Chemical flooding oil displacement surfactant synthesis process

Abstract

The invention belongs to the technical field of petroleum geology oilfield chemical flooding experiments, and discloses a chemical flooding oil displacement surfactant synthesis process. The yield and quality of the petroleum sulfonate surfactant are improved by adjusting and optimizing various process parameters such as the concentration of sulfonating agent SO3, the molar ratio of SO3 to raw oil aromatic hydrocarbon, the reaction temperature, the rotating speed of a scraper blade, the effective tube pass of a reactor, the neutralization and saponification reflux proportion of colloidal sulfonic acid and the like.

Description

Technical Field

[0001] The invention belongs to the technical field of petroleum geology and oil field chemical flooding experiments, and in particular relates to a chemical flooding oil displacement surfactant synthesis process. Background Art

[0002] Chemical flooding in oil fields takes a long time to implement, has a wide range of applications, and has relatively systematic and standardized field tests. The outstanding problems are poor stability of the composite system, many damages, and low oil displacement efficiency. In order to solve the practical problems that it is difficult to maintain the composite ultra-low interfacial activity, the amount and cost of surfactants implemented in the field are too high, and the water control and oil stabilization capabilities are far less than expected, a new process for the synthesis of petroleum sulfonates, a surfactant miscible with crude oil, is explored to reduce the constraints of surfactants in the implementation of chemical flooding fields, effectively reduce costs, improve the oil washing efficiency of the composite system, and enhance the production increase effect and overall economic benefits of field implementation. Summary of the invention

[0003] In order to overcome the shortcomings of the prior art, the present invention provides a chemical flooding oil surfactant synthesis process, by adjusting and optimizing the sulfonating agent SO 3 The concentration of SO 3 The output and quality of petroleum sulfonate surfactants can be improved by adjusting various process parameters such as the molar ratio of crude oil aromatics, reaction temperature, scraper speed, effective tube length of reactor, and ratio of colloidal sulfonic acid neutralization and saponification reflux.

[0004] The above object of the present invention is achieved through the following technical scheme: a chemical flooding oil displacement surfactant synthesis process, specifically the synthesis of petroleum sulfonate, the steps are:

[0005] S1. Filter, pressurize, cool and dry the air to make it dry air, and melt the sulfur to make it liquid sulfur;

[0006] S2. The dry air and liquid sulfur produced in step S1 are mixed and burned to form sulfur dioxide;

[0007] S3. catalytically oxidizing sulfur dioxide to sulfur trioxide by a vanadium pentoxide catalyst;

[0008] S4. dilute sulfur trioxide for later use;

[0009] S5. oxidizing the crude oil and heavy alkylbenzene mixture into sulfonated feedstock oil;

[0010] S6. The sulfonated raw oil generated in step S5 is cooled by a cooler and then passed into a scraped film sulfonator. At the same time, the diluted sulfur trioxide after dilution in step S4 is passed into the scraped film sulfonator. The scraped film sulfonator is also protected by nitrogen cooled by a cooler. The diluted sulfur trioxide and the sulfonated raw oil are subjected to sulfonation reaction in the scraped film sulfonator.

[0011] S7. The product of the reaction in step S6 is passed into a gas-liquid separator to be decomposed into petroleum sulfonic acid and tail gas. The tail gas is passed through a demister and then into an absorption tower. The absorption tower is provided with a tail gas treatment channel and a Na 2 SO 3 Export, Na 2 SO 3 By Na 2 SO 3 outlet, and the rest goes to tail gas treatment through tail gas treatment channel;

[0012] S8. The petroleum sulfonic acid produced in step S7 is passed through a pipeline, a branch is provided on the pipeline to connect the aging device, the aging device is also provided with a water inlet, the colleagues of the petroleum sulfonic acid are aged by water to be kept warm, and a uniform sulfonic acid is generated;

[0013] S9. The uniform sulfonic acid produced in step S8 is mixed with NaOH to carry out neutralization and saponification reaction, and the product is cooled by a cooler to generate a product petroleum sulfonate.

[0014] Furthermore, in step S1, the air boost pressure is 70 MPa and the drying time is ≥ 48 h.

[0015] Furthermore, the flow rate of the drying air in step S2 is 50 to 150 m 3 / h, the flow rate of liquid sulfur is 30-100kg / h, and the viscosity of liquid sulfur is <500mPa.s.

[0016] Furthermore, in step S5, the molar ratio of crude oil to heavy alkylbenzene is (5-10):1.

[0017] Furthermore, the concentration of the diluted sulfur trioxide gas introduced in step S6 is 3-6%, and the air temperature is 40-60°C.

[0018] Furthermore, the sulfonation process in the scraped film sulfonator in step S6 is specifically as follows: during the downward flow of the mixed material on the inner wall of the scraped film sulfonator reaction cylinder, the mixed material is quickly scraped and smeared by the scraper, and the liquid film is continuously converted and replaced, and the mixed material is mixed with the dry air carrying a certain concentration of SO 3 The gases contact, mix, and evenly and fully undergo sulfonation reaction; the heat suddenly released by the sulfonation reaction is removed by rapid cooling through jacket circulating water.

[0019] Furthermore, in step S6, the sulfonation reaction temperature in the scraped film sulfonator is 50°C to 60°C.

[0020] Furthermore, in step S6, the scraper speed of the scraped film sulfonator is 80-90 r / min.

[0021] Compared with the prior art, the present invention has the following beneficial effects: According to the statistics of multiple pilot synthesis experiments, after the pilot sulfonation reaction, there is more than 6% SO3 Restored to SO 2 , with >4% SO 3 Failed to participate in the reaction or effectively utilize. The final product of the composite oil scraping sulfonated synthetic petroleum sulfonate has an effective active matter content of 54.2-67.5%, unsulfonated oil 21.2-27.9%, inorganic salt 2.2-3.6%, and water 9.8-13.9%. The active matter contains 73.9-77.5% monosulfonate, 21.9-24.2% disulfonate, 0.43-1.57% polysulfonate, and a molecular weight of 334-523. The self-produced and synthesized petroleum sulfonates do not need to be purified and refined, and are easier to store, transport and mix. The cost is only half of the price of purchased surfactants, and the economic and performance advantages are obvious. ① The petroleum sulfonate surfactant synthesized with crude oil produced in the chemical flooding field as raw material is more easily miscible with crude oil and achieves ultra-low interfacial tension, strong emulsification and oil washing capabilities, small rock adsorption loss, wide distribution range of ultra-low interfacial tension concentration, stable oil displacement performance, and great potential for improving underground crude oil recovery. It is the preferred, inexpensive and most suitable surfactant for chemical flooding. The present invention adopts a scraped film sulfonation process to overcome the common drawbacks of uneven sulfonation, over-sulfonation, easy coking, easy nodulation, difficult transportation, and difficult neutralization in the existing sulfonation process, and uses heavy alkylbenzene to compound the vacuum distillation dewaxed crude oil of Honggang Oilfield to improve The sulfonation efficiency and product yield, the quality and performance of the synthetic petroleum sulfonate are greatly improved; the active matter content of the synthetic petroleum sulfonate by the new scraping film sulfonation process of the present invention is greater than 53%, and it is very easy to achieve ultra-low interfacial activity oil washing ability with Honggang crude oil when compounded with polymer or alkali. The physical model oil displacement efficiency of its compounded polymer / surfactant binary composite system is greater than 15.8%, and the physical model oil displacement efficiency of the polymer / surfactant / alkali ternary composite system is greater than 19.1%, which is 4.5-7.8% higher than other surfactants; the present invention uses Honggang crude oil as raw material to synthesize petroleum sulfonate, which can be directly used in the chemical composite flooding field without purification and refining, and storage, transportation and mixing become simple and easy, creating conditions for compounding a stable and efficient oil displacement system, reducing the implementation cost of the Honggang chemical composite flooding field, and improving the oil increase effect and economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0023] Figure 1 It is a schematic diagram of the petroleum sulfonate synthesis process and the scraped film sulfonator;

[0024] Figure 2 This is a diagram of the steps for the synthesis of petroleum sulfonates and the testing of active ingredient content;

[0025] Figure 3 It is the relationship curve between the percentage of active matter and influencing factors;

[0026] Figure 4It is the relationship curve between interfacial tension and influencing factors;

[0027] Figure 5 It is SO in exhaust gas 3 Relationship curve between content and influencing factors;

[0028] Figure 6 It is SO in exhaust gas 2 Relationship curve between content and influencing factors;

[0029] Figure 7 This is the relationship curve between the percentage of monosulfonic acid and influencing factors.

[0030] In the figure, 1. sulfonation raw material inlet; 2. sulfonation gas inlet; 3. N2 inlet; 4. scraped film sulfonator; 5. gas-liquid separator; 6. circulation pump; 7. cooler; 8. aging device; 9. hydrator; 10. water inlet; 11. neutralizer; 12. NaOH inlet; 13. petroleum sulfonate outlet; 14. demister; 15. absorption tower; 16. tail gas treatment; 17. Na2SO3 outlet; 18. cooling water inlet; 19. cooling water outlet. DETAILED DESCRIPTION

[0031] The present invention is described in detail below by specific examples, but the protection scope of the present invention is not limited. Unless otherwise specified, the experimental methods used in the present invention are all conventional methods, and the experimental equipment, materials, reagents, etc. used can be obtained from commercial channels.

[0032] Example 1

[0033] A chemical flooding surfactant synthesis process, specifically the synthesis of petroleum sulfonate, the steps are:

[0034] S1. Filter, pressurize, cool and dry the air to make it dry air, and melt the sulfur to make it liquid sulfur;

[0035] S2. The dry air and liquid sulfur produced in step S1 are mixed and burned to form sulfur dioxide;

[0036] S3. catalytically oxidizing sulfur dioxide to sulfur trioxide by a vanadium pentoxide catalyst;

[0037] S4. dilute sulfur trioxide for later use;

[0038] S5. oxidizing the crude oil and heavy alkylbenzene mixture into sulfonated feedstock oil;

[0039] S6. The sulfonated raw oil generated in step S5 is cooled by a cooler and then passed into a scraped film sulfonator. At the same time, the diluted sulfur trioxide after dilution in step S4 is passed into the scraped film sulfonator. The scraped film sulfonator is also protected by nitrogen cooled by a cooler. The diluted sulfur trioxide and the sulfonated raw oil are subjected to sulfonation reaction in the scraped film sulfonator.

[0040] S7. The product of the reaction in step S6 is passed into a gas-liquid separator to be decomposed into petroleum sulfonic acid and tail gas. The tail gas is passed through a demister and then into an absorption tower. The absorption tower is provided with a tail gas treatment channel and a Na 2 SO 3 Export, Na 2 SO 3 By Na 2 SO 3 outlet, and the rest goes to tail gas treatment through tail gas treatment channel;

[0041] S8. The petroleum sulfonic acid produced in step S7 is passed through a pipeline, a branch is provided on the pipeline to connect the aging device, the aging device is also provided with a water inlet, the colleagues of the petroleum sulfonic acid are aged by water to be kept warm, and a uniform sulfonic acid is generated;

[0042] S9. The uniform sulfonic acid produced in step S8 is mixed with NaOH to carry out neutralization and saponification reaction, and the product is cooled by a cooler to generate a product petroleum sulfonate.

[0043] Petroleum sulfonate synthesis process and scraped film sulfonator Figure 1 .

[0044] The scraped film sulfonator inherits the advantages of the falling film sulfonator, eliminates its weaknesses, and overcomes many drawbacks of the existing sulfonation synthesis process. The scraped film synthesis process is continuously improved and perfected based on the synthesis experience and lessons, with the expansion of production scale, optimization of process flow, and improvement of petroleum sulfonate yield and quality as the starting point and foothold.

[0045] ① Use active scraper technology to increase the strong turbulence of the liquid, increase the effective tube length of the sulfonation reaction in the sulfonator, and strengthen SO 3 The contact probability with high-viscosity raw oil can improve the uniformity of sulfonation and the efficiency of sulfonation reaction.

[0046] The intermittent sulfonation reaction time is 3 to 4 hours, the continuous sulfonation reaction time is 1 to 2 hours, the membrane sulfonation reaction time is <1 minute, the kettle sulfonator reaction time is 2 to 5 hours, and the tubular sulfonator reaction time is mainly determined by the length of the sulfonation equipment. The optimal reaction time corresponding to different sulfonation processes varies greatly. The length of the sulfonation reaction time directly affects the composition and performance of the final product. If the reaction time is too short, the reaction is incomplete, the sulfonation rate is low, and the product yield is low; if the reaction time is too long, it will be over-sulfonated, oxidized and poly-sulfonated, with many by-products, and the total production capacity per unit time will also be reduced. The Honggang crude oil scraping film sulfonation process synthesizes petroleum sulfonates, and the optimal effective tube length of the reactor is 3.5 to 4.5m.

[0047] ②Optimize the sulfonation reaction temperature.

[0048] The reaction temperature affects the sulfonation rate and efficiency, and also affects the composition and content of the final product. The sulfonation temperature affects the position where the sulfonic group enters the aromatic ring, thereby affecting the water solubility of the sulfonated product. The sulfonation reaction is an irreversible instantaneous reaction. If the sulfonation is carried out at a low temperature, the yield of monosulfonic acid is high and the side reactions are few, but the reaction speed is slow, the sulfonation rate is low, the viscosity of the raw materials and products is high, and the transmission fluidity is poor. If the sulfonation is carried out at a high temperature, the transmission viscosity of the reaction materials can be reduced, the mass transfer can be accelerated, the reaction speed is fast, and the sulfonation rate is high, but too high a reaction temperature will produce a large amount of high-viscosity side reaction products, the yield of monosulfonic acid is low, oxidation + over-sulfonation coking, the texture is hard and charred, and the product nodules and aggregation are difficult to transport. In the synthesis of petroleum sulfonates by the scraped film sulfonation process of Honggang crude oil, the optimal anti-sulfonation temperature is 50℃~60℃ in terms of product performance and yield.

[0049] ③Optimize SO 3 The molar ratio of aromatics to the feed oil (feed flow rate).

[0050] The yield of effective active substances increases with the sulfonating agent SO 3 The content of SO in tail gas increases with the increase of the molar ratio of raw material aromatics (the flow rate of raw material oil decreases). When the molar ratio is greater than 1.50, the trend becomes gentle. When the molar ratio is greater than 1.60, the content of SO in tail gas increases with the increase of the molar ratio of raw material aromatics (the flow rate of raw material oil decreases). 3 The content of SO in tail gas increases. 2 The content of SO increases with the increase of molar ratio. 3 Gradually excessive, the reaction intensifies, the side reactions increase, the monosulfonic acid content decreases, and the polysulfonic acid content increases. In the scraped film sulfonation process of Honggang crude oil to synthesize petroleum sulfonates, considering the product performance and yield, the sulfonating agent SO 3 The suitable range of the molar ratio with the raw material aromatic hydrocarbon is 1.5 to 1.6:1.

[0051] ④Optimize sulfonating agent SO 3 concentration

[0052] As the concentration of SO3 gas increases, SO 3 The diffusion rate to the liquid film surface is accelerated, SO 3 The contact probability with crude oil increases, the reaction intensifies, the sulfonation reaction efficiency and product conversion rate increase, SO 3 The products have good ultra-low interfacial activity when the concentration is within the range of 3.5% to 4.5%. 3 When the concentration is higher than 4.5%, the content of monosulfonic acid decreases, the content of polysulfonic acid increases, and the content of SO in tail gas 3 、SO 2 The concentration increases. The aromatic content in the crude oil increases, SO 3 The concentration needs to be increased accordingly. The Honggang crude oil scraping film sulfonation process synthesizes petroleum sulfonates. Considering the product performance and yield, the sulfonating agent SO 3The optimal concentration is 3.8-4.5% (v / v).

[0053] ⑤Optimize scraper speed

[0054] The scraper speed is greater than 80r / min, SO 3 The gas and the crude oil liquid film can achieve sufficient contact at the two-phase interface, the reaction tends to be complete, the yield of effective active substances tends to be flat, and the product has good ultra-low interfacial activity. The optimal scraper speed for synthesizing petroleum sulfonate from Honggang crude oil varies with the viscosity of the proportioned materials and increases with the increase of the viscosity of the proportioned materials. An intelligent frequency converter can be used to automatically adjust the scraper speed to 60-120r / min according to the mass transfer resistance and the frequency of liquid film renewal. Under the condition of a certain reaction tube, as the aromatic content, molecular weight, and viscosity in the crude oil increase, the reaction temperature, SO 3 The molar ratio of aromatics in the crude oil, SO 3 The concentration and scraper speed need to be increased accordingly. From the perspective of energy saving and consumption reduction, the appropriate range of scraper speed is 80-90r / min.

[0055] ⑥Aging and hydration process

[0056] Aging temperature: Aging has little effect on the yield of active substances, but has a greater impact on the ultra-low interfacial activity of the product. The ultra-low interfacial activity of the product aged at 50℃~55℃ is the best. This is because some aromatic sulfonates will undergo structural reorganization during the aging process, and the entrained SO 3 The reaction will continue at the optimum sulfonation reaction temperature. Above 55°C, there is a risk of over-sulfonation and the product's ultra-low interfacial activity deteriorates.

[0057] Aging time: The length of aging time has almost no effect on the yield of effective active substances. The product aged for 10 to 15 minutes has the best ultra-low interfacial activity. If the aging time is too long (after 15 minutes), the ultra-low interfacial activity will slightly deteriorate.

[0058] Hydration ratio: To improve the stability and fluidity of sulfonic acid, hydrate after aging, add 1-2% hot water above 50℃ to the sulfonic acid for spraying and gelation treatment, stir and keep warm for 5-20 minutes to form a uniform micelle system, which is more conducive to liquid alkali neutralization and saponification, so as to increase the output of mono- and di-sulfonic acids and improve the ultra-low interfacial activity of the final product. Adding too much water will cause some unstable sulfonic acid groups to fall off, and will also aggravate the corrosion of pipelines.

[0059] ⑦ Neutralization saponification reaction

[0060] In order to realize the continuous production and automation of control operation of neutralization and saponification, based on the existing mature membrane sulfonation process, the scraped film sulfonation synthesis process uses the reflux and pipeline mixing method to solve the problem that there is no solvent and high viscosity petroleum sulfonic acid is difficult to neutralize and saponify uniformly. After the neutralization and saponification of liquid alkali NaOH, the moisture content of the sulfonate product is generally controlled at about 15%, which is convenient for storage, pouring and transportation.

[0061] ⑧ Using vacuum distillation dewaxed crude oil as the main material, heavy alkylbenzene and alkylbenzene as additives and diluents, compounding petroleum sulfonate can make the oil-water reach ultra-low interfacial tension (10 -3 mN / m). More than 80% of the components in the raw oil come from crude oil, and petroleum sulfonate products have natural miscibility with crude oil. Adding organic solvents such as alkylbenzene, olefins, and higher alcohols to the raw oil not only plays a dilution role, but also participates in the sulfonation reaction and increases the water solubility and yield of the sulfonated product.

[0062] ⑨ Introduce protective nitrogen at the top of the sulfonator to reduce equipment corrosion, coking and over-sulfonation reactions. In the aging stage, add aging and hydration processes such as atomized hot water spray to improve the uniformity and fluidity of colloidal sulfonic acid, reduce pipeline blockage and corrosion, inhibit the shedding of unstable sulfonic acid groups, overcome the disadvantages of uneven sulfonation, heavy over-sulfonation, and many side reactions, and solve the problems of easy coking, easy nodules, difficult transportation, and difficult neutralization. Reasonably adjust the reflux ratio, install a rotor pump and a rotary ejector to improve the circulation efficiency, eliminate the problems of easy agglomeration and accumulation in continuous neutralization and saponification reactions, and realize continuous production of neutralization and saponification.

[0063] Figure 2 This is a diagram of the steps for the synthesis of petroleum sulfonate and the test of active content. The petroleum sulfonate is synthesized using a scraped film sulfonator, with a material flow rate of 30-100 kg / h (viscosity <500 mPa.s), a SO3 gas concentration of 3-6% (air temperature 40-60°C), and a carrying air flow rate of 50-150 m 3 / h, 70MPa, drying for more than 48h, insulation water flow rate 150~350kg / h (water temperature 45~60℃), variable frequency speed 60~120r / min. The mixture of Honggang crude oil and heavy alkylbenzene (or alkylbenzene, 5~10:1) after vacuum distillation dewaxing flows downward on the inner wall of the scraped film sulfonator reaction cylinder. The scraper quickly scrapes and smears, and the liquid film is continuously converted, replaced and refurbished, and the dry air carries a certain concentration of SO 3The gas contacts, mixes, and evenly and fully undergoes the sulfonation reaction; the heat suddenly released by the sulfonation reaction is quickly cooled and removed by the jacket circulating water, ensuring that the entire sulfonation process is gentle and the temperature changes are small, avoiding nodules, coking, and over-sulfonation. The gas-liquid separator is fed and discharged at a uniform speed. After sulfonation, the acid material is separated from the gas and liquid, treated with heat preservation water, and aged, and then NaOH is added for neutralization and saponification reaction, and finally a petroleum sulfonate surfactant is generated.

[0064] Taking the oil sulfonate flooding performance as an indicator, the results of the pilot synthesis orthogonal test are as follows:

[0065] ① (Raw material) Aromatic conversion rate and effective active matter content factors, sulfonator tube process > scraper speed > sulfonation reaction temperature > SO 3 Molar ratio to aromatics>SO 3 Concentration (see Figure 3 ). ②The factor of ultra-low interfacial activity of the product, SO 3 Molar ratio to aromatics > sulfonator tube > sulfonation reaction temperature > scraper speed > SO 3 Concentration > aging temperature > aging time (see Figure 4 ). ③SO in tail gas 3 Factors affecting residual concentration: sulfonator tube process > sulfonation reaction temperature > scraper speed > SO 3 Concentration>SO 3 The molar ratio of aromatic hydrocarbons (see Figure 5 ) ④ SO in tail gas 2 Concentration factor, sulfonator tube > SO 3 Molar ratio to aromatics>SO 3 Concentration > sulfonation reaction temperature > scraper speed (see Figure 6 ) ⑤ Factors affecting the content of monosulfonic acid: sulfonator tube length > scraper speed > sulfonation reaction temperature > SO 3 Concentration>SO 3 The molar ratio of aromatic hydrocarbons (see Figure 7 ).

[0066] According to the results of multiple pilot-scale synthesis experiments, there is more than 6% SO 3 Restored to SO 2 , with >4% SO 3Failed to participate in the reaction or be effectively utilized. The final product of the composite oil scraping sulfonated synthetic petroleum sulfonate has an effective active matter content of 54.2-67.5%, unsulfonated oil 21.2-27.9%, inorganic salt 2.2-3.6%, and water 9.8-13.9%. The active matter contains 73.9-77.5% monosulfonate, 21.9-24.2% disulfonate, 0.43-1.57% polysulfonate, and a molecular weight of 334-523. The self-produced synthetic petroleum sulfonate does not need to be purified and refined, and storage, transportation and mixing are simpler, and the cost is only half of the price of purchased surfactants.

[0067] The above-described embodiments are only preferred embodiments of the present invention, but not all feasible embodiments of the present invention. For those skilled in the art, any obvious changes made thereto without departing from the principles and spirit of the present invention should be considered to be included in the scope of protection of the claims of the present invention.

Claims

1. A chemical flooding oil surfactant synthesis process, It is characterized in that Specifically, the synthesis of petroleum sulfonate comprises the following steps: S1. Filter, pressurize, cool and dry the air to make it dry air, and melt the sulfur to make it liquid sulfur; S2. The dry air and liquid sulfur produced in step S1 are mixed and burned to form sulfur dioxide; S3. catalytically oxidizing sulfur dioxide to sulfur trioxide by a vanadium pentoxide catalyst; S4. dilute sulfur trioxide for later use; S5. oxidizing the crude oil and heavy alkylbenzene mixture to form a sulfonated feedstock oil; S6. The sulfonated raw oil generated in step S5 is cooled by a cooler and then passed into a scraped film sulfonator. At the same time, the diluted sulfur trioxide after dilution in step S4 is passed into the scraped film sulfonator. The scraped film sulfonator is also protected by nitrogen cooled by a cooler. The diluted sulfur trioxide and the sulfonated raw oil are subjected to sulfonation reaction in the scraped film sulfonator. S7. The product of the reaction in step S6 is passed into a gas-liquid separator to be decomposed into petroleum sulfonic acid and tail gas. The tail gas is passed through a demister and then into an absorption tower. The absorption tower is provided with a tail gas treatment channel and a Na 2 SO 3 Export, Na 2 SO 3 By Na 2 SO 3 outlet, and the rest goes to tail gas treatment through tail gas treatment channel; S8. The petroleum sulfonic acid produced in step S7 is passed through a pipeline, a branch is provided on the pipeline to connect the aging device, the aging device is also provided with a water inlet, the colleagues of the petroleum sulfonic acid are aged by water to be kept warm, and a uniform sulfonic acid is generated; S9. The uniform sulfonic acid produced in step S8 is mixed with NaOH to carry out neutralization and saponification reaction, and the product is cooled by a cooler to generate a product petroleum sulfonate.

2. The chemical flooding oil surfactant synthesis process according to claim 1, It is characterized in that In the step S1, the air boost pressure is 70 MPa and the drying time is ≥ 48 h.

3. The chemical flooding oil surfactant synthesis process according to claim 1, It is characterized in that The flow rate of the drying air in step S2 is 50-150 m 3 / h, the flow rate of liquid sulfur is 30-100kg / h, and the viscosity of liquid sulfur is <500mPa.s.

4. The chemical flooding oil surfactant synthesis process according to claim 1, It is characterized in that In step S5, the molar ratio of crude oil to heavy alkylbenzene is (5-10):

1.

5. The chemical flooding oil surfactant synthesis process according to claim 1, It is characterized in that The concentration of the diluted sulfur trioxide gas introduced in step S6 is 3-6%, and the temperature is 40-60°C.

6. The chemical flooding oil surfactant synthesis process according to claim 1, It is characterized in that The sulfonation process in the scraped film sulfonator in step S6 is specifically as follows: during the downward flow of the mixed material on the inner wall of the scraped film sulfonator reaction cylinder, the mixed material is quickly scraped and smeared by the scraper, and the liquid film is continuously converted and replaced, and the mixed material is mixed with the dry air carrying a certain concentration of SO 3 The gases contact, mix, and evenly and fully cause the sulfonation reaction; the heat suddenly released by the sulfonation reaction is quickly cooled and removed by circulating water in the jacket.

7. The chemical flooding oil surfactant synthesis process according to claim 1, It is characterized in that In the step S6, the sulfonation reaction temperature in the scraped film sulfonator is 50°C to 60°C.

8. The chemical flooding oil surfactant synthesis process according to claim 6, It is characterized in that The scraper speed of the scraped film sulfonator is 80-90 r / min.

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