially available qualified product for oilfield drilling fluid;

[0062] The second step is to add sodium carbonate to the above container while stirring, measure the pH while adding, adjust the pH to 8.5, and continue stirring for 5 hours. The sodium carbonate is a chemically pure product;

[0063] The third step is to add 1.6% of the total mass of a protective glue agent to the mixed solution in the container while stirring, stir evenly, and continue stirring for 7 hours. The protective glue agent is an industrial grade partially hydrolyzed polyacrylamide with a hydrolysis degree of 50% and a molecular weight of 15 million, and a combination thereof;

[0064] The fourth step is to add the fracturing flowback fluid of 3 times the volume of the gel liquid prepared in the third step into the above container at a uniform speed while stirring, and control the adding speed to 30% of the volume of the gel liquid prepared in the third step per hour, and continue stirring for 6 hours. The fracturing flowback fluid is the flowback fluid after the construction of the guar gum-based fracturing fluid used in the fracturing fluid production operation of the oil and gas field is completed.

[0065] The beneficial results of the present invention are as follows: since the present invention firstly prepares a bentonite slurry with a high concentration with clean water, and adds a gel protector to protect and stabilize the colloid formed by the bentonite, when the fracturing flowback fluid rich in KCl is added, the drilling fluid remains stable and the bentonite does not settle. At the same time, the KCl in the flowback fluid can be used to improve the inhibition of the drilling fluid, the clay expansion rate is reduced by 42%, and the resource utilization of waste is realized.

[0066] In some comprehensive embodiments, a method for preparing a strong inhibitory drilling fluid using fracturing flowback fluid comprises the following steps:

[0067] The first step is to add clean water into a container, add 5%-10% of the mass of the clean water with bentonite while stirring, and continue stirring for 3h-10h, wherein the clean water is weakly alkaline water and the bentonite is a commercially available qualified product for oilfield drilling fluid;

[0068] The second step is to add sodium carbonate to the above container while stirring, measure the pH while adding, adjust the pH to 8.5-10, and continue stirring for 5-6.5 hours;

[0069] The third step is to add 0.5%-1.6% of the total weight of the protective agent to the mixed liquid in the container while stirring, stir evenly, and continue stirring for 6h-9h;

[0070] The fourth step is to uniformly add 1.5 to 3 times the volume of the fracturing flowback fluid prepared in the third step into the above container while stirring, and control the adding speed to 20% to 50% of the volume of the glue prepared in the third step per hour. After all the fracturing flowback fluid is added, continue stirring for 2h to 6h; the fracturing flowback fluid is a strongly inhibitory flowback fluid.

[0071] Since the present invention firstly uses clean water to prepare bentonite slurry with a high concentration, the clay has been dispersed into smaller sheet structures, and the addition of a gel protector has a protective and stabilizing effect on the colloid formed by the bentonite, and has a certain shielding effect on potassium ions. The fracturing return fluid rich in potassium ions can be prepared so that the drilling fluid remains stable, the bentonite does not settle, and the KCl in the return fluid is used to improve the inhibition of the drilling fluid, the clay expansion rate is reduced by 30-50%, and the resource utilization of waste is achieved at the same time.

[0072] In one aspect of the present application, the clean water is weakly alkaline water containing calcium ions, magnesium ions and potassium ions. The cations in the weakly alkaline water can better moisturize the pulp.

[0073] In one aspect of the present application, the total content of calcium and magnesium ions is no more than 1000 mg / L, and the content of potassium ions is no more than 100 mg / L.

[0074] In one aspect of the present application, the adhesive protecting agent is industrial grade polyvinyl alcohol 1788.

[0075] In one aspect of the present application, the gel protective agent is polyvinyl pyrrolidone.

[0076] In one aspect of the present application, the adhesive protecting agent is industrial-grade partially hydrolyzed polyacrylamide with a hydrolysis degree of 50% and a molecular weight of 15 million, and a composition thereof.

[0077] In one aspect of the present application, in the fourth step, a fracturing return fluid of 3 times the volume of the glue prepared in the third step is added at a uniform speed, and the addition rate is 50% of the volume of the glue prepared in the third step per hour; or, a fracturing return fluid of 1.5 times the volume of the glue prepared in the third step is added at a uniform speed, and the addition rate is 20% of the volume of the glue prepared in the third step per hour.

[0078] In one aspect of the present application, the fracturing flowback fluid is the flowback fluid after the construction of guar gum-based fracturing fluid used in oil and gas field fracturing fluid production operations is completed, or the flowback fluid after the construction of polymer-based fracturing fluid used in oil and gas field fracturing fluid production operations is completed, or the flowback fluid after the construction of viscoelastic surfactant fracturing fluid used in oil and gas field fracturing fluid production operations is completed.

[0079] In one aspect of the present application, the fracturing flowback fluid is a fracturing flowback fluid containing KCl. The fracturing flowback fluid rich in potassium ions can be formulated so that the drilling fluid remains stable and the bentonite does not settle.

[0080] A water-based drilling fluid, wherein the water-based drilling fluid is prepared according to the method according to any one of claims 1-9.

[0081] The beneficial results of the present invention are as follows: since the present invention firstly prepares a bentonite slurry with a high concentration with clean water, the clay has been dispersed into smaller sheet structures, and the addition of a gel protector has a protective and stabilizing effect on the colloid formed by the bentonite, and has a certain shielding effect on potassium ions, the fracturing flowback fluid rich in potassium ions can be prepared so that the drilling fluid remains stable, the bentonite does not settle, and the KCl in the flowback fluid is used to improve the inhibition of the drilling fluid, the clay expansion rate is reduced by 30-50%, and the resource utilization of waste is realized at the same time.

[0082] It should be noted that although the above embodiments have been described in this article, the scope of patent protection of the present invention is not limited thereby. Therefore, based on the innovative concept of the present invention, changes and modifications made to the embodiments described herein, or equivalent structures or equivalent process changes made using the contents of the present invention specification, directly or indirectly applying the above technical solutions to other related technical fields are all included in the scope of protection of the patent of the present invention.

Claims

1. A method for preparing a strong inhibitory drilling fluid using fracturing flowback fluid, characterized in that: The following steps are involved: The first step is to add clean water into a container, add 5%-10% of the mass of the clean water with bentonite while stirring, and continue stirring for 3h-10h, wherein the clean water is weakly alkaline water and the bentonite is a commercially available qualified product for oilfield drilling fluid; The second step is to add sodium carbonate to the above container while stirring, measure the pH while adding, adjust the pH to 8.5-10, and continue stirring for 5-6.5 hours; The third step is to add 0.5%-1.6% of the total weight of the protective agent to the mixed liquid in the container while stirring, stir evenly, and continue stirring for 6h-9h; The fourth step is to uniformly add 1.5 to 3 times the volume of the fracturing flowback fluid prepared in the third step into the above container while stirring, and control the adding speed to 20% to 50% of the volume of the glue prepared in the third step per hour. After all the fracturing flowback fluid is added, continue stirring for 2h to 6h; the fracturing flowback fluid is a strongly inhibitory flowback fluid.

2. The method for preparing a strong inhibitory drilling fluid using fracturing flowback fluid according to claim 1, characterized in that: The clean water is weakly alkaline water containing calcium ions, magnesium ions and potassium ions.

3. The method for preparing a strong inhibitory drilling fluid using fracturing flowback fluid according to claim 2, characterized in that: The total content of calcium and magnesium ions shall not exceed 1000 mg / L, and the content of potassium ions shall not exceed 100 mg / L.

4. The method for preparing a strong inhibitory drilling fluid using fracturing flowback fluid according to claim 1, characterized in that: The adhesive protecting agent is industrial grade polyvinyl alcohol 1788.

5. The method for preparing a strong inhibitory drilling fluid using fracturing flowback fluid according to claim 1, characterized in that: The protective glue agent is polyvinyl pyrrolidone.

6. The method for preparing a strong inhibitory drilling fluid using fracturing flowback fluid according to claim 1, characterized in that: The adhesive protecting agent is industrial-grade partially hydrolyzed polyacrylamide with a hydrolysis degree of 50% and a molecular weight of 15 million and a composition thereof.

7. The method for preparing a strong inhibitory drilling fluid using fracturing flowback fluid according to claim 1, characterized in that: In the fourth step, a fracturing flowback fluid of 3 times the volume of the glue prepared in the third step is added at a controlled uniform speed, and the adding speed is 50% of the volume of the glue prepared in the third step per hour; Or, control the uniform speed of adding fracturing flowback fluid of 1.5 times the volume of the glue prepared in the third step, and the adding speed is 20% of the volume of the glue prepared in the third step per hour.

8. The method for preparing a strong inhibitory drilling fluid using fracturing flowback fluid according to claim 1, characterized in that: The fracturing flowback fluid is the flowback fluid after the construction of guar gum-based fracturing fluid used in oil and gas field fracturing fluid production operations is completed, the flowback fluid after the construction of polymer-based fracturing fluid used in oil and gas field fracturing fluid production operations is completed, or the flowback fluid after the construction of viscoelastic surfactant fracturing fluid used in oil and gas field fracturing fluid production operations is completed.

9. The method for preparing a strong inhibitory drilling fluid using fracturing flowback fluid according to claim 1, characterized in that: The fracturing flowback fluid is a fracturing flowback fluid containing KCl.

10. A water-based drilling fluid, characterized in that: The water-based drilling fluid is prepared according to the method described in any one of claims 1-9.