Multi-effect fluid ion regulating agent and preparation method thereof

Abstract

The invention discloses a multi-effect fluid ion regulating agent and a preparation method thereof. The structural formula of the multi-effect fluid ion regulation and control agent is as shown in formula I, R is linear alkyl or naphthenic base, and the number of carbon atoms is 2-8; m represents the number of substituted acetic acid on amido and is 1-3; and n represents the number of amino groups and is 1-2. An amine compound and sodium chloroacetate are subjected to a substitution reaction to prepare a multi-effect fluid ion regulation and control agent; according to the processing technology provided by the invention, the yield of the ion regulation and control agent can reach 80% or above; the maximum binding rate of the multi-effect fluid ion regulation and control agent to divalent ions such as Ca < 2 + > and Mg < 2 + > is 85%, and the particle size of coalescence particles is controllable between 800 nm and 2400 nm; the one-dose multi-effect fluid ion regulation and control agent provided by the invention has the effect of improving the crude oil recovery rate, and the recovery rate can be improved by 12.5%. # imgabs0 #

Description

Technical Field

[0001] The present invention relates to a multi-functional fluid ion regulation agent and its preparation method, belonging to the technical field of oil displacement agents for oil fields. Background Art

[0002] In the middle and late stages of oilfield development, enhanced oil recovery (EOR) technologies mainly using partially hydrolyzed polyacrylamide (HPAM) and its derivatives have achieved great results and benefits in the application of polymer flooding in oil fields worldwide for more than half a century. The recoverable reserves suitable for chemical flooding in domestic offshore oil fields are 1.23 billion tons, with huge resource potential. Preliminary tests have verified the feasibility and economic effectiveness of polymer flooding technology. The preparation of fresh water-based polymer solutions requires a large amount of fresh water, and is restricted by various factors such as transportation, storage, and cost. Using seawater to prepare chemical agent solutions for oil displacement can effectively avoid these disadvantages. However, the salinity of produced water in offshore oil fields is 30,000 mg / L, and the concentration of divalent ions such as Ca 2+ and Mg 2+ is about 800 mg / L. The high salinity and complex ion composition will have a great impact on the performance of chemical agents for oil displacement. In addition, the ion changes during the flow of chemical flooding fluids will also have a greater impact on the application performance of chemical agents for oil displacement in offshore oil fields. There are mainly the following aspects: (1) The high salinity of the fluid will cause viscosity loss of the polymer; (2) The high Ca 2+ and Mg 2+ in the fluid will consume a large amount of OH - in the crosslinking system, generating calcium hydroxide and magnesium hydroxide precipitates, affecting the crosslinking reaction and resulting in a decline in the temperature and shear resistance of the system; (3) The presence of calcium and magnesium ions will cause polymer flocculation and precipitation, not only increasing the economic cost but also easily causing environmental pollution. Ion regulation during the flow of displacement fluids in chemical flooding in offshore oil fields will have an important impact on the synergistic effect of chemical flooding in the whole scenario and process from the injection end to the formation to the production end. Summary of the Invention

[0003] The purpose of the present invention is to provide a multi-functional fluid ion regulation agent, which has an amine multi-substituted acetic acid structure and can form coalescence particles with micron or nanometer size through complexation with divalent ions such as Ca 2+ and Mg 2+ in the fluid, reducing the fluid hardness and having the effect of improving oil recovery.

[0004] The multi-functional fluid ion regulation agent provided by the present invention has a structural formula as shown in Formula I:

[0005]

[0006]

[0007] In Formula I, R is a linear alkyl group or a cycloalkyl group, with 2 - 8 carbon atoms; m represents the number of substituted acetic acids on the amino group, which is 1 - 3; n represents the number of amino groups, which is 1 - 2.

[0008] Specifically, the structural formula of the one - agent multi - effect fluid ion regulation agent can be any of the following:

[0009]

[0010] The one - agent multi - effect fluid ion regulation agent of the present invention is obtained by a substitution reaction of an amine compound and sodium chloroacetate;

[0011] The specific steps can be any of the following:

[0012] 1) Dissolve sodium chloroacetate in water, slowly dropwise add the amine compound, and after dropping, heat the mixed solution under reflux for reaction; after the reaction is completed, cool to room temperature, adjust the pH of the solution to 2 - 3 with concentrated hydrochloric acid; then evaporate and concentrate the solution to obtain a white solid, collect the solid and wash away sodium chloride with a large amount of water, and the obtained crude product can be obtained the one - agent multi - effect fluid ion regulation agent after recrystallization with hot water;

[0013] 2) Under the condition of pH 7 - 8, slowly add ammonium chloride solution to the sodium chloroacetate solution, then adjust to pH 9 - 10, and acidify with hydrochloric acid solution, and collect the precipitate to obtain.

[0014] Among them, the amine compounds include ethylenediamine, butanediamine, 1,4 - cyclohexanediamine, ammonium chloride, benzylamine, bis(pyridin - 2 - ylmethyl)amine, and iminodiacetic acid.

[0015] Preferably, the temperature of the substitution reaction is 60 - 100 °C, more preferably 90 °C, and the time is 0.5 - 2 h, more preferably 1 h.

[0016] Preferably, the molar ratio of sodium chloroacetate to the amine compound is 0.5:1 - 8:1, more preferably 6:1.

[0017] The one - agent multi - effect fluid ion regulation agent of the present invention can also be obtained by a substitution reaction of iminodiacetic acid and 2 - chloromethylpyridine;

[0018] The specific steps can be:

[0019] In the presence of sodium hydroxide, iminodiacetic acid and 2 - chloromethylpyridine hydrochloride are refluxed for 3 - 5 h, and then sodium hydroxide is added and stirred for 1 - 2 h; then concentrated hydrochloric acid is added to the reaction system to acidify to 2 - 3;

[0020] The one - agent multi - effect fluid ion regulation agent of the present invention can also be obtained by a substitution reaction of glycine and 2 - chloromethylpyridine;

[0021] The specific steps may be as follows:

[0022] Neutralize the aqueous solution of 2-chloromethylpyridine or its hydrochloride with sodium hydroxide, then add glycine and reflux for 3 - 4 h; then add sodium hydroxide and continue refluxing for 10 - 12 h; adjust the pH of the solution to 2 - 3 with concentrated hydrochloric acid.

[0023] The mass concentration of the concentrated hydrochloric acid is 6 mol / L.

[0024] The multi-functional fluid ion regulation agent provided by the present invention can be used in oilfield oil displacement, and has a binding effect on divalent ions such as Ca 2+ , Mg 2+ etc., and the coalescence particle size is controllable; it can improve the oil recovery rate.

[0025] The present invention has the following beneficial technical effects:

[0026] ① The multi-functional fluid ion regulation agent of the present invention can be prepared by the substitution reaction of an amine compound and sodium chloroacetate; ② The processing technology provided by the present invention can make the yield of the ion regulation agent reach more than 80%; ③ The multi-functional fluid ion regulation agent provided by the present invention has a maximum binding rate of 85% for divalent ions such as Ca 2+ , Mg 2+ etc., and the coalescence particle size is controllable between 800 - 2400 nm; ④ The multi-functional fluid ion regulation agent provided by the present invention has the effect of improving the oil recovery rate, and the amplitude of improving the recovery rate can reach 12.5%. Description of the Drawings

[0027] Figure 1 It is the synthesis reaction equation for preparing nitrilotriacetic acid in Example 1 of the present invention.

[0028] Figure 2 It is the synthesis reaction equation for preparing 2,2'-((pyridin-2-ylmethyl)azo)diacetic acid in Example 2 of the present invention.

[0029] Figure 3 It is the synthesis reaction equation for preparing bis(pyridin-2-ylmethyl)glycine in Example 3 of the present invention.

[0030] Figure 4 It is the synthesis reaction equation for preparing benzylamine diacetic acid in Example 4 of the present invention.

[0031] Figure 5 It is the synthesis reaction equation for preparing butanediaminetetraacetic acid in Example 5 of the present invention.

[0032] Figure 6 It is the synthesis reaction equation for preparing 1,4-cyclohexanediaminetetraacetic acid in Example 6 of the present invention.

[0033] Figure 7 SEM images of coalescence particles of the oil-displacing fluid before and after adding a multi-functional fluid ion regulation agent (Figure a is the SEM image of the coalescence particles without adding the agent; Figures b and c are the SEM images of the coalescence particles after adding the agent). Detailed implementation manners

[0034] Unless otherwise specified, the experimental methods used in the following examples are all conventional methods.

[0035] Unless otherwise specified, the materials, reagents, etc. used in the following examples can all be obtained from commercial channels.

[0036] Examples 1 and 2, Synthesis of nitrilotriacetic acid

[0037] Add 8.85 g of chloroacetic acid to a flask, stir and heat until melted, and then add an aqueous NaOH solution (3.70 g / 10 mL). Keep it at 80 - 90 °C for 5 - 6 h, concentrate it under vacuum, heat it to 60 °C, and adjust the pH to 7 - 8 with saturated sodium carbonate solution. At 80 °C, slowly add 4.0 g of saturated ammonium chloride solution. Then adjust the pH to 9 - 10 with 1 M NaOH. After standing at room temperature for 4 h, add HCl (6 M) to the mother liquor to adjust the pH to 2 - 3, filter, wash with water (cold water), and air-dry. The yield is 66%.

[0038] Example 2, Synthesis of 2,2'-((pyridin-2-ylmethyl)azo)diacetic acid

[0039] Add iminodiacetic acid (6.55 g, 50 mmol) to a solution of 4.0 g (100 mmol) of NaOH, 20 mL of H 2 O and 60 mL of absolute ethanol and stir evenly. Dissolve 8.2 g (50 mmol) of 2-chloromethylpyridine hydrochloride in 17 mL of H 2 O, and dissolve 4.0 g (100 mmol) of NaOH in 7 mL of H 2 O. Heat the reaction mixture to 70 °C, stir for 4 h, and then add 4.0 g of NaOH. Stir the reaction mixture for another 1 h, and then evaporate the amber solution to leave a yellow solid. Add 50 mL of H 2 O, acidify it with concentrated hydrochloric acid to 2 - 3 to obtain a white solid recrystallized from methamphetamine. The yield is 35.7%.

[0040] Example 3, Synthesis of bis(pyridin-2-ylmethyl)glycine (L-3)

[0041] Dissolve 2-chloromethylpyridine hydrochloride (16.4 g, 100 mmol) in 40 mL of H 2In O, slowly neutralize with potassium hydroxide solution (0.20 g / mL), strictly controlling the solution temperature not to exceed 25 °C. Then add glycine (3.75 g, 50 mmol), and then carry out reflux heating for 2 h. Then slowly add potassium hydroxide solution dropwise to the mixture and continue reflux heating for 12 h. After stopping heating, use hydrochloric acid solution to adjust the pH value of the reaction mixture to 2 - 3. Precipitate forms and is collected, with a yield of 51%.

[0042] Example 4, Synthesis of Benzylamine Diacetic Acid

[0043] Dissolve chloroacetic acid (9.5 g, 100 μmol) in water (35 mL) and cool to 50 °C, then neutralize with NaOH solution (0.17 g / mL). Add the base slowly to avoid the solution temperature exceeding 20 °C. Then add benzylamine (50 μmol, 5.5 mL) and carry out reflux heating for 1 h. Dropwise add the NaOH solution to the mixture and then carry out reflux heating for 1 h. After stopping heating, adjust the pH value to 2 - 3 with hydrochloric acid. Precipitate forms and is collected, with a yield of 64%.

[0044] Example 5, Synthesis and Optimization of Butanediamine Tetraacetic Acid

[0045] Add sodium chloroacetate to a round-bottom flask containing 100 mL of deionized water, stir until dissolved, then slowly dropwise add butanediamine. After dropping, reflux the mixture for 1 h, cool to room temperature and let it stand overnight, and then use concentrated hydrochloric acid to adjust the pH of the solution to 2 - 3. Then evaporate and concentrate the solution to obtain a white solid. Collect the solid and wash away sodium chloride with a large amount of water. The obtained crude product is recrystallized from hot water to obtain butanediamine tetraacetic acid.

[0046] (1) Optimization of Reactant Dosage

[0047] By changing the molar ratio of reactants sodium chloroacetate and butanediamine, fixing the reaction temperature at 90 °C and the reaction time at 1 h, and taking the yield as the preferred index, the optimal dosage of reactants is preferred. The experimental results are shown in Table 1. When the molar ratio of sodium chloroacetate:butanediamine is 6:1, the yield of butanediamine tetraacetic acid is the highest, reaching 88%.

[0048] Table 1 Optimization of Reactant Dosage for the Synthesis of Butanediamine Tetraacetic Acid

[0049] Serial number Sodium chloroacetate: Butanediamine (molar ratio) <![CDATA[H 2 O / mL]]> Reaction temperature / °C Reaction time / h Yield / % ① 1：1 100 90 1 65 ② 1：2 100 90 1 61 ③ 2：1 100 90 1 73 ④ 4：1 100 90 1 78 ⑤ 6：1 100 90 1 88 ⑥ 8：1 100 90 1 85

[0050] (2) Optimization of Reaction Temperature

[0051] Change the reaction temperature, fix the molar ratio of the reactants sodium chloroacetate and butanediamine at 6:1, and the reaction time at 1 h. Using the yield as the evaluation index, optimize the optimal reaction temperature. The experimental results are shown in Table 2. As the reaction temperature increases, the yield increases; when the reaction temperature is greater than 90 °C, the yield no longer increases, indicating that the reactants have completely reacted, and even if the reaction temperature is further increased, the yield will not continue to increase. Therefore, the optimal reaction temperature is 90 °C, at which the yield is the highest, and the yield of ethylenediaminetetraacetic acid is 88%.

[0052] Table 2 Optimization of the reaction temperature for the synthesis of ethylenediaminetetraacetic acid

[0053] Serial number Sodium chloroacetate: Butanediamine (molar ratio) <![CDATA[H 2 O / mL]]> Reaction temperature / °C Reaction time / h Yield / % ① 6：1 100 60 1 35 ② 6：1 100 70 1 54 ③ 6：1 100 80 1 71 ④ 6：1 100 90 1 88 ⑤ 6：1 100 100 1 88

[0054] (3) Optimization of the reaction time

[0055] Change the reaction time, fix the molar ratio of the reactants sodium chloroacetate and butanediamine at 6:1, and the reaction temperature at 90 °C. Using the yield as the evaluation index, optimize the optimal reaction time. The experimental results are shown in Table 3. As the reaction time increases, the yield first gradually increases, and when the reaction time is greater than 1 h, the yield no longer changes upon continued reaction. This is because the reaction has been completed at this time. Therefore, when the reaction temperature is 90 °C and the reaction time is 1 h, the yield is the highest, and the yield of ethylenediaminetetraacetic acid is 88%.

[0056] Table 3 Optimization of the reaction time for the synthesis of ethylenediaminetetraacetic acid

[0057]

[0058] Example 6. Synthesis of 1,4-cyclohexanediaminetetraacetic acid

[0059] Add sodium chloroacetate to a round-bottom flask containing 100 mL of deionized water, stir until dissolved, then slowly add 1,4-cyclohexanediamine dropwise. After the addition is complete, reflux the mixture for 1 h, cool to room temperature, and let it stand overnight. Then, adjust the pH of the solution to 2.3 using concentrated hydrochloric acid. Evaporate and concentrate the solution to obtain a white solid, collect the solid, wash away sodium chloride with a large amount of water, and recrystallize the obtained crude product from hot water to obtain 1,4-cyclohexanediaminetetraacetic acid.

[0060] (1) Optimization of the reactant dosage

[0061] By changing the molar ratio of the reactants sodium chloroacetate and 1,4-cyclohexanediamine, fixing the reaction temperature at 90 °C and the reaction time at 1 h, and using the yield as the optimization index, optimize the optimal dosage of the reactants. The experimental results are shown in Table 4. When the molar ratio of sodium chloroacetate to 1,4-cyclohexanediamine is 6:1, the yield of 1,4-cyclohexanediaminetetraacetic acid is the highest, at 83%.

[0062] Table 4 Optimization of the reactant dosage for the synthesis of 1,4-cyclohexanediaminetetraacetic acid

[0063] Serial number Sodium chloroacetate: 1,4-Cyclohexanediamine (molar ratio) <![CDATA[H 2 O / mL]]> Reaction temperature / °C Reaction time / h Yield / % ① 1：1 100 90 1 62 ② 1：2 100 90 1 59 ③ 2：1 100 90 1 65 ④ 4：1 100 90 1 76 ⑤ 6：1 100 90 1 83 ⑥ 8：1 100 90 1 72

[0064] (2) Optimization of reaction temperature

[0065] Change the reaction temperature, fix the molar ratio of sodium chloroacetate to 1,4-cyclohexanediamine as 6:1, the reaction time as 1 h, and use the yield as the evaluation index to optimize the optimal reaction temperature. The experimental results are shown in Table 5. As the reaction temperature increases, the yield increases; when the reaction temperature is greater than 90 °C, the yield no longer increases, indicating that the reactants have reacted completely, and even if the reaction temperature is continued to be increased, the yield will not continue to increase. Therefore, the optimal reaction temperature is 90 °C, at which the yield is the highest, and the yield of 1,4-cyclohexanediaminetetraacetic acid is 83%.

[0066] Table 5 Optimization of reaction temperature for the synthesis of 1,4-cyclohexanediaminetetraacetic acid

[0067] Serial number Sodium chloroacetate: 1,4-Cyclohexanediamine (molar ratio) <![CDATA[H 2 O / mL]]> Reaction temperature / °C Reaction time / h Yield / % ① 6：1 100 60 1 26 ② 6：1 100 70 1 43 ③ 6：1 100 80 1 67 ④ 6：1 100 90 1 83 ⑤ 6：1 100 100 1 83

[0068] (3) Optimization of reaction time

[0069] Change the reaction time, fix the molar ratio of sodium chloroacetate to 1,4-cyclohexanediamine as 6:1, the reaction temperature as 90 °C, and use the yield as the evaluation index to optimize the optimal reaction time. The experimental results are shown in Table 6. As the reaction time increases, the yield gradually increases at first. When the reaction time is greater than 1 h and the reaction continues, the yield no longer changes. This is because the reaction has been completed at this time. Therefore, when the reaction temperature is 90 °C and the reaction time is 1 h, the yield is the highest, and the yield of 1,4-cyclohexanediaminetetraacetic acid is 83%.

[0070] Table 6 Optimization of reaction time for the synthesis of 1,4-cyclohexanediaminetetraacetic acid

[0071]

[0072] Example 7. The binding rate of ions and the coalescence particle size of the multi-functional fluid ion regulation agent to Ca 2+ and Mg 2+ Ion binding rate and coalescence particle size

[0073] Based on the ion content of the formation water in a certain high-calcium and high-magnesium offshore oilfield, simulate the formation water, and the ion content is shown in Table 7. Use an AA-7003 atomic absorption spectrophotometer to detect the binding effect of the multi-functional fluid ion regulation agent on ions. Use an S-3500 laser particle size analyzer to analyze the coalescence particle size. Ultrasonically treat the simulated formation water added with the ion regulation agent that has been placed for 30 d, and the ultrasonic time is 20 m i n , to make it evenly dispersed to test the particle size. The experimental results are shown in Tables 8-14.

[0074] Analysis of the Ion Content in the Formation Water of a High Calcium-Magnesium Oilfield in the Sea

[0075]

[0076]

[0077] From the experimental results, it can be seen that the ion binding rates of the seven agents all increase with the increase in the agent concentration. The maximum binding rates are as follows: diethylenetriaminepentaacetic acid > 1,4-cyclohexanediaminetetraacetic acid > ethylenediaminetetraacetic acid (EDTA) > nitrilotriacetic acid > 2,2',2''-((pyridin-2-ylmethyl)azanediyl)diacetic acid > benzylamine diacetic acid > bis(pyridin-2-ylmethyl)glycine. The maximum ion binding rate of bis(pyridin-2-ylmethyl)glycine is the lowest, with an ion binding rate of 51.7% at a concentration of 1000 mg / L. The maximum ion binding rate of diethylenetriaminepentaacetic acid is 85%. It is speculated that the more carboxyl groups in the agent structure, the relatively stronger the ion binding ability.

[0078] The particle sizes of the seven coalescence particles all increase with the increase in the agent concentration. The particle sizes of the coalescence particles are in the order of nitrilotriacetic acid > ethylenediaminetetraacetic acid (EDTA) > bis(pyridin-2-ylmethyl)glycine > benzylamine diacetic acid > diethylenetriaminepentaacetic acid > 1,4-cyclohexanediaminetetraacetic acid > 2,2',2''-((pyridin-2-ylmethyl)azanediyl)diacetic acid. Among them, the particle size of the coalescence particles of nitrilotriacetic acid is the largest, ranging from 900 to 3200 nm. The particle size of the coalescence particles of 2,2',2''-((pyridin-2-ylmethyl)azanediyl)diacetic acid is the smallest, ranging from 800 to 2000 nm. This may be because nitrilotriacetic acid contains three carboxyl groups, forming the largest coalescence particles. Bis(pyridin-2-ylmethyl)glycine has two pyridine rings in its structure, so the coalescence particles are relatively large. Benzylamine diacetic acid contains a benzene ring in its structure, which is more stable than the pyridine ring in 2,2',2''-((pyridin-2-ylmethyl)azanediyl)diacetic acid, so the particle size of the coalescence particles is relatively large. Ethylenediaminetetraacetic acid (EDTA), diethylenetriaminepentaacetic acid, and 1,4-cyclohexanediaminetetraacetic acid have similar molecular structures. Among them, the structure of 1,4-cyclohexanediaminetetraacetic acid is relatively compact, so compared with the other two agents, its coalescence particle size is smaller and the regulation effect is better.

[0079] Based on the comprehensive ion binding rate and particle size data, the performance of 1,4-cyclohexanediaminetetraacetic acid is the most excellent.

[0080] Table 8 The Ion Binding Rates of Nitrilotriacetic Acid to Ca 2+ 、Mg 2+ Ion Binding Rates.

[0081] Serial number <![CDATA[Drug concentration / mg·L -1 > <![CDATA[N(Mg 2+ +Ca 2+ ):n M > Ion binding rate / % Particle size / nm ① 62.5 66.6:1 49.2 964.9 ② 125 33.3:1 51.5 1272 ③ 250 16.7:1 53 1656 ④ 500 8.35:1 55.8 2716 ⑤ 1000 4.18:1 61.9 3120

[0082] Table 9 Binding rates of 2,2'-((pyridin-2-ylmethyl)azo)diacetic acid to Ca 2+ , Mg 2+ ions

[0083] Serial number <![CDATA[Drug concentration / mg·L -1 > <![CDATA[N(Mg 2+ +Ca 2+ ):n M > Ion binding rate / % Particle size / nm ① 62.5 78.1:1 49.2 832.9 ② 125 39.1:1 49.2 1199 ③ 250 19.6:1 50.7 1442 ④ 500 9.8:1 51.1 1722 ⑤ 1000 4.9:1 56 1906

[0084] Table 10 Binding rates of bis(pyridin-2-ylmethyl)glycine to Ca 2+ , Mg 2+ ions.

[0085] Serial number <![CDATA[Drug concentration / mg·L -1 > <![CDATA[N(Mg 2+ +Ca 2+ ):n M > Ion binding rate / % Particle size / nm ① 62.5 89.6:1 49.6 1060 ② 125 44.8:1 48.8 1734 ③ 250 22.4:1 49 2302 ④ 500 11.2:1 49.4 2352 ⑤ 1000 5.6:1 51.7 2705

[0086] Table 11 Binding rates of benzylamine diacetic acid to Ca 2+ , Mg 2+ ions

[0087] Serial number <![CDATA[Drug concentration / mg·L -1 > <![CDATA[N(Mg 2+ +Ca 2+ ):n M > Ion binding rate / % Particle size / nm ① 62.5 77.8:1 45.6 895 ② 125 38.9:1 46 1023 ③ 250 19.5:1 46.5 1357 ④ 500 9.8:1 48.1 2031 ⑤ 1000 4.9:1 53.4 2643

[0088] Table 12 Binding rates of butanediaminetetraacetic acid to Ca 2+ , Mg 2+ ions

[0089] Serial number <![CDATA[Drug concentration / mg·L -1 > <![CDATA[N(Mg 2+ +Ca 2+ ):n M > Ion binding rate / % Particle size / nm ① 62.5 111.6:1 50 896 ② 125 55.8:1 49 1094 ③ 250 27.9:1 48 1552 ④ 500 14:1 52 2262 ⑤ 1000 7:1 85 2441

[0090] Table 13 Binding rates of 1,4-cyclohexanediaminetetraacetic acid to Ca 2+ , Mg 2+ ions

[0091]

[0092]

[0093] Table 14 Binding rates of ethylenediaminetetraacetic acid (EDTA) to Ca 2+ , Mg 2+ ions

[0094] Serial number <![CDATA[Drug concentration / mg·L -1 > <![CDATA[N(Mg 2+ +Ca 2+ ):N M > Ion binding rate / % Particle size / nm ① 62.5 117.2:1 45 921 ② 125 58.6:1 46 1235 ③ 250 29.3:1 47 1860 ④ 500 14.7:1 49 2457 ⑤ 1000 7.4:1 69 2792

[0095] Example 8 Changes in the size and morphology of coalesced particles before and after adding the multi-functional fluid ion regulation agent to the oil displacement fluid

[0096] The coalesced particle samples of the oil displacement fluid before and after adding the multi-functional fluid ion regulation agent (Example 6) were freeze-dried using a freeze dryer. After 24 hours, they were taken out. Then, a small amount of the dried coalesced particle samples was placed on the conductive adhesive. After gold spraying, the microscopic morphology of the coalesced particles before and after adding the agent was observed using a Quanta 450 environmental scanning electron microscope. The experimental results are shown in Figure 7。The natural coalesced particle crystal phase is calcite with a particle size of 56.02 μm (D50). After adding the agent, the coalesced particle crystal phase is vaterite with a particle size of 1023 nm (D50).

[0097] Example 9: Performance of an agent with multiple effects for fluid ion regulation in enhancing crude oil recovery

[0098] The core flooding experiment was used to simulate the oil displacement process of the coalesced particles. The oil used in the experiment was a mixture of crude oil and aviation kerosene at a ratio of 1:1 (density 0.8893 g / cm 3 , viscosity 17.5 mPa·s (50 °C)). An artificial homogeneous cylindrical core with dimensions of The experimental steps are as follows:

[0099] ① The agent solution (prepared in Example 6), simulated formation water, and simulated oil were respectively filled in intermediate containers;

[0100] ② The simulated oil was injected into the core to establish the initial oil saturation. The constant-speed pump was turned on, and the simulated formation water was injected into the core at an injection rate of 1 mL / min until the economic limit of water flooding was reached. The injection volume and pressure difference were recorded, and the permeability was calculated using Darcy's formula to obtain the primary water flooding recovery rate;

[0101] ③ The agent solution was injected into the core at an injection rate of 1 mL / min for 1.5 PV, and the injection volume and pressure difference were recorded to calculate the agent flooding recovery rate;

[0102] ④ The simulated formation water was injected into the core at an injection rate of 1 mL / min until the economic limit of recovery was reached, and the injection volume and pressure difference were recorded to calculate the recovery rate of the secondary water flooding.

[0103] At 100 °C and a formation environment of 13000 mg / L, injecting 1.5 PV of 1000 mg / L agent in an alternating injection manner can obtain a maximum recovery rate of 12.5%.

Claims

1. A multi-effect fluid ion regulating agent, the structural formula of which is shown in Formula I: In formula I, R is a straight chain alkyl or cycloalkyl group with 2-8 carbon atoms; m represents the number of acetic acid substituted on the amine group, which is 1-3; and n represents the number of amine groups, which is 1-2.

2. The multi-effect fluid ion regulating agent according to claim 1, characterized in that: The structural formula of the multi-effect fluid ion regulating agent can be any of the following:

3. The method for preparing a multi-effect fluid ion regulating agent according to claim 1, comprising the following steps 1), 2) or 3): 1) Amine compounds and sodium chloroacetate are reacted to obtain the product; 2) Iminodiacetic acid and 2-chloromethylpyridine are subjected to substitution reaction to obtain the product; 3) Glycine and 2-chloromethylpyridine are reacted to obtain the product.

4. The preparation method according to claim 3, characterized in that: 1), the substitution reaction step is any of the following: a) dissolving sodium chloroacetate in water, adding an amine compound dropwise, and heating the mixture to reflux for reaction after the addition is complete; cooling to room temperature after the reaction is complete, and adjusting the pH of the solution to 2-3 with concentrated hydrochloric acid; The solution is then evaporated and concentrated to obtain a white solid, the solid is collected and washed with water to remove the sodium chloride, and the obtained crude product is then recrystallized with hot water to obtain the multi-effect fluid ion regulating agent; b) Under the condition of pH 7-8, slowly add ammonium chloride solution to sodium chloroacetate solution, adjust the pH to 9-10, acidify with hydrochloric acid solution, and collect the precipitate to obtain the product.

5. The preparation method according to claim 4, characterized in that: The amine compounds include ethylenediamine, butanediamine, 1,4-cyclohexanediamine, ammonium chloride, benzylamine, bis(pyridin-2-ylmethyl)amine and iminodiacetic acid.

6. The preparation method according to claim 5, characterized in that: The temperature of the substitution reaction is 60-100° C. and the time is 0.5-2 h.

7. The preparation method according to claim 6, characterized in that: The molar ratio of the sodium chloroacetate to the amine compound is 0.5:1-8:

1.

8. The preparation method according to claim 7, characterized in that: After the substitution reaction is completed, the pH value of the reaction solution is adjusted to 2-3 with concentrated hydrochloric acid and then evaporated and concentrated to obtain a crude product, which is then washed with water and purified by hot water recrystallization.

9. The preparation method according to claim 3, characterized in that: 2), the substitution reaction steps are as follows: in the presence of sodium hydroxide, iminodiacetic acid and 2-chloromethylpyridine or its hydrochloride are refluxed for 3-5 hours, sodium hydroxide is added and the stirring reaction is continued for 1-2 hours; then concentrated hydrochloric acid is added to the reaction system to acidify to 2-3.

10. The preparation method according to claim 3, characterized in that: 3), the steps of the substitution reaction are as follows: neutralizing the aqueous solution of 2-chloromethylpyridine or its hydrochloride with sodium hydroxide, then adding glycine for reflux reaction for 3-4 hours; then adding sodium hydroxide to continue reflux reaction for 10-12 hours; adjusting the pH of the solution to 2-3 with concentrated hydrochloric acid.

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