Oil-based paraffin remover and inhibitor and preparation method thereof

Abstract

The invention relates to the technical field of oil-based paraffin removal and inhibition, and discloses an oil-based paraffin removal and inhibition agent and a preparation method thereof, dimethylbenzene has rapid dissolving capacity and large saturated paraffin dissolving amount, similar dissolution of wax can be realized, and a molecular structure of a polyacrylate pour point and viscosity reducer has two long-chain lipophilic groups and a sodium sulfonate hydrophilic group at the same time, so that the oil-based paraffin removal and inhibition agent is prepared. The structure of the oleophylic group is similar to that of paraffin, and the oleophylic group can be co-crystallized with paraffin to inhibit continuous growth of wax crystals; hydrophilic groups extend outside, so that paraffin separated out is prevented from being combined with the hydrophilic groups to form a three-dimensional network structure, wax crystals are prevented from being mutually bonded, and the paraffin control and removal effects are further achieved; the polyacrylate pour-point-depressing and viscosity-reducing agent has good solubility in crude oil, and alkyl side chains of the polyacrylate pour-point-depressing and viscosity-reducing agent can fully act with paraffin in the crude oil, so that the structural form of wax crystals is changed, the flowing space of liquid oil is increased, the flowing resistance of the crude oil is reduced, and the pour-point-depressing and viscosity-reducing effects on the crude oil are achieved.

Description

Technical Field

[0001] The invention relates to the technical field of oil-based wax removal and prevention, in particular to an oil-based wax removal and prevention agent and a preparation method thereof. Background Art

[0002] Waxing of crude oil is a common phenomenon. During the oil production process, wax in crude oil continuously precipitates and grows in the form of crystals and is deposited in downhole equipment, seriously affecting the normal production of oil wells. It may even cause serious problems such as pipe string jamming and ground pipeline blockage, causing many inconveniences to crude oil production and construction operations, and seriously reducing the production of oil and natural gas. Severe wax deposition in the wellbore leads to frequent on-site wax cleaning operations and high operating costs, which greatly increases the cost of crude oil production. Therefore, it is urgent to develop a wax cleaning and wax prevention agent that has both wax cleaning and wax prevention effects to effectively solve the problem of wax deposition in the wellbore.

[0003] In order to inhibit and remove the deposited paraffin, people have used various methods to deal with the deposited wax. The wax removal and prevention technologies currently developed and used at home and abroad mainly include mechanical wax removal technology, heating wax removal and prevention technology, lined oil pipe wax prevention technology, chemical wax removal and prevention technology, etc. Among them, the chemical wax removal and prevention method can change the total amount of wax in crude oil and inject it from the annular space of the oil casing without affecting the normal production of the oil well and other operations; currently, certain agents are used in the use of chemical wax removal and prevention technology to produce viscosity reduction and unblocking effects; chemical wax removal and prevention agents mainly include oil-based wax removal and prevention agents, water-based wax removal and prevention agents, and emulsion wax removal and prevention agents, among which emulsion wax removal agents must have stable preparation and storage conditions. The water-based wax remover and wax inhibitor have to be demulsified immediately after reaching the bottom of the well, otherwise it will not have the effect of wax removal and prevention. The water-based wax remover and wax inhibitor is slow to take effect after being added to the oil well, and its fluidity is poor when used in the severe winter. The oil-based wax remover and wax inhibitor is widely used in domestic chemical wax removal and prevention technology due to its strong adaptability to crude oil, fast wax dissolving speed, fast effect after being added to the oil well, low product solidification point, and convenient use in winter. It is the most actively studied wax remover and wax inhibitor. However, the oil-based wax remover and wax inhibitor currently generally has the problem of single performance. The commonly used solvents with good wax removal performance are mainly carbon disulfide, carbon tetrachloride and other substances, but these solvents have the problems of high toxicity, low flash point, and easy to cause poisoning of oil refining catalysts.

[0004] The invention synthesizes a polyacrylate pour point and viscosity reducer containing both a hydrophilic group and a lipophilic group, wherein the lipophilic group forms a eutectic with paraffin, and the paraffin precipitated after the hydrophilic group is blocked combines with the paraffin to form a three-dimensional network structure, and compounding an oil-based wax removing and preventing agent solvent and an auxiliary agent to obtain an oil-based wax removing and preventing agent with a fast wax dissolving rate, which does not contain harmful substances such as organic chlorine and carbon disulfide, has high wax prevention efficiency and is environmentally friendly. Summary of the invention

[0005] The purpose of the present invention is to overcome the shortcomings of the prior art, provide an oil-based wax removal and prevention agent and a preparation method, solve the problem of poor wax removal and prevention effect in the prior art, and further play a role in reducing the freezing point and viscosity of crude oil.

[0006] To achieve the above object, the technical solution adopted by the present invention is: An oil-based wax remover and wax inhibitor comprises the following components in parts by weight: 70-99 parts of xylene, 10-35 parts of straight-run gasoline, 2-10 parts of mutual solvents, 0.5-5 parts of surfactants, 1-15 parts of polyacrylate pour point and viscosity reducers, and 0.1-0.5 parts of quick penetrants.

[0007] The preparation method of the polyacrylate pour point and viscosity reducing agent comprises the following steps: (1) Add sodium 3-chloro-2-hydroxypropyl sulfonate, ethanol and deionized water to a reaction flask equipped with a reflux condenser, stir evenly, then add allylamine hydrochloride and sodium carbonate, stir to react, and after the reaction is completed, cool to room temperature, filter, recrystallize from ethanol, and dry to obtain sodium 3-(allylamino)-2-hydroxypropane-1-sulfonate. The preparation process is as follows:

[0008] (2) Add sodium 3-(allylamino)-2-hydroxypropane-1-sulfonate and toluene to a reaction flask equipped with a reflux condenser and a water separator, stir evenly, add triethylamine and long-chain alkyl acyl chloride, heat to 105-120°C and react for 8-14 hours. When no water is produced in the water separator, cool, extract and separate, concentrate the organic phase to obtain sodium olefin sulfonate acrylate monomer. The preparation process is as follows:

[0009] (3) Add sodium olefin sulfonate acrylate monomer and toluene to a reaction flask equipped with a reflux condenser, stir evenly, then add N,N'-methylenebisacrylamide and initiator ammonium persulfate, stir to react, and after the reaction is completed, cool to room temperature and concentrate to obtain a polyacrylate pour point and viscosity reducer.

[0010] Furthermore, in step (1), the ratio of sodium 3-chloro-2-hydroxypropyl sulfonate, allylamine hydrochloride, and sodium carbonate is 1 mol: (1.05-1.2) mol: (2.5-4) mol.

[0011] Furthermore, in step (1), the reaction temperature is 75-90° C. and the reaction time is 8-16 h.

[0012] Furthermore, in step (2), the long-chain alkyl acyl chloride is any one of palmitoyl chloride, heptadecanoyl chloride, stearyl chloride and nonadecanoyl chloride.

[0013] Furthermore, in step (2), the ratio of sodium 3-(allylamino)-2-hydroxypropane-1-sulfonate, triethylamine, and long-chain alkyl acyl chloride is 1 mol: (2.1-2.2) mol: (2.2-2.5) mol.

[0014] Furthermore, in step (3), the ratio of sodium olefin sulfonate acrylate monomer, N,N'-methylenebisacrylamide, and ammonium persulfate is 1 mol: (0.03-0.06) mol: (0.02-0.05) mol.

[0015] Furthermore, in step (3), the reaction temperature is 60-80° C. and the reaction time is 4-10 h.

[0016] Furthermore, the mutual solvent is ethylene glycol monobutyl ether or diethylene glycol ethyl ether.

[0017] Furthermore, the surfactant is OP-10; and the rapid penetrating agent is polyoxyethylene octanol ether.

[0018] Further, xylene, straight-run gasoline, mutual solvent and surfactant are added to the reaction bottle, stirred at a temperature of 20-35°C and a rotation speed of 600-1000r / min for 10-30min, and after uniform dispersion, a quick penetrant is added, stirring is continued for 5-20min, and then a polyacrylate pour point and viscosity reducer is added, stirred evenly, to obtain an oil-based wax remover and inhibitor.

[0019] By adopting the above technical solution, the beneficial effects of the present invention are: The invention firstly reacts sodium 3-chloro-2-hydroxypropyl sulfonate and allylamine hydrochloride under the action of sodium carbonate to obtain sodium 3-(allylamino)-2-hydroxypropane-1-sulfonate, then uses the hydroxyl group of sodium 3-(allylamino)-2-hydroxypropane-1-sulfonate and long-chain alkyl chloride to undergo esterification reaction under the action of triethylamine to obtain sodium olefin sulfonate acrylate monomer, then undergoes polymerization reaction under the action of initiator ammonium persulfate and cross-linking agent N,N'-methylenebisacrylamide to obtain polyacrylate pour point and viscosity reducer, and finally compounded with xylene, straight-run gasoline, mutual solvent and penetrant to obtain oil-based wax remover and inhibitor.

[0020] Polyacrylate pour point and viscosity reducer is a comb-shaped polymer, and its molecular structure has two long-chain lipophilic groups and sodium sulfonate hydrophilic groups. The structure of the lipophilic group is similar to that of paraffin, and can form a eutectic with paraffin, so that the wax crystals will not continue to grow. The hydrophilic group is extended outside, hindering the paraffin precipitated later from combining with it to form a three-dimensional network structure, which can prevent the wax crystals from sticking to each other, change the spatial network structure and wax crystal morphology of wax crystals in the oil phase, reduce the adsorption of wax crystals, and further play a wax-proof role; at the same time, the molecular chain of polyacrylate pour point and viscosity reducer is relatively long, which spreads throughout the entire oil phase, and can make the formed crystal nuclei in a dispersed state to prevent the wax crystals from growing further; in addition, the polyacrylate pour point and viscosity reducer has a structural unit similar to that of wax crystals, and has good solubility in crude oil. The alkyl side chain on the molecular chain can fully react with the paraffin in the crude oil to make the molecular chain more extended, and can produce adsorption eutectic with wax crystals, thereby changing the structural morphology of the wax crystals, increasing the flow space of liquid oil, and reducing the flow resistance of crude oil, thereby playing a pour point and viscosity reducing role, and facilitating the smooth progress of mining work.

[0021] The 2-octanol polyoxyethylene ether penetrant added to the wax removal and prevention agent has a very strong penetrating effect. After being added, the wax removal and prevention agent can fully contact and react with the wax crystals in the crude oil and wax sample, dissolve and disperse the deposited wax, and at the same time, it can be adsorbed on the surface of the wax crystals during the precipitation and growth stage of the wax crystals to prevent the wax crystals from continuing to grow and deposit, playing a certain anti-wax effect; according to the "like dissolves like" principle, wax crystals can be dissolved in the polyacrylate degreasing and viscosity reducing agent, xylene has fast dissolving ability and a large saturated wax dissolving capacity, which can achieve "like dissolves like" for wax, and the mutual solvent can make the various components in the wax removal and prevention agent dissolve well in the wax solvent, so that it can better contact and react with the wax in the crude oil, thereby accelerating the wax dissolution rate and improving the wax removal effect of the wax removal agent; at the same time, the surfactant has a strong emulsifying ability, which can achieve emulsification reversal viscosity reduction and reduce the viscosity of crude oil. DETAILED DESCRIPTION

[0022] In order to more clearly understand the above-mentioned purpose, features and advantages of the present invention, the present invention is further described in detail below in conjunction with specific embodiments. It should be noted that the embodiments of the present application and the features in the embodiments can be combined with each other without conflict.

[0023] Sodium 3-chloro-2-hydroxypropane sulfonate, CAS number is 126-83-0.

[0024] Palmitoyl chloride, CAS number is 112-67-4.

[0025] Heptadecanoyl chloride, CAS number is 40480-10-2.

[0026] Stearoyl chloride, CAS number is 112-76-5.

[0027] Nonadecanoyl chloride, CAS number is 59410-47-8.

[0028] Straight-run gasoline, No. 120 solvent gasoline.

[0029] Example 1 (1) Add 20 mmol of sodium 3-chloro-2-hydroxypropylsulfonate, 150 mL of ethanol and 15 mL of deionized water to a reaction flask equipped with a reflux condenser. After stirring evenly, add 22 mmol of allylamine hydrochloride and 60 mmol of sodium carbonate. React at 85 °C for 12 h, cool to room temperature, filter, recrystallize from ethanol, and dry to obtain sodium 3-(allylamino)-2-hydroxypropane-1-sulfonate.

[0030] (2) Add 15 mmol of sodium 3-(allylamino)-2-hydroxypropane-1-sulfonate and 180 mL of toluene to a reaction flask equipped with a reflux condenser and a water separator, stir evenly, then add 32.4 mmol of triethylamine and 35.4 mmol of palmitoyl chloride, heat to 115°C and react for 12 h. When no water is produced in the water separator, cool, extract and separate the liquids, and concentrate the organic phase to obtain sodium olefin sulfonate acrylate monomer.

[0031] (3) Add 5 mmol of sodium olefin sulfonate acrylate monomer and 110 mL of toluene to a reaction flask equipped with a reflux condenser, stir evenly, then add 0.25 mmol of N,N'-methylenebisacrylamide and 0.2 mmol of initiator ammonium persulfate, react at 75 °C for 7 h, cool to room temperature, and concentrate to obtain a polyacrylate pour point and viscosity reducer.

[0032] (4) Add 99 g of xylene, 10 g of straight-run gasoline, 2 g of ethylene glycol monobutyl ether and 0.5 g of OP-10 into a reaction bottle and stir at 25 °C and 800 r / min for 25 min. After uniform dispersion, add 0.2 g of JFC-2 penetrant, continue stirring for 10 min, then add 1 g of polyacrylate pour point and viscosity reducer and stir evenly to obtain an oil-based paraffin remover and inhibitor.

[0033] Example 2 (1) Add 80 mmol of sodium 3-chloro-2-hydroxypropylsulfonate, 400 mL of ethanol and 40 mL of deionized water to a reaction flask equipped with a reflux condenser. After stirring evenly, add 84 mmol of allylamine hydrochloride and 200 mmol of sodium carbonate. React at 90 °C for 8 h, cool to room temperature, filter, recrystallize from ethanol, and dry to obtain sodium 3-(allylamino)-2-hydroxypropane-1-sulfonate.

[0034] (2) Add 50 mmol of sodium 3-(allylamino)-2-hydroxypropane-1-sulfonate and 500 mL of toluene to a reaction flask equipped with a reflux condenser and a water separator, stir evenly, then add 105 mmol of triethylamine and 110 mmol of heptadecanoyl chloride, heat to 120°C and react for 8 h. When no water is produced in the water separator, cool, extract and separate the liquids, concentrate the organic phase to obtain sodium olefin sulfonate acrylate monomer.

[0035] (3) Add 25 mmol of sodium olefin sulfonate acrylate monomer and 500 mL of toluene to a reaction flask equipped with a reflux condenser, stir evenly, then add 0.75 mmol of N,N'-methylenebisacrylamide and 0.5 mmol of initiator ammonium persulfate, react at 80 °C for 4 h, cool to room temperature, and concentrate to obtain a polyacrylate pour point and viscosity reducer.

[0036] (4) Add 95 g of xylene, 15 g of straight-run gasoline, 4 g of diethylene glycol ethyl ether and 1.5 g of OP-10 into a reaction bottle, stir at 35 °C and 1000 r / min for 10 min. After uniform dispersion, add 0.2 g of JFC-2 penetrant, continue stirring for 5 min, then add 5 g of polyacrylate pour point and viscosity reducer, stir evenly, and obtain an oil-based paraffin remover and inhibitor.

[0037] Example 3 (1) Add 15 mmol of sodium 3-chloro-2-hydroxypropyl sulfonate, 150 mL of ethanol and 15 mL of deionized water to a reaction flask equipped with a reflux condenser. After stirring, add 18 mmol of allylamine hydrochloride and 60 mmol of sodium carbonate. React at 75 °C for 16 h, cool to room temperature, filter, recrystallize from ethanol, and dry to obtain sodium 3-(allylamino)-2-hydroxypropane-1-sulfonate.

[0038] (2) Add 30 mmol of sodium 3-(allylamino)-2-hydroxypropane-1-sulfonate and 450 mL of toluene to a reaction flask equipped with a reflux condenser and a water separator, stir evenly, then add 66 mmol of triethylamine and 75 mmol of stearyl chloride, heat to 105°C and react for 14 h. When no water is produced in the water separator, cool, extract and separate the liquids, and concentrate the organic phase to obtain sodium olefin sulfonate acrylate monomer.

[0039] (3) Add 8 mmol of sodium olefin sulfonate acrylate monomer and 200 mL of toluene to a reaction flask equipped with a reflux condenser, stir evenly, then add 0.48 mmol of N,N'-methylenebisacrylamide and 0.4 mmol of initiator ammonium persulfate, react at 60 °C for 10 h, cool to room temperature, and concentrate to obtain a polyacrylate pour point and viscosity reducer.

[0040] (4) Add 85 g of xylene, 25 g of straight-run gasoline, 6 g of diethylene glycol ethyl ether and 3 g of OP-10 into a reaction bottle, stir at 20 °C and 600 r / min for 30 min. After uniform dispersion, add 0.3 g of octanol polyoxyethylene ether JFC-2 penetrant and continue stirring for 20 min. Then, add 8 g of polyacrylate pour point and viscosity reducer and stir evenly to obtain an oil-based paraffin remover and inhibitor.

[0041] Example 4 (1) In a reaction flask equipped with a reflux condenser, 14 mmol of sodium 3-chloro-2-hydroxypropylsulfonate, 112 mL of ethanol and 10 mL of deionized water were added and stirred evenly. Then, 16.1 mmol of allylamine hydrochloride and 49 mmol of sodium carbonate were added and reacted at 80 °C for 15 h. The mixture was cooled to room temperature, filtered, recrystallized from ethanol and dried to obtain sodium 3-(allylamino)-2-hydroxypropane-1-sulfonate.

[0042] (2) Add 10 mmol of sodium 3-(allylamino)-2-hydroxypropane-1-sulfonate and 130 mL of toluene to a reaction flask equipped with a reflux condenser and a water separator, stir evenly, then add 21.2 mmol of triethylamine and 24 mmol of nonadecanoyl chloride, heat to 110° C. and react for 12 h. When no water is produced in the water separator, cool, extract and separate the liquids, and concentrate the organic phase to obtain sodium olefin sulfonate acrylate monomer.

[0043] (3) Add 30 mmol of sodium olefin sulfonate acrylate monomer and 660 mL of toluene to a reaction flask equipped with a reflux condenser, stir evenly, then add 1.56 mmol of N,N'-methylenebisacrylamide and 1.35 mmol of initiator ammonium persulfate, react at 75 °C for 10 h, cool to room temperature, and concentrate to obtain a polyacrylate pour point and viscosity reducer.

[0044] (4) Add 75 g of xylene, 30 g of straight-run gasoline, 8 g of ethylene glycol monobutyl ether and 4 g of OP-10 into a reaction bottle and stir at 25 °C and 850 r / min for 15 min. After uniform dispersion, add 0.4 g of JFC-2 penetrant, continue stirring for 10 min, then add 11 g of polyacrylate pour point and viscosity reducer and stir evenly to obtain an oil-based paraffin remover and inhibitor.

[0045] Example 5 (1) Add 5 mmol of sodium 3-chloro-2-hydroxypropylsulfonate, 45 mL of ethanol and 5 mL of deionized water to a reaction flask equipped with a reflux condenser. After stirring, add 5.9 mmol of allylamine hydrochloride and 19 mmol of sodium carbonate. React at 85 °C for 12 h, cool to room temperature, filter, recrystallize from ethanol, and dry to obtain sodium 3-(allylamino)-2-hydroxypropane-1-sulfonate.

[0046] (2) Add 3 mmol of sodium 3-(allylamino)-2-hydroxypropane-1-sulfonate and 39 mL of toluene to a reaction flask equipped with a reflux condenser and a water separator, stir evenly, add 6.6 mmol of triethylamine and 7.2 mmol of stearyl chloride, heat to 110°C and react for 14 h. When no water is produced in the water separator, cool, extract and separate the liquids, and concentrate the organic phase to obtain sodium olefin sulfonate acrylate monomer.

[0047] (3) Add 15 mmol of sodium olefin sulfonate acrylate monomer and 300 mL of toluene to a reaction flask equipped with a reflux condenser, stir evenly, then add 0.73 mmol of N,N'-methylenebisacrylamide and 0.75 mmol of initiator ammonium persulfate, react at 80 °C for 7 h, cool to room temperature, and concentrate to obtain a polyacrylate pour point and viscosity reducer.

[0048] (4) Add 70 g of xylene, 35 g of straight-run gasoline, 10 g of ethylene glycol monobutyl ether and 5 g of OP-10 into a reaction bottle, stir at 35 °C and 900 r / min for 25 min. After uniform dispersion, add 0.5 g of JFC-2 penetrant, continue stirring for 15 min, then add 15 g of polyacrylate pour point and viscosity reducer, stir evenly, and obtain an oil-based paraffin remover and inhibitor.

[0049] Comparative Example 1 Add 99g of xylene, 10g of straight-run gasoline, 2g of ethylene glycol monobutyl ether and 0.5g of OP-10 into a reaction bottle, stir at a temperature of 25°C and a rotation speed of 800r / min for 25min, and after uniform dispersion, add 0.2g of octanol polyoxyethylene ether JFC-2 penetrant, continue stirring for 10min, and after uniform stirring, obtain an oil-based paraffin remover and inhibitor.

[0050] Comparative Example 2 (1) To a reaction flask equipped with a reflux condenser, 5 mmol of sodium 3-(allylamino)-2-hydroxypropane-1-sulfonate (prepared in Example 1) and 110 mL of toluene were added, and after stirring evenly, 0.25 mmol of N,N'-methylenebisacrylamide and 0.2 mmol of initiator ammonium persulfate were added, and the mixture was reacted at 75°C for 7 h, cooled to room temperature, and concentrated to obtain a polymer modifier.

[0051] (2) Add 99 g of xylene, 10 g of straight-run gasoline, 2 g of ethylene glycol monobutyl ether and 0.5 g of OP-10 into a reaction bottle, stir at 25 °C and 800 r / min for 25 min, and after uniform dispersion, add 0.2 g of octanol polyoxyethylene ether JFC-2 penetrant, continue stirring for 10 min, then add 1 g of polymer improver and stir evenly to obtain an oil-based paraffin remover and inhibitor.

[0052] Wax prevention rate test: referring to the standard SY / T6300-2009 "Technical conditions for wax cleaners and wax inhibitors for oil production", the wax prevention rate of wax cleaners and wax inhibitors at different temperatures was tested by the circulating wax tube method. The wax prevention rate f is calculated as f=(m1-m0) / m1, where f is the wax prevention rate (%), m1 is the wax content of the oil sample without oil-based wax cleaner and wax inhibitor (g), and m0 is the wax content of the oil sample with oil-based wax cleaner and wax inhibitor (g).

[0053] Wax dissolution rate test: refer to the standard SY / T6300-2009 "Technical conditions for wax removers and wax inhibitors for oil production" to carry out the wax dissolution rate test. Add 15mL of the oil-based wax remover and wax inhibitor prepared in the embodiment and the comparative example into the wax dissolution test device, respectively. The water bath temperature is 30°C. After the solution is kept at a constant temperature, a wax ball with a mass of m is placed in the wax remover and wax inhibitor solution, and the time t required for the wax ball to dissolve completely at room temperature is recorded. The calculation formula of the wax dissolution rate V is: V=m / t, where V is the wax dissolution rate (g / min), m is the mass of the wax ball (g), and t is the time required for the wax ball to dissolve completely (min).

[0054] Table 1 Wax resistance and wax dissolving performance test

[0055] It can be seen from the test results in the above table that as the content of the polyacrylate pour point and viscosity reducer in the oil-based paraffin remover increases, its paraffin prevention rate is significantly improved. The paraffin prevention rate in Example 5 reaches 75.92%. This is because the polyacrylate pour point and viscosity reducer is a comb-shaped polymer, and its molecular structure simultaneously has two long-chain lipophilic groups and a sodium sulfonate hydrophilic group. The structure of the lipophilic group is similar to that of paraffin, and can be eutectic with paraffin, so that the wax crystals will not continue to grow. The hydrophilic group extends outward, hindering the subsequent precipitated paraffin from combining with it to form a three-dimensional network structure, which can prevent the wax crystals from sticking to each other, reduce the adsorption of wax crystals, and further play the role of paraffin prevention; at the same time, the molecular chain of the polyacrylate pour point and viscosity reducer is relatively long, which is distributed throughout the entire oil phase, and can make the formed paraffin crystal nuclei in a dispersed state, preventing the further growth of the wax crystals.

[0056] The penetrant added to the wax removing and preventing agent has a very strong penetrating effect. After being added, the wax removing and preventing agent can fully contact and react with the wax crystals in the crude oil and wax sample, dissolve and disperse the deposited wax, and at the same time, it can be adsorbed on the surface of the wax crystals during the precipitation and growth stage of the wax crystals to prevent the wax crystals from continuing to grow and deposit, thus playing a certain anti-wax effect. According to the "like dissolves like" principle, wax crystals can be dissolved in the polyacrylate degreasing and viscosity reducing agent, and xylene has a fast dissolving ability and a large saturated wax dissolving capacity, which can achieve "like dissolves like" for wax. The mutual solvent can make the various components in the wax removing and preventing agent dissolve well in the wax solvent, so that it can better contact and react with the paraffin in the crude oil, thereby accelerating the wax dissolution rate and improving the wax removing effect of the wax removing agent.

[0057] In Comparative Example 1, no polyacrylate pour point and viscosity reducer was added, and its wax prevention rate was only 32.53%. Its wax prevention and dissolving ability relied solely on the added mutual solvent and organic solvent, and the wax prevention effect was poor. Comparative Example 2 did not contain a long-chain alkane structure similar to paraffin, but contained a sodium sulfonate hydrophilic group, which could prevent wax crystals from sticking to each other and had a certain wax prevention effect, but the wax prevention effect was not as good as that of the embodiment.

[0058] Crude oil viscosity test: refer to standard SY / T0520-2008 "Determination of Crude Oil Viscosity by Rotational Viscometer Balance Method" for testing, add the wax removal and prevention agents prepared in the examples and comparative examples to the crude oil in a solid state at room temperature, heat to 80°C, keep the temperature constant for 1 hour, take out, cool naturally to room temperature, place in a closed environment for 48 hours, and use a rotary digital display viscometer to measure the crude oil viscosity, and the test temperatures are 20°C, 30°C, and 40°C, respectively.

[0059] Table 2 Crude oil viscosity test

[0060] It can be seen from the test results in the above table that at low temperatures, the viscosity of crude oil continues to decrease with the increase in the content of polyacrylate pour point and viscosity reducer, indicating that the addition of oil-based paraffin remover effectively reduces the low-temperature viscosity of crude oil. This is because the molecular structure of the polyacrylate pour point and viscosity reducer contains two long-chain lipophilic groups and sodium sulfonate hydrophilic groups. The structure of the lipophilic group is similar to that of paraffin, and it can form a eutectic with paraffin, so that the wax crystals will not continue to grow. The hydrophilic group extends outward, hindering the subsequent precipitation of paraffin and combining with it to form a three-dimensional network structure, which can prevent the wax crystals from sticking to each other, so that the wax wrapped in the crude oil dissolves, and then acts together with mutual solvents, surfactants, etc., and penetrates into the oil along the cracks in the deposited wax and the cracks between the wax and the oil well pipe wall to increase the contact surface, increase the dissolution rate of paraffin, and then reduce the viscosity of the crude oil, increase the fluidity of the crude oil, and facilitate the smooth progress of the mining work.

[0061] At 40°C, the viscosity of the crude oil in Comparative Example 1 is 170.3 mPa·s, the viscosity of the crude oil in Comparative Example 2 is 162.1 mPa·s, and the viscosity of the crude oil in Example 1 is 151.9 mPa·s. The viscosity difference between the example and the comparative example is reduced. This is because the temperature plays a major role in the influence of the crude oil viscosity at this time. The higher the temperature, the smaller the crude oil viscosity. This shows that the oil-based paraffin removal and prevention agent prepared by the present invention can significantly improve the low-temperature fluidity of crude oil.

[0062] Crude oil pour point test: Tested with reference to the standard SY / T0541-1994 "Determination of Crude Oil Pour Point", the wax remover and the crude oil prepared in the examples and comparative examples were stirred evenly at a mass ratio of 1:9, then heat treated at 60°C, cooled at a cooling rate of 0.5°C / min, and the fluidity of the sample was observed every 2°C until the highest temperature when the test tube was placed horizontally for 5s and the sample did not flow was the pour point of the crude oil. Table 3 Crude oil pour point test

[0063] It can be seen from the test results in the above table that with the increase of the content of the polyacrylate pour point depressant and viscosity reducer, the pour point of the crude oil is effectively reduced. The pour point of the crude oil in Comparative Example 1 is 21.6°C, while that in Example 5 is only 10.1°C, and the pour point reduction effect is obvious. This is because the polyacrylate pour point depressant and viscosity reducer has a structural unit similar to that of the wax crystal, has good solubility in crude oil, and the alkyl side chain on the molecular chain can fully react with the paraffin in the crude oil to make the molecular chain more extended, and can produce adsorption eutectics with the wax crystal, thereby changing the structural morphology of the wax crystal, hindering the subsequent precipitation of paraffin and combining with it to form a three-dimensional network structure, increasing the flow space of the liquid oil, reducing the flow resistance of the crude oil, and further playing a pour point reduction effect.

[0064] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An oil-based wax remover and inhibitor, characterized in that: The oil-based wax remover and inhibitor comprises the following components in parts by weight: 70-99 parts of xylene, 10-35 parts of straight-run gasoline, 2-10 parts of mutual solvents, 0.5-5 parts of surfactants, 1-15 parts of polyacrylate pour point and viscosity reducers, and 0.1-0.5 parts of rapid penetrants; The preparation method of the polyacrylate pour point and viscosity reducing agent comprises the following steps: (1) Add sodium 3-chloro-2-hydroxypropyl sulfonate, ethanol and deionized water to a reaction flask equipped with a reflux condenser, stir evenly, then add allylamine hydrochloride and sodium carbonate, stir to react, and after the reaction is completed, cool to room temperature, filter, recrystallize from ethanol, and dry to obtain sodium 3-(allylamino)-2-hydroxypropane-1-sulfonate; (2) Add sodium 3-(allylamino)-2-hydroxypropane-1-sulfonate and toluene to a reaction flask equipped with a reflux condenser and a water separator, stir evenly, add triethylamine and long-chain alkyl acyl chloride, heat to 105-120°C and react for 8-14 hours. When no water is produced in the water separator, cool, extract and separate the liquid, and concentrate the organic phase to obtain sodium olefin sulfonate acrylate monomer; (3) Add sodium olefin sulfonate acrylate monomer and toluene to a reaction flask equipped with a reflux condenser, stir evenly, then add N,N'-methylenebisacrylamide and initiator ammonium persulfate, stir to react, and after the reaction is completed, cool to room temperature and concentrate to obtain a polyacrylate pour point and viscosity reducer.

2. The oil-based wax remover and inhibitor according to claim 1, characterized in that: In the step (1), the ratio of sodium 3-chloro-2-hydroxypropyl sulfonate, allylamine hydrochloride and sodium carbonate is 1 mol: (1.05-1.2) mol: (2.5-4) mol.

3. The oil-based paraffin remover and inhibitor according to claim 1, characterized in that: In the step (1), the reaction temperature is 75-90° C. and the reaction time is 8-16 h.

4. The oil-based paraffin remover and inhibitor according to claim 1, characterized in that: In the step (2), the long-chain alkyl acyl chloride is any one of palmitoyl chloride, heptadecanoyl chloride, stearyl chloride and nonadecanoyl chloride.

5. The oil-based wax removing and preventing agent according to claim 1, characterized in that: In the step (2), the ratio of sodium 3-(allylamino)-2-hydroxypropane-1-sulfonate, triethylamine, and long-chain alkyl acyl chloride is 1 mol: (2.1-2.2) mol: (2.2-2.5) mol.

6. The oil-based paraffin remover and inhibitor according to claim 1, characterized in that: In the step (3), the ratio of sodium olefin sulfonate acrylate monomer, N,N'-methylenebisacrylamide, and ammonium persulfate is 1 mol: (0.03-0.06) mol: (0.02-0.05) mol.

7. The oil-based paraffin remover and inhibitor according to claim 1, characterized in that: In the step (3), the reaction temperature is 60-80° C. and the reaction time is 4-10 h.

8. The oil-based paraffin remover and inhibitor according to claim 1, characterized in that: The mutual solvent is ethylene glycol monobutyl ether or diethylene glycol ethyl ether.

9. The oil-based wax removing and preventing agent according to claim 1, characterized in that: The surfactant is OP-10; the rapid penetrating agent is polyoxyethylene octanol ether.

10. A method for preparing the oil-based paraffin remover and inhibitor according to any one of claims 1 to 9, characterized in that: The preparation method is carried out according to the following steps: xylene, straight-run gasoline, mutual solvent and surfactant are added into a reaction bottle, stirred for 10-30 minutes at a temperature of 20-35°C and a rotation speed of 600-1000r / min, and after being evenly dispersed, a rapid penetrant is added, stirring is continued for 5-20 minutes, and then a polyacrylate pour point and viscosity reducer is added, and stirring is evenly performed to obtain an oil-based wax remover and inhibitor.

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