Anhydride acylated fatty alcohol polyether block co-promoter, method of making and use
By modifying the structure of the anhydride-acylated fatty alcohol polyether block mixin, the problem of insufficient performance of traditional additives at the CO2-crude oil interface was solved, achieving a highly efficient miscible oil displacement effect and improving oil displacement efficiency.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- QINGDAO UNIV OF SCI & TECH
- Filing Date
- 2026-04-13
- Publication Date
- 2026-06-02
AI Technical Summary
Traditional fatty alcohol polyether additives have limitations in improving CO2-crude oil interface properties and miscible oil displacement capabilities, including simple structure, insufficient interfacial film strength, and difficulty in meeting the requirements for efficient miscible oil displacement.
By modifying the structure of fatty alcohol polyether blocks through acid anhydride acylation, a novel molecule with "lipophilic chain-polyether block-ester linkage group" is constructed, achieving directional arrangement of the molecule at the CO2-crude oil interface and CO2 affinity.
It improved the directional alignment of molecules at the CO2-crude oil interface and CO2 affinity, reduced the minimum miscibility pressure, and improved the oil displacement efficiency, achieving a demixing efficiency of 26.46%.
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Figure CN122127586A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of blending agent preparation technology, and in particular to an anhydride acylated fatty alcohol polyether block blending agent, its preparation method and application. Background Technology
[0002] In recent years, with the increasing demand for enhanced oil recovery technologies, the development of environmentally friendly and efficient oilfield chemicals has attracted much attention. CO2 flooding, as an important enhanced oil recovery technology, faces challenges in achieving complete miscibility under most oil reservoir conditions in my country due to the generally low reservoir pressure. This limits the sweep efficiency and oil washing effect of the flooding system, often failing to achieve ideal displacement results in practical applications. Fatty alcohol polyether compounds, with their tunable structure and excellent interfacial properties, have shown great potential in improving the CO2-crude oil interface characteristics and enhancing the miscibility of the system, and have become a key research direction in this field.
[0003] While traditional fatty alcohol polyether additives can improve interfacial conditions to some extent, their molecular structures are mostly simple linear lipophilic chains-polyoxyolefin block skeletons, with limited structural diversity and tunability. On the one hand, conventional polyether molecules are loosely arranged at the CO2-crude oil interface, resulting in insufficient interfacial film strength and limited control over minimum miscibility pressure. On the other hand, the single ether bond CO2-loving structure makes it difficult to achieve precise control of interfacial performance, and its ability to improve miscibility under complex reservoir conditions is insufficient, making it difficult to meet the actual needs of efficient miscible flooding. Summary of the Invention
[0004] In order to overcome the above-mentioned problems in the prior art, the present invention proposes an anhydride acylated fatty alcohol polyether block blending agent, its preparation method and application.
[0005] The technical solution adopted by this invention to solve its technical problem is: an anhydride-acylated fatty alcohol polyether block blending agent, which modifies the structure of the fatty alcohol polyether block intermediate by anhydride acylation modification, and has the following general structural formula: Where R1 takes the value C8-C 24 x takes values from 0 to 35; n takes values from 0 to 35; R2 takes values from C1 to C6.
[0006] A method for preparing an anhydride-acylated fatty alcohol polyether block blending accelerator, used to prepare the blending accelerator as described above, specifically includes: Step 1: In a high-temperature, high-pressure polymerization reactor, using fatty alcohol as the initiator, an inorganic strong base catalyst and a crown ether complexing agent are added, and the mixture is vacuum dehydrated for 1 hour at 90℃-120℃; then, the temperature is raised to 135℃-155℃, and ring-opening polymerization is carried out with propylene oxide and ethylene oxide to synthesize fatty alcohol polyether block intermediate C. n POx EO y Where n takes values from 8 to 24, x takes values from 0 to 35, and y takes values from 0 to 35; Step 2: The acid anhydride and the fatty alcohol polyether block intermediate obtained in Step 1 are fed into the mixture at a molar ratio of (1.00-1.50):1.00. Then, an organic strong acid catalyst is added, and the reaction system is stirred at room temperature for half an hour. Then, the temperature is raised to 60℃-90℃ to continue the esterification reaction, and finally the acid anhydride acylated fatty alcohol polyether block blending agent is obtained.
[0007] In the above-mentioned method for preparing an anhydride-acylated fatty alcohol polyether block blending accelerator, the molar ratio of fatty alcohol, propylene oxide and ethylene oxide in step 1 is adjusted according to the actual degree of polymerization requirement, and the degree of polymerization of propylene oxide and ethylene oxide is a variable value.
[0008] In the preparation method of the above-mentioned anhydride acylated fatty alcohol polyether block blending agent, the amount of inorganic strong base catalyst added in step 1 is 0.2%–0.5% of the theoretical yield of fatty alcohol polyether block intermediate, and the amount of crown ether complexing agent added is 1.00–1.50 times the amount of catalyst.
[0009] In the above-mentioned method for preparing an anhydride-acylated fatty alcohol polyether block blending agent, the inorganic strong base is selected from any one or more of potassium hydroxide, sodium hydroxide, potassium methoxide, potassium ethoxide, sodium methoxide, and sodium ethoxide.
[0010] The preparation method of the above-mentioned acid anhydride acylated fatty alcohol polyether block blending agent, wherein the crown ether complexing agent is selected from any one or more of 18-crown 6, dicyclohexane 18-crown 6, benzo 18-crown 6, and dimethyl 18-crown 6.
[0011] The preparation method of the above-mentioned anhydride acylated fatty alcohol polyether block blending agent, wherein the fatty alcohol is selected from one or more fatty alcohols having 8 to 24 carbon atoms.
[0012] In the above-mentioned method for preparing an anhydride-acylated fatty alcohol polyether block blending agent, the amount of organic strong acid catalyst added in step 2 is 0.16%-0.48% of the mass of the fatty alcohol polyether block intermediate.
[0013] In the above-mentioned method for preparing an anhydride-acylated fatty alcohol polyether block blending agent, the organic strong acid catalyst is selected from any one or more of p-toluenesulfonic acid, methanesulfonic acid, benzenesulfonic acid, dodecylbenzenesulfonic acid, and trifluoromethanesulfonic acid.
[0014] An application of an anhydride-acylated fatty alcohol polyether block blending agent in reducing the minimum miscibility pressure of a CO2 flooding system in offshore oilfields is disclosed. The method employs an anhydride-acylated fatty alcohol polyether block blending agent as described above or an anhydride-acylated fatty alcohol polyether block blending agent prepared based on the above preparation method. The concentration of the anhydride-acylated fatty alcohol polyether block blending agent used for blending is 1.0 wt%.
[0015] The beneficial effects of this invention are that it provides an anhydride-acylated fatty alcohol polyether block blending agent, which undergoes an esterification reaction with the terminal hydroxyl groups of the fatty alcohol polyether via anhydride acylation reagents such as acetic anhydride / propionic anhydride, constructing a novel molecule with a "lipophilic chain-polyether block-ester linkage group". The amphiphilic nature of this structure enhances the molecule's directional alignment ability at the CO2-crude oil interface, the flexible polyether segments impart conformational self-adaptation properties, and the weakly polar head group formed by the terminal ester group modification exhibits excellent carbon dioxide affinity through specific interactions with CO2 molecules (Lewis acid-base interaction). Experiments show that this blending agent exhibits excellent demixing effects in oilfield crude oil-CO2 systems. At an addition amount of 1.0 wt%, the blending efficiency of the anhydride-acylated fatty alcohol polyether block blending agent can reach up to 26.46%, demonstrating significant application value in the field of carbon dioxide enhanced oil recovery in oilfields. Attached Figure Description
[0016] Figure 1 The anhydride-acylated fatty alcohol polyether block NMR spectrum analysis of the prepared sample obtained in Example 1; Figure 2 The anhydride-acylated fatty alcohol polyether block NMR spectrum analysis of the prepared in Example 2; Figure 3 The anhydride-acylated fatty alcohol polyether block NMR spectrum analysis of the prepared in Example 3; Figure 4 The anhydride-acylated fatty alcohol polyether block NMR spectrum analysis of the prepared in Example 4; Figure 5 Fourier transform infrared spectroscopy analysis of the anhydride acylated fatty alcohol polyether blocks prepared in Examples 1-4; Figure 6 The graph shows the effect of the anhydride acylated fatty alcohol polyether blocks prepared in Examples 1-4 on the minimum miscibility pressure of CO2 in an oil field. Detailed Implementation
[0017] To enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.
[0018] Example 1 This embodiment provides a method for preparing an anhydride-acylated fatty alcohol polyether block blending agent, with the following structural formula: Includes the following steps: S1. In a high-temperature and high-pressure polymerization reactor, 200.00 g of dodecanol, 2.01 g of potassium hydroxide catalyst, and 5.85 g of 18-crown-6 complexing agent were added. The mixture was then vacuum dehydrated at 100°C for 1 hour. Subsequently, the temperature was raised to 145°C, and propylene oxide was added at a rate of 3 ml / min, with a final addition of 374.19 g of propylene oxide. The temperature was lowered to 135°C, and ethylene oxide was added at a rate of 2 ml / min, with a final addition of 94.62 g of ethylene oxide. The mixture was then heated to 145°C and aged for 1 hour to synthesize the fatty alcohol polyether block intermediate (C). 12 PO6EO2).
[0019] S2. Take the 62.29g C 12 PO6EO2 and 15.41 g of acetic anhydride were placed in a three-necked flask, followed by the addition of 0.20 g of p-toluenesulfonic acid as a catalyst. The reaction system was first stirred at room temperature for half an hour, and then the temperature was raised to 60 °C to continue the esterification reaction. The esterification rate was monitored periodically until it remained constant, at which point the reaction was stopped, thus preparing an anhydride-acylated fatty alcohol polyether block. The 1H NMR spectrum analysis of this anhydride-acylated fatty alcohol polyether block is as follows: Figure 1 As shown.
[0020] Example 2 This embodiment provides a method for preparing an anhydride-acylated fatty alcohol polyether block blending agent, with the following structural formula: Includes the following steps: S1. In a high-temperature and high-pressure polymerization reactor, 200.00 g of dodecanol, 2.29 g of potassium hydroxide catalyst, and 6.69 g of 18-crown-6 complexing agent were added. The mixture was then vacuum dehydrated at 110 °C for 1 hour. Subsequently, the temperature was raised to 155 °C, and propylene oxide was added at a rate of 3 ml / min, with a final addition of 374.19 g of propylene oxide. The temperature was lowered to 145 °C, and ethylene oxide was added at a rate of 2 ml / min, with a final addition of 189.25 g of ethylene oxide. The mixture was then heated to 155 °C and aged for 1 hour to synthesize the fatty alcohol polyether block intermediate (C). 12 PO6EO4).
[0021] S2. Take the 36.53g C 12PO6EO4 and 7.69 g of acetic anhydride were placed in a three-necked flask, followed by the addition of 0.12 g of p-toluenesulfonic acid as a catalyst. The reaction system was first stirred at room temperature for half an hour, and then the temperature was raised to 60 °C to continue the esterification reaction. The esterification rate was monitored periodically until it remained constant, at which point the reaction was stopped, thus preparing an anhydride-acylated fatty alcohol polyether block. The 1H NMR spectrum analysis of this anhydride-acylated fatty alcohol polyether block is as follows: Figure 2 As shown.
[0022] Example 3 This embodiment provides a method for preparing an anhydride-acylated fatty alcohol polyether block blending agent, with the following structural formula: Includes the following steps: S1. In a high-temperature and high-pressure polymerization reactor, 200.00 g of dodecanol, 2.01 g of potassium hydroxide catalyst, and 5.85 g of 18-crown-6 complexing agent were added. The mixture was then vacuum dehydrated at 100°C for 1 hour. Subsequently, the temperature was raised to 145°C, and propylene oxide was added at a rate of 3 ml / min, with a final addition of 374.19 g of propylene oxide. The temperature was lowered to 135°C, and ethylene oxide was added at a rate of 2 ml / min, with a final addition of 94.62 g of ethylene oxide. The mixture was then heated to 145°C and aged for 1 hour to synthesize the fatty alcohol polyether block intermediate (C). 12 PO6EO2).
[0023] S2. Take the 61.61g C 12 PO6EO2 and 19.63 g of propionic anhydride were placed in a three-necked flask, followed by the addition of 0.20 g of p-toluenesulfonic acid as a catalyst. The reaction system was first stirred at room temperature for half an hour, and then the temperature was raised to 80 °C to continue the esterification reaction. The esterification rate was monitored periodically until it remained constant, at which point the reaction was stopped, thus preparing an anhydride-acylated fatty alcohol polyether block. The 1H NMR spectrum analysis of this anhydride-acylated fatty alcohol polyether block is as follows: Figure 3 As shown.
[0024] Example 4 This embodiment provides a method for preparing an anhydride-acylated fatty alcohol polyether block blending agent, with the following structural formula: Includes the following steps: S1. In a high-temperature and high-pressure polymerization reactor, 200.00 g of dodecanol, 2.29 g of potassium hydroxide catalyst, and 6.69 g of 18-crown-6 complexing agent were added. The mixture was then vacuum dehydrated at 110 °C for 1 hour. Subsequently, the temperature was raised to 155 °C, and propylene oxide was added at a rate of 3 ml / min, with a final addition of 374.19 g of propylene oxide. The temperature was lowered to 145 °C, and ethylene oxide was added at a rate of 2 ml / min, with a final addition of 189.25 g of ethylene oxide. The mixture was then heated to 155 °C and aged for 1 hour to synthesize the fatty alcohol polyether block intermediate (C). 12 PO6EO4).
[0025] S2. Take the 72.94g C 12 PO6EO2 and 19.54 g of propionic anhydride were placed in a three-necked flask, followed by the addition of 0.23 g of p-toluenesulfonic acid as a catalyst. The reaction system was first stirred at room temperature for half an hour, and then the temperature was raised to 80 °C to continue the esterification reaction. The esterification rate was monitored periodically until it remained constant, at which point the reaction was stopped, thus preparing an anhydride-acylated fatty alcohol polyether block. The 1H NMR spectrum analysis of this anhydride-acylated fatty alcohol polyether block is shown below. Figure 4 As shown.
[0026] Figure 5 Fourier transform infrared spectra of the anhydride-acylated fatty alcohol polyether blocks prepared in Examples 1-4.
[0027] The minimum miscibility pressure (MMP) reduction performance of the anhydride-acylated fatty alcohol polyether block miscible accelerators prepared in Examples 1-4 was tested. Crude oil samples from a Chinese oilfield were used for evaluation. The Visibility Ingress (VIT) method was employed. The oil phase was injected into a high-temperature, high-pressure visible cell and heated to 70°C. CO2 bubbles were suspended in the oil phase using a capillary tube, and the pressure was gradually increased. The bubble morphology was recorded and the interfacial tension was calculated. The pressure at which the interfacial tension approached zero and the bubble outline was about to dissipate was defined as the MMP. The MMP between pure CO2 and crude oil was initially measured to be 24.87 MPa. The MMP of "CO2 + 1.0 wt% anhydride-acylated fatty alcohol polyether block miscible accelerator" was then determined using the same method. The MMPs of Examples 1, 2, 3, and 4 were 19.45 MPa, 18.29 MPa, 18.76 MPa, and 19.52 MPa, respectively. Example 2 showed the best MMP reduction effect, with a reduction efficiency of up to 26.46%. The effect of this anhydride-acylated fatty alcohol polyether block mixer on the minimum miscibility pressure of CO2 in a certain oilfield is as follows: Figure 6 As shown.
[0028] The anhydride-acylated fatty alcohol polyether block blending agent provided by this invention achieves structural innovation through precise molecular regulation. This structure uses fatty alcohol polyether blocks as basic units, and introduces acylation modification through anhydride acylation, forming a molecular configuration with a well-defined block structure. Further anhydride acylation modification on this basis constructs regular lipophilic and CO2-loving segments within the molecule, successfully achieving a precise balance and controllable adjustment of lipophilic-CO2-loving properties.
[0029] This innovative molecular design offers three key structural advantages: First, the block structure significantly enhances the molecule's ability to arrange itself in an orderly manner at the phase interface; second, the fatty alcohol polyether block endows the molecule with appropriate flexibility and conformational freedom, enabling it to adapt to multiphase interface environments; and finally, the synergistic effect of anhydride acylation modification and polyether segments achieves a precise balance between lipophilic and CO2-loving properties. Particularly noteworthy is the specific interaction between the acylated group and supercritical carbon dioxide molecules in this structure, which gives it excellent CO2-loving properties.
[0030] Experimental verification shows that this anhydride-acylated fatty alcohol polyether block blending accelerator exhibits excellent interfacial activity in a crude oil-CO2 system test at an oilfield, achieving a maximum blending reduction efficiency of 26.46% at an addition of 1.0 wt%. This unique performance, resulting from structural innovation, demonstrates significant application value in oil and gas development fields such as carbon dioxide enhanced oil recovery.
[0031] The above embodiments are merely exemplary embodiments of the present invention and are not intended to limit the present invention. The catalyst used in the present invention can promote the formation of alkoxide active centers from fatty alcohols, thereby initiating the ring-opening polymerization of epoxides; the complexing agent can coordinate with metal ions, improving the stability of the active center and the uniformity of polymerization. The embodiments are merely illustrative of the catalyst and complexing agent and are not limited thereto. All kinds of catalysts and complexing agents listed in the claims are theoretically feasible from the perspective of reaction mechanism and coordination principle, and can achieve the corresponding catalytic and complexation stabilization effects. Based on the disclosure of the present invention, those skilled in the art can reasonably select the corresponding catalysts and complexing agents according to actual process requirements. Such conventional selections and substitutions do not depart from the protection scope of the present invention. Modifications or equivalent substitutions made by those skilled in the art to the present invention within the substance and protection scope of the present invention should all fall within the protection scope of the present invention.
Claims
1. An anhydride-acylated fatty alcohol polyether block blending agent, characterized in that, The fatty alcohol polyether block intermediate was structurally modified by anhydride acylation, and the general structural formula is as follows: Where R1 takes the value C8-C 24 x takes values from 0 to 35; n takes values from 0 to 35; R2 takes values from C1 to C6.
2. A method for preparing an anhydride-acylated fatty alcohol polyether block blending agent, characterized in that, The preparation of the mixing aid as described in claim 1 specifically includes: Step 1: In a high-temperature, high-pressure polymerization reactor, using fatty alcohol as the initiator, an inorganic strong base catalyst and a crown ether complexing agent are added, and the mixture is vacuum dehydrated for 1 hour at 90℃-120℃; then, the temperature is raised to 135℃-155℃, and ring-opening polymerization is carried out with propylene oxide and ethylene oxide to synthesize fatty alcohol polyether block intermediate C. n PO x EO y Where n takes values from 8 to 24, x takes values from 0 to 35, and y takes values from 0 to 35; Step 2: The acid anhydride and the fatty alcohol polyether block intermediate obtained in Step 1 are fed into the mixture at a molar ratio of (1.00-1.50):1.
00. Then, an organic strong acid catalyst is added, and the reaction system is stirred at room temperature for half an hour. Then, the temperature is raised to 60℃-90℃ to continue the esterification reaction, and finally the acid anhydride acylated fatty alcohol polyether block blending agent is obtained.
3. The method for preparing an anhydride-acylated fatty alcohol polyether block blending agent according to claim 2, characterized in that, In step 1, the molar ratio of fatty alcohol, propylene oxide, and ethylene oxide is adjusted according to the actual degree of polymerization requirement, and the degree of polymerization of propylene oxide and ethylene oxide is a variable value.
4. The preparation method of an anhydride-acylated fatty alcohol polyether block blending agent according to claim 2, characterized in that, In step 1, the amount of inorganic strong base catalyst added is 0.2%–0.5% of the theoretical yield of fatty alcohol polyether block intermediate, and the amount of crown ether complexing agent added is 1.00–1.50 times the amount of catalyst.
5. The preparation method of an anhydride-acylated fatty alcohol polyether block blending agent according to claim 4, characterized in that, The inorganic strong base is selected from any one or more of potassium hydroxide, sodium hydroxide, potassium methoxide, potassium ethoxide, sodium methoxide, and sodium ethoxide.
6. The method for preparing an anhydride-acylated fatty alcohol polyether block blending agent according to claim 4, characterized in that, The crown ether complexing agent is selected from any one or more of 18-crown 6, dicyclohexane 18-crown 6, benzo 18-crown 6, and dimethyl 18-crown 6.
7. The preparation method of an anhydride-acylated fatty alcohol polyether block blending agent according to claim 2, characterized in that, The fatty alcohol is selected from one or more fatty alcohols having 8 to 24 carbon atoms.
8. The method for preparing an anhydride-acylated fatty alcohol polyether block blending agent according to claim 2, characterized in that, In step 2, the amount of organic strong acid catalyst added is 0.16%-0.48% of the mass of the fatty alcohol polyether block intermediate.
9. The method for preparing an anhydride-acylated fatty alcohol polyether block blending agent according to claim 8, characterized in that, The organic strong acid catalyst is selected from any one or more of p-toluenesulfonic acid, methanesulfonic acid, benzenesulfonic acid, dodecylbenzenesulfonic acid, and trifluoromethanesulfonic acid.
10. An application of an anhydride-acylated fatty alcohol polyether block miscibility enhancer in reducing the minimum miscibility pressure of a CO2 flooding system in offshore oilfields, characterized in that... An anhydride-acylated fatty alcohol polyether block blending agent prepared by means of the anhydride acylated fatty alcohol polyether block blending agent as described in claim 1 or by means of the preparation method described in any one of claims 2-9, wherein the concentration of the anhydride-acylated fatty alcohol polyether block blending agent used for blending is 1.0 wt%.