CN116622360A - Fracturing fluid and hydraulic fracturing process comprising a (co)polymer of 2-acrylamide-2-methylpropanesulfonic acid in hydrated crystalline form - Google Patents

Abstract

The invention belongs to the technical field of fracturing fluid preparation, and discloses a fracturing fluid and a hydraulic fracturing method of a (co) polymer of 2-acrylamide-2-methylpropanesulfonic acid in a hydrated crystal form. According to the preparation method of the polymeric ferric sulfate, an organic framework is added in the process of synthesizing the polymeric ferric sulfate, a metal-organic coordination structure of the organic framework-iron ions is formed, a framework system is formed, and the coagulation effect of the polymeric ferric sulfate and the capability of removing organic impurities in wastewater are improved through the adsorption effect of the framework system, so that the fracturing effect of fracturing fluid is improved; meanwhile, the preparation method of the 2-acrylamide-2-methylpropanesulfonic acid can be used for preparing the high-quality 2-acrylamide-2-methylpropanesulfonic acid, so that the quality of the fracturing fluid is greatly improved.

Description

A (co)comprising 2-acrylamide-2-methylpropanesulfonic acid in hydrated crystalline form Polymeric fracturing fluids and hydraulic fracturing

technical field

The invention belongs to the technical field of fracturing fluid preparation, and in particular relates to a fracturing fluid comprising a (co)polymer of 2-acrylamide-2-methylpropanesulfonic acid in a hydrated crystal form and a hydraulic fracturing method.

Background technique

Hydraulic fracturing is the use of surface high-pressure pumps to squeeze fracturing fluid with high viscosity into the oil layer through the wellbore. When the rate of injection of fracturing fluid exceeds the absorption capacity of the oil layer, a very high pressure will be formed on the oil layer at the bottom of the well. When this pressure exceeds the fracture pressure of the oil layer near the bottom of the well, the oil layer will be pushed open and fractures will be generated. At this time, if the fracturing fluid is continuously squeezed into the oil layer, the fracture will continue to expand into the oil layer. In order to keep the fractures opened, the sand-carrying fluid with proppant (usually quartz sand) is squeezed into the oil layer. After the sand-carrying fluid enters the fracture, on the one hand, the fracture can continue to extend forward; It can support the cracks that have been opened so that they will not close. Then inject displacement fluid to replace all the sand-carrying fluid in the wellbore into the fracture, and support the fracture with quartz sand. Finally, the injected high-viscosity fracturing fluid will be automatically degraded and discharged out of the wellbore, leaving one or more fractures of varying length, width, and height in the oil layer, creating a new fluid channel between the oil layer and the wellbore. After fracturing, the production of oil and gas wells generally increases significantly; however, the fracturing fluids of the (co)polymers of 2-acrylamide-2-methylpropanesulfonic acid in the form of hydrated crystals currently use polyferric sulfate as a raw material The coagulation effect and the ability to remove organic impurities in wastewater are poor, which affects the fracturing effect of the fracturing fluid; at the same time, the quality of the raw material 2-acrylamide-2-methylpropanesulfonic acid used is poor, which affects the quality of the fracturing fluid.

Through the above analysis, the problems and defects in the prior art are:

(1) The fracturing fluid of the (co)polymer of 2-acrylamide-2-methylpropanesulfonic acid in the existing hydrated crystalline form adopts poor coagulation effect of raw material polyferric sulfate and the ability to remove organic impurities in waste water, Affect the fracturing effect of fracturing fluid.

(2) The quality of the raw material 2-acrylamide-2-methylpropanesulfonic acid used is poor, which affects the quality of the fracturing fluid.

Contents of the invention

Aiming at the problems existing in the prior art, the present invention provides a fracturing fluid and a hydraulic fracturing method comprising a (co)polymer of 2-acrylamide-2-methylpropanesulfonic acid in a hydrated crystal form.

The present invention is achieved in that a fracturing fluid comprising a (co)polymer of 2-acrylamide-2-methylpropanesulfonic acid in hydrated crystalline form and a hydraulic fracturing process comprising:

Step 1, weighing 2 parts of polyferric sulfate, 30 parts of liquid carbon dioxide base liquid, and 3 parts of 2-acrylamide-2-methylpropanesulfonic acid in parts by weight;

The 2-acrylamide-2-methylpropanesulfonic acid includes 2-acrylamide-2-methylpropanesulfonic acid in the form of hydrated crystals;

The preparation method of the liquid carbon dioxide base liquid:

The carbon dioxide gas produced during the high-temperature calcination of limestone (or dolomite) is washed with water, removed of impurities, and compressed to produce gaseous carbon dioxide; the raw material gas of carbon dioxide enters the degreaser for pre-purification, and then passes through the cooler to drop below 36°C and cool down The final carbon dioxide feed gas enters the buffer tank for pressure buffering;

The carbon dioxide raw material gas after pressure stabilization enters the desulfurizer for desulfurization treatment; the carbon dioxide raw material gas after desulfurization treatment enters the purifier for purification treatment from the desulfurizer;

First, the purified carbon dioxide gas is compressed by a compressor, and then cooled by a cooler to obtain a liquid carbon dioxide base liquid;

Step 2: Mixing polymerized ferric sulfate, liquid carbon dioxide base fluid, and 2-acrylamide-2-methylpropanesulfonic acid to obtain fracturing fluid.

Further, the preparation method of the polyferric sulfate is as follows:

(1) Carry out impurity removal material to iron powder, ferrous sulfate and iron powder generation reduction reaction generate ferrous sulfate; Add sulfuric acid in ferrous sulfate aqueous solution and carry out acidification, obtain the first mixed solution; Add ferrous sulfate in the first mixed solution Sodium nitrate, the temperature is controlled at 90 ° C, and oxygen or air is passed through, and the reaction is carried out for 210 minutes to obtain the second mixed solution;

(2) Add an organic framework and a co-solvent to the second mixed solution, the amount of the added substance of the organic framework is less than the sum of the amount of substances contained in the second mixed solution of ferric ions and ferrous ions; the control temperature is 60°C , and fully react to obtain the third mixed solution; the third mixed solution is post-treated to separate and obtain polyferric sulfate;

Wherein, the organic skeleton molecule includes more than two coordination groups, and the coordination groups are selected from at least one of carboxyl, hydroxyl, methylamino, pyridine nitrogen, pyrazine nitrogen, and cyano groups, and any two coordination groups The spacing between the coordinating atoms in the group includes at least two carbon atoms;

The organic skeleton molecule also includes an aromatic system, and the aromatic system includes one of a benzene ring, a biphenyl-like structure, an acene-like aromatic hydrocarbon structure, a quinoline-like structure, and a polypyridine structure;

The co-solvent is an organic solvent miscible with water.

Further, the coordinating group is a carboxyl group or a phenolic hydroxyl group directly connected to the aromatic system.

Further, on the organic skeleton, there is a branch connected to the aromatic system, and the branch shown is an alkyl group with 3-6 carbons or an alkoxy group with 3-6 carbons.

Further, the ratio of the amount of the organic skeleton to the added ferrous sulfate is 0.2:1.

Further, the reaction time is 6h.

Further, the preparation method of the 2-acrylamide-2-methylpropanesulfonic acid is as follows:

1) Weigh 20 parts of acrylonitrile, 6 parts of concentrated sulfuric acid, 0.5 parts of modified isobutylene, 3 parts of sulfur trioxide, 1 part of acrylic acid, and 30 parts of glacial acetic acid by weight; mix acrylonitrile with dehydrating agent and additives evenly, Prepare the first mixture for subsequent use;

2) Under the condition of temperature ≤ 0°C, add concentrated sulfuric acid into the first mixture, mix well to obtain the second mixture; heat the second mixture and keep the temperature at 85°C, add modified isobutylene into the second mixture In the mixture, stir, carry out sulfonation reaction, make the 3rd mixture;

3) adding glacial acetic acid to the reacted product, and mixing uniformly to obtain the fourth mixture; under vacuum, the fourth mixture is subjected to vacuum distillation to remove acrylonitrile to obtain the fifth mixture; the fifth mixture is cooled After the treatment, filter or centrifuge, and the centrifugal precipitate is 2-acrylamide-2-methylpropanesulfonic acid.

Further, the content of free sulfur trioxide in the concentrated sulfuric acid is 4%.

Further, the low temperature condition is that the temperature is 1°C;

The temperature of the heating condition is 32°C;

The temperature during the distillation process is 81° C., and the relative pressure is 0.01-0.2 MPa.

Further, a hydraulic fracturing method, injecting the fracturing fluid into underground rock formations.

Combining the above-mentioned technical solutions and technical problems to be solved, please analyze the advantages and positive effects of the technical solutions to be protected by the present invention from the following aspects:

First, in view of the technical problems existing in the above-mentioned prior art and the difficulty of solving the problems, closely combine the technical solution to be protected in the present invention and the results and data in the research and development process, etc., to analyze in detail how the technical solution of the present invention solves it Technical problems, some creative technical effects brought about after solving the problems. The specific description is as follows:

In the present invention, an organic framework is added in the process of synthesizing polymeric ferric sulfate through the preparation method of polymerized ferric sulfate to form a metal-organic coordination structure of organic framework-iron ions, and a framework system is formed. Through the adsorption of the framework system, the polymerized ferric sulfate Its own coagulation effect and the ability to remove organic impurities in wastewater, thereby improving the fracturing effect of fracturing fluid; at the same time, high-quality 2-acrylamide-2-methylpropanesulfonic acid can be prepared by the preparation method Methylpropanesulfonic acid, thus greatly improving the quality of fracturing fluid.

Second, regarding the technical solution as a whole or from the perspective of a product, the technical effects and advantages of the technical solution to be protected by the present invention are specifically described as follows:

In the present invention, an organic framework is added in the process of synthesizing polymeric ferric sulfate through the preparation method of polymerized ferric sulfate to form a metal-organic coordination structure of organic framework-iron ions, and a framework system is formed. Through the adsorption of the framework system, the polymerized ferric sulfate Its own coagulation effect and the ability to remove organic impurities in wastewater, thereby improving the fracturing effect of fracturing fluid; at the same time, high-quality 2-acrylamide-2-methylpropanesulfonic acid can be prepared by the preparation method Methylpropanesulfonic acid, thus greatly improving the quality of fracturing fluid.

Description of drawings

Fig. 1 is a flow chart of a fracturing fluid and a hydraulic fracturing method comprising a (co)polymer of 2-acrylamide-2-methylpropanesulfonic acid in a hydrated crystal form provided by an embodiment of the present invention.

Fig. 2 is a flow chart of the preparation method of polyferric sulfate provided by the embodiment of the present invention.

Fig. 3 is a flowchart of the preparation method of 2-acrylamide-2-methylpropanesulfonic acid provided by the embodiment of the present invention.

Detailed ways

In order to make the object, technical solution and advantages of the present invention more clear, the present invention will be further described in detail below in conjunction with the examples. It should be understood that the specific embodiments described here are only used to explain the present invention, not to limit the present invention.

1. Explain the embodiment. In order to make those skilled in the art fully understand how to implement the present invention, this part is an explanatory embodiment for explaining the technical solution of the claims.

As shown in Figure 1, the present invention provides a fracturing fluid and hydraulic fracturing method comprising a (co)polymer of 2-acrylamide-2-methylpropanesulfonic acid in a hydrated crystalline form comprising the following steps:

S101, weighing 2 parts of polyferric sulfate, 30 parts of liquid carbon dioxide base liquid, and 3 parts of 2-acrylamide-2-methylpropanesulfonic acid in parts by weight;

The 2-acrylamide-2-methylpropanesulfonic acid includes 2-acrylamide-2-methylpropanesulfonic acid in the form of hydrated crystals;

The preparation method of the liquid carbon dioxide base liquid:

The carbon dioxide gas produced during the high-temperature calcination of limestone (or dolomite) is washed with water, removed of impurities, and compressed to produce gaseous carbon dioxide; the raw material gas of carbon dioxide enters the degreaser for pre-purification, and then passes through the cooler to drop below 36°C and cool down The final carbon dioxide feed gas enters the buffer tank for pressure buffering;

The carbon dioxide raw material gas after pressure stabilization enters the desulfurizer for desulfurization treatment; the carbon dioxide raw material gas after desulfurization treatment enters the purifier for purification treatment from the desulfurizer;

First, the purified carbon dioxide gas is compressed by a compressor, and then cooled by a cooler to obtain a liquid carbon dioxide base liquid;

S102, mixing the polymerized ferric sulfate, liquid carbon dioxide base fluid, and 2-acrylamide-2-methylpropanesulfonic acid to obtain a fracturing fluid.

As shown in Figure 2, the preparation method of polyferric sulfate provided by the invention is as follows:

S201, removing impurities from the iron powder, reducing iron sulfate and iron powder to generate ferrous sulfate; adding sulfuric acid to the ferrous sulfate aqueous solution for acidification to obtain a first mixed solution; adding nitrous acid to the first mixed solution Sodium, the temperature is controlled at 90°C, and oxygen or air is passed through, and the reaction is carried out for 210 minutes to obtain the second mixed solution;

S202, adding an organic framework and a co-solvent to the second mixed solution, the amount of substances added to the organic framework is less than the sum of the amounts of ferric ions and ferrous ions contained in the second mixed solution; the temperature is controlled to 60°C, and fully react to obtain the third mixed solution; the third mixed solution is post-treated to separate and obtain polyferric sulfate;

Wherein, the organic skeleton molecule includes more than two coordination groups, and the coordination groups are selected from at least one of carboxyl, hydroxyl, methylamino, pyridine nitrogen, pyrazine nitrogen, and cyano groups, and any two coordination groups The spacing between the coordinating atoms in the group includes at least two carbon atoms;

The organic skeleton molecule also includes an aromatic system, and the aromatic system includes one of a benzene ring, a biphenyl-like structure, an acene-like aromatic hydrocarbon structure, a quinoline-like structure, and a polypyridine structure;

The co-solvent is an organic solvent miscible with water.

The coordinating group provided by the present invention is a carboxyl group or a phenolic hydroxyl group directly connected to an aromatic system.

On the organic skeleton provided by the present invention, a branch is connected to the aromatic system, and the branch shown is an alkyl group with 3 to 6 carbons or an alkoxy group with 3 to 6 carbons.

The ratio of the amount of the organic skeleton provided by the invention to the added ferrous sulfate is 0.2:1.

The reaction time provided by the present invention is 6h.

As shown in Figure 3, the preparation method of 2-acrylamide-2-methylpropanesulfonic acid provided by the present invention is as follows:

S301, weigh 20 parts of acrylonitrile, 6 parts of concentrated sulfuric acid, 0.5 parts of modified isobutylene, 3 parts of sulfur trioxide, 1 part of acrylic acid, and 30 parts of glacial acetic acid in parts by weight; mix acrylonitrile with dehydrating agent and additives evenly, Prepare the first mixture for subsequent use;

S302, under the condition that the temperature is ≤0°C, add concentrated sulfuric acid to the first mixture, and mix uniformly to obtain the second mixture; heat the second mixture and keep the temperature at 85°C, and add modified isobutylene to the second In the mixture, stir, carry out sulfonation reaction, make the 3rd mixture;

S303, adding glacial acetic acid to the reacted product, and mixing uniformly to obtain a fourth mixture; performing vacuum distillation on the fourth mixture in a vacuum state to remove acrylonitrile to obtain a fifth mixture; lowering the temperature of the fifth mixture After the treatment, filter or centrifuge, and the centrifugal precipitate is 2-acrylamide-2-methylpropanesulfonic acid.

The content of free sulfur trioxide in the concentrated sulfuric acid provided by the invention is 4%.

The low temperature condition provided by the present invention is that the temperature is 1°C;

The temperature of the heating condition is 32°C;

The temperature during the distillation process is 81° C., and the relative pressure is 0.01-0.2 MPa.

In a hydraulic fracturing method provided by the invention, the fracturing fluid is injected into an underground rock formation.

2. Application examples. In order to prove the creativity and technical value of the technical solution of the present invention, this part is the application example of the claimed technical solution on specific products or related technologies.

In the present invention, an organic framework is added in the process of synthesizing polymeric ferric sulfate through the preparation method of polymerized ferric sulfate to form a metal-organic coordination structure of organic framework-iron ions, and a framework system is formed. Through the adsorption of the framework system, the polymerized ferric sulfate Its own coagulation effect and the ability to remove organic impurities in wastewater, thereby improving the fracturing effect of fracturing fluid; at the same time, high-quality 2-acrylamide-2-methylpropanesulfonic acid can be prepared by the preparation method Methylpropanesulfonic acid, thus greatly improving the quality of fracturing fluid.

It should be noted that the embodiments of the present invention can be realized by hardware, software, or a combination of software and hardware. The hardware part can be implemented using dedicated logic; the software part can be stored in memory and executed by a suitable instruction execution system such as a microprocessor or specially designed hardware. Those of ordinary skill in the art will understand that the above-described devices and methods can be implemented using computer-executable instructions and/or contained in processor control code, for example, on a carrier medium such as a magnetic disk, CD or DVD-ROM, such as a read-only memory Such code is provided on a programmable memory (firmware) or on a data carrier such as an optical or electronic signal carrier. The device and its modules of the present invention may be implemented by hardware circuits such as VLSI or gate arrays, semiconductors such as logic chips, transistors, etc., or programmable hardware devices such as field programmable gate arrays, programmable logic devices, etc., It can also be realized by software executed by various types of processors, or by a combination of the above-mentioned hardware circuits and software such as firmware.

3. Evidence of the relevant effects of the embodiment. The embodiment of the present invention has achieved some positive effects in the process of research and development or use, and indeed has great advantages compared with the prior art. The following content is described in conjunction with the data and charts of the test process.

In the present invention, an organic framework is added in the process of synthesizing polymeric ferric sulfate through the preparation method of polymerized ferric sulfate to form a metal-organic coordination structure of organic framework-iron ions, and a framework system is formed. Through the adsorption of the framework system, the polymerized ferric sulfate Its own coagulation effect and the ability to remove organic impurities in wastewater, thereby improving the fracturing effect of fracturing fluid; at the same time, high-quality 2-acrylamide-2-methylpropanesulfonic acid can be prepared by the preparation method Methylpropanesulfonic acid, thus greatly improving the quality of fracturing fluid.

The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Anyone familiar with the technical field within the technical scope disclosed in the present invention, whoever is within the spirit and principles of the present invention Any modifications, equivalent replacements and improvements made within shall fall within the protection scope of the present invention.

Claims (10)

1. A fracturing fluid of a (co) polymer of 2-acrylamide-2-methylpropanesulfonic acid in a hydrated crystalline form, characterized in that the preparation method of the fracturing fluid of the (co) polymer of 2-acrylamide-2-methylpropanesulfonic acid in a hydrated crystalline form comprises the following steps:

step one, weighing 2 parts of polymeric ferric sulfate, 30 parts of liquid carbon dioxide base solution and 3 parts of 2-acrylamide-2-methylpropanesulfonic acid according to parts by weight;

the 2-acrylamide-2-methylpropanesulfonic acid comprises 2-acrylamide-2-methylpropanesulfonic acid in a hydrated crystalline form;

the preparation method of the liquid carbon dioxide base solution comprises the following steps:

the carbon dioxide gas generated in the process of calcining limestone (or dolomite) at high temperature is subjected to water washing, impurity removal and compression to obtain gas carbon dioxide; the carbon dioxide raw material gas enters an oil remover for pre-purification, then is cooled to below 36 ℃ through a cooler, and enters a buffer tank for pressure buffering;

the carbon dioxide raw material gas after pressure stabilization enters a desulfurizer to carry out desulfurization treatment; the carbon dioxide raw material gas after desulfurization treatment enters a purifier from a desulfurizer to be purified;

firstly, compressing purified carbon dioxide gas through a compressor, and then cooling through a cooler to obtain liquid carbon dioxide base solution;

and step two, mixing polymeric ferric sulfate, liquid carbon dioxide base solution and 2-acrylamide-2-methylpropanesulfonic acid to obtain the fracturing fluid.

2. The fracturing fluid of a (co) polymer of 2-acrylamido-2-methylpropanesulfonic acid in hydrated crystalline form according to claim 1, characterized in that said polymeric ferric sulfate is prepared by the process comprising:

(1) Removing impurities from iron powder, and carrying out reduction reaction on ferric sulfate and the iron powder to generate ferrous sulfate; adding sulfuric acid into the ferrous sulfate aqueous solution for acidification to obtain a first mixed solution; adding sodium nitrite into the first mixed solution, controlling the temperature to be 90 ℃, introducing oxygen or air, and reacting for 210min to obtain a second mixed solution;

(2) Adding an organic framework and a cosolvent into the second mixed solution, wherein the amount of added substances of the organic framework is smaller than the sum of the amounts of substances of iron ions and ferrous ions contained in the second mixed solution; controlling the temperature to be 60 ℃ and fully reacting to obtain a third mixed solution; carrying out post-treatment on the third mixed solution, and separating to obtain polymeric ferric sulfate;

wherein the organic framework molecule comprises more than two coordination groups, the coordination groups are at least one of carboxyl, hydroxyl, methylamino, pyridine nitrogen, pyrazine nitrogen and cyano, and the interval between the coordination atoms in any two coordination groups comprises at least two carbon atoms;

the organic framework molecule also comprises an aromatic system, wherein the aromatic system comprises one of benzene rings, biphenyl-like structures, acene aromatic hydrocarbon structures, quinoline structures and multi-bipyridine structures;

the cosolvent is an organic solvent miscible with water.

3. The fracturing fluid of a (co) polymer of 2-acrylamido-2-methylpropanesulfonic acid in hydrated crystalline form according to claim 2, wherein said coordinating group is a carboxyl or phenolic hydroxyl group directly linked to an aromatic system.

4. The fracturing fluid of a (co) polymer of 2-acrylamido-2-methylpropanesulfonic acid in hydrated crystalline form according to claim 2, wherein said organic framework has a branched chain attached to the aromatic system, said branched chain being a 3-6 carbon alkyl or 3-6 carbon alkoxy group.

5. Fracturing fluid of a (co) polymer of 2-acrylamido-2-methylpropanesulfonic acid in hydrated crystalline form according to claim 2, characterized in that the ratio of the amount of organic framework to the amount of substance added of ferrous sulphate is 0.2:1.

6. Fracturing fluid of (co) polymers of 2-acrylamido-2-methylpropanesulfonic acid in hydrated crystalline form according to claim 2, characterized in that said reaction time is 6h.

7. The fracturing fluid of a (co) polymer of 2-acrylamido-2-methylpropanesulfonic acid in hydrated crystalline form according to claim 1, characterized in that said preparation process of 2-acrylamido-2-methylpropanesulfonic acid is as follows:

1) Weighing 20 parts of acrylonitrile, 6 parts of concentrated sulfuric acid, 0.5 part of modified isobutene, 3 parts of sulfur trioxide, 1 part of acrylic acid and 30 parts of glacial acetic acid according to parts by weight; uniformly mixing acrylonitrile, a dehydrating agent and an additive to prepare a first mixture for standby;

2) Adding concentrated sulfuric acid into the first mixture at the temperature of less than or equal to 0 ℃ and uniformly mixing to obtain a second mixture; heating the second mixture to a temperature of 85 ℃, adding the modified isobutene into the second mixture, stirring, and carrying out sulfonation reaction to obtain a third mixture;

3) Adding glacial acetic acid into the reacted product, and uniformly mixing to obtain a fourth mixture; performing reduced pressure distillation treatment on the fourth mixture under a vacuum state to remove acrylonitrile and obtain a fifth mixture; and cooling the fifth mixture, and then filtering or centrifuging, wherein the centrifugal precipitate is the 2-acrylamide-2-methylpropanesulfonic acid.

8. The fracturing fluid of a (co) polymer of 2-acrylamido-2-methylpropanesulfonic acid in hydrated crystalline form according to claim 7, wherein the content of free sulfur trioxide in concentrated sulfuric acid is 4%.

9. The fracturing fluid of a (co) polymer of 2-acrylamido-2-methylpropanesulfonic acid in hydrated crystalline form according to claim 7, wherein said low temperature conditions are a temperature of 1 ℃;

the temperature of the heating condition is 32 ℃;

the temperature in the distillation treatment process is 81 ℃, and the relative pressure is 0.01-0.2MPa.

10. A hydraulic fracturing method comprising preparing the fracturing fluid of any of claims 1-9, and injecting the fracturing fluid into a subterranean formation.