CN117986284A - CO (carbon monoxide)2Wettability regulator, preparation method thereof and oil reservoir wettability regulating method - Google Patents

Abstract

The invention discloses a CO ₂ wettability regulator, a preparation method thereof and a method for regulating oil reservoir wettability. The CO ₂ wettability regulator has a structure shown as a formula (I): Wherein R ₁ is C1-C8 alkyl, R ₂ is H or C1-C4 alkyl, R ₃ is C1-C20 alkyl, ar is aromatic group, m is an integer of 1-10, and n is an integer of 0-10. The CO ₂ wettability regulator has certain solubility in CO ₂ and crude oil, so that asphaltenes precipitated in a stratum can be stripped under the condition of CO ₂ oil extraction, and the wettability of the stratum is improved, thereby improving the CO ₂ oil extraction efficiency.

Description

CO 2 wettability regulator, preparation method thereof and oil reservoir wettability regulating method

Technical Field

The invention relates to the field of oil extraction in oil fields, in particular to a CO ₂ wettability regulator, a preparation method thereof and a method for regulating oil reservoir wettability.

Background

The CCUS is a new development trend of CCS (Carbon Capture and Storage, carbon capture and sequestration) technology, namely, purifying carbon dioxide discharged in the production process, and then putting the purified carbon dioxide into a new production process for recycling instead of simply sequestration. Compared with CCS, the method can recycle carbon dioxide, can generate economic benefit and has more practical operability. The method can be divided into capturing, conveying, utilizing and sealing links. Wherein the utilization of CO ₂ refers to the utilization of the physical, chemical or biological action of CO ₂, and the emission of CO ₂ is reduced, and meanwhile, the energy yield and efficiency increase, mineral resource yield increase, chemical conversion synthesis, biological agricultural product yield increase utilization, consumer product production utilization and the like are realized, so that the method is an emission reduction way with additional economic benefits.

Among the many CO ₂ utilization projects, carbon dioxide flooding has become one of the important technologies for enhanced oil recovery. The united states is the earliest and most widely used country for carbon dioxide flooding tests. Since 1970, carbon dioxide was injected into oil fields in texas as a technical means for Enhanced Oil Recovery (EOR), with a total amount of carbon dioxide injected per year of up to 2000 to 3000 tens of thousands of tons, of which about 300 tens of thousands of tons originate from the tail gas of coal gasification plants and fertilizer plants, mostly from natural carbon dioxide reservoirs. And are still in use until now. The CO ₂ -EOR miscible flooding oil recovery rate is improved within the range of 4-12%. The CO ₂ -EOR non-miscible oil displacement project is less, and the benefit is relatively poorer.

In the early stage, people focus on the swelling viscosity reduction, oil-water interfacial tension reduction and other effects of CO ₂, but in the CO ₂ oil extraction process, particularly in the thick oil cold extraction process, CO ₂ is dissolved in crude oil, so that the light components are easy to extract while the expansion viscosity reduction effect is achieved, and the heavy components are left in a reservoir. Bitumen is the main component of heavy components, which can alter the wettability of the oil layer. As macromolecules, asphaltenes and other polar substances in crude oil can be adsorbed on the surface of rock particles, so that the wettability of the rock particles is changed. Particularly when the ability of crude oil to dissolve asphaltenes is reduced, the adsorption of asphaltenes on the rock surface becomes stronger, resulting in the conversion of the rock into the oleophilic direction. Moreover, the longer the asphaltene contacts the rock, the greater the likelihood of the wettability being oleophilic. A series of studies by Al-Mutairi et Al show that in CO ₂ -EOR, under the CO ₂ environment, hydrophilic rock stratum is more beneficial to the extraction of crude oil, residual oil is reduced, and the potential of reservoir and EOR is obviously affected by the transition of rock wettability caused by asphaltene deposition.

Therefore, rock wettability change in the CO ₂ oil displacement process becomes a hot spot for domestic and foreign research. Different reservoir characteristics often also lead to different wettability transition results. Most of the current foreign research based on non-heavy oil reservoirs shows that CO ₂ flooding can make the wetting of the formation more hydrophilic. Current foreign research on changes in wettability of CO ₂ flooding is mainly still in the indoor research stage, and the influence of chemicals on this process is rarely evaluated.

Disclosure of Invention

The invention aims to solve the technical problems that the formation asphaltene precipitates after long-term CO ₂ is driven, the wettability becomes oil wet and the subsequent thick oil is difficult to extract, and provides a CO ₂ wettability regulator.

To achieve the above object, a first aspect of the present invention provides a CO ₂ wettability modifier, the CO ₂ wettability modifier having a structure as shown in formula (I):

In the formula (I), R ₁ is C1-C8 alkyl; r ₂ is H or C1-C4 alkyl; r ₃ is C1-C20 alkyl; ar is an aromatic group; m is an integer of 1 to 10, and n is an integer of 0 to 10.

Preferably, R ₁ is C1-C4 alkyl; r ₂ is H or alkyl of C1-C2; r ₃ is C1-C12 alkyl; ar is phenyl; m is an integer of 1 to 4, such as1, 2,3, 4; n is an integer of 0 to 4, such as 0, 1,2, 3, 4.

The above alkyl group may be a substituted or unsubstituted alkyl group.

The second aspect of the invention provides a preparation method of the CO ₂ wettability regulator, which comprises the following steps:

(1) Nucleophilic reaction of a compound of formula (II) with halopropene in the presence of a base and a catalyst I to obtain a reaction mixture containing the compound of formula (II);

In the formula (II) and the formula (III), R ₃ is C1-C20 alkyl, preferably C1-C12 alkyl; ar is an aromatic group, preferably phenyl; m is an integer of 1 to 10, and n is an integer of 0 to 10.

The nucleophilic reaction is as follows:

wherein X is a halogen atom.

The halogenated propylene in the step (1) is at least one of chloropropene, bromopropene or iodopropylene.

The alkali in the step (1) is an inorganic alkali or an organic alkali, preferably an inorganic alkali, more preferably at least one of NaOH and KOH, and saturated NaOH and KOH solution can be used.

The catalyst I in the step (1) is a phase transfer catalyst, preferably an alkyl halogeno ammonium salt, and more preferably at least one of tetrabutylammonium bromide or tetrabutylammonium iodide.

In the step (1), the molar ratio of the compound of formula (II), the halopropene, the alkali and the catalyst is preferably 1 (1-5): 1-10): 0.01-0.1, preferably 1 (1-2): 5-10): 0.01-0.05.

The nucleophilic reaction conditions in step (1) include: the temperature is 25-100 ℃, preferably 40-90 ℃; the reaction time is 2 to 24 hours, preferably 4 to 8 hours.

After the end of the step (1), the method can further comprise the steps of separating the catalyst I from the reaction mixture and purifying to obtain the compound of the formula (II).

(2) And (3) carrying out addition reaction on the obtained compound shown in the formula (II) and organosiloxane in the presence of a catalyst II to obtain the CO ₂ wettability regulator.

The organosiloxane has a structure represented by formula (IV):

In the formula (IV), R ₁ is a C1-C8 alkyl group, preferably a C1-C4 alkyl group, and R ₂ is H or a C1-C4 alkyl group, preferably H or a C1-C2 alkyl group.

The addition reaction is as follows:

the catalyst II in the step (2) is a noble metal catalyst, preferably a platinum catalyst, and more preferably at least one of chloroplatinic acid and cisplatin chloride (cisplatin ).

In step (2), the molar ratio of the compound of formula (III), the organosiloxane and the catalyst II is preferably 1 (1-2): 0.0005-0.05, preferably 1 (1-1.2): 0.001-0.01.

In the step (2), the reaction is performed under a protective gas atmosphere such as N ₂.

One or more of methanol, isopropanol, isobutanol, toluene or benzene can be used as a solvent in the step (2).

The addition reaction conditions in step (2) include: n ₂ is protected by gas, the temperature is 50-150 ℃, and the preferable temperature is 80-120 ℃; the reaction time is 2 to 24 hours, preferably 6 to 12 hours.

After the end of the step (2), a step of separating the catalyst II from the reaction mixture and removing impurities and the like in an optional order to obtain the CO ₂ wettability regulator shown in the formula (I) may be further included.

In a third aspect the invention provides a method of reservoir wettability adjustment comprising injecting into a reservoir a CO ₂ wettability adjuster as described above.

In the oil reservoir wettability adjustment method, the oil reservoir is carried out under the CO ₂ throughput or CO ₂ flooding condition.

The CO ₂ wettability regulator and CO ₂ are injected together or after being dissolved into CO ₂, and the injection amount is 0.01-2 wt% of the CO ₂.

The CO ₂ wettability regulator provided by the invention not only has better surface activity, but also can reduce the interfacial tension of CO ₂ and oil by 10m N/m or lower so as to emulsify asphaltene, and meanwhile, the CO ₂ wettability regulator can effectively improve the formation wettability from strong oil wetting to weak oil wetting or neutral wetting, and in addition, the CO ₂ wettability regulator has better acid resistance after being aged for 24 hours under the environment of pH 4-7 at 90 ℃. Therefore, the CO ₂ wettability regulator disclosed by the invention can adapt to actual working conditions of CO ₂ throughput and CO ₂ oil displacement, and can improve the oil extraction efficiency under the working conditions.

The inventor believes that the technical effect is not separated from the structure of the wettability modifier in the invention, and the traditional siloxane is structurally optimized, so that on one hand, the high surface-to-surface activity of the traditional siloxane is maintained, on the other hand, the EO/PO segment is introduced to adjust the solubility of the chemical agent in CO ₂, thereby assisting injection, and the most critical is that the introduction of the aryl enhances the interaction of the chemical agent and crude oil, thereby utilizing asphaltenes adsorbed by the stratum and helping to improve the wettability of the stratum.

The preparation method of the CO ₂ wettability regulator can obtain the CO ₂ wettability regulator through nucleophilic reaction and addition reaction, and has the advantages of simple preparation method, easy control, low cost and higher popularization and application value.

The oil reservoir wettability adjustment method provided by the invention adopts the CO ₂ wettability adjustment agent, can adjust formation wettability, enhances oil recovery, and has higher advantages especially in the working conditions of CO ₂ throughput and CO ₂ oil displacement.

Detailed Description

The present invention is described in detail below with reference to specific embodiments, and it should be noted that the following embodiments are only for further description of the present invention and should not be construed as limiting the scope of the present invention, and some insubstantial modifications and adjustments of the present invention by those skilled in the art from the present disclosure are still within the scope of the present invention.

The endpoints and any values of the ranges disclosed herein are not limited to the precise range or value, and are understood to encompass values approaching those ranges or values. For numerical ranges, one or more new numerical ranges may be found between the endpoints of each range, between the endpoint of each range and the individual point value, and between the individual point value, in combination with each other, and are to be considered as specifically disclosed herein.

The specific conditions are not noted in the examples and are carried out according to conventional conditions or conditions recommended by the manufacturer. The reagents or instruments used are not known to the manufacturer and are available either directly or prepared according to the preparation methods disclosed in the prior art.

Example 1

To a vigorously stirred mixture of compound 1A (100 mmol), saturated NaOH solution (500 mmol) and tetrabutylammonium bromide (5 mmol) was slowly added dropwise bromopropene (200 mmol) at room temperature, and then gradually warmed to 70℃for 8h. After the reaction, cooling to room temperature, suction filtering to obtain a filtrate, washing the filtrate with water, extracting the filtrate with petroleum ether, taking an upper organic phase, drying the upper organic phase with anhydrous MgSO ₄ for 24 hours, and distilling under reduced pressure to remove the solvent and unreacted bromopropene to obtain the compound 1B.

Under the protection of N ₂, a certain amount of compound 1B (100 mmol) and an isopropanol solution (0.1 mmol) of chloroplatinic acid are added into a dry three-neck flask, stirred, heated to 60 ℃, activated for 30min, then compound 1C (110 mmol) is added dropwise, and the temperature is slowly raised to 120 ℃ for reaction for 8h. After the reaction, the reaction solution was washed with water to remove chloroplatinic acid and isopropyl alcohol, the organic phase was extracted with petroleum ether and dried over anhydrous MgSO ₄ for 12 hours, and then petroleum ether was distilled off under reduced pressure to obtain CO ₂ wettability regulator R1.

Example 2

To a vigorously stirred mixture of compound 2A (100 mmol), saturated KOH solution (600 mmol) and tetrabutylammonium bromide (5 mmol) was slowly added dropwise bromopropene (150 mmol) at room temperature, and then gradually warmed to 80℃for 8h. After the reaction was completed, cooling to room temperature, suction filtration was performed to obtain a filtrate, the upper organic phase was taken out of the filtrate by washing with water and dried over anhydrous MgSO ₄ for 12 hours, and the solvent and unreacted bromopropene were distilled off under reduced pressure to obtain compound 2B.

Under the protection of N ₂, a certain amount of compound 2B (100 mmol) and an isopropanol solution (0.1 mmol) of chloroplatinic acid are added into a dry three-neck flask, stirred, heated to 60 ℃, activated for 30min, then compound 2C (110 mmol) is added dropwise, and the temperature is slowly raised to 110 ℃ for reaction for 10h. After the reaction, the reaction solution was washed with water to remove chloroplatinic acid and isopropyl alcohol, the organic phase was extracted with petroleum ether and dried over anhydrous MgSO ₄ for 12 hours, and then petroleum ether was distilled off under reduced pressure to obtain CO ₂ wettability regulator R2.

Example 3

A wettability modifier was prepared by the method of example 1, except that compound 3A was used instead of compound 1A in example 1, to obtain CO ₂ wettability modifier R3.

Comparative example 1

A wettability modifier was prepared by the method of example 1, except that compound D was used in place of compound 1A of example 1 to obtain CO ₂ wettability modifier R4.

The compounds used in examples 1 to 3 and comparative example 1 are shown in Table 1:

TABLE 1 Structure of Compounds

The structure of compound A, C, D is shown below:

example 4CO ₂ wettability modifier acid resistance experiments.

The wettability modifiers prepared in examples 1 to 3 and comparative example 1 were each prepared as a 1% solution (the solvent was deionized water) and divided into three parts, one of which was placed at room temperature, one of which was placed in an autoclave, aged at ph=4, 90 ℃ for 24 hours, and one of which was placed in the autoclave, aged at ph=7, 90 ℃ for 24 hours. The composition of the solutions was then examined using liquid chromatography, respectively, as shown in Table 2. The results show that the prepared wettability regulator is not obviously decomposed before and after aging and has excellent acid resistance.

TABLE 2 acid resistance experiments on CO ₂ wettability modifier

Example 5 interfacial tension test of surfactant.

The interfacial tension of CO ₂ and winning crude oil (5000 Pa.s) under formation conditions (15 MPa,90 ℃) was measured using an OCA-25 high temperature high pressure interfacial tension tester, then 1% of the wettability modifiers of examples 1-3 and comparative example 1 (relative to the amount of CO ₂) were injected, and the interfacial tension was continuously tested, and the data are presented in Table 3. The results show that the injection of the wettability regulator can effectively reduce the interfacial tension between CO ₂ and winning crude oil, and is helpful for solving the problem of asphaltene precipitation caused by CO ₂ oil extraction, and the comparison of the comparative example 1 and the comparative example 1 shows that the wettability regulator has a 22% difference in the interfacial tension drop of CO ₂/oil on the basis of a structural difference of one benzene ring, thus the capability of reducing the interfacial tension of oil and water is obviously improved by introducing aromatic groups.

TABLE 3 wettability modifier CO ₂/oil interfacial tension

Example 6 contact angle test.

The contact angle between the winning crude oil (5000 mpa.s) and the quartz plate was measured in the CO ₂ environment under formation conditions (15 mpa,90 ℃) using an OCA-25 high temperature high pressure interfacial tension tester, then 1% of the wettability modifiers of examples 1 to 3 and comparative example 1 (relative to the amount of CO ₂) was injected, and the contact angle was further tested, and the data are shown in table 4.

The results show that the wettability of the quartz plate can be adjusted from oil wet to weak oil wet and even neutral wet by injecting the wettability modifier, the CO ₂ oil extraction efficiency can be improved, the contact angle of the quartz plate cannot be adjusted to a weak oil wet and even neutral wet range by comparing the comparative example 1 with the comparative example 1 on the basis of one benzene ring difference of the structure, and the fact that the wettability modifier can be introduced to remarkably improve the capability of adjusting the contact angle of oil/CO ₂ by introducing aromatic groups is shown.

Table 4 contact angle test

Surface active agent	Without any means for	Example 1	Example 2	Example 3	Comparative example 1
						Contact angle (°)	120	92	88	97	110

Comparative example 1

The impact of a siloxane-based nonionic surfactant (PEG) 3-TS on the decontamination value of Glu-C12 washcloth was also reported in article "Cleaning Efficiency of Amino-Acid Surfactants with PolyoxyethyleneEther and Isopropanol in Liquid Carbon Dioxide", which also indirectly evaluated the solubility of the surfactant in CO ₂, but the application of the surfactant in the oil recovery field was not investigated in the article, and the molecular host structure from the structural molecule was too CO ₂ -philic to act with asphaltenes compared to the present invention, limiting its application in the oil recovery field.

The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited thereto. Within the scope of the technical idea of the invention, a number of simple variants of the technical solution of the invention are possible, including combinations of the individual technical features in any other suitable way, which simple variants and combinations should likewise be regarded as being disclosed by the invention, all falling within the scope of protection of the invention.

Claims (10)

1. A CO ₂ wettability modifier having a structure as shown in formula (I):

Wherein R ₁ is C1-C8 alkyl, preferably C1-C4 alkyl; r ₂ is H or C1-C4 alkyl, preferably H or C1-C2 alkyl; r ₃ is C1-C20 alkyl, preferably C1-C12 alkyl; ar is an aromatic group, preferably phenyl; m is an integer of 1 to 10, and n is an integer of 0 to 10.

2. A method of preparing the CO ₂ wettability modifier according to claim 1, comprising the steps of:

(1) Reacting a compound of formula (II) with halopropene in the presence of a base and a catalyst I to obtain a compound of formula (II),

In the formula (II) and the formula (III), R ₃ is C1-C20 alkyl; ar is an aromatic group; m is an integer of 1 to 10, and n is an integer of 0 to 10.

(2) The obtained compound of formula (II) is reacted with organosiloxane in the presence of a catalyst II to obtain the CO ₂ wettability regulator.

3. The preparation method according to claim 2, characterized in that:

the halogenated propylene is at least one of chloropropene, bromopropene or iodopropylene; and/or the number of the groups of groups,

The organosiloxane has a structure represented by formula (IV):

R ₁ is C1-C8 alkyl, R ₂ is H or C1-C4 alkyl.

4. The preparation method according to claim 2, characterized in that in step (1):

The alkali is inorganic alkali or organic alkali, preferably inorganic alkali, and further preferably at least one of NaOH and KOH; and/or the number of the groups of groups,

The catalyst I is a phase transfer catalyst, preferably an alkyl halogenated ammonium salt, and more preferably at least one of tetrabutylammonium bromide and tetrabutylammonium iodide.

5. The preparation method according to claim 2, characterized in that in step (1):

The reaction conditions include: the temperature is 25-100 ℃, preferably 40-90 ℃; the reaction time is 2 to 24 hours, preferably 4 to 8 hours; and/or the number of the groups of groups,

The molar ratio of the compound of formula (II), the halopropene, the alkali and the catalyst is 1 (1-5): 1-10): 0.01-0.1, preferably 1 (1-2): 5-10): 0.01-0.05.

6. The preparation method according to claim 2, characterized in that in step (2):

the catalyst II is a noble metal catalyst, preferably a platinum catalyst, and more preferably at least one of chloroplatinic acid and cisplatin chloride.

7. The preparation method according to claim 2, characterized in that in step (2):

the reaction conditions include: the temperature is 50-150 ℃, preferably 80-120 ℃; the reaction time is 2 to 24 hours, preferably 6 to 12 hours; and/or the number of the groups of groups,

The molar ratio of the compound of formula (III), the organosiloxane and the catalyst II is 1 (1-2): 0.0005-0.05, preferably 1 (1-1.2): 0.001-0.01.

8. A method of reservoir wettability adjustment comprising injecting the CO ₂ wettability adjustment agent of claim 1 into a reservoir.

9. The method of reservoir wettability adjustment of claim 8, wherein:

the reservoir is conditioned under CO ₂ throughput or CO ₂ flooding conditions.

10. The method of reservoir wettability adjustment of claim 8, wherein:

The CO ₂ wettability regulator and CO ₂ are injected together or after being dissolved into CO ₂, and the injection amount is 0.01-2 wt% of the CO ₂.