Discharge aiding agent for fracture acidizing as well as preparation method and application of discharge aiding agent

Abstract

The invention belongs to the technical field of tertiary oil recovery, and relates to a discharge aiding agent for fracture acidizing 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-benzene disulfonic acid in batches, controlling the temperature to be below 10 DEG C, maintaining the pH value to be 7-8, and continuously reacting for 10-20 minutes; 2, 2-bis (3-amino-4-hydroxyphenyl) hexafluoropropane is added in batches, the temperature is controlled to be 20 DEG C or below, and the pH value is maintained to be 7-8; reacting for 30 to 50 minutes; adding lauryl aminopropionic acid, slowly stirring and heating to 60-70 DEG C, maintaining the pH value to be 8-9, and carrying out heat preservation reaction for 100-120 minutes; and after the reaction is finished, adjusting the pH to 2-3 by using hydrochloric acid, cooling to below 10 DEG C, separating out a solid, filtering and drying to obtain the product discharge aiding agent. The cleanup additive has the advantages of low surface tension, low interfacial tension, low critical micelle concentration and high flowback rate.

Description

Technical Field

[0001] The invention belongs to the technical field of tertiary oil recovery and relates to a drainage aid for fracturing and acidification and a preparation method and application thereof. Background Art

[0002] Acid fracturing technology is the most widely used technology in the development of oil and gas fields in my country. The main purpose of this technology is to improve the conductivity of the production layer to increase production. It means to press the formation open, and then the acid squeezed into the formation flows along the cracks, and the residual liquid chemically dissolves the rocks on the crack wall to improve the physical properties of the reservoir. Simply put, in the process of oil and gas field development, when other proppants are not applicable, the use of acid fracturing technology can effectively increase the production of oil and gas fields.

[0003] Whether the acid or fracturing fluid injected into the formation can be returned in time is an important factor in the success or failure of the process. In particular, for wells with low formation energy and poor permeability, it is more difficult to return the treated fluid after the acid fracturing operation. If no corresponding boosting measures are taken, it will cause new damage and pollution to the formation, leading to construction failure.

[0004] The method of adding drainage aids to fracturing fluid is relatively simple. By adding drainage aids with excellent performance, the surface tension of the liquid phase can be effectively reduced, the wettability of the rock can be changed, and the capillary resistance of the rock can be reduced, the return rate of the fracturing fluid can be increased, and blockage and damage to the formation can be prevented. At the same time, the reservoir conductivity can be improved to increase oil and gas production. In addition, the method of adding drainage aids to fracturing fluid has the advantages of low cost, simple operation, and high return rate.

[0005] CN109135718A discloses a method for preparing a fracturing acidification foaming and drainage agent, which belongs to the technical field of drainage agents. The foam-stabilizing surfactant prepared by the present invention is mainly composed of zwitterionic surfactants, which have a large relative molecular weight and a larger surface area. After sacrificing part of the foaming ability, it can form a denser and more solid interface film on the surface of the solid and liquid phases, so that the bubbles are not easy to break; the dodecyl sulfobetaine molecules have a higher positive charge and are easy to associate with the negatively charged sodium dodecyl sulfate molecules. The hydrophobic force and electrostatic force between the two molecules work together to enhance the effect of compounding and make up for the lack of foaming ability of the foam-stabilizing surfactant; the fracturing acidification foaming and drainage agent prepared by the invention is a dual-purpose agent, which avoids the trouble of compounding the foaming agent and the drainage agent during construction, and at the same time, the foaming is fast, the bubble strength is high, the use is simpler, and the cost is reduced. Sodium hydride is used in the configuration process of the invention, which is a dangerous product and cannot be promoted on a large scale.

[0006] CN102533243A discloses a fracturing acidification drainage aid and a preparation method thereof. The drainage aid is composed of the following components: (1) 0.01-0.5wt% of fluorinated carbon chain Gemini surfactant G1 or G2; (2) 1-35wt% of nonionic surfactant; (3) 5-30wt% of small molecule alcohol; (4) 0-10wt% of alkylbenzyldimethylammonium chloride or alkyltrimethylammonium chloride; (5) the balance is water. The preparation method comprises: adding / or not adding alkylbenzyldimethylammonium chloride or alkyltrimethylammonium chloride to a nonionic surfactant, dissolving it in a mixed solvent of water and small molecule alcohol, stirring to fully dissolve it, then adding a fluorinated carbon chain surfactant, continuing to stir, and cooling to room temperature to obtain the obtained product. The fracturing acidification drainage aid described in the invention can significantly reduce surface tension, increase water contact angle, reduce capillary force, and improve the backflow efficiency of injected fluid. However, the drainage aid system of the invention uses a large number of drugs and the configuration is relatively complicated, which is not conducive to popularization and use. Summary of the invention

[0007] The present invention aims at the above-mentioned deficiencies of the prior art and provides a drainage aid for fracturing acidification and its preparation method and application. The drainage aid of the present invention 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 invention is to provide a method for preparing a drainage agent for fracturing and acidizing, the preparation method specifically comprising the following steps:

[0009] (1) Add cyanuric chloride and water into a reactor, stir to make a slurry, cool it to below 5° C. with ice brine, add 5-amino-4-hydroxy-1,3-benzenedisulfonic acid in batches, control the temperature below 10° C., and simultaneously add sodium hydroxide solution dropwise to maintain the pH at 7-8. After the addition is complete, continue the reaction for 10-20 minutes;

[0010] (2) Add 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane in batches to the above reactor, control the reaction temperature below 20° C., and simultaneously add sodium hydroxide solution dropwise to maintain the pH at 7-8; after the addition is complete, continue the reaction for 30-50 minutes;

[0011] (3) Add laurylaminopropionic acid to the reactor all at once, slowly stir and heat to 60-70° C., while adding sodium hydroxide solution dropwise, maintaining the pH at 8-9, and keep the reaction warm for 100-120 minutes;

[0012] (4) After the reaction is completed, adjust the pH to 2-3 with hydrochloric acid, cool to below 10°C, precipitate the solid, filter and dry to obtain the product drainage agent.

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

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

[0015] The synthesis formula of the main components of the fracturing acidizing drainage agent of the present invention is:

[0016]

[0017] Another object of the present invention is to disclose a drainage aid prepared by the above preparation method, wherein the molecular structure of the main component of the drainage aid is as follows:

[0018]

[0019] The third object of the present invention is to disclose the application of the above drainage aid in oil field fracturing and acidizing.

[0020] The fracturing acidizing drainage agent of the present invention belongs to a composite special surfactant, the lipophilic group is dodecyl, fluoroalkyl, and the hydrophilic group is sulfonic acid, carboxylic acid. It has lower surface tension and interfacial tension than conventional surfactants, and lower critical micelle concentration, so the dosage when used is lower. The molecule of the present invention contains multiple ring structures, has strong rigidity, and has strong heat and salt resistance. The present invention can effectively reduce liquid phase interfacial tension, increase wetting angle, change rock wettability, thereby reducing rock capillary resistance, increasing fracturing fluid return rate, and preventing blockage and damage to formations.

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

[0022] (1) The fracturing acidizing drainage agent of the present invention has the characteristics of low surface tension and low interfacial tension, with the lowest surface tension reaching 24.5 mN / m and the lowest interfacial tension reaching 0.0066 mN / m;

[0023] (2) The fracturing acidizing drainage agent of the present invention has the characteristic of low critical micelle concentration, which is as low as 18 mg / L;

[0024] (3) The drainage aid for fracturing and acidizing of the present invention has the characteristic of high drainage rate, and the drainage rate can reach up to 96.2%. DETAILED DESCRIPTION

[0025] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0026] The technical solution of the present invention is further described below in conjunction with specific embodiments:

[0027] Example 1

[0028] (1) Add 0.05 mol of cyanuric chloride and 277 g of water into a reactor, stir to make a slurry, cool it to below 5° C. with ice brine, add 0.04 mol of 5-amino-4-hydroxy-1,3-benzenedisulfonic acid in batches, control the temperature below 10° C., and simultaneously add sodium hydroxide solution dropwise to maintain the pH at 7-8. After the addition is complete, continue the reaction for 10 min;

[0029] (2) Add 0.04 mol of 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane in batches to the above reactor, control the reaction temperature below 20° C., and simultaneously add sodium hydroxide solution dropwise to maintain the pH at 7-8; continue the reaction for 30 min after the addition is complete;

[0030] (3) Add 0.06 mol of laurylaminopropionic acid into the reactor at one time, slowly stir and heat to 60° C., and simultaneously dropwise add sodium hydroxide solution, maintain the pH at 8-9, and keep the reaction warm for 120 min;

[0031] (4) After the reaction is completed, adjust the pH to 2-3 with hydrochloric acid, cool to below 10°C, precipitate the solid, filter and dry to obtain the product drainage agent.

[0032] Example 2

[0033] (1) Add 0.05 mol of cyanuric chloride and 298 g of water into a reactor, stir to make a slurry, cool it to below 5° C. with ice brine, add 0.045 mol of 5-amino-4-hydroxy-1,3-benzenedisulfonic acid in batches, control the temperature below 10° C., and simultaneously add sodium hydroxide solution dropwise to maintain the pH at 7-8. After the addition is complete, continue the reaction for 20 min;

[0034] (2) Add 0.06 mol of 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane in batches to the above reactor, control the reaction temperature below 20° C., and simultaneously add sodium hydroxide solution dropwise to maintain the pH at 7-8; continue the reaction for 40 min after the addition is complete;

[0035] (3) Add 0.04 mol of laurylaminopropionic acid into the reactor at one time, slowly stir and heat to 65° C., and simultaneously dropwise add sodium hydroxide solution, maintain the pH at 8-9, and keep the reaction warm for 100 min;

[0036] (4) After the reaction is completed, adjust the pH to 2-3 with hydrochloric acid, cool to below 10°C, precipitate the solid, filter and dry to obtain the product drainage agent.

[0037] Example 3

[0038] (1) Add 0.05 mol of cyanuric chloride and 316 g of water into a reactor, stir to make a slurry, cool it to below 5° C. with ice brine, add 0.055 mol of 5-amino-4-hydroxy-1,3-benzenedisulfonic acid in batches, control the temperature below 10° C., and simultaneously add sodium hydroxide solution dropwise to maintain the pH at 7-8. After the addition is complete, continue the reaction for 15 minutes;

[0039] (2) Add 0.045 mol of 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane in batches to the above reactor, control the reaction temperature below 20° C., and simultaneously add sodium hydroxide solution dropwise to maintain the pH at 7-8; continue the reaction for 50 min after the addition is complete;

[0040] (3) Add 0.048 mol of laurylaminopropionic acid into the reactor at one time, slowly stir and heat to 62° C., and simultaneously dropwise add sodium hydroxide solution, maintain the pH at 8-9, and keep the reaction warm for 110 min;

[0041] (4) After the reaction is completed, adjust the pH to 2-3 with hydrochloric acid, cool to below 10°C, precipitate the solid, filter and dry to obtain the product drainage agent.

[0042] Example 4

[0043] (1) Add 0.05 mol of cyanuric chloride and 330 g of water into a reactor, stir to make a slurry, cool it to below 5° C. with ice brine, add 0.06 mol of 5-amino-4-hydroxy-1,3-benzenedisulfonic acid in batches, control the temperature below 10° C., and simultaneously add sodium hydroxide solution dropwise to maintain the pH at 7-8. After the addition is complete, continue the reaction for 10 min;

[0044] (2) Add 0.05 mol of 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane in batches to the above reactor, control the reaction temperature below 20° C., and simultaneously add sodium hydroxide solution dropwise to maintain the pH at 7-8; continue the reaction for 30 min after the addition is complete;

[0045] (3) Add 0.042 mol of laurylaminopropionic acid into the above reactor at one time, slowly stir and heat to 70° C., and simultaneously dropwise add sodium hydroxide solution, maintain pH 8-9, and keep the reaction warm for 115 min;

[0046] (4) After the reaction is completed, adjust the pH to 2-3 with hydrochloric acid, cool to below 10°C, precipitate the solid, filter and dry to obtain the product drainage agent.

[0047] Example 5

[0048] (1) Add 0.05 mol of cyanuric chloride and 358 g of water into a reactor, stir to make a slurry, cool it to below 5° C. with ice brine, add 0.048 mol of 5-amino-4-hydroxy-1,3-benzenedisulfonic acid in batches, control the temperature below 10° C., and simultaneously add sodium hydroxide solution dropwise to maintain pH 7-8. After the addition is complete, continue the reaction for 20 min;

[0049] (2) Add 0.053 mol of 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane in batches to the above reactor, control the reaction temperature below 20° C., and simultaneously add sodium hydroxide solution dropwise to maintain the pH at 7-8; continue the reaction for 35 min after the addition is complete;

[0050] (3) Add 0.051 mol of laurylaminopropionic acid into the reactor at one time, slowly stir and heat to 66° C., and simultaneously dropwise add sodium hydroxide solution, maintain the pH at 8-9, and keep the reaction warm for 105 min;

[0051] (4) After the reaction is completed, adjust the pH to 2-3 with hydrochloric acid, cool to below 10°C, precipitate the solid, filter and dry to obtain the product drainage agent.

[0052] Example 6

[0053] (1) Add 0.05 mol of cyanuric chloride and 368 g of water into a reactor, stir to make a slurry, cool it to below 5° C. with ice brine, add 0.05 mol of 5-amino-4-hydroxy-1,3-benzenedisulfonic acid in batches, control the temperature below 10° C., and simultaneously add sodium hydroxide solution dropwise to maintain the pH at 7-8. After the addition is complete, continue the reaction for 15 minutes;

[0054] (2) Add 0.05 mol of 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane in batches to the above reactor, control the reaction temperature below 20° C., and simultaneously add sodium hydroxide solution dropwise to maintain the pH at 7-8; continue the reaction for 45 minutes after the addition is complete;

[0055] (3) Add 0.052 mol of laurylaminopropionic acid into the reactor at one time, slowly stir and heat to 70° C., and simultaneously dropwise add sodium hydroxide solution, maintain the pH at 8-9, and keep the reaction warm for 120 min;

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

[0057] Example 7 Testing of surface tension and interfacial tension

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

[0059] From Table 1 we can see that:

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

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

[0062] Example 8 Test of critical micelle concentration

[0063] The critical micelle concentration was determined by referring to the method in GB / T 11276-2007 "Determination of critical micelle concentration of surfactants". During the test, the drainage aid of the present invention (Examples 1-6) was adjusted to pH 7-8. The test results are shown in Table 1. The FC-3150 drainage aid produced by Xinxiang Shengqing New Materials Co., Ltd. was used for comparative experiments.

[0064] From Table 1 we can see that:

[0065] The fracturing acidizing drainage agent (Examples 1-6) of the present invention has the characteristic of low critical micelle concentration, which is lower than 25 mg / L and can reach as low as 18 mg / L; while the comparative example is 130 mg / L, which is significantly higher than the present invention.

[0066] Example 9 Test of drainage aid rate

[0067] The drainage aid of the present invention (Examples 1-6) was prepared into a solution with a concentration of 100 mg / L with distilled water and the pH was adjusted to 7-8. The drainage rate was determined according to the method 6.8.1 in SY / T 5755-2016 "Method for evaluating the performance of drainage aids for fracturing and acidizing". The test results are shown in Table 1. The FC-3150 drainage aid of Xinxiang Shengqing New Materials Co., Ltd. was used for comparative experiments.

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

[0069]

[0070] From Table 1 we can see that:

[0071] The drainage aid for fracturing acidification of the present invention (Examples 1-6) has the characteristic of high drainage aid rate, which is higher than 95% and reaches 96.2% at the highest. The drainage aid rate of the comparative example is 80.8%, which is obviously lower than that of the present invention.

[0072] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.

Claims

1. A method for preparing a drainage agent for fracturing and acidizing, characterized in that: The preparation method specifically comprises the following steps: (1) Add cyanuric chloride and water into a reactor, stir to make a slurry, cool it to below 5° C. with ice brine, add 5-amino-4-hydroxy-1,3-benzenedisulfonic acid in batches, control the temperature below 10° C., and simultaneously add sodium hydroxide solution dropwise to maintain the pH at 7-8. After the addition is complete, continue the reaction for 10-20 minutes; (2) Add 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane in batches to the above reactor, control the reaction temperature below 20° C., and simultaneously add sodium hydroxide solution dropwise to maintain the pH at 7-8; after the addition is complete, continue the reaction for 30-50 minutes; (3) Add lauryl aminopropionic acid to the reactor all at once, slowly stir and heat to 60-70° C., and simultaneously dropwise add sodium hydroxide solution, maintain the pH at 8-9, and keep the reaction warm for 100-120 min; (4) After the reaction is completed, adjust the pH to 2-3 with hydrochloric acid, cool to below 10°C, precipitate the solid, filter and dry to obtain the product drainage agent.

2. The synthesis method according to claim 1, characterized in that: 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-laurylaminopropionic acid are 0.8-1.2 moles, 0.8-1.2 moles and 0.8-1.2 moles respectively.

3. 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.

4. A drainage agent prepared according to the synthesis method according to any one of claims 1 to 3.

5. Use of the drainage aid according to claim 4 in oil field fracturing and acidizing.

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