A modified fulvic acid asphaltene inhibitor and preparation method thereof
Through the preparation of modified chlorosulfan asphaltene inhibitors, crosslinked esterification reactions are used to generate inhibitors with excellent inhibitory performance, solving the problem of blockage caused by asphaltene precipitation in the oil field, and achieving effective dispersion and stability of asphaltene.
Patent Information
- Application Number
- CN202411695269.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-25
- Publication Date
- 2025-04-01
AI Technical Summary
When the prior art solves the problem of blockage caused by asphaltene precipitation in oil fields, there are problems such as physical removal method that can only be performed after the blockage occurs, the heat treatment method has strong temperature dependence and may cause formation damage, the microbial method has poor high temperature stability and high cost, and the chemical additive method has limited effect and high cost.
A modified chlorofu acid asphaltene inhibitor is used, which obtains a petroleum asphaltene inhibitor with excellent inhibitory properties by copolymerizing hexadecimal methacrylate, butyl acrylate and styrene, and crosslinking esterification reaction with chlorofu acid through a kneader.
Through the adhesion between asphaltene and modified chlorosulfuric acid, this inhibitor effectively adsorbs asphaltene, inhibits the interaction force between asphaltene molecules, significantly improves the dispersion and stability of asphaltene, and solves the asphaltene precipitation problem in oil field wellbore deblocking.
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Figure CN119735760A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of oilfield plugging relief, in particular to a modified fulvic acid asphaltene inhibitor and a preparation method thereof. Background Art
[0002] With the continuous development of science and technology, the world's demand for energy is increasing, and oil is still the most needed of many forms of energy. With the exploitation of a large amount of light conventional crude oil, the proportion of reserves continues to decline, and the abundant heavy oil has great mining value. Heavy oil is difficult to extract because it contains a large amount of asphaltene, which is the largest component in heavy oil in terms of molecular weight and polarity. Conventional methods cannot effectively solve the problem of large accumulation and precipitation of asphaltene and rapid increase in viscosity, resulting in low oil recovery efficiency. It is necessary to explore and form an ideal precipitation inhibitor to reduce the blockage of asphaltene deposition.
[0003] The methods for removing asphaltene precipitation in domestic and foreign research mainly include physical removal, thermal treatment, microbial method, chemical additives, etc.
[0004] Physical removal is one of the most commonly used methods for removing asphaltene deposits, including scraping with a sucker rod, scraping with a steel wire, and strong negative pressure plugging. Physical removal can only be performed after a plugging occurs and cannot solve the problem at the source. Thermal methods for plugging removal mainly include injecting liquid (steam and hot water / gas / oil), setting up downhole heaters, increasing heat release, etc., the purpose of which is to increase the solubility of solid deposits and disperse them in the oil phase.
[0005] The disadvantage of the thermodynamic method is that as the temperature decreases, the solid particles may settle again, the deblocking effect is limited by the capacity of the equipment, and sometimes it may cause formation damage.
[0006] Biological plugging removal is to use anaerobic / aerobic bacteria or microorganisms (such as fungi) to biodegrade asphaltene deposits and convert asphaltene into light hydrocarbons to achieve the purpose of plugging removal. However, there are also some disadvantages, such as poor microbial stability at high temperatures and high heavy metal content; the microbial process is slow and difficult to control, and it is prone to corrosion.
[0007] Chemical deplugging is one of the most common methods for deasphalting. Generally, some surfactants containing benzene rings are added to disperse asphaltene precipitation, but the effect is minimal. When ionic liquids are added, the asphaltene particles are significantly smaller and more uniform, but the price is higher. Natural fatty acids can also be used as asphaltene precipitation inhibitors, but they are used in higher concentrations. Summary of the invention
[0008] The technical problems to be solved by the present invention are that the physical removal method can only be carried out after blockage occurs and cannot be prevented; the thermal treatment method has strong temperature dependence and equipment limitations and may cause formation damage; the microbial method has poor high-temperature stability, high heavy metal content, slow and difficult to control process, and is prone to corrosion; the chemical additive method has limited effect, high cost, and requires high concentration use.
[0009] The technical scheme adopted by the present invention is: a modified fulvic acid asphaltene inhibitor, comprising fulvic acid, hexadecyl methacrylate, butyl acrylate and styrene copolymer, and styrene-methacrylate polymer; fulvic acid is selected as a raw material, hexadecyl methacrylate, butyl acrylate and styrene are firstly copolymerized, and the styrene-methacrylate polymer and fulvic acid are subjected to cross-linking esterification reaction by a kneader to obtain styrene-acrylic acid cross-linking copolymer modified fulvic acid, thereby obtaining a petroleum asphaltene inhibitor with excellent inhibition performance.
[0010] A method for preparing a modified fulvic acid asphaltene inhibitor comprises the following steps:
[0011] S1: Add a certain amount of 5% PVA1788 solution to a reaction bottle, add a certain amount of water, heat to a certain temperature and stir for a period of time to foam, stir and mix hexadecyl methacrylate, butyl acrylate and styrene, add them to the reaction bottle, continue stirring for a period of time, heat to a certain temperature and add initiator, set a certain stirring speed and then conduct polymerization reaction. After the reaction is completed, filter with a filter of a certain mesh and wash with water. Centrifuge and dry the obtained product to obtain styrene-methacrylate polymer;
[0012] S2: Styrene-methacrylate polymer, fulvic acid, crosslinking agent and a small amount of solvent are mixed evenly, added into a small kneader, a catalyst is added, and the kneader is turned on after heating to a set temperature. After kneading for a period of time, the product is poured out, washed with water, centrifuged, dried, and ground into fine powder of a certain mesh size to obtain styrene-methacrylate crosslinked copolymer modified fulvic acid asphaltene inhibitor.
[0013] As a further solution of the present invention: in S1, the mass ratio of 5% PVA1788 solution, water, hexadecyl methacrylate, butyl acrylate and styrene is 5:45:15:(1.5-2.2):1.5.
[0014] As a further solution of the present invention: in the S1, 5% PVA1788 solution and water are added and stirred at a temperature of 40-50°C for 10-15 minutes; and the mixed monomer is added and stirred for 10-15 minutes.
[0015] As a further solution of the present invention: in S1, the temperature of adding the initiator and raising the temperature is 70-80°C, and the initiator is azobisisobutyronitrile.
[0016] As a further solution of the present invention: in S1, the stirring temperature is 70°C to 80°C; the reaction time of the polymerization reaction is 3 to 6 hours; the mesh size of the filter for filtering the product is 150-200 mesh, and the drying temperature is room temperature 20-25°C.
[0017] As a further solution of the present invention: in S2, the solvent is one of ethyl acetate, butyl acetate and ethanol.
[0018] As a further solution of the present invention: in S2, the mass ratio of the styrene-methylacrylate polymer, fulvic acid, and cross-linking agent is 1.2: (1.4-1.8): 0.05.
[0019] As a further solution of the present invention: in S2, the cross-linking agent is 1,4-BDDMA, the catalyst is concentrated sulfuric acid; the temperature of the kneading machine is set at 50-65°C, the speed of the kneading machine is 25-35r / min; and the kneading time is 1.5-2h.
[0020] As a further solution of the present invention: in S2, the water washing is performed 2 to 3 times; and the final product is ground to a mesh size of 80-120.
[0021] Beneficial effects of the present invention:
[0022] The invention provides a method for preparing an asphaltene inhibitor based on modified fulvic acid. The method selects fulvic acid as a raw material, firstly copolymerizes hexadecyl methacrylate, butyl acrylate and styrene, and then crosslinks and esterifies styrene-methacrylate polymer with fulvic acid through a kneader to obtain styrene-acrylic acid crosslinked copolymer modified fulvic acid, thereby obtaining a petroleum asphaltene inhibitor with excellent inhibitory performance.
[0023] The fulvic acid modified by cross-linking copolymerization of styrene-methacrylate polymers of the present invention can be used as a new type of petroleum asphaltene inhibitor in oil field wellbore unblocking. Its inhibition mechanism lies in the affinity between asphaltene and modified fulvic acid. The modified fulvic acid has a large number of lipophilic groups, which can effectively adsorb asphaltene and inhibit the interaction between asphaltene molecules. The asphaltene inhibitor product has good dispersibility and stability. BRIEF DESCRIPTION OF THE DRAWINGS
[0024] Figure 1 The invention discloses a styrene-methylacrylate polymer of a modified fulvic acid asphaltene inhibitor and a preparation method thereof. DETAILED DESCRIPTION
[0025] The present invention will be further described below.
[0026] A modified fulvic acid asphaltene inhibitor comprises fulvic acid, hexadecyl methacrylate, butyl acrylate and styrene copolymer, and styrene-methacrylate polymer. The fulvic acid is selected as a raw material, hexadecyl methacrylate, butyl acrylate and styrene are firstly copolymerized, and the styrene-methacrylate polymer and the fulvic acid are subjected to cross-linking esterification reaction by a kneader to obtain styrene-acrylic acid cross-linking copolymer modified fulvic acid, thereby obtaining a petroleum asphaltene inhibitor with excellent inhibitory performance.
[0027] The fulvic acid modified by cross-linking copolymerization of styrene-methacrylate polymer of the present invention can be used as a new type of petroleum asphaltene inhibitor in oil field wellbore unblocking. Its inhibition mechanism lies in the affinity between asphaltene and modified fulvic acid. The modified fulvic acid has a large number of lipophilic groups, which can effectively adsorb asphaltene and inhibit the interaction between asphaltene molecules. The asphaltene inhibitor product has good dispersibility and stability.
[0028] A method for preparing an asphaltene inhibitor based on modified fulvic acid comprises the following steps:
[0029] A certain amount of 5% PVA1788 aqueous solution was added into a 250ml four-necked flask with a reflux condenser and a probe thermometer, and the temperature was raised to 45°C and stirred continuously for 10-15min. Three monomers, hexadecyl methacrylate, butyl acrylate and styrene, were added into a 100ml beaker and mixed evenly, and then added into a 250ml four-necked flask, and stirred and heated to 70°C-80°C to make them dispersed evenly, and then the initiator was added. The stirring speed was set to 200r / min, and the polymerization reaction was carried out for 3-6h. After the polymerization reaction was completed, the sample was filtered through a 150-200 mesh filter, rinsed with water 2-3 times, and then dried at room temperature. After drying, milky white small particles of styrene-methacrylate polymer were obtained.
[0030] Then, a certain amount of the above-mentioned styrene-methacrylate polymer, fulvic acid, 1,4BDDMA and solvent were added to a small kneader with a volume of 500 ml, mixed evenly, and concentrated sulfuric acid was added as a catalyst. The temperature was set to 50-65°C, the kneader speed was 25-35r / min, and the kneading time was 1.5-2h. After 2-3 times of water washing, centrifugation was performed, and drying was performed at room temperature to obtain a styrene-methacrylate copolymer modified fulvic acid asphaltene inhibitor.
[0031] Example 1
[0032] Add 45g 5% PVA1788 and 150g aqueous solution into a 500ml four-necked flask with a reflux condenser and a probe thermometer, heat to 45°C and continue stirring for 15min, add 15g hexadecyl methacrylate, 5g butyl acrylate and 5g styrene into a 100ml beaker, mix well and add into a 500ml four-necked flask, stir and heat to 75°C to make it dispersed evenly, add 1.4g azobisisobutyronitrile as initiator, set the stirring speed to 200r / min, carry out polymerization reaction for 6h, filter the sample with a 200-mesh filter after the polymerization reaction, rinse with water 3 times and dry at room temperature, and obtain milky white small granular styrene-methacrylate polymer after drying.
[0033] Then, 50g of the above styrene-methacrylate polymer, 70g of fulvic acid, 0.45g of 1,4BDDMA and 100g of ethanol were added to a small kneader with a volume of 500ml, mixed evenly, and 5g of concentrated sulfuric acid was added as a catalyst. The temperature was set to 60°C, the kneader speed was 25r / min, and the kneading time was 2h. After kneading, the product was poured out, washed with water 3 times, and then centrifuged in a centrifuge and dried at room temperature to obtain a styrene-methacrylate copolymer modified fulvic acid asphaltene inhibitor.
[0034] Example 2
[0035] Add 45g 5% PVA1788 and 150g aqueous solution into a 500ml four-necked flask with a reflux condenser and a probe thermometer, heat to 45°C and continue stirring for 15min, add 15g hexadecyl methacrylate, 6g butyl acrylate and 5g styrene into a 100ml beaker, mix well and add into a 500ml four-necked flask, stir and heat to 70°C to make it dispersed evenly, add 1.4g azobisisobutyronitrile as initiator, set the stirring speed to 150r / min, carry out polymerization reaction for 5h, filter the sample with a 150-mesh filter after the polymerization reaction, rinse with water 3 times and dry at room temperature, and obtain milky white small granular styrene-methacrylate polymer after drying.
[0036] Then, 50g of the above styrene-methacrylate polymer, 80g of fulvic acid, 0.45g of 1,4BDDMA and 120g of ethyl acetate were added to a small kneader with a volume of 500ml, mixed evenly, and 5g of concentrated sulfuric acid was added as a catalyst. The temperature was set to 65°C, the kneader speed was 35r / min, and the kneading time was 2h. After kneading, the product was poured out, washed with water twice, and then centrifuged in a centrifuge and dried at room temperature to obtain a styrene-methacrylate copolymer modified fulvic acid asphaltene inhibitor.
[0037] Example 3
[0038] Add 45g 5% PVA1788 and 150g aqueous solution into a 500ml four-necked flask with a reflux condenser and a probe thermometer, heat to 45°C and continue stirring for 10min, add 15g hexadecyl methacrylate, 6g butyl acrylate and 5g styrene into a 100ml beaker, mix well and add into a 500ml four-necked flask, stir and heat to 70°C to make it dispersed evenly, add 1.4g azobisisobutyronitrile as initiator, set the stirring speed to 2000r / min, carry out polymerization reaction for 6h, filter the sample with a 200-mesh filter after the polymerization reaction, rinse with water 3 times and dry at room temperature, and obtain milky white granular styrene-methacrylate polymer after drying.
[0039] Then, 50g of the above styrene-methacrylate polymer, 80g of fulvic acid, 0.45g of 1,4BDDMA and 120g of butyl acetate were added to a small kneader with a volume of 500ml, and after being mixed evenly, 5g of concentrated sulfuric acid was added as a catalyst, and the temperature was set to 60°C, the kneader speed was 30r / min, and the kneading time was 1.5h. After kneading, the product was poured out, washed with water 3 times, and then centrifuged in a centrifuge and dried at room temperature to obtain a styrene-methacrylate copolymer modified fulvic acid asphaltene inhibitor.
[0040] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features thereof may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.
Claims
1. A modified fulvic acid asphaltene inhibitor, characterized in that: The invention comprises fulvic acid, hexadecyl methacrylate, butyl acrylate and styrene copolymer, and styrene-methacrylate polymer. fulvic acid is selected as the raw material, hexadecyl methacrylate, butyl acrylate and styrene are copolymerized firstly, and the styrene-methacrylate polymer and fulvic acid are cross-linked and esterified by a kneader to obtain styrene-acrylic acid cross-linked copolymer modified fulvic acid, thereby obtaining a petroleum asphaltene inhibitor with excellent inhibitory performance.
2. A method for preparing a modified fulvic acid asphaltene inhibitor, characterized in that: The following steps are involved: S1: Add 5% PVA1788 solution to a reaction bottle, add water, heat and stir to produce bubbles, stir and mix hexadecyl methacrylate, butyl acrylate and styrene, add to the reaction bottle, continue stirring, add initiator after heating, set the stirring speed and carry out polymerization reaction; after the reaction is completed, filter with a filter and wash with water; centrifuge and dry the obtained product to obtain styrene-methacrylate polymer; S2: Evenly mix styrene-methacrylate polymer, fulvic acid, crosslinking agent and solvent, add into a small kneader, add catalyst, start the kneader after heating, pour out the product after kneading, wash with water, centrifuge, dry, grind into fine powder, and obtain styrene-methacrylate crosslinked copolymer modified fulvic acid asphaltene inhibitor.
3. The method for preparing a modified fulvic acid asphaltene inhibitor according to claim 2, characterized in that: In the S1, the mass ratio of 5% PVA1788 solution, water, hexadecyl methacrylate, butyl acrylate and styrene is 5:45:15:(1.5-2.2):1.
5.
4. The method for preparing a modified fulvic acid asphaltene inhibitor according to claim 2, characterized in that: In the S1, 5% PVA1788 solution and water are added and stirred at 40-50°C for 10-15 minutes; and mixed monomers are added and stirred for 10-15 minutes.
5. The method for preparing a modified fulvic acid asphaltene inhibitor according to claim 2, characterized in that: In S1, the temperature of adding the initiator and raising the temperature is 70-80° C., and the initiator is azobisisobutyronitrile.
6. The method for preparing a modified fulvic acid asphaltene inhibitor according to claim 2, characterized in that: In S1, the stirring temperature is 70°C to 80°C; the reaction time of the polymerization reaction is 3 to 6 hours; the mesh number of the filter screen for product filtration is 150-200 mesh, and the drying temperature is room temperature 20-25°C.
7. The method for preparing a modified fulvic acid asphaltene inhibitor according to claim 2, characterized in that: In the S2, the solvent is one of ethyl acetate, butyl acetate and ethanol.
8. The method for preparing a modified fulvic acid asphaltene inhibitor according to claim 2, characterized in that: In S2, the mass ratio of the styrene-methacrylate polymer, fulvic acid, and cross-linking agent is 1.2:(1.4-1.8):0.
05.
9. The method for preparing a modified fulvic acid asphaltene inhibitor according to claim 2, characterized in that: In S2, the cross-linking agent is 1,4-BDDMA, the catalyst is concentrated sulfuric acid; the temperature of the kneader is set at 50-65° C., the kneader speed is 25-35 r / min; and the kneading time is 1.5-2 h.
10. The method for preparing a modified fulvic acid asphaltene inhibitor according to claim 2, characterized in that: In S2, the water washing is performed 2 to 3 times; and the final product is ground to a mesh size of 80-120.