CN111763511A

CN111763511A - Preparation and liquid preparation method of integrated self-crosslinking thickener modified polymer for fracturing

Info

Publication number: CN111763511A
Application number: CN202010594871.6A
Authority: CN
Inventors: 刘福建; 贾振福; 辛勇亮; 邹旭辉; 王立祥; 王愉; 刘挺; 秦鹏; 张磊; 屈川; 曹会
Original assignee: Sichuan Shenhe New Material Technology Co ltd; Fracturing Co Of Cnpc Greatwall Drilling Co
Current assignee: Sichuan Shenhe New Material Technology Co ltd; Fracturing Co Of Cnpc Greatwall Drilling Co
Priority date: 2020-06-28
Filing date: 2020-06-28
Publication date: 2020-10-13
Anticipated expiration: 2040-06-28
Also published as: CN111763511B

Abstract

The invention relates to the field of fracturing fluid for oil and gas field reconstruction, in particular to fracturing fluid emulsion stock solution and a preparation method thereof, slickwater and suspended sand fracturing fluid. The fracturing fluid emulsion stock solution is mainly prepared by polymerization reaction of an oil phase and a water phase; the preparation method comprises the following steps: adding a molecular weight regulator and a metal ion removing agent into the water phase, and regulating the pH value of the water phase to be weakly acidic; mixing and stirring the mixture and the oil phase until the viscosity of the mixed phase is 1000-1200mPa.s, cooling to below 10 ℃ under the protection of nitrogen, adding an initiator, controlling the reaction temperature to be not more than 40 ℃, finishing the reaction, and cooling to room temperature to obtain the fracturing fluid emulsion stock solution. The mass fraction of the fracturing fluid emulsion stock solution in the slick water is 0.06-0.12%; the mass fraction of the fracturing fluid emulsion stock solution in the suspended sand fracturing fluid is 1-2%.

Description

Preparation and liquid preparation method of integrated self-crosslinking thickener modified polymer for fracturing

Technical Field

The invention relates to the field of fracturing fluid for oil and gas field reconstruction, in particular to a preparation and liquid preparation method of an integrated self-crosslinking thickening agent modified polymer for fracturing.

Background

The fracturing fluid is a heterogeneous unstable chemical system formed by a plurality of additives according to a certain proportion, is a working fluid used for fracturing modification of an oil-gas layer, and has the main functions of transmitting high pressure formed by ground equipment into a stratum, enabling the stratum to fracture to form a fracture and conveying a propping agent along the fracture.

The method is characterized in that a high-pressure large-displacement pump is adopted on the ground, a liquid pressure transmission principle is utilized, fracturing fluid is injected into an oil layer at a pressure larger than the absorption capacity of the oil layer, the pressure in a shaft is gradually increased, so that high pressure is suppressed at the bottom of a well, and when the pressure is larger than the ground stress near the well wall and the tensile strength of stratum rocks, cracks are generated in the stratum near the bottom of the well: and continuously injecting a sand carrying fluid with a propping agent, extending the fracture forwards and filling the fracture with the propping agent, and closing the fracture on the propping agent after closing the well, so that a sand filling fracture with a certain geometric dimension and high flow conductivity is formed in the stratum near the bottom of the well, and the purpose of increasing the production and injection of the well is achieved.

The multifunctional emulsion type salt-tolerant fracturing fluid disclosed in the patent is rich in additives, such as a cleanup additive, a clay stabilizer, a cross-linking agent, a polymer breaking aid and the like, and is complicated in construction, various in procedure and invisibly increased in cost.

In order to increase the sand suspension performance of the salt-resistant multifunctional fracturing fluid, an additive cross-linking agent is required to improve the performance of the salt-resistant multifunctional fracturing fluid, so that the construction difficulty and the labor cost are increased, and a demulsifier is added, so that the salt-resistant multifunctional fracturing fluid has various additives and is complicated to construct.

Both of these patents suffer from poor ease of construction and high cost, and require additives and cross-linking agents to suspend the sand.

The inventor finds that the two patents and other existing fracturing fluids in the market are difficult to meet the requirement that one fracturing fluid is used for multiple purposes, namely different fracturing fluid emulsion stock solutions are required for preparing different slick water and sand carrying fluids; the existing slickwater and sand-carrying liquid belong to two different types of systems, liquid preparation is required in advance, and online continuous liquid preparation cannot be realized at present; the application of the demulsifier to the oil field can be realized only by adding the demulsifier.

Disclosure of Invention

In order to solve or improve the problems in the prior art, the invention aims to provide a fracturing fluid emulsion stock solution, slick water and suspended sand fracturing fluid and a preparation method thereof, which solve the problem that the existing fracturing fluid cannot realize one dose of multi-use.

In order to solve the technical problem that the existing fracturing fluid cannot realize one dose with multiple purposes, the embodiment of the invention adopts the technical scheme that:

a fracturing fluid emulsion stock solution is mainly prepared by polymerization reaction of an oil phase and a water phase;

the water phase comprises the following components in percentage by weight: 15-20% of acrylamide, 7-10% of water-soluble salt of acrylic acid, 5-10% of water-soluble salt of AMPS, 2.5-5% of N, N' -diacetone propionamido ethylenediamine and the balance of water; the water phase is weakly acidic;

the oil phase consists of the following components: white oil, emulsifier and water.

Further, the oil phase consists of the following components in percentage by weight: 85% of No. 10 white oil, 10% of span80 emulsifier and 5% of Tween 60 emulsifier.

Further, the water phase consists of the following components in percentage by weight: 17.5 percent of acrylamide, 7.76 percent of water-soluble salt of acrylic acid, 5.8 percent of water-soluble salt of AMPS, 2.9 percent of N, N' -diacetone propionamido ethylenediamine and the balance of water.

Further, the weight ratio of the oil phase to the water phase is 3: 7.

Further, the viscosity of the stock solution is 1000-1200 mPa.s.

Further, the composition also comprises a molecular weight regulator sodium formate, a urea mixture and a metal ion removing agent diethylene triamine pentaacetic acid pentasodium; the initiator for the polymerization reaction is a mixture of ammonium persulfate and sodium bisulfite; wherein the mass ratio of the molecular weight regulator sodium formate to urea is 1: 3.

Further, the pH value of the water phase is 6.3-6.5.

It is another object of the present invention to provide a method for making a fracturing fluid emulsion stock.

The preparation method of the fracturing fluid emulsion stock solution comprises the following steps:

adding a molecular weight regulator sodium formate, a urea mixture (the mass ratio of sodium formate to urea is 1:3) and a metal ion removing agent diethylene triamine pentaacetic acid pentasodium into the water phase, and regulating the pH value of the water phase to be weakly acidic; mixing and stirring the mixture and the oil phase until the viscosity of the mixed phase is 1000-1200mPa.s, cooling to below 10 ℃ under the protection of nitrogen, adding an initiator, controlling the reaction temperature to be not more than 40 ℃, finishing the reaction, and cooling to room temperature to obtain the fracturing fluid emulsion stock solution.

Another object of the present invention is to provide a slickwater.

A slickwater comprising an emulsion; the emulsion is a fracturing fluid emulsion stock solution, and the mass fraction of the fracturing fluid emulsion stock solution is 0.06-0.12%.

Another object of the present invention is to provide a sand-suspending fracturing fluid.

A suspended sand fracturing fluid comprising an emulsion; the emulsion is a fracturing fluid emulsion stock solution, and the mass fraction of the fracturing fluid emulsion stock solution is 1-2%.

The invention has the following beneficial effects:

1. the invention provides a fracturing fluid emulsion stock solution, a preparation method thereof, slickwater and suspended sand fracturing fluid, wherein the fracturing fluid emulsion stock solution prepared from a water phase and an oil phase is mainly adopted, so that the technical problems that one agent is not multipurpose in the prior art, and different fracturing fluid emulsions are needed for preparing different slickwater or suspended sand fracturing fluids are solved, and the technical problems that the prior art cannot continuously prepare fluids on line, needs to prepare the fluids in advance, and can be used only by adding a demulsifier in an oil field are solved.

2. The fracturing fluid emulsion stock solution can be prepared into slick water and suspended sand fracturing fluid only by changing the dosage according to the situation, and has the function of one dosage for multiple purposes.

3. The fracturing fluid emulsion stock solution can realize self-crosslinking, a self-crosslinking monomer N, N '-diacetone propionamido ethylenediamine is added in the synthesis, the ketone carbonyl on the N, N' -diacetone propionamido ethylenediamine is utilized, and the ketone carbonyl chain extender is used for enabling a polymer to generate reactions such as crosslinking grafting and the like, and the solution can be continuously prepared without preparing the solution in advance.

4. The slickwater or sand-suspending fracturing fluid prepared from the fracturing fluid emulsion stock solution has the advantages of better demulsification performance and quick dissolution time under the condition of not adding a demulsifier.

5. The fracturing fluid emulsion stock solution is simple in preparation method and convenient to use.

Drawings

FIG. 1 is a graph showing the measurement of the resistance reduction of low specific slickwater in example 7, and a graph showing the measurement of the resistance reduction of an emulsion containing no N, N' -diacetoneamidoethylenediamine monomer.

FIG. 2 is a graph showing the measurement of the resistance reduction of the low specific slickwater in 2% potassium chloride water of example 7 on the left, and the measurement of the resistance reduction of the emulsion containing no N, N' -diacetoneamidoethylenediamine monomer on the right.

FIG. 3 is a graph of a high-ratio sand suspension experiment of example 7.

FIG. 4 is a diagram showing the rheological measurement of a fracturing fluid emulsion stock solution with a mass fraction of 1.5% in a potassium chloride solution with a mass fraction of 2%. (the left side is the self-crosslinking integrated emulsion rheology of the invention; the right side is the emulsion without introducing the N, N' -diacetone propionamido ethylenediamine monomer).

FIG. 5 is a graph showing the gel breaking effect of the high-rate sand-suspended fracturing fluid of example 7 (the left side shows that the gel breaking fluid: diesel oil is 1:3 (mass ratio);

the right side is the gel breaking liquid: diesel oil 1:1 (mass ratio)).

Fig. 6 is an appearance view of the fracturing fluid emulsion stock of example 7.

Detailed Description

The invention is further explained below with reference to the drawings and the specific embodiments.

The weakly acidic in the present invention means that the pH value is 5.5 to 6.5. AMPS is 2-acrylamide-2-methylpropanesulfonic acid.

Example 1 preparation of fracturing fluid emulsion stock

The composition of the aqueous phase of the fracturing fluid emulsion stock is shown in table 1 below.

TABLE 1

Name (R)	Quality (g)
		Acrylamide	210
Acrylic acid sodium salt	98
		AMPS sodium salt	70
N, N' -diacetoneamidoethylenediamine	35
		Flake caustic soda	Proper amount of
Deionized water	987
		Molecular weight regulator (mass ratio sodium formate: urea ═ 1:3)	500mg
Metal ion removing agent	5000mg

The composition of the oil phase of the fracturing fluid emulsion stock is shown in table 2 below.

TABLE 2

Name (R)	Quality (g)
		No. 10 white oil	510
span80	60
		Tween 60	30

Weighing the raw materials of the oil phase and the water phase according to the raw materials in the table 1 and the table 2 respectively to prepare the oil phase and the water phase; according to the mass ratio of the oil phase to the water phase of 3:7 until the viscosity is 1000-1200mPa.s, introducing nitrogen with the purity of 99.99 percent for at least 30min, reducing the temperature of the system to 10 ℃, starting adding composite initiators, namely ammonium persulfate and sodium bisulfite, controlling the reaction temperature to be not more than 40 ℃ until the reaction is finished and cooling to room temperature, thus obtaining the fracturing fluid emulsion stock solution with the solid content of about 20 percent, which is prepared by online mixing of the integrated self-crosslinking thickener modified polymer for fracturing.

Dissolving the obtained emulsion stock solution in different water qualities in proportion to perform kinematic viscosity measurement, and measuring the resistance reduction rate by adopting a method of NBT14003.2-2016 test according to the energy industry standard at normal temperature with the pipe diameter of 14mm and the flow rate of 11m/s, wherein the method is shown in Table 3;

TABLE 3 emulsion viscosity and drag reduction measurements

Example 2 preparation of fracturing fluid emulsion stock

The composition of the aqueous phase of the fracturing fluid emulsion stock is shown in table 4 below.

TABLE 4

The composition of the oil phase of the fracturing fluid emulsion stock is shown in table 5 below.

TABLE 5

Name (R)	Quality (g)
		No. 10 white oil	510
span80	60
		Tween 60	30

Weighing the raw materials of the oil phase and the water phase according to the raw materials in the table 4 and the table 5 respectively to prepare the oil phase and the water phase; according to the mass ratio of the oil phase to the water phase of 3:7 until the viscosity is 1000-1200mPa.s, introducing nitrogen with the purity of 99.99 percent for at least 30min, reducing the temperature of the system to 10 ℃, starting adding composite initiators, namely ammonium persulfate and sodium bisulfite, controlling the reaction temperature to be not more than 40 ℃ until the reaction is finished and cooling to room temperature, thus obtaining the fracturing fluid emulsion stock solution with the solid content of about 31 percent, which is prepared by online mixing of the integrated self-crosslinking thickener modified polymer for fracturing.

Dissolving the obtained emulsion stock solution in different water qualities in proportion to perform kinematic viscosity measurement, and measuring the resistance reduction rate by adopting a method of NBT14003.2-2016 test according to the energy industry standard at normal temperature with the pipe diameter of 14mm and the flow rate of 11m/s, wherein the method is shown in Table 6;

TABLE 6 emulsion viscosity and drag reduction measurements

Example 3 preparation of fracturing fluid emulsion stock

The composition of the aqueous phase of the fracturing fluid emulsion stock is shown in table 7 below.

TABLE 7

Name (R)	Quality (g)
		Acrylamide	252
Acrylic acid sodium salt	112
		AMPS sodium salt	126
N, N' -diacetoneamidoethylenediamine	42
		Flake caustic soda	Proper amount of
Deionized water	868
		Molecular weight regulator (mass ratio sodium formate: urea ═ 1:3)	500mg
Removing metal ionsSub-agent	5000mg

The composition of the oil phase of the fracturing fluid emulsion stock is shown in table 8 below.

TABLE 8

Name (R)	Quality (g)
		No. 10 white oil	510
span80	60
		Tween 60	30

Weighing the raw materials of the oil phase and the water phase according to the raw materials in the table 7 and the table 8 respectively to prepare the oil phase and the water phase; according to the mass ratio of the oil phase to the water phase of 3:7 until the viscosity is 1000-1200mPa.s, introducing nitrogen with the purity of 99.99 percent for at least 30min, reducing the temperature of the system to 10 ℃, starting adding composite initiators, namely ammonium persulfate and sodium bisulfite, controlling the reaction temperature to be not more than 40 ℃ until the reaction is finished and cooling to room temperature, thus obtaining the fracturing fluid emulsion stock solution with the solid content of about 26 percent for online mixing of the integrated self-crosslinking thickener modified polymer for fracturing.

Dissolving the obtained emulsion stock solution in different water qualities in proportion to perform kinematic viscosity measurement, and measuring the resistance reduction rate by adopting a method of NBT14003.2-2016 test according to the energy industry standard at normal temperature with the pipe diameter of 14mm and the flow rate of 11m/s, wherein the method is shown in Table 9;

TABLE 9 emulsion viscosity and drag reduction measurements

EXAMPLE 4 preparation of fracturing fluid emulsion stock

The composition of the aqueous phase of the fracturing fluid emulsion stock is shown in table 10 below.

Watch 10

Name (R)	Quality (g)
		Acrylamide	250
Acrylic acid sodium salt	130
		AMPS sodium salt	130
N, N' -diacetoneamidoethylenediamine	65
		Flake caustic soda	Proper amount of
Deionized water	825
		Molecular weight regulator (mass ratio sodium formate: urea ═ 1:3)	500mg
Metal ion removing agent	5000mg

The composition of the oil phase of the fracturing fluid emulsion stock is shown in table 11 below.

TABLE 11

Weighing the raw materials of the oil phase and the water phase according to the raw materials in the table 10 and the table 11 respectively to prepare the oil phase and the water phase; according to the mass ratio of the oil phase to the water phase of 3:7 until the viscosity is 1000-1200mPa.s, introducing nitrogen with the purity of 99.99 percent for at least 30min, reducing the temperature of the system to 10 ℃, starting adding composite initiators, namely ammonium persulfate and sodium bisulfite, controlling the reaction temperature to be not more than 40 ℃ until the reaction is finished and cooling to room temperature, thus obtaining the fracturing fluid emulsion stock solution with the solid content of about 28 percent for online mixing of the fracturing integrated self-crosslinking thickener modified polymer.

Dissolving the obtained emulsion stock solution in different water qualities in proportion to perform kinematic viscosity measurement, and measuring the resistance reduction rate by adopting a method of NBT14003.2-2016 test according to the energy industry standard at normal temperature with the pipe diameter of 14mm and the flow rate of 11m/s, wherein the method is shown in Table 12;

TABLE 12 emulsion viscosity and drag reduction measurements

Example 5 preparation of fracturing fluid emulsion stock

The composition of the aqueous phase of the fracturing fluid emulsion stock is shown in table 13 below.

Watch 13

The composition of the oil phase of the fracturing fluid emulsion stock is shown in table 14 below.

TABLE 14

Name (R)	Quality (g)
		No. 10 white oil	510
span80	60
		Tween 60	30

Weighing the raw materials of the oil phase and the water phase according to the raw materials in the table 13 and the table 14 respectively to prepare the oil phase and the water phase; according to the mass ratio of the oil phase to the water phase of 3:7 until the viscosity is 1000-1200mPa.s, introducing nitrogen with the purity of 99.99 percent for at least 30min, reducing the temperature of the system to 10 ℃, starting adding composite initiators, namely ammonium persulfate and sodium bisulfite, controlling the reaction temperature to be not more than 40 ℃ until the reaction is finished and cooling to room temperature, thus obtaining the fracturing fluid emulsion stock solution with the solid content of about 23 percent, which is prepared by online mixing of the fracturing integrated self-crosslinking thickener modified polymer.

Dissolving the obtained emulsion stock solution in different water qualities in proportion to perform kinematic viscosity measurement, and measuring the resistance reduction rate by adopting a method of NBT14003.2-2016 testing according to the energy industry standard at normal temperature with the pipe diameter of 14mm and the flow rate of 11m/s, wherein the method is shown in Table 15;

TABLE 15 emulsion viscosity and drag reduction measurements

Example 6 preparation of fracturing fluid emulsion stock

The aqueous phase composition of the fracturing fluid emulsion stock is shown in Table 16 below

TABLE 16

Name (R)	Quality (g)
		Acrylamide	220
Acrylic acid sodium salt	108
		AMPS sodium salt	80
N, N' -diacetoneamidoethylenediamine	40
		Flake caustic soda	Proper amount of
Deionized water	952
		Molecular weight regulator (mass ratio sodium formate: urea ═ 1:3)	500mg
Metal ion removing agent	5000mg

The oil phase of the fracturing fluid emulsion stock had the following composition as shown in Table 17

TABLE 17

Name (R)	Quality (g)
		No. 10 white oil	510
span80	60
		Tween 60	30

Weighing the raw materials of the oil phase and the water phase according to the raw materials in the tables 16 and 17 respectively to prepare the oil phase and the water phase; according to the mass ratio of the oil phase to the water phase of 3:7 until the viscosity is 1000-1200mPa.s, introducing nitrogen with the purity of 99.99 percent for at least 30min, reducing the temperature of the system to 10 ℃, starting adding composite initiators, namely ammonium persulfate and sodium bisulfite, controlling the reaction temperature to be not more than 40 ℃ until the reaction is finished and cooling to room temperature, thus obtaining the fracturing fluid emulsion stock solution with the solid content of about 22 percent for online mixing of the fracturing integrated self-crosslinking thickener modified polymer.

Dissolving the obtained emulsion stock solution in different water qualities in proportion to perform kinematic viscosity measurement, and measuring the resistance reduction rate by adopting a method of NBT14003.2-2016 test according to the energy industry standard at normal temperature with the pipe diameter of 14mm and the flow rate of 11m/s, as shown in Table 18;

TABLE 18 emulsion viscosity and drag reduction measurements

Example 7 preparation of slickwater and sand-suspended fracturing fluid

The aqueous phase composition of the fracturing fluid emulsion stock was as follows in Table 19

Watch 19

The oil phase of the fracturing fluid emulsion stock had the following composition as shown in Table 19

Watch 19

Name (R)	Quality (g)
		No. 10 white oil	510
span80	60
		Tween 60	30

Weighing the raw materials of the oil phase and the water phase according to the tables 18 and 19 respectively to prepare the oil phase and the water phase; according to the mass ratio of the oil phase to the water phase of 3:7 until the viscosity is 1000-1200mPa.s, introducing nitrogen with the purity of 99.99 percent for at least 30min, reducing the temperature of the system to 10 ℃, starting adding composite initiators, namely ammonium persulfate and sodium bisulfite, controlling the reaction temperature to be not more than 40 ℃ until the reaction is finished and cooling to room temperature, thus obtaining the fracturing fluid emulsion stock solution with the solid content of about 25 percent, which is prepared by online mixing of the integrated self-crosslinking thickener modified polymer for fracturing.

The embodiment 7 of the invention provides a method for preparing slickwater and suspended sand fracturing fluid.

According to the first preparation example, the effective components of the water phase can be increased under the condition of fixing the oil-water ratio according to the performance requirement, the solid content is increased within a certain range (not more than 33%), and the corresponding performance is improved to a certain extent.

Wherein said slickwater comprises an emulsion; the emulsion is a fracturing fluid emulsion stock solution, and the mass fraction of the fracturing fluid emulsion stock solution is 0.06-0.12%.

Wherein the sand suspending fracturing fluid comprises an emulsion; the emulsion is a fracturing fluid emulsion stock solution, and the mass fraction of the fracturing fluid emulsion stock solution is 1-2%.

The fracturing fluid emulsion stock solutions prepared in the examples 1 to 6 were prepared into slick water and sand-carrying fluid as follows:

low-proportion slick water 1: adding an integral self-crosslinking thickening agent for fracturing, which accounts for 0.08 percent of the mass fraction of the slickwater, into the clear water in proportion, and stirring until the components are completely dissolved to obtain the slickwater.

Low-ratio slickwater 2: adding an integrated self-crosslinking thickening agent for fracturing modified polymer emulsion stock solution accounting for 0.1 percent of the mass fraction of the slickwater into 2 percent of potassium chloride solution in proportion, and stirring until the polymer emulsion stock solution is completely dissolved to obtain the slickwater.

High-proportion sand suspension: adding an integrated self-crosslinking thickening agent modified polymer emulsion stock solution for fracturing, which accounts for 1% of the mass fraction of the sand suspension, into clear water in proportion, and uniformly stirring to obtain the sand suspension.

Preparation example two, the mass fraction of the fracturing fluid emulsion stock solution in the slickwater was adjusted to 0.06% or 0.12% in the above manner, and the like.

And the third preparation example can adopt the above mode to adjust the mass fraction of the fracturing fluid emulsion stock solution in the suspended sand fracturing fluid to 1.5 percent or 2 percent and the like for preparation.

Example 8 product Performance testing

By comparison of actual tests, example 7 of the present application is a more preferred embodiment. The appearance of the fracturing fluid emulsion stock prepared according to example 7 and compounded on-line with the integrated self-crosslinking thickener modified polymer is shown in fig. 6. The performance of the slickwater and suspended sand fracturing fluid prepared by the fracturing fluid is analyzed according to the following detection experiments 1-5 as follows.

Detection 1: the viscosity and the resistivity of the fracturing fluid integrated self-crosslinking thickener-modified polymer original emulsion in example 7 at different concentrations were determined according to the method of the final viscosity and the resistivity of the fracturing fluid in the same condition of the existing commercial emulsion without the N, N' -diacetone propionamido ethylenediamine monomer (hereinafter, referred to as "ND monomer"): and measuring the resistance reduction rate by adopting an energy industry standard NBT14003.2-2016 test method. Specific viscosity and drag reduction values are shown in table 20:

table 20: example 7 Final viscosity and drag reduction of the original emulsion self-crosslinking System with an emulsion containing no ND monomer

As shown in table 20, under the same measurement conditions, the viscosity and the resistance reduction rate of the integrated self-crosslinking thickener with different concentrations and the emulsion without the N, N '-diacetone propionamido ethylenediamine monomer under the same conditions are higher than those of the existing product, which indicates that the product performance obtained by introducing the N, N' -diacetone propionamido ethylenediamine monomer is significantly improved.

And (3) detection 2: the low specific slickwater 1, 2 according to example 7 was tested for drag reduction in the same situation as the emulsion on the market without the N, N' -diacetoneamidoethylenediamine monomer (ND monomer), method: the resistance reduction rate is measured by adopting an energy industry standard NBT14003.2-2016 testing method at the pipe diameter of 14mm and the flow rate of 11m/s at normal temperature. The specific drag reduction values are shown in table 21:

TABLE 21 drag reduction of inventive and ND-free monomer emulsions

As shown in the left picture of figure 1, the low proportion of slickwater 1 is added with the fracturing integrated self-crosslinking thickening agent modified polymer emulsion stock solution accounting for 0.08 percent of the mass fraction of the slickwater; as shown in the left graph of fig. 1, the initial drag reduction was measured to be greater than 80%, and the drag reduction after 5 minutes of shearing was measured to be greater than 70%; as shown in the right panel of FIG. 1, the emulsion without ND monomer was found to have a drag reduction of 72% in the same case, which is lower than the performance of the product of the present invention.

And (3) detection: the low specific slickwater 1, 2 according to example 7 was tested for drag reduction in the same situation as the emulsion on the market without the N, N' -diacetoneamidoethylenediamine monomer (ND monomer), method: the resistance reduction rate is measured by adopting an energy industry standard NBT14003.2-2016 testing method at the pipe diameter of 14mm and the flow rate of 11m/s at normal temperature. The specific drag reduction values are shown in table 22:

TABLE 22 drag reduction of inventive products with ND-free monomer emulsions

As shown in the left diagram of fig. 2, the low-proportion slickwater 2 is added with the fracturing integrated self-crosslinking thickener modified polymer emulsion stock solution accounting for 0.1 percent of the mass fraction of the slickwater, and the initial drag reduction rate is detected to be more than 75 percent in a 2 percent potassium chloride solution, the drag reduction rate is detected to be more than 70 percent after 5min of shearing, and the drag reduction rate is still close to 70 percent after 500 s; as shown in the right graph of FIG. 2, the emulsion without the N, N' -diacetone propionamido ethylenediamine monomer was found to have a resistance reduction of 68% in the same case, which is lower than the performance of the product of the present invention.

And (4) detection: adding 1.5 percent of the original emulsion of the embodiment 7 into clean water according to the proportion, respectively and slowly adding 20-40 ceramsite with different concentrations in a stirring state, stirring for 3-5min, stopping stirring, standing and observing, as shown in figure 3, respectively adding 20-40 mesh ceramsite accounting for 25 percent, 35 percent and 45 percent of the mass fraction of the high proportion of the suspended sand liquid into the high proportion of the suspended sand liquid, standing and observing for 30min, wherein the ceramsite almost has no sedimentation, and the ceramsite shows good sand suspending performance. Specific viscosity values are shown in table 23:

TABLE 23 viscosity of the inventive and ND-FREE MONOMER EMULSIONS

Numbering	Sample (I)	Concentration of	Temperature of	Initial viscosity	Final viscosity
						1	EXAMPLE 7 stock emulsion	1.5％	110℃	75-78	≥40mPa.s
2	Non-self-crosslinking emulsions	2.0％	100℃	54-57	＜40mPa.s

As can be seen from the left graph shown in fig. 4, 1.5% by mass of the fracturing integrated self-crosslinking thickener-modified polymer emulsion stock solution is added to a 2% potassium chloride solution, and is uniformly stirred, and the resistance reducing rate is measured by using the energy industry standard NBT14003.2-2016 resistance reducing agent performance index and the test method, wherein 11 in fig. 4 represents a viscosity curve, 12 represents a shear rate curve, and 13 represents a temperature curve.

As can be seen from the left diagram of FIG. 4, the temperature is 110 ℃ for 170s^-1The constant-speed shearing is carried out for 60min under the condition of (1), the result is obtained, and the viscosity is more than 40mPa.s after the shearing is finished, which shows that the high-viscosity high-temperature-resistant and salt-resistant rubber has good temperature resistance and salt resistance.

Comparing with the right graph of FIG. 4, it can be seen that the emulsion synthesized without ND monomer is prepared by adding 2% of the polymer emulsion stock solution into 2% potassium chloride solution at 100 deg.C for 170s^-1The constant-speed shearing is carried out for 60min under the condition of (1), the result is obtained, and the viscosity is less than 40mPa.s after the shearing is finished, which shows that the self-crosslinking integrated emulsion obtained by introducing the ND monomer is more shear-resistant and temperature-resistant.

And (5) detection: dissolving the original emulsion in example 7 in water according to the concentration of 1.5%, adding 0.03% of a gel breaker ammonium persulfate, and completely breaking gel at the temperature of 60 ℃ to obtain a gel breaking liquid; mixing the gel breaking solution with diesel according to the proportion of 1: 3. 1:1, stirring at a high speed for emulsification, then placing the mixture at a constant temperature of 60 ℃ for observing the volume of separated gel breaking liquid at different time and calculating the emulsion breaking rate, wherein the specific emulsion breaking rate value is shown in a table 24:

TABLE 24 demulsification Rate of the present invention

As shown in figure 6, after the high-proportion sand suspension fracturing fluid is subjected to gel breaking, the gel breaking fluid and diesel oil are mixed and emulsified according to the ratio of 1:3 (the left figure of figure 6) to 1:1 (the right figure of figure 6), and are subjected to emulsion breaking at the temperature of 60 ℃, after 6 hours, the emulsion breaking fluid obtained by two groups of experiments is more than 90%, and the system shows a good emulsion breaking effect.

In summary, the fracturing fluid emulsion stock solution of the embodiment, and the slick water and sand suspension fracturing fluid prepared from the fracturing fluid emulsion stock solution can realize self-crosslinking, and can be continuously prepared without preparing the fluid in advance. The fracturing fluid emulsion stock solution is simple in preparation method and convenient to use; the slickwater or sand-suspending fracturing fluid prepared from the fracturing fluid emulsion stock solution has the advantages of better demulsification performance and quick dissolution time under the condition of not adding a demulsifier. The fracturing fluid emulsion stock solution of the embodiment can be used for preparing the slick water and suspended sand fracturing fluid with good effect only by changing the dosage according to the condition, and one dosage of the fracturing fluid emulsion stock solution is more than one dosage

The function of the medicine is.

The present invention is not limited to the above-described alternative embodiments, and various other forms of products can be obtained by anyone in light of the present invention. The above detailed description should not be taken as limiting the scope of the invention, which is defined in the claims, and which the description is intended to be interpreted accordingly.

Claims

1. A multi-purpose integrated self-crosslinking fracturing fluid emulsion stock solution is characterized in that: it is prepared by polymerization reaction of oil phase and water phase;

the water phase comprises the following components in percentage by weight: 15-20% of acrylamide, 7-10% of water-soluble salt of acrylic acid, 5-10% of water-soluble salt of AMPS, 2.5-5% of N, N' -diacetone propionamido ethylenediamine and the balance of deionized water; the water phase is weakly acidic;

2. The fracturing fluid emulsion stock solution of claim 1, wherein: the oil phase comprises the following components in percentage by weight: 85% of No. 10 white oil, 10% of span80 emulsifier and 5% of Tween 60 emulsifier.

3. The fracturing fluid emulsion stock solution of claim 2, wherein: the water phase comprises the following components in percentage by weight: 17.5 percent of acrylamide, 7.76 percent of water-soluble salt of acrylic acid, 5.8 percent of water-soluble salt of AMPS, 2.9 percent of N, N' -diacetone propionamido ethylenediamine and the balance of water.

4. A fracturing fluid emulsion stock according to any one of claims 1 to 3, wherein: the weight ratio of the oil phase to the water phase was 3: 7.

5. The fracturing fluid emulsion stock solution of claim 4, wherein: the viscosity of the stock solution is 1000-1200 mPa.s.

6. The fracturing fluid emulsion stock solution of claim 5, wherein: it also comprises a molecular weight regulator and a metal ion removing agent; the initiator for the polymerization reaction is a mixture of ammonium persulfate and sodium bisulfite; the molecular weight regulator is a mixture of sodium formate and urea.

7. The fracturing fluid emulsion stock solution of claim 6, wherein: the pH value of the water phase is 6.3-6.5.

8. A method of making the fracturing fluid emulsion stock of any of claims 1 to 7 comprising the steps of:

adding a mixture of sodium formate and urea serving as molecular weight regulators and a metal ion removing agent into the water phase, and regulating the pH value of the water phase to be weakly acidic; mixing and stirring the mixture and the oil phase until the viscosity of the mixed phase is 1000-1200mPa.s, cooling to below 10 ℃ under the protection of nitrogen, adding an initiator, controlling the reaction temperature to be not more than 40 ℃, finishing the reaction, and cooling to room temperature to obtain the fracturing fluid emulsion stock solution.

9. A slickwater comprising an emulsion; the fracturing fluid is characterized in that the emulsion is the fracturing fluid emulsion stock solution as claimed in any one of claims 1 to 7, and the mass fraction of the fracturing fluid emulsion stock solution is 0.06 to 0.12 percent.

10. A suspended sand fracturing fluid comprising an emulsion; the fracturing fluid is characterized in that the emulsion is the fracturing fluid emulsion stock solution as claimed in any one of claims 1 to 7, and the mass fraction of the fracturing fluid emulsion stock solution is 1 to 2 percent.