Oil-soluble thick oil viscosity reducer as well as preparation method and application thereof

Abstract

The invention relates to an oil-soluble thick oil viscosity reducer as well as a preparation method and application thereof. The invention relates to an oil-soluble thick oil viscosity reducer, which consists of an alkenyl ester copolymer and a fatty acid ester surfactant in a mass ratio of 100: (0.5-50). The preparation method of the oil-soluble thick oil viscosity reducer comprises the following steps: step 1, preparing a mixed solution; 2, discharging air in the reactor, continuously introducing nitrogen or inert gas, dropwise adding 2-4 parts of carbon disulfide into the mixed solution, and stirring after dropwise adding to obtain an oily solution; step 3, heating the oily solution to 60-75 DEG C, heating the oily solution to 90-105 DEG C for reflux, and performing reduced pressure distillation to obtain distillation residues; step 4, heating the distillation residues under the condition of 110-150 DEG C, and naturally cooling to obtain an intermediate; and step 5, uniformly mixing the intermediate with a fatty acid ester surfactant according to a mass ratio of 100: (0.5-50) to obtain the oil-soluble thick oil viscosity reducer.

Description

Technical Field

[0001] The invention relates to an oil-soluble heavy oil viscosity reducer and a preparation method and application thereof, belonging to the field of oilfield chemical additives. Background Art

[0002] Heavy oil has the characteristics of high density, high freezing point, high viscosity and difficult flow, which makes it difficult to mine and transport. Therefore, physical or chemical methods must be used to modify or modify the heavy oil to reduce the viscosity in order to achieve smooth recovery.

[0003] At present, the commonly used heavy oil recovery methods at home and abroad include thermal recovery, diluent blending, chemical viscosity reduction, etc. For example, Chinese patent CN113669039B discloses a steam-assisted heavy oil thermal recovery system, which relates to the field of heavy oil thermal recovery. The system includes: a heat collection and storage subsystem, including a solar heat collection device and a heat storage device, which is used to provide and store high-temperature thermal energy; a wind and solar power generation subsystem, including a photovoltaic power generation array, a wind turbine generator set and an electronic control device, which is used to utilize wind energy and solar radiation energy to complement each other and realize the scheduling of electric energy; and a steam injection thermal recovery subsystem, which is used to couple high-temperature thermal energy and electric energy according to the principle of energy cascade utilization to provide the energy required for heavy oil thermal recovery. Chinese invention patent application CN108915654A discloses a heavy oil recovery method and system. The heavy oil production method comprises: firstly, using a hydraulic fracturing system to inject fracturing fluid into a heavy oil formation where the heavy oil is located through an oil well to generate cracks in the heavy oil formation; then, using a microwave heating system to heat the heavy oil to reduce the viscosity of the heavy oil and allow the heavy oil to penetrate into the oil well along the cracks; and finally, using a drainage system to produce the heavy oil in the oil well.

[0004] However, there are still many problems with conventional heavy oil production methods. For example, conventional thermal recovery technology has high energy consumption, and "condensation pipe accidents" are prone to occur, especially when the oil is shut down and restarted, making it difficult to meet the requirements of integrated heavy oil production and transportation. The diluent blending method blends in dehydrated light crude oil, which turns it into mixed water-containing oil and needs to be dehydrated again, which increases energy consumption, and the physical properties of the dilute crude oil will be reduced after blending.

[0005] Chemical viscosity reduction is a method of reducing the viscosity of heavy oil by adding chemical agents to it. This technology is simple to construct and has low operating costs. It is currently the most promising viscosity reduction technology. Commonly used chemical viscosity reducers include catalytic viscosity reducers, emulsified viscosity reducers, and oil-soluble viscosity reducers.

[0006] The oil-soluble viscosity reducer penetrates into the molecular layers of colloid or asphaltene, and reduces the viscosity of heavy oil by destroying or weakening the aggregated associations between macromolecules such as heavy oil colloid, high melting point wax, asphaltene, etc. It has the advantages of small dosage, simplicity, high efficiency and less pollution.

[0007] Oil-soluble viscosity reducers reduce viscosity in the same oil phase. Heavy oil and extra-heavy oil are in colloidal form, with low light oil content and high viscosity of the continuous phase, which is much higher than the viscosity of water. The apparent viscosity of the colloidal phase is proportional to the viscosity of the continuous phase. Therefore, the viscosity reduction rate of oil-soluble viscosity reducers is far from reaching the viscosity reduction rate of emulsified viscosity reduction with water as the continuous phase. Oil-soluble viscosity reducers have certain limitations in reducing viscosity. In order to increase the viscosity reduction rate, in actual applications, solvent dilution, heating viscosity reduction and other viscosity reduction technologies can be combined to achieve the purpose of viscosity reduction.

[0008] Oil-soluble chemical viscosity reduction technology is a promising method that overcomes the defects of chemical emulsification viscosity reduction technology. However, it is very difficult to develop oil-soluble viscosity reducers. At present, the viscosity reduction rate for heavy oil is not high enough. Few people abroad have conducted research, and domestic research progress is very slow. In addition, oil-soluble viscosity reducers can only play a significant viscosity reduction role when they fully interact with the colloid and asphaltene molecules of heavy oil. Downhole mixing conditions have a great influence on their application. At present, there are no reports on the use of oil-soluble viscosity reducers alone for viscosity reduction mining in domestic and foreign literature.

[0009] At the same time, the oil-soluble polymers currently used for crude oil viscosity reduction in China mainly include EVA and PAMA (copolymers of acrylates and methacrylates), and the development of new heavy oil viscosity reducers has been slow. From the actual situation, there are two problems that have become bottlenecks, one is the mechanism of action of the viscosity reducer, and the other is the selectivity of the viscosity reducer for crude oil. For this reason, it is proposed that the research on viscosity reducers should introduce polar or surface-active side chains on the original ester-type molecular skeleton, and use the spatial effect of polar groups and surfactant groups and the ability to reduce the solid-liquid interfacial tension to improve the dispersion of wax crystals, colloids, and asphaltene.

[0010] At present, oil-soluble viscosity reducers are mainly divided into two categories: condensation products and homopolymers or copolymers of unsaturated monomers. Most of the current oil-soluble viscosity reducers need to be obtained through condensation or polymerization reactions, which leads to complex synthesis processes and high raw material costs. Compared with emulsified viscosity reducers, oil-soluble viscosity reducers can be added directly, with simple processes and no need for large amounts of water emulsification and subsequent water treatment. In complex reservoir environments, it is an economically feasible means. In recent years, there have been few studies on oil-soluble viscosity reducers, and most of them are limited to the laboratory test stage and are rarely used in actual field operations. In addition, the existing oil-soluble viscosity reducers have poor fluidity and high addition amounts.

[0011] Oil-soluble viscosity reducers have the advantage of high contact efficiency with crude oil, and can effectively depolymerize and disperse heavy components in heavy oil, reduce crude oil viscosity, and improve flow properties. However, the existing preparation methods of oil-soluble viscosity reducers still have problems such as cumbersome washing steps and difficulty in filtering oily substances to varying degrees. Summary of the invention

[0012] Technical problem: In view of the problems of complicated washing steps and difficult filtration of oily substances in the above-mentioned prior art, the present invention provides an oil-soluble heavy oil viscosity reducer and its preparation method and application.

[0013] The preparation method of the invention has simple process, strong repeatability, does not require complicated steps such as washing and filtering, and is suitable for large-scale industrial production.

[0014] The oil-soluble heavy oil viscosity reducer of the present invention introduces amide groups, sulfonic acid groups, quaternary ammonium groups, ester groups, etc. during the preparation process, so that it can form hydrogen bonds with asphaltene colloids and other polar substances. At the same time, anions and cations form hydration films in water-containing oil, thereby greatly improving the viscosity reduction effect.

[0015] The technical solution is: an oil-soluble heavy oil viscosity reducer, composed of an olefin ester copolymer and a fatty acid ester surfactant, wherein:

[0016] The mass ratio of the olefin ester copolymer to the fatty acid ester surfactant is 100:0.5-50.

[0017] A method for preparing an oil-soluble heavy oil viscosity reducer, in terms of molar parts, comprises the following steps:

[0018] Step 1: Prepare the mixed solution

[0019] Add 1 part of copolymer, 2-5 parts of alcohol, 5-20 parts of deionized water and 1-2 parts of dialkylamine into a reactor, stir at 50-90°C until the copolymer is completely dissolved, then add oil-soluble base oil, stir evenly to obtain a mixed solution; or

[0020] Add 1 part of copolymer, 2-5 parts of alcohol, 5-20 parts of deionized water and 1-2 parts of trialkylamine into a reactor, heat at 50-90° C. until the copolymer is completely dissolved, then add oil-soluble base oil and 1-2 parts of dialkylamine, stir evenly to obtain a mixed solution;

[0021] Step 2, exhaust the air in the reactor in step 1, then continue to introduce nitrogen or inert gas, under the protection of nitrogen or inert gas, drop 2-4 parts of carbon disulfide into the mixed solution, and stir at 20° C.-30° C. for at least 5 hours after the dropwise addition to obtain an oily solution;

[0022] Step 3, heating the oily solution in step 2 to 60°C-75°C and maintaining it for at least 1 hour, heating the oily solution to 90°C-105°C and refluxing it for at least 2 hours, and then performing reduced pressure distillation to obtain a distillation residue;

[0023] Step 4, heating the distillation residue in step 3 at 110° C.-150° C. for at least 1 hour, and cooling naturally to obtain an intermediate;

[0024] Step 5: Evenly mix the intermediate described in step 4 with a fatty acid ester surfactant in a mass ratio of 100:0.5-50 to obtain an oil-soluble heavy oil viscosity reducer.

[0025] Furthermore, the copolymer in step one is one of ethylene-vinyl acetate copolymer, propylene-propylene acetate copolymer and butene-butylene acetate copolymer.

[0026] Furthermore, the dialkylamine in step 1 is a C16-C26 aliphatic diamine or a C14-C24 alicyclic diamine.

[0027] Furthermore, the trialkylamine in step 1 is a C6-C9 trialkylamine.

[0028] Furthermore, the alcohol in step 1 is n-butanol or n-pentanol.

[0029] Furthermore, the amount of the oil-soluble base oil added in step 1 is 200 g-500 g / mole based on the molar amount of the copolymer.

[0030] Furthermore, the oil-soluble base oil is vegetable oil or mineral oil.

[0031] Furthermore, the vegetable oil is one or more of corn oil, cottonseed oil, peanut oil and soybean oil.

[0032] Furthermore, the mineral oil is cyclohexane oil.

[0033] Furthermore, the rate of adding carbon disulfide in step 2 is 0.1 g / min-3.0 g / min.

[0034] Furthermore, the specific process conditions of the reduced pressure distillation in step three are: distillation for 10 min to 100 min under a vacuum degree of -0.099 MPa to -0.06 MPa.

[0035] Furthermore, the fatty acid ester surfactant in step five is one or more of fatty acid methyl ester, fatty acid ethylene glycol ester, fatty acid glyceride and fatty acid sucrose ester.

[0036] An oil-soluble heavy oil viscosity reducer is prepared by any one of the above-mentioned preparation methods of the oil-soluble heavy oil viscosity reducer.

[0037] The application of the above oil-soluble heavy oil viscosity reducer in heavy oil production.

[0038] The positive effect of the present invention is to solve the technical problems that the washing steps are complicated and the oily matter is difficult to filter, which exist to varying degrees in the preparation of the oil-soluble viscosity reducer.

[0039] The principle of the present invention is that by adding a certain amount of fatty acid ester surfactant to the olefin ester copolymer, the olefin ester copolymer with weak polarity is more easily dispersed in the oily solvent, and the oil solubility of the oil-soluble viscosity reducer is further improved.

[0040] The preparation process of the invention is simple and highly repeatable and is suitable for large-scale industrial production.

[0041] The invention does not emit harmful gases during the reduced pressure distillation process; does not require cumbersome processes such as filtering and washing during the preparation process, and does not generate waste liquid.

[0042] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0043] (1) The present invention effectively solves the common problems of poor oil solubility and low effective content in current oil-soluble viscosity reducers. Since the effective ingredient in the oil-soluble viscosity reducer is an olefin copolymer, the oil solubility of the oil-soluble viscosity reducer mainly depends on the hydrocarbon groups carried by the olefin copolymer itself. The hydrocarbon groups with long chain structures and high degree of branching have good oil solubility, but are difficult to synthesize. Short-chain hydrocarbon groups are easier to synthesize, but have poor room temperature stability after mixing with oily solvents, and are prone to stratification and precipitation. The present invention uses this as a basis for raw material screening and process optimization. The oil-soluble heavy oil viscosity reducer finally obtained has good room temperature stability. No precipitation or stratification occurs when it is placed at 25°C for 72 hours.

[0044] (2) The present invention adds a certain amount of fatty acid ester surfactant to the olefin ester copolymer, so that the olefin ester copolymer with weak polarity is more easily dispersed in the oily solvent, thereby further improving the oil solubility of the oil-soluble heavy oil viscosity reducer.

[0045] (3) The present invention performs a vacuum treatment on the reaction system and fills it with nitrogen or an inert gas before adding CS2 dropwise, thereby maintaining a reducing atmosphere in the reaction system before the reaction, making it difficult to be oxidized to a high-valent state by air, and thus more easily linked to the characteristic group of carbamic acid. Therefore, there is substantially no solid precipitate in the olefin ester copolymer prepared by the method, and the prepared oil-soluble heavy oil viscosity reducer has a higher effective content.

[0046] (4) The preparation process of the present invention is simple, highly repeatable, and suitable for large-scale industrial production; the by-products distilled out during the vacuum distillation process of the present invention can be recycled, and no harmful gas is emitted during the distillation process; the preparation process does not require cumbersome processes such as filtering and washing, and no waste liquid is generated.

[0047] Other features and advantages of the present invention will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1The present invention discloses a flow chart of a method for preparing an oil-soluble heavy oil viscosity reducer. DETAILED DESCRIPTION

[0049] The specific embodiments of the present invention are described in detail below.

[0050] The endpoint values ​​and any values ​​of the range disclosed in the present invention are not limited to the precise range or value, 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 regarded as specifically disclosed in this article.

[0051] Taking ethylene-vinyl acetate copolymer as an example, the structural formula of ethylene-vinyl acetate copolymer is as follows: Wherein m and n are positive integers.

[0052] The specific reaction of step one is as follows:

[0053] Chain Initiation:

[0054]

[0055]

[0056] Chain Growth:

[0057]

[0058]

[0059] Chain Termination:

[0060]

[0061] Example 1

[0062] A method for preparing an oil-soluble heavy oil viscosity reducer comprises the following steps:

[0063] Step 1: Mix the copolymer, alcohol, deionized water and trialkylamine in a molar ratio of 1:2:5:1 at 50°C and stir until the copolymer is completely dissolved, then add mineral oil and dialkylamine and stir evenly to obtain a mixed solution; wherein:

[0064] Add 250 g of mineral oil per mole of copolymer;

[0065] 1 mole of dialkylamine is added per mole of copolymer;

[0066] The copolymer is ethylene-vinyl acetate copolymer;

[0067] The dialkylamine is a C16 aliphatic diamine;

[0068] The alcohol is preferably n-butanol;

[0069] The trialkylamine is a C6 trialkylamine. In another embodiment, the trialkylamine is triethylamine.

[0070] The mineral oil is naphthenic oil;

[0071] Step 2: Vacuum the mixed solution in step 1 to remove air, then introduce nitrogen, and under the protection of nitrogen atmosphere, drop CS2 into the mixed solution at a rate of 1.0 g / min, the molar ratio of the added CS2 to the copolymer in step 1 is 4:1, and after the dropwise addition is completed, stir at a temperature of 25° C. for 18 hours to obtain an oily solution;

[0072] Step 3, heating the oily solution in step 2 to 65° C. and maintaining it for 1 hour, raising the temperature to 100° C. and reflux for 4 hours, and then distilling it at a vacuum degree of -0.08 MPa for 60 minutes to obtain a distillation residue;

[0073] Step 4, heating the distillation residue in step 3 at 120° C. for 3 h, and cooling naturally to obtain an intermediate;

[0074] Step 5: Evenly mix the intermediate in step 4 with a fatty acid ester surfactant at a mass ratio of 100:20 to obtain an oil-soluble heavy oil viscosity reducer.

[0075] Furthermore, the fatty acid ester surfactant is fatty acid methyl ester.

[0076] The oil-soluble heavy oil viscosity reducer prepared in this example has good room temperature stability, and there is no precipitation or stratification after being placed at room temperature of 25° C. for 72 hours.

[0077] The oil-soluble heavy oil viscosity reducer prepared in this embodiment has a heavy oil viscosity reduction rate of >85% at 50° C. and an impurity content of ≤0.2%.

[0078] Example 2

[0079] A method for preparing an oil-soluble heavy oil viscosity reducer comprises the following steps:

[0080] Step 1: Mix the copolymer, alcohol, deionized water and trialkylamine at a molar ratio of 1:3:5:2 at a temperature of 70°C until the copolymer is completely dissolved, then add mineral oil and dialkylamine, stir evenly to obtain a mixed solution, wherein:

[0081] 500 g of mineral oil was added to each mole of copolymer;

[0082] Add 2.0 mol of dialkylamine per mol of copolymer;

[0083] The copolymer is propylene-propylene acetate copolymer;

[0084] The trialkylamine is a C6 trialkylamine. In another embodiment, the trialkylamine is tripropylamine;

[0085] The dialkylamine is a C16 aliphatic diamine. In another embodiment, the dialkylamine is diisodecylamine;

[0086] The mineral oil is naphthenic oil; the alcohol is n-pentanol;

[0087] Step 2: Vacuum the mixed solution in step 1 to remove air, then introduce helium, and under the protection of the helium atmosphere, drop CS2 into the mixed solution at a rate of 3.0 g / min, wherein the molar ratio of the added CS2 to the copolymer in step 1 is 3:1, and after the dropwise addition is completed, stir at 30° C. for 5 h to obtain an oily solution;

[0088] Step 3, heating the oily solution in step 2 to 75° C. and maintaining it for 1 hour, then raising the temperature to 105° C. and reflux for 2 hours, and then distilling it at a vacuum degree of -0.099 MPa for 10 minutes to obtain a distillation residue;

[0089] Step 4, heating the distillation residue in step 3 at 150° C. for 1 h, and cooling naturally to obtain an intermediate;

[0090] Step 5: Evenly mix the intermediate in step 4 with a fatty acid ester surfactant at a mass ratio of 100:50 to obtain an oil-soluble heavy oil viscosity reducer.

[0091] Further, the fatty acid ester surfactant is fatty acid methyl ester. In another embodiment, the fatty acid ester surfactant is fatty acid ethylene glycol ester. In another embodiment, the fatty acid ester surfactant is fatty acid glyceride. In another embodiment, the fatty acid ester surfactant is fatty acid sucrose ester.

[0092] The oil-soluble heavy oil viscosity reducer prepared in this example has good room temperature stability, and there is no precipitation or stratification after being placed at room temperature of 25° C. for 72 hours.

[0093] The oil-soluble heavy oil viscosity reducer prepared in this embodiment has a heavy oil viscosity reduction rate of >85% at 50° C. and an impurity content of ≤0.2%.

[0094] Example 3

[0095] A method for preparing an oil-soluble heavy oil viscosity reducer comprises the following steps:

[0096] Step 1: Mix the copolymer, alcohol, deionized water and trialkylamine at a molar ratio of 1:3:20:2 at a temperature of 90°C until the copolymer is completely dissolved, then add vegetable oil and dialkylamine, stir evenly to obtain a mixed solution, wherein:

[0097] 500 g of vegetable oil was added to each mole of copolymer;

[0098] 2.2 mol of dialkylamine was added to each mol of copolymer;

[0099] The copolymer is propylene-propylene acetate copolymer;

[0100] The trialkylamine is a C9 trialkylamine;

[0101] The dialkylamine is a C26 aliphatic diamine;

[0102] The vegetable oil is corn oil;

[0103] The alcohol is n-butanol;

[0104] Step 2: Vacuum the mixed solution in step 1 to remove air, then introduce neon gas, and under the protection of the neon atmosphere, drop CS2 into the mixed solution at a rate of 0.1 g / min, wherein the molar ratio of the added CS2 to the copolymer in step 1 is 2:1, and after the dropwise addition is completed, stir at a temperature of 20° C. for 24 hours to obtain an oily solution;

[0105] Step 3, heating the oily solution in step 2 to 60° C. and maintaining it for 2 h, then raising the temperature to 105° C. and refluxing it for 2 h, and then distilling it for 100 min at a vacuum degree of -0.060 MPa to obtain a distillation residue;

[0106] Step 4, heating the distillation residue in step 3 at 110° C. for 6 h, and cooling naturally to obtain an intermediate;

[0107] Step 5: Evenly mix the intermediate in step 4 with a fatty acid ester surfactant at a mass ratio of 100:0.5 to obtain an oil-soluble heavy oil viscosity reducer.

[0108] Furthermore, the fatty acid ester surfactant is fatty acid ethylene glycol ester.

[0109] The oil-soluble heavy oil viscosity reducer prepared in this example has good room temperature stability, and there is no precipitation or stratification after being placed at room temperature of 25° C. for 72 hours.

[0110] The oil-soluble heavy oil viscosity reducer prepared in this embodiment has a heavy oil viscosity reduction rate of >85% at 50° C. and an impurity content of ≤0.2%.

[0111] Example 4

[0112] A method for preparing an oil-soluble heavy oil viscosity reducer comprises the following steps:

[0113] Step 1: Mix the copolymer, alcohol, deionized water and trialkylamine at a molar ratio of 1:3:5:2 at a temperature of 80°C until the copolymer is completely dissolved, then add vegetable oil and dialkylamine, stir evenly to obtain a mixed solution, wherein:

[0114] 300 g of vegetable oil was added to each mole of copolymer;

[0115] 1.5 mol of dialkylamine was added to each mol of copolymer;

[0116] The copolymer is a butene-butylene acetate copolymer;

[0117] The dialkylamine is a C20 alicyclic diamine. In another embodiment, the dialkylamine is N, N-isooctylcyclohexylamine;

[0118] The alcohol is n-pentanol;

[0119] The trialkylamine is a C7 trialkylamine;

[0120] The vegetable oil is cottonseed oil;

[0121] Step 2: Vacuum the mixed solution in step 1 to remove air, then introduce argon, and under the protection of argon atmosphere, drop CS2 into the mixed solution at a rate of 0.1 g / min, wherein the molar ratio of the added CS2 to the copolymer in step 1 is 3:1, and after the dropwise addition is completed, stir at 30°C for 5 hours to obtain an oily solution;

[0122] Step 3, heating the oily solution in step 2 to 75° C. and maintaining it for 1 hour, then raising the temperature to 90° C. and refluxing for 6 hours, and then distilling it at a vacuum degree of -0.060 MPa for 100 minutes to obtain a distillation residue;

[0123] Step 4, heating the distillation residue in step 3 at 110° C. for 6 h, and cooling naturally to obtain an intermediate;

[0124] Step 5: Evenly mix the intermediate in step 4 with a fatty acid ester surfactant at a mass ratio of 100:50 to obtain an oil-soluble heavy oil viscosity reducer.

[0125] Furthermore, the fatty acid ester surfactant is a mixture of fatty acid methyl ester, fatty acid ethylene glycol ester and fatty acid glyceride in equal mass ratio.

[0126] The oil-soluble heavy oil viscosity reducer prepared in this example has good room temperature stability, and there is no precipitation or stratification after being placed at room temperature of 25° C. for 72 hours.

[0127] The oil-soluble heavy oil viscosity reducer prepared in this embodiment has a heavy oil viscosity reduction rate of >85% at 50° C. and an impurity content of ≤0.2%.

[0128] Example 5

[0129] A method for preparing an oil-soluble heavy oil viscosity reducer comprises the following steps:

[0130] Step 1: Mix the copolymer, alcohol, deionized water and trialkylamine at a molar ratio of 1:3:5:2 at a temperature of 90°C until the copolymer is completely dissolved, then add mineral oil and dialkylamine, and stir evenly to obtain a mixed solution, wherein:

[0131] 300 g of mineral oil was added to each mole of copolymer;

[0132] 1.2 mol of dialkylamine was added to each mol of copolymer;

[0133] The copolymer is propylene-propylene acetate copolymer;

[0134] The dialkylamine is N,N-tetradecylcyclohexylamine;

[0135] The trialkylamine is triethylamine;

[0136] The mineral oil is naphthenic oil;

[0137] The alcohol is n-pentanol;

[0138] Step 2: Vacuum the mixed solution in step 1 to remove air, then introduce nitrogen, and under the protection of nitrogen atmosphere, drop CS2 into the mixed solution at a rate of 3.0 g / min, the molar ratio of the added CS2 to the copolymer in step 1 is 2:1, and after the dropwise addition is completed, stir at a temperature of 20°C for 24 hours to obtain an oily solution;

[0139] Step 3, heating the oily solution in step 2 to 75°C and maintaining it for 1 hour, then raising the temperature to 105°C and refluxing for 2 hours, and then distilling it at a vacuum degree of -0.060 MPa for 50 minutes to obtain a distillation residue;

[0140] Step 4, heating the distillation residue in step 3 at 110° C. for 4 h, and cooling naturally to obtain an intermediate;

[0141] Step 5: Evenly mix the intermediate in step 4 with a fatty acid ester surfactant at a mass ratio of 100:20 to obtain an oil-soluble heavy oil viscosity reducer.

[0142] Furthermore, the fatty acid ester surfactant is a mixture of fatty acid methyl ester and fatty acid sucrose ester in equal mass ratio.

[0143] The oil-soluble heavy oil viscosity reducer prepared in this example has good room temperature stability, and there is no precipitation or stratification after being placed at room temperature of 25° C. for 72 hours.

[0144] The oil-soluble heavy oil viscosity reducer prepared in this embodiment has a heavy oil viscosity reduction rate of >85% at 50° C. and an impurity content of ≤0.2%.

[0145] Example 6

[0146] A method for preparing an oil-soluble heavy oil viscosity reducer comprises the following steps:

[0147] Step 1: Mix the copolymer, alcohol, deionized water and trialkylamine at a molar ratio of 1:3:9:2 at a temperature of 60°C until the copolymer is completely dissolved, then add vegetable oil and dialkylamine, and stir evenly to obtain a mixed solution, wherein:

[0148] 200 g of mineral oil was added to each mole of copolymer;

[0149] 1.0 mol of dialkylamine was added to each mol of copolymer;

[0150] The copolymer is propylene-propylene acetate copolymer;

[0151] The trialkylamine is tripropylamine;

[0152] The dialkylamine is N,N-octadecylcyclohexylamine;

[0153] The vegetable oil is peanut oil;

[0154] The alcohol is n-butanol;

[0155] Step 2: Vacuum the mixed solution in step 1 to remove air, then introduce nitrogen, and under the protection of nitrogen atmosphere, drop CS2 into the mixed solution at a rate of 3.0 g / min, the molar ratio of the added CS2 to the copolymer in step 1 is 2:1, and after the dropwise addition is completed, stir at a temperature of 20°C for 24 hours to obtain an oily solution;

[0156] Step 3, heating the oily solution in step 2 to 60° C. and maintaining it for 2 h, then raising the temperature to 105° C. and refluxing it for 2 h, and then distilling it at a vacuum degree of -0.099 MPa for 100 min to obtain a distillation residue;

[0157] Step 4, heating the distillation residue in step 3 at 150° C. for 1 h, and cooling naturally to obtain an intermediate;

[0158] Step 5: Evenly mix the intermediate in step 4 with a fatty acid ester surfactant at a mass ratio of 100:10 to obtain an oil-soluble heavy oil viscosity reducer.

[0159] Furthermore, the fatty acid ester surfactant is fatty acid ethylene glycol ester.

[0160] The oil-soluble heavy oil viscosity reducer prepared in this example has good room temperature stability, and there is no precipitation or stratification after being placed at room temperature of 25° C. for 72 hours.

[0161] The oil-soluble heavy oil viscosity reducer prepared in this embodiment has a heavy oil viscosity reduction rate of >85% at 50° C. and an impurity content of ≤0.2%.

[0162] Example 7

[0163] A method for preparing an oil-soluble heavy oil viscosity reducer comprises the following steps:

[0164] Step 1: Mix the copolymer, alcohol, deionized water and dialkylamine at a molar ratio of 1:3:7:1.5 at a temperature of 90°C until the copolymer is completely dissolved, then add vegetable oil and stir evenly to obtain a mixed solution, wherein:

[0165] 250 g of vegetable oil was added to each mole of copolymer;

[0166] The copolymer is propylene-propylene acetate copolymer;

[0167] The dialkylamine is N,N-tetradecylcyclohexylamine; the vegetable oil is peanut oil;

[0168] The alcohol is n-butanol;

[0169] Step 2: Vacuum the mixed solution in step 1 to remove air, then introduce nitrogen, and under the protection of nitrogen atmosphere, drop CS2 into the mixed solution at a rate of 3.0 g / min, the molar ratio of the added CS2 to the copolymer in step 1 is 2:1, and after the dropwise addition is completed, stir at a temperature of 30°C for 5 hours to obtain an oily solution;

[0170] Step 3, heating the oily solution in step 2 to 75° C. and maintaining it for 1 hour, then raising the temperature to 105° C. and reflux for 2 hours, and then distilling it at a vacuum degree of -0.099 MPa for 10 minutes to obtain a distillation residue;

[0171] Step 4, heating the distillation residue in step 3 at 110° C. for 1 h, and cooling naturally to obtain an intermediate;

[0172] Step 5: Evenly mix the intermediate in step 4 with a fatty acid ester surfactant at a mass ratio of 100:10 to obtain an oil-soluble heavy oil viscosity reducer.

[0173] Furthermore, the fatty acid ester surfactant is fatty acid glyceride.

[0174] The oil-soluble heavy oil viscosity reducer prepared in this example has good room temperature stability, and there is no precipitation or stratification after being placed at room temperature of 25° C. for 72 hours.

[0175] The oil-soluble heavy oil viscosity reducer prepared in this embodiment has a heavy oil viscosity reduction rate of >85% at 50° C. and an impurity content of ≤0.2%.

[0176] Example 8

[0177] A method for preparing an oil-soluble heavy oil viscosity reducer comprises the following steps:

[0178] Step 1: Mix the copolymer, alcohol, deionized water and dialkylamine at a molar ratio of 1:3:5:2.2 at a temperature of 60°C until the copolymer is completely dissolved, then add vegetable oil and stir evenly to obtain a mixed solution, wherein:

[0179] 500 g of vegetable oil was added to each mole of copolymer;

[0180] The copolymer is ethylene-vinyl acetate copolymer;

[0181] The dialkylamine is N,N-octadecylcyclohexylamine;

[0182] The alcohol is n-butanol;

[0183] The vegetable oil is soybean oil;

[0184] Step 2: Vacuum the mixed solution in step 1 to remove air, then introduce nitrogen, and under the protection of nitrogen atmosphere, drop CS2 into the mixed solution at a rate of 0.1 g / min, the molar ratio of the added CS2 to the copolymer in step 1 is 3:1, and after the dropwise addition is completed, stir at a temperature of 30°C for 5 hours to obtain an oily solution;

[0185] Step 3, heating the oily solution in step 2 to 75° C. and maintaining it for 1 hour, then raising the temperature to 105° C. and refluxing it for 2 hours, and then distilling it at a vacuum degree of -0.060 MPa for 100 minutes to obtain a distillation residue;

[0186] Step 4, heating the distillation residue in step 3 at 110° C. for 6 h, and cooling naturally to obtain an intermediate;

[0187] Step 5: Evenly mix the intermediate in step 4 with a fatty acid ester surfactant at a mass ratio of 100:30 to obtain an oil-soluble heavy oil viscosity reducer.

[0188] Furthermore, the fatty acid ester surfactant is a mixture of fatty acid methyl ester and fatty acid ethylene glycol ester in equal mass ratio.

[0189] The oil-soluble heavy oil viscosity reducer prepared in this example has good room temperature stability, and there is no precipitation or stratification after being placed at room temperature of 25° C. for 72 hours.

[0190] The oil-soluble heavy oil viscosity reducer prepared in this embodiment has a heavy oil viscosity reduction rate of >85% at 50° C. and an impurity content of ≤0.2%.

[0191] Example 9

[0192] A method for preparing an oil-soluble heavy oil viscosity reducer comprises the following steps:

[0193] Step 1: Mix the copolymer, alcohol, deionized water and dialkylamine at a molar ratio of 1:3:20:1.0 at a temperature of 90°C until the copolymer is completely dissolved, then add vegetable oil and stir evenly to obtain a mixed solution, wherein:

[0194] 200 g of vegetable oil was added to each mole of copolymer;

[0195] The copolymer is propylene-propylene acetate copolymer;

[0196] The dialkylamine is N,N-isooctylcyclohexylamine;

[0197] The alcohol is n-pentanol;

[0198] The vegetable oil is corn oil;

[0199] Step 2: Vacuum the mixed solution in step 1 to remove air, then introduce nitrogen, and under the protection of nitrogen atmosphere, drop CS2 into the mixed solution at a rate of 3.0 g / min, the molar ratio of the added CS2 to the copolymer in step 1 is 2:1, and after the dropwise addition is completed, stir at a temperature of 20°C for 10 hours to obtain an oily solution;

[0200] Step 3, heating the oily solution in step 2 to 70° C. and maintaining it for 1 hour, raising the temperature to 100° C. and reflux for 4 hours, and then distilling it at a vacuum degree of -0.060 MPa for 100 minutes to obtain a distillation residue;

[0201] Step 4, heating the distillation residue in step 3 at 150° C. for 1 h, and cooling naturally to obtain an intermediate;

[0202] Step 5: Evenly mix the intermediate in step 4 with a fatty acid ester surfactant at a mass ratio of 100:0.5 to obtain an oil-soluble heavy oil viscosity reducer.

[0203] Furthermore, the fatty acid ester surfactant is fatty acid methyl ester.

[0204] The oil-soluble heavy oil viscosity reducer prepared in this example has good room temperature stability, and there is no precipitation or stratification after being placed at room temperature of 25° C. for 72 hours.

[0205] The oil-soluble heavy oil viscosity reducer prepared in this embodiment has a heavy oil viscosity reduction rate of >85% at 50° C. and an impurity content of ≤0.2%.

[0206] Example 10

[0207] A method for preparing an oil-soluble heavy oil viscosity reducer comprises the following steps:

[0208] Step 1: Mix the copolymer, alcohol, deionized water and dialkylamine at a molar ratio of 1:3:7:2 at a temperature of 90°C until the copolymer is completely dissolved, then add vegetable oil and stir evenly to obtain a mixed solution, wherein:

[0209] 400 g of vegetable oil was added to each mole of copolymer;

[0210] The copolymer is propylene-propylene acetate copolymer;

[0211] The dialkylamine is diisooctylamine;

[0212] The vegetable oil is corn oil;

[0213] The alcohol is n-butanol;

[0214] Step 2: Vacuum the mixed solution in step 1 to remove air, then introduce nitrogen, and under the protection of nitrogen atmosphere, drop CS2 into the mixed solution at a rate of 0.1 g / min, the molar ratio of the added CS2 to the copolymer in step 1 is 2:1, and after the dropwise addition is completed, stir at a temperature of 20°C for 24 hours to obtain an oily solution;

[0215] Step 3, heating the oily solution in step 2 to 60° C. and maintaining it for 2 h, then raising the temperature to 105° C. and refluxing it for 2 h, and then distilling it for 100 min at a vacuum degree of -0.060 MPa to obtain a distillation residue;

[0216] Step 4, heating the distillation residue in step 3 at 110° C. for 6 h, and cooling naturally to obtain an intermediate;

[0217] Step 5: Evenly mix the intermediate in step 4 with a fatty acid ester surfactant at a mass ratio of 100:0.5 to obtain an oil-soluble heavy oil viscosity reducer.

[0218] Furthermore, the fatty acid ester surfactant is a mixture of fatty acid glyceride and fatty acid sucrose ester in equal mass ratio.

[0219] The oil-soluble heavy oil viscosity reducer prepared in this example has good room temperature stability, and there is no precipitation or stratification after being placed at room temperature of 25° C. for 72 hours.

[0220] The oil-soluble heavy oil viscosity reducer prepared in this embodiment has a heavy oil viscosity reduction rate of >85% at 50° C. and an impurity content of ≤0.2%.

[0221] Embodiment 11

[0222] A method for preparing an oil-soluble heavy oil viscosity reducer comprises the following steps:

[0223] Step 1: Mix the copolymer, alcohol, deionized water and dialkylamine at a molar ratio of 1:3:10:1.8 at a temperature of 80°C until the copolymer is completely dissolved, then add vegetable oil and stir evenly to obtain a mixed solution, wherein:

[0224] 400 g of vegetable oil was added to each mole of copolymer;

[0225] The copolymer is propylene-propylene acetate copolymer;

[0226] The dialkylamine is diisodecylamine;

[0227] The vegetable oil is soybean oil;

[0228] The alcohol is n-pentanol;

[0229] Step 2: Vacuum the mixed solution in step 1 to remove air, then introduce nitrogen, and under the protection of nitrogen atmosphere, drop CS2 into the mixed solution at a rate of 3.0 g / min, the molar ratio of the added CS2 to the copolymer in step 1 is 2:1, and after the dropwise addition is completed, stir at a temperature of 30°C for 5 hours to obtain an oily solution;

[0230] Step 3, heating the oily solution in step 2 to 75° C. and maintaining it for 1 hour, then raising the temperature to 105° C. and refluxing it for 2 hours, and then distilling it for 10 minutes under a vacuum degree of -0.095 MPa to obtain a distillation residue;

[0231] Step 4, heating the distillation residue in step 3 at 150° C. for 1 h, and cooling naturally to obtain an intermediate;

[0232] Step 5: Evenly mix the intermediate in step 4 with a fatty acid ester surfactant at a mass ratio of 100:50 to obtain an oil-soluble heavy oil viscosity reducer.

[0233] Furthermore, the fatty acid ester surfactant is a mixture of fatty acid methyl ester, fatty acid ethylene glycol ester, fatty acid glyceride and fatty acid sucrose ester in equal mass ratio.

[0234] The oil-soluble heavy oil viscosity reducer prepared in this example has good room temperature stability, and there is no precipitation or stratification after being placed at room temperature of 25° C. for 72 hours.

[0235] The oil-soluble heavy oil viscosity reducer prepared in this embodiment has a heavy oil viscosity reduction rate of >85% at 50° C. and an impurity content of ≤0.2%.

[0236] Example 12

[0237] A method for preparing an oil-soluble heavy oil viscosity reducer comprises the following steps:

[0238] Step 1: Mix the copolymer, alcohol, deionized water and dialkylamine at a molar ratio of 1:3:5:1.8 at a temperature of 80°C until the copolymer is completely dissolved, then add vegetable oil and stir evenly to obtain a mixed solution, wherein:

[0239] 200 g of vegetable oil was added to each mole of copolymer;

[0240] The copolymer is propylene-propylene acetate copolymer;

[0241] The dialkylamine is diisotridecylamine;

[0242] The alcohol is n-pentanol;

[0243] The vegetable oil is corn oil;

[0244] Step 2: Vacuum the mixed solution in step 1 to remove air, then introduce nitrogen, and under the protection of nitrogen atmosphere, drop CS2 into the mixed solution at a rate of 0.5 g / min, the molar ratio of the added CS2 to the copolymer in step 1 is 2:1, and after the dropwise addition is completed, stir at a temperature of 20°C for 20 hours to obtain an oily solution;

[0245] Step 3, heating the oily solution in step 2 to 70° C. and maintaining it for 1.5 h, raising the temperature to 100° C. and reflux for 4 h, and then distilling it at a vacuum degree of -0.060 MPa for 100 min to obtain a distillation residue;

[0246] Step 4, heating the distillation residue in step 3 at 110° C. for 6 h, and cooling naturally to obtain an intermediate;

[0247] Step 5: uniformly mix the intermediate in step 4 with a fatty acid ester surfactant at a mass ratio of 100:50 to obtain an oil-soluble heavy oil viscosity reducer.

[0248] Furthermore, the fatty acid ester surfactant is fatty acid ethylene glycol ester.

[0249] The oil-soluble heavy oil viscosity reducer prepared in this example has good room temperature stability, and there is no precipitation or stratification after being placed at room temperature of 25° C. for 72 hours.

[0250] The oil-soluble heavy oil viscosity reducer prepared in this embodiment has a heavy oil viscosity reduction rate of >85% at 50° C. and an impurity content of ≤0.2%.

[0251] Embodiment 14

[0252] An oil-soluble heavy oil viscosity reducer, composed of an olefin ester copolymer and a fatty acid ester surfactant, wherein:

[0253] The mass ratio of the olefin ester copolymer to the fatty acid ester surfactant is 100:0.5.

[0254] Embodiment 15

[0255] An oil-soluble heavy oil viscosity reducer, composed of an olefin ester copolymer and a fatty acid ester surfactant, wherein:

[0256] The mass ratio of the olefin ester copolymer to the fatty acid ester surfactant is 100:50.

[0257] Example 16

[0258] An oil-soluble heavy oil viscosity reducer, composed of an olefin ester copolymer and a fatty acid ester surfactant, wherein:

[0259] The mass ratio of the olefin ester copolymer to the fatty acid ester surfactant is 100:20.

[0260] Embodiment 17

[0261] A method for preparing an oil-soluble heavy oil viscosity reducer, in terms of molar parts, comprises the following steps:

[0262] Step 1: Prepare the mixed solution

[0263] 1 part of copolymer, 2 parts of alcohol, 5 parts of deionized water and 1 part of dialkylamine were added into the reactor, stirred at 50°C until the copolymer was completely dissolved, and then the oil-soluble base oil was added, stirred evenly to obtain a mixed solution;

[0264] Step 2: Expel the air in the reactor in step 1, then continue to introduce nitrogen, and under the protection of nitrogen, add 2 parts of carbon disulfide (CS 2) was added dropwise to the mixed solution, and after the addition was completed, the mixture was stirred at 20°C for 5 hours to obtain an oily solution;

[0265] Step 3, heating the oily solution in step 2 to 60° C. and maintaining it for 1 hour, heating the oily solution to 90° C. and refluxing it for 2 hours, and then performing reduced pressure distillation to obtain a distillation residue;

[0266] Step 4, heating the distillation residue in step 3 at 110° C. for 1 h, and cooling naturally to obtain an intermediate;

[0267] Step 5: Evenly mix the intermediate described in step 4 with a fatty acid ester surfactant in a mass ratio of 100:0.5 to obtain an oil-soluble heavy oil viscosity reducer.

[0268] Furthermore, the copolymer in step one is ethylene-vinyl acetate copolymer.

[0269] Further, the dialkylamine in step 1 is a C16 aliphatic diamine. In another embodiment, the dialkylamine in step 1 is a C14 alicyclic diamine.

[0270] Furthermore, the alcohol in step 1 is n-butanol.

[0271] Furthermore, the amount of the oil-soluble base oil added in step 1 is 200 gg / mole based on the molar amount of the copolymer.

[0272] Furthermore, the oil-soluble base oil is vegetable oil.

[0273] Furthermore, the vegetable oil is corn oil. In another embodiment, the vegetable oil is a mixture of equal mass of corn oil, cottonseed oil, peanut oil and soybean oil. In another embodiment, the vegetable oil is cottonseed oil. In another embodiment, the vegetable oil is peanut oil. In another embodiment, the vegetable oil is soybean oil.

[0274] Furthermore, the rate of adding carbon disulfide in step 2 is 0.1 g / min.

[0275] Furthermore, the specific process conditions of the reduced pressure distillation in step three are: distillation for 100 minutes under a vacuum degree of -0.099 MPa.

[0276] Further, the fatty acid ester surfactant described in step 5 is fatty acid methyl ester. In another embodiment, the fatty acid ester surfactant described in step 5 is a mixture of fatty acid methyl ester, fatty acid ethylene glycol ester, fatty acid glyceride and fatty acid sucrose ester. In another embodiment, the fatty acid ester surfactant described in step 5 is fatty acid ethylene glycol ester. In another embodiment, the fatty acid ester surfactant described in step 5 is fatty acid glyceride. In another embodiment, the fatty acid ester surfactant described in step 5 is fatty acid sucrose ester.

[0277] An oil-soluble heavy oil viscosity reducer is prepared by any one of the above-mentioned preparation methods of the oil-soluble heavy oil viscosity reducer.

[0278] The oil-soluble heavy oil viscosity reducer prepared in this example has good room temperature stability, and there is no precipitation or stratification after being placed at room temperature of 25° C. for 72 hours.

[0279] The oil-soluble heavy oil viscosity reducer prepared in this embodiment has a heavy oil viscosity reduction rate of >85% at 50° C. and an impurity content of ≤0.2%.

[0280] The application of the above oil-soluble heavy oil viscosity reducer in heavy oil production.

[0281] Embodiment 18

[0282] The method is similar to Example 17, except that the preparation process of the mixed solution in step 1 is slightly different:

[0283] Step 1: Add 1 part of copolymer, 2 parts of alcohol, 5 parts of deionized water and 1 part of trialkylamine into a reactor, heat at 50°C until the copolymer is completely dissolved, then add oil-soluble base oil and 1 part of dialkylamine, stir evenly to obtain a mixed solution, wherein:

[0284] The trialkylamine in step 1 is a C6 trialkylamine.

[0285] Embodiment 19

[0286] A method for preparing an oil-soluble heavy oil viscosity reducer, in terms of molar parts, comprises the following steps:

[0287] Step 1: Prepare the mixed solution

[0288] 1 part of copolymer, 5 parts of alcohol, 20 parts of deionized water and 2 parts of dialkylamine were added into a reactor, stirred at 90°C until the copolymer was completely dissolved, and then an oil-soluble base oil was added, and stirred evenly to obtain a mixed solution;

[0289] Step 2: Expel the air in the reactor in step 1, then continue to introduce helium, and under the protection of helium, add 4 parts of carbon disulfide (CS 2) was added dropwise to the mixed solution, and after the addition was completed, the mixture was stirred at 30° C. for 6 h to obtain an oily solution;

[0290] Step 3, heating the oily solution in step 2 to 75° C. and maintaining it for 1.5 h, heating the oily solution to 105° C. and refluxing it for 2.5 h, and then performing reduced pressure distillation to obtain a distillation residue;

[0291] Step 4, heating the distillation residue in step 3 at 150° C. for 1.2 h, and cooling naturally to obtain an intermediate;

[0292] Step 5: Evenly mix the intermediate described in step 4 with a fatty acid ester surfactant in a mass ratio of 100:50 to obtain an oil-soluble heavy oil viscosity reducer.

[0293] Furthermore, the copolymer in step one is propylene-propylene acetate copolymer.

[0294] Further, the dialkylamine in step 1 is a C26 aliphatic diamine. In another embodiment, the dialkylamine in step 1 is a C24 alicyclic diamine.

[0295] Furthermore, the alcohol in step 1 is n-pentanol.

[0296] Furthermore, the amount of the oil-soluble base oil added in step 1 is 500 g / mole based on the molar amount of the copolymer.

[0297] Furthermore, the oil-soluble base oil is mineral oil.

[0298] Furthermore, the mineral oil is cyclohexane oil.

[0299] Furthermore, the rate of adding carbon disulfide in step 2 is 3.0 g / min.

[0300] Furthermore, the specific process conditions of the reduced pressure distillation in step three are: distillation for 10 minutes under a vacuum degree of -0.06 MPa.

[0301] Furthermore, the fatty acid ester surfactant in step five is fatty acid methyl ester.

[0302] An oil-soluble heavy oil viscosity reducer is prepared by any one of the above-mentioned preparation methods of the oil-soluble heavy oil viscosity reducer.

[0303] The oil-soluble heavy oil viscosity reducer prepared in this example has good room temperature stability, and there is no precipitation or stratification after being placed at room temperature of 25° C. for 72 hours.

[0304] The oil-soluble heavy oil viscosity reducer prepared in this embodiment has a heavy oil viscosity reduction rate of >85% at 50° C. and an impurity content of ≤0.2%.

[0305] The application of the above oil-soluble heavy oil viscosity reducer in heavy oil production.

[0306] Embodiment 20

[0307] The method is similar to Example 17, except that the preparation process of the mixed solution in step 1 is slightly different:

[0308] Step 1: Add 1 part of copolymer, 5 parts of alcohol, 20 parts of deionized water and 2 parts of trialkylamine into a reactor, heat at 90°C until the copolymer is completely dissolved, then add oil-soluble base oil and 2 parts of dialkylamine, stir evenly to obtain a mixed solution, wherein:

[0309] The trialkylamine in step 1 is a C9 trialkylamine.

[0310] Embodiment 21

[0311] A method for preparing an oil-soluble heavy oil viscosity reducer, in terms of molar parts, comprises the following steps:

[0312] Step 1: Prepare the mixed solution

[0313] 1 part of copolymer, 3 parts of alcohol, 15 parts of deionized water and 1.5 parts of dialkylamine were added into a reactor, stirred at 60°C until the copolymer was completely dissolved, and then the oil-soluble base oil was added, stirred evenly to obtain a mixed solution;

[0314] Step 2: Expel the air in the reactor in step 1, then continue to introduce neon gas, and under the protection of neon gas, add 3 parts of carbon disulfide (CS 2 ) was added dropwise to the mixed solution, and after the addition was completed, the mixture was stirred at 25° C. for 6 h to obtain an oily solution;

[0315] Step 3, heating the oily solution in step 2 to 65° C. and maintaining it for 1.1 h, heating the oily solution to 100° C. and refluxing it for 2.5 h, and then performing reduced pressure distillation to obtain a distillation residue;

[0316] Step 4, heating the distillation residue in step 3 at 130° C. for 1.5 h, and cooling naturally to obtain an intermediate;

[0317] Step 5: Evenly mix the intermediate described in step 4 with a fatty acid ester surfactant in a mass ratio of 100:30 to obtain an oil-soluble heavy oil viscosity reducer.

[0318] Furthermore, the copolymer in step one is a butene-butylene acetate copolymer.

[0319] Furthermore, the dialkylamine in step 1 is a C20 aliphatic diamine. In another embodiment, the dialkylamine in step 1 is a C20 alicyclic diamine.

[0320] Furthermore, the alcohol in step 1 is n-butanol.

[0321] Furthermore, the amount of the oil-soluble base oil added in step 1 is 300 g / mole based on the molar amount of the copolymer.

[0322] Furthermore, the oil-soluble base oil is mineral oil.

[0323] Furthermore, the mineral oil is cyclohexane oil.

[0324] Furthermore, the rate of adding carbon disulfide in step 2 is 2.0 g / min.

[0325] Furthermore, the specific process conditions of the reduced pressure distillation in step three are: distillation for 30 minutes under a vacuum degree of -0.03 MPa.

[0326] Furthermore, the fatty acid ester surfactant in step five is fatty acid ethylene glycol ester.

[0327] An oil-soluble heavy oil viscosity reducer is prepared by any one of the above-mentioned preparation methods of the oil-soluble heavy oil viscosity reducer.

[0328] The oil-soluble heavy oil viscosity reducer prepared in this example has good room temperature stability, and there is no precipitation or stratification after being placed at room temperature of 25° C. for 72 hours.

[0329] The oil-soluble heavy oil viscosity reducer prepared in this embodiment has a heavy oil viscosity reduction rate of >85% at 50° C. and an impurity content of ≤0.2%.

[0330] The application of the above oil-soluble heavy oil viscosity reducer in heavy oil production.

[0331] Embodiment 22

[0332] The method is similar to Example 17, except that the preparation process of the mixed solution in step 1 is slightly different:

[0333] Step 1: Add 1 part of copolymer, 3 parts of alcohol, 10 parts of deionized water and 1.5 parts of trialkylamine into a reactor, heat at 75°C until the copolymer is completely dissolved, then add oil-soluble base oil and 1.5 parts of dialkylamine, stir evenly to obtain a mixed solution, wherein:

[0334] The trialkylamine in step 1 is a C7 trialkylamine.

[0335] The above describes the embodiments of the present invention in detail. However, the present invention is not limited to the above embodiments, and various changes can be made within the knowledge of ordinary technicians in the relevant technical field without departing from the purpose of the present invention.

Claims

1. An oil-soluble heavy oil viscosity reducer, characterized in that: It is composed of olefin ester copolymer and fatty acid ester surfactant, wherein: The mass ratio of the olefin ester copolymer to the fatty acid ester surfactant is 100:0.5-50.

2. A method for preparing the oil-soluble heavy oil viscosity reducer according to claim 1, characterized in that: In terms of molar parts, the steps are as follows: Step 1: Prepare the mixed solution Add 1 part of copolymer, 2-5 parts of alcohol, 5-20 parts of deionized water and 1-2 parts of dialkylamine into a reactor, stir at 50-90°C until the copolymer is completely dissolved, then add oil-soluble base oil, stir evenly to obtain a mixed solution; or Add 1 part of copolymer, 2-5 parts of alcohol, 5-20 parts of deionized water and 1-2 parts of trialkylamine into a reactor, heat at 50-90° C. until the copolymer is completely dissolved, then add oil-soluble base oil and 1-2 parts of dialkylamine, stir evenly to obtain a mixed solution; Step 2, exhaust the air in the reactor in step 1, then continue to introduce nitrogen or inert gas, under the protection of nitrogen or inert gas, drop 2-4 parts of carbon disulfide into the mixed solution, and stir at 20° C.-30° C. for at least 5 hours after the dropwise addition to obtain an oily solution; Step 3, heating the oily solution in step 2 to 60°C-75°C and maintaining it for at least 1 hour, heating the oily solution to 90°C-105°C and refluxing it for at least 2 hours, and then performing reduced pressure distillation to obtain a distillation residue; Step 4, heating the distillation residue in step 3 at 110° C.-150° C. for at least 1 hour, and cooling naturally to obtain an intermediate; Step 5: Evenly mix the intermediate described in step 4 with a fatty acid ester surfactant in a mass ratio of 100:0.5-50 to obtain an oil-soluble heavy oil viscosity reducer.

3. The method for preparing an oil-soluble heavy oil viscosity reducer according to claim 2, characterized in that: The copolymer in step 1 is one of ethylene-vinyl acetate copolymer, propylene-propylene acetate copolymer and butylene-butylene acetate copolymer.

4. The method for preparing an oil-soluble heavy oil viscosity reducer according to claim 2, characterized in that: The dialkylamine in step 1 is a C16-C26 aliphatic diamine or a C14-C24 alicyclic diamine.

5. The method for preparing an oil-soluble heavy oil viscosity reducer according to claim 2, characterized in that: The trialkylamine in step 1 is a C6-C9 trialkylamine.

6. The method for preparing an oil-soluble heavy oil viscosity reducer according to claim 2, characterized in that: The alcohol in step 1 is n-butanol or n-pentanol.

7. The method for preparing an oil-soluble heavy oil viscosity reducer according to claim 2, characterized in that: The amount of the oil-soluble base oil added in step 1 is 200 g-500 g / mole based on the molar weight of the copolymer.

8. The method for preparing an oil-soluble heavy oil viscosity reducer according to claim 2, characterized in that: The oil-soluble base oil is vegetable oil or mineral oil.

9. The method for preparing an oil-soluble heavy oil viscosity reducer according to claim 8, characterized in that: The vegetable oil is one or more of corn oil, cottonseed oil, peanut oil and soybean oil; The mineral oil is naphthenic oil.

10. The method for preparing an oil-soluble heavy oil viscosity reducer according to claim 2, characterized in that: The rate of adding carbon disulfide in step 2 is 0.1 g / min-3.0 g / min.

11. The method for preparing an oil-soluble heavy oil viscosity reducer according to claim 2, characterized in that: The specific process conditions of the reduced pressure distillation in step 3 are: distillation for 10 min to 100 min under a vacuum degree of -0.099 MPa to -0.06 MPa.

12. The method for preparing an oil-soluble heavy oil viscosity reducer according to claim 2, characterized in that: The fatty acid ester surfactant in step 5 is one or more of fatty acid methyl ester, fatty acid ethylene glycol ester, fatty acid glyceride and fatty acid sucrose ester.

13. An oil-soluble heavy oil viscosity reducer prepared by the preparation method of the oil-soluble heavy oil viscosity reducer according to any one of claims 2 to 12.

14. Use of the oil-soluble heavy oil viscosity reducer according to claim 1 or 13 in heavy oil production.

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