Fracturing acidizing cleanup aid, its preparation method and application

Abstract

The application belongs to the technical field of tertiary oil recovery, and relates to a cleanup agent for fracturing acidification and a preparation method and application thereof.The preparation method comprises the following steps: adding cyanuric chloride and water into a reactor, adding 5-amino-4-hydroxy-1,3-benzenedisulfonic acid in batches, controlling the temperature below 10 DEG C, maintaining the pH value at 7-8, and continuing to react for 10-20 min; adding 2,2-bis(3-amino-4-hydroxyphenyl) hexafluoropropane in batches, controlling the temperature below 20 DEG C, and maintaining the pH value at 7-8; reacting for 30-50 min; adding laurylaminopropionic acid, slowly stirring, heating to 60-70 DEG C, maintaining the pH value at 8-9, and heat-insulating and reacting for 100-120 min; after the reaction is completed, adjusting the pH value to 2-3 by using hydrochloric acid, cooling to below 10 DEG C, precipitating the solid, filtering and drying to obtain the product cleanup agent.The cleanup agent has the advantages of low surface tension, low interfacial tension, low critical micelle concentration and high flowback rate.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of tertiary oil recovery, and relates to a cleanup agent for acid fracturing, a preparation method and application thereof. BACKGROUND

[0002] The acid fracturing technology is a widely used technology in the development of oil and gas fields in China at present, and the main purpose of the technology is to improve the flow conductivity of the production layer and increase production. It refers to the process of pressing the formation, then extruding the acid liquid into the formation along the cracks, and chemically corroding the rock on the crack wall by the residual liquid, so as to improve the physical properties of the reservoir. In simple terms, in the process of oil and gas field development, when other proppants are not applicable, the acid fracturing technology can effectively improve the production of oil and gas fields.

[0003] Whether the acid liquid or fracturing fluid pressed into the formation can be returned in time is an important factor for the success of the process. Especially for wells with low formation energy and poor permeability, it is more difficult to return the treatment liquid after acid fracturing operation. If appropriate boosting measures are not taken, it will cause new damage and pollution to the formation, resulting in construction failure.

[0004] The method of adding cleanup agent to the fracturing fluid is relatively simple. By adding cleanup agent with excellent performance, the liquid surface tension can be effectively reduced, the wettability of the rock can be changed, the capillary resistance of the rock can be reduced, the fracturing fluid return rate can be improved, the formation can be prevented from being blocked and damaged, and the reservoir flow conductivity can be improved to increase oil and gas production. In addition, the method of adding cleanup agent to the fracturing fluid has the advantages of low cost, simple operation, high return rate, etc.

[0005] CN109135718A discloses a preparation method of a fracturing acidizing foaming cleanup agent, and belongs to the technical field of cleanup agents. The prepared stable foam surface active agent is mainly composed of zwitterionic surfactant, has large relative molecular weight and large surface area, can form a more dense and more firm interface film on the solid-liquid two-phase surface after sacrificing part of the foaming capacity, so that the bubbles are not easy to break; the dodecyl sulfobetaine molecule has high positive electric property and is easy to associate with the negatively charged dodecyl sodium sulfate molecule, the hydrophobic force and electrostatic force between the two molecules jointly act, can enhance the compounding effect, and make up for the deficiency of the stable foam surface active agent in foaming capacity; the prepared fracturing acidizing foaming cleanup agent is dual-purpose, avoids the trouble of compounding foaming agent and cleanup agent during construction, has fast foaming, high bubble strength, is more convenient to use, and reduces the cost. Sodium hydride is used in the configuration process of the application, which is a dangerous product and cannot be widely promoted.

[0006] CN102533243A discloses a fracturing acidizing cleanup additive and a preparation method thereof. The cleanup additive is composed of the following components: (1) fluorine-containing carbon chain Gemini surfactant G1 or G2: 0.01-0.5 wt%; (2) non-ionic surfactant: 1-35 wt%; (3) small molecule alcohol: 5-30 wt%; (4) alkyl benzyl dimethyl ammonium chloride or alkyl trimethyl ammonium chloride: 0-10 wt%; and (5) the balance is water. The preparation method comprises the following steps: adding the non-ionic surfactant with or without alkyl benzyl dimethyl ammonium chloride or alkyl trimethyl ammonium chloride into a mixed solvent of water and small molecule alcohol, stirring to dissolve, then adding the fluorine-containing carbon chain surfactant, continuing to stir, and cooling to room temperature to obtain the fracturing acidizing cleanup additive. The fracturing acidizing cleanup additive can significantly reduce the surface tension, increase the water contact angle, reduce the capillary force, and improve the flowback efficiency of the injected fluid. However, the cleanup additive system of the present application uses a large variety of chemicals and is complicated to configure, which is not conducive to popularization and use. SUMMARY

[0007] The present application provides a fracturing acidizing cleanup additive, a preparation method and application thereof. The cleanup additive has the advantages of low surface tension, low interfacial tension, low critical micelle concentration and high flowback rate.

[0008] One of the purposes of the present application is to provide a preparation method of a fracturing acidizing cleanup additive, which specifically comprises the following steps:

[0009] (1) adding cyanuric chloride and water into a reactor, stirring to form a slurry, cooling the slurry to below 5℃ with ice salt water, adding 5-amino-4-hydroxy-1,3-benzenedisulfonic acid in batches, controlling the temperature to be below 10℃, simultaneously adding sodium hydroxide solution dropwise, maintaining pH 7-8, continuing to react for 10-20 min after the addition is completed;

[0010] (2) adding 2,2-bis(3-amino-4-hydroxyphenyl) hexafluoropropane into the above reactor in batches, controlling the reaction temperature to be below 20℃, simultaneously adding sodium hydroxide solution dropwise, maintaining pH 7-8; continuing to react for 30-50 min after the addition is completed;

[0011] (3) adding lauryl aminopropionic acid into the above reactor at one time, slowly stirring and heating to 60-70℃, simultaneously adding sodium hydroxide solution dropwise, maintaining pH 8-9, and maintaining the reaction for 100-120 min;

[0012] (4) after the reaction is completed, adjusting pH to 2-3 with hydrochloric acid, cooling to below 10℃, precipitating the solid, filtering and drying to obtain the product cleanup additive.

[0013] In the present application, preferably, based on 1 mole of cyanuric chloride, the amount of 5-amino-4-hydroxy-1,3-benzenedisulfonic acid, 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane and p-laurylaminopropionic acid is 0.8-1.2 moles, 0.8-1.2 moles and 0.8-1.2 moles, respectively.

[0014] In the present application, preferably, in step (1), the mass ratio of water to cyanuric chloride is 30-40:1.

[0015] The synthesis equation of the main component of the cleanup additive for fracturing acidizing is as follows:

[0016]

[0017] Another object of the present application discloses the cleanup additive prepared by the above preparation method, and the molecular structure formula of the main component of the cleanup additive is as follows:

[0018]

[0019] The third object of the present application discloses the application of the above cleanup additive in oilfield fracturing acidizing.

[0020] The cleanup additive for fracturing acidizing belongs to a composite special surfactant, the lipophilic group is dodecyl and fluoroalkyl, and the hydrophilic group is sulfonic acid group and carboxylic acid group. Compared with conventional surfactants, the cleanup additive has lower surface tension and interfacial tension, and lower critical micelle concentration, so that the usage amount is lower. The molecule of the present application contains multiple ring structures, which has strong rigidity and strong temperature resistance and salt resistance. The present application can effectively reduce the liquid interfacial tension, increase the wetting angle, change the rock wettability, thereby reducing the rock capillary resistance, improving the fracturing fluid flowback rate, preventing plugging and damaging the formation.

[0021] Compared with the prior art, the present application has the following advantages and beneficial effects:

[0022] (1) The cleanup additive for fracturing acidizing has the characteristics of low surface tension and low interfacial tension, and the lowest surface tension reaches 24.5 mN / m, and the lowest interfacial tension reaches 0.0066 mN / m;

[0023] (2) The cleanup additive for fracturing acidizing has the characteristics of low critical micelle concentration, and the lowest reaches 18 mg / L;

[0024] (3) The cleanup additive for fracturing acidizing has the characteristics of high cleanup rate, and the highest cleanup rate reaches 96.2%. DETAILED DESCRIPTION

[0025] The endpoints of the ranges and any values disclosed herein are not limited to the precise values recited as the exact dimensions are not considered critical for the purposes of the invention. The ranges should be interpreted as being inclusive of the recited values and the ranges should be interpreted as being inclusive of the endpoints.

[0026] The technical solutions of the present application are further described below in combination with specific examples:

[0027] Example 1

[0028] (1) 0.05 mol cyanuric chloride and 277 g water were added into a reactor, and stirred to form a slurry, which was cooled to below 5°C with ice salt water, 0.04 mol 5-amino-4-hydroxy-1,3-benzenedisulfonic acid was added in batches, the temperature was controlled below 10°C, and sodium hydroxide solution was added dropwise to maintain pH 7-8, and after the addition was completed, the reaction was continued for 10 min;

[0029] (2) 0.04 mol 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane was added in batches into the above reactor, the reaction temperature was controlled below 20°C, and sodium hydroxide solution was added dropwise to maintain pH 7-8; after the addition was completed, the reaction was continued for 30 min;

[0030] (3) 0.06 mol laurylaminopropionic acid was added into the above reactor at one time, and slowly stirred and heated to 60°C, while sodium hydroxide solution was added dropwise to maintain pH 8-9, and the reaction was maintained for 120 min;

[0031] (4) After the reaction was completed, the pH was adjusted to 2-3 with hydrochloric acid, and the temperature was lowered to below 10°C, and the solid was precipitated, filtered and dried to obtain the product of the discharge aid.

[0032] Example 2

[0033] (1) 0.05 mol cyanuric chloride and 277 g water were added into a reactor, and stirred to form a slurry, which was cooled to below 5°C with ice salt water, 0.04 mol 5-amino-4-hydroxy-1,3-benzenedisulfonic acid was added in batches, the temperature was controlled below 10°C, and sodium hydroxide solution was added dropwise to maintain pH 7-8, and after the addition was completed, the reaction was continued for 10 min;

[0034] (2) 0.04 mol 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane was added in batches into the above reactor, the reaction temperature was controlled below 20°C, and sodium hydroxide solution was added dropwise to maintain pH 7-8; after the addition was completed, the reaction was continued for 30 min;

[0035] (3) In the above reactor, 0.04 mol lauryl amino propionic acid was added at one time, slowly stirred and heated to 65°C, while sodium hydroxide solution was added dropwise to maintain pH 8-9, and the reaction was maintained for 100 min;

[0036] (4) After the reaction was completed, the pH was adjusted to 2-3 with hydrochloric acid, and the temperature was lowered to below 10°C, and the solid was precipitated, filtered and dried to obtain the product.

[0037] Example 3

[0038] (1) In the reactor, 0.05 mol of cyanuric chloride and 316 g of water were added, stirred to form a slurry, cooled to below 5°C with ice salt water, and 0.055 mol of 5-amino-4-hydroxy-1,3-benzenedisulfonic acid was added in batches, the temperature was controlled below 10°C, and sodium hydroxide solution was added dropwise to maintain pH 7-8, and after addition was completed, the reaction was continued for 15 min;

[0039] (2) In the above reactor, 0.045 mol of 2,2-bis(3-amino-4-hydroxyphenyl) hexafluoropropane was added in batches, the reaction temperature was controlled below 20°C, and sodium hydroxide solution was added dropwise to maintain pH 7-8; after addition was completed, the reaction was continued for 50 min;

[0040] (3) In the above reactor, 0.048 mol lauryl amino propionic acid was added at one time, slowly stirred and heated to 62°C, while sodium hydroxide solution was added dropwise to maintain pH 8-9, and the reaction was maintained for 110 min;

[0041] (4) After the reaction was completed, the pH was adjusted to 2-3 with hydrochloric acid, and the temperature was lowered to below 10°C, and the solid was precipitated, filtered and dried to obtain the product.

[0042] Example 4

[0043] (1) In the reactor, 0.05 mol of cyanuric chloride and 330 g of water were added, stirred to form a slurry, cooled to below 5°C with ice salt water, and 0.06 mol of 5-amino-4-hydroxy-1,3-benzenedisulfonic acid was added in batches, the temperature was controlled below 10°C, and sodium hydroxide solution was added dropwise to maintain pH 7-8, and after addition was completed, the reaction was continued for 10 min;

[0044] (2) In the above reactor, 0.05 mol of 2,2-bis(3-amino-4-hydroxyphenyl) hexafluoropropane was added in batches, the reaction temperature was controlled below 20°C, and sodium hydroxide solution was added dropwise to maintain pH 7-8; after addition was completed, the reaction was continued for 30 min;

[0045] (3) In the above reactor, 0.042 mol lauryl amino propionic acid was added at one time, slowly stirred and heated to 70°C, while sodium hydroxide solution was added dropwise to maintain pH 8-9, and the reaction was maintained for 115 min;

[0046] (4) After the reaction was completed, the pH was adjusted to 2-3 with hydrochloric acid, the temperature was lowered to below 10°C, and the solid was precipitated, filtered, and dried to obtain the product cleanup agent.

[0047] Example 5

[0048] (1) In the reactor, 0.05 mol cyanuric chloride and 358 g water were added, stirred to form a slurry, and cooled to below 5°C with ice salt water. 0.048 mol 5-amino-4-hydroxy-1,3-benzenedisulfonic acid was added in batches, the temperature was controlled below 10°C, sodium hydroxide solution was added dropwise to maintain pH 7-8, and after the addition was completed, the reaction was continued for 20 min;

[0049] (2) In the above reactor, 0.053 mol 2,2-bis(3-amino-4-hydroxyphenyl) hexafluoropropane was added in batches, the reaction temperature was controlled below 20°C, sodium hydroxide solution was added dropwise to maintain pH 7-8; after the addition was completed, the reaction was continued for 35 min;

[0050] (3) In the above reactor, 0.051 mol lauryl amino propionic acid was added at one time, slowly stirred and heated to 66°C, while sodium hydroxide solution was added dropwise to maintain pH 8-9, and the reaction was maintained for 105 min;

[0051] (4) After the reaction was completed, the pH was adjusted to 2-3 with hydrochloric acid, the temperature was lowered to below 10°C, and the solid was precipitated, filtered, and dried to obtain the product cleanup agent.

[0052] Example 6

[0053] (1) In the reactor, 0.05 mol cyanuric chloride and 368 g water were added, stirred to form a slurry, and cooled to below 5°C with ice salt water. 0.05 mol 5-amino-4-hydroxy-1,3-benzenedisulfonic acid was added in batches, the temperature was controlled below 10°C, sodium hydroxide solution was added dropwise to maintain pH 7-8, and after the addition was completed, the reaction was continued for 15 min;

[0054] (2) In the above reactor, 0.05 mol 2,2-bis(3-amino-4-hydroxyphenyl) hexafluoropropane was added in batches, the reaction temperature was controlled below 20°C, sodium hydroxide solution was added dropwise to maintain pH 7-8; after the addition was completed, the reaction was continued for 45 min;

[0055] (3) Add 0.052 mol of lauryl aminopropionic acid to the above reactor at once, stir slowly and heat to 70°C, while adding sodium hydroxide solution dropwise, maintain pH 8-9, and keep the reaction at the temperature for 120 min;

[0056] (4) After the reaction is complete, adjust the pH to 2-3 with hydrochloric acid, cool down to below 10°C, precipitate the solid, filter and dry to obtain the product drainage aid.

[0057] Example 7: Testing of Surface Tension and Interfacial Tension

[0058] The drainage aid of this invention (Examples 1-6) was prepared into a 100 mg / L solution with distilled water and the pH was adjusted to 7-8. Surface tension and interfacial tension were measured according to the method in SY / T 5370-2018 "Methods for Determination of Surface and Interfacial Tension". The oil phase used for interfacial tension was dehydrated crude oil from an oil production plant in Shengli Oilfield, with a viscosity of 92 mPa·s. The test results are shown in Table 1. A comparative experiment was conducted using FC-3150 drainage aid from Xinxiang Shengqing New Materials Co., Ltd.

[0059] As can be seen from Table 1:

[0060] (1) The fracturing acidizing aid of the present invention (Examples 1-6) has the characteristic of low surface tension, with the surface tension being less than 25.5 mN / m and reaching as low as 24.5 mN / m; while the comparative example is 28.4 mN / m, which is significantly higher than that of the present invention.

[0061] (2) The fracturing acidizing aid of the present invention (Examples 1-6) has the characteristic of low interfacial tension, with the interfacial tension all below 0.022mN / m, and the lowest reaching 0.0066mN / m, while the comparative example is 0.28mN / m, which is significantly higher than that of the present invention.

[0062] Example 8: Test of Critical Micelle Concentration

[0063] The critical micelle concentration was determined according to the method in GB / T 11276-2007 "Determination of Critical Micelle Concentration of Surfactants". During the test, the pH of the discharge aid of this invention (Examples 1-6) was adjusted to 7-8. The test results are shown in Table 1. A comparative experiment was conducted using FC-3150 discharge aid from Xinxiang Shengqing New Materials Co., Ltd.

[0064] As can be seen from Table 1:

[0065] The fracturing and acidizing pumping aid of the present invention (Examples 1-6) has the characteristic of low critical micelle concentration, with the critical micelle concentration all below 25 mg / L, and the lowest reaching 18 mg / L; while the comparative example has 130 mg / L, which is significantly higher than that of the present invention.

[0066] Example 9: Testing of Assisted Ovulation Rate

[0067] The cleanup agent (Examples 1-6) of the present application was configured into a solution with a concentration of 100 mg / L with distilled water and adjusted to pH 7-8, the cleanup rate was determined by referring to the method of 6.8.1 in SY / T 5755-2016 “Performance Evaluation Method for Fracturing Acidizing Cleanup Agent”, and the test results are shown in Table 1. The FC-3150 cleanup agent of Shengqing New Materials Co., Ltd. of Xinxiang City was used as a comparative experiment.

[0068] Table 1 Test results of surface tension, interfacial tension, critical micelle concentration, cleanup rate

[0069]

[0070] From Table 1, it can be seen that:

[0071] The cleanup agent (Examples 1-6) of the present application for fracturing acidizing has the characteristics of high cleanup rate, and the cleanup rate is higher than 95%, and the highest reaches 96.2%; while the cleanup rate of the comparative example is 80.8%, which is significantly lower than the present application.

[0072] The above describes the preferred embodiments of the present application, but the present application is not limited thereto. Within the technical concept of the present application, various simple modifications can be made to the technical solutions of the present application, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be considered as disclosed by the present application, and all belong to the protection scope of the present application.

Claims

1. A method for preparing a fracturing and acidizing aid, characterized in that, The preparation method specifically includes the following steps: (1) Add cyanuric chloride and water to the reactor, stir to make it into a slurry, cool it to below 5°C with ice-salt water, add 5-amino-4-hydroxy-1,3-benzenedisulfonic acid in batches, control the temperature to below 10°C, add sodium hydroxide solution dropwise at the same time, maintain pH 7-8, and continue the reaction for 10-20 minutes after the addition is complete. (2) Add 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane in batches to the above reactor, control the reaction temperature below 20°C, and add sodium hydroxide solution dropwise to maintain pH 7-8; continue the reaction for 30-50 min after the addition is complete. (3) Add lauryl aminopropionic acid into the reactor at once, stir slowly and heat to 60-70℃, while adding sodium hydroxide solution dropwise, maintain pH 8-9, and keep the reaction at the temperature for 100-120 min; (4) After the reaction is complete, adjust the pH to 2-3 with hydrochloric acid, cool down to below 10°C, precipitate the solid, filter and dry to obtain the product discharge aid; Based on 1 mole of cyanuric chloride, the amounts of 5-amino-4-hydroxy-1,3-benzenedisulfonic acid, 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane, and p-lauroaminopropionic acid are 0.8-1.2 moles, 0.8-1.2 moles, and 0.8-1.2 moles, respectively.

2. The synthesis method according to claim 1, characterized in that, In step (1), the mass ratio of the water to cyanuric chloride is 30-40:

1.

3. The excretion aid prepared by the synthesis method according to any one of claims 1-2.

4. The application of the drainage aid according to claim 3 in oilfield fracturing and acidizing.

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