Preparation method of petroleum sulfonate surfactant for oil displacement
By using catalytic cracking slurry and low-aromatic dewaxed oil as raw materials, combined with diluents and sulfonating agents, the coking problem in the preparation of petroleum sulfonates was solved, and the preparation of high-performance petroleum sulfonates was achieved, meeting the needs of tertiary oil recovery and improving the utilization rate of raw materials.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- PETROCHINA CO LTD
- Filing Date
- 2024-12-30
- Publication Date
- 2026-06-30
AI Technical Summary
Existing petroleum sulfonate preparation processes suffer from problems such as easy coking during sulfonation, short sulfonation cycle, reactor blockage, poor quality stability, poor salt and temperature resistance, and low reaction yield, which are particularly difficult to solve in the preparation of high-viscosity raw materials.
Petroleum sulfonate surfactants were prepared by using catalytic cracking slurry oil and low-aromatic dewaxing oil as raw materials, adding diluents and sulfonating agents to carry out sulfonation, neutralization and aging reactions. The molar ratio of sulfonating agent to raw oil was controlled at 1.0 to 1.5:1. The solution was neutralized to pH 8 to 10 with sodium hydroxide alkali solution. The reaction temperature was 50 to 70°C and the reaction time was 30 to 60 minutes.
The prepared petroleum sulfonate surfactant can effectively reduce the oil-water interfacial tension to 10-3 mN/m, meeting the requirements of tertiary oil recovery combined flooding. The product has stable performance and is suitable for use alone or in combination as an oil displacement agent, which broadens the source of raw materials and increases the added value of by-products.
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Abstract
Description
Technical Field
[0001] This invention belongs to the field of petroleum sulfonate preparation technology, and specifically relates to a method for preparing a petroleum sulfonate surfactant for oil displacement. More specifically, it relates to a method for preparing a petroleum sulfonate surfactant capable of achieving tertiary oil recovery. Background Technology
[0002] In the oilfield development sector, tertiary oil recovery technology is considered a key "treasure trove" for tapping the potential of crude oil. It cleverly integrates cutting-edge physical, chemical, and biological technologies to open up new paths for improving crude oil recovery rates. Among these technologies, chemical composite flooding is the "trump card," demonstrating exceptional capability in tackling the challenging problem of high water-cut oilfields. It often increases crude oil recovery rates by over 20%, significantly rewriting the profitability of oilfield development. Of particular note is how to leverage existing refinery distillate resources to tailor high-performance, low-cost petroleum sulfonate surfactants for oil displacement, a key issue that has become a focal point for the industry.
[0003] Petroleum sulfonates are anionic surfactants synthesized from petroleum distillates. Based on national energy needs, petroleum sulfonates and alkylbenzene sulfonates for oil displacement are currently the primary surfactants used in pilot tests, field trials, and industrial-scale promotion trials of oilfield chemical flooding. The demand for these two surfactants is very high. However, the feedstock distillates and extracted oils for petroleum sulfonates vary depending on the properties of crude oil from different oilfields. In particular, due to the high viscosity of these feedstocks, the preparation process of petroleum sulfonates still suffers from problems such as easy coking during sulfonation, short sulfonation cycles, poor quality stability, poor salt and temperature resistance, significant heat loss due to adsorption, and low reaction yield. The short sulfonation cycle is caused by reactor blockage due to coking, requiring regular cleaning. These problems pose difficulties for research and large-scale production.
[0004] Petroleum sulfonate products are synthesized from a wide variety of distillate oils available from refineries, resulting in low costs. Chinese invention patent CN1458220A, titled "Low-Alkali / Alkali-Free Composite Flooding Formula for Tertiary Oil Recovery," uses vacuum distillate oil as its raw material. Due to the low molecular weight of this raw material, it often needs to be compounded with other types of surfactants to achieve good compatibility. Furthermore, the alkali-free system described in the patent requires the addition of salt to replace the alkali. Chinese invention patent CN1128006C, titled "Petroleum Sulfonate Surfactants for Oilfields, Their Preparation Method, and Their Application in Tertiary Oil Recovery," also suffers from a narrow range of raw material molecular weights, poor product compatibility, and the need for extraction to separate unreacted oil during the synthesis process due to the low aromatic content of the selected raw material. Chinese invention patent CN108485625A relates to anionic surfactants, heavy oil viscosity reducers, and their preparation method, involving the addition reaction of long-chain polyetheramines and methyl acrylate in a solvent at a specific molar ratio. However, this method reduces viscosity during oil recovery, not during preparation, and still suffers from coking issues. Chinese invention patent CN106243002A relates to a petroleum sulfonate oil displacement agent and its preparation method. The method involves sulfonating ketone-benzene dewaxing oil or furfural extract with sulfur trioxide, followed by neutralization to obtain petroleum sulfonates. While this method improves the reaction yield, the absence of other solvents during the reaction makes it prone to coking, resulting in a short reactor cleaning cycle. Chinese invention patent CN104403652 provides a method for preparing a petroleum sulfonate surfactant for oil displacement. This method uses vacuum distillate oils (VDI II, VDI III, and VDI IV) as raw materials, undergoing sulfonation, aging, and neutralization steps to obtain the petroleum sulfonate surfactant. However, this method adds a large amount of solvent oil as a diluent to address the coking problem caused by the high viscosity of the raw materials. Although this method partially solves the coking problem, the large amount of solvent oil generated during the reaction process needs to be separated and recovered using organic solvents after sulfonation, leading to a cumbersome process and environmental issues.
[0005] Based on the above, there is an urgent need to develop a method that can solve the problem of excessive coking and acid sludge production clogging the reactor during the preparation of petroleum sulfonates without introducing a large amount of diluent. Summary of the Invention
[0006] To overcome the shortcomings of existing technologies, this invention provides a method for preparing petroleum sulfonate surfactants for oil displacement. The petroleum sulfonate surfactants obtained by the method provided by this invention have a surface tension of 10. -3 With a strength of mN / m, the product performance meets the requirements for tertiary oil recovery composite flooding. This product can be used alone as an oil displacement agent or in combination with other additives as a tertiary oil recovery flooding agent.
[0007] The purpose of this invention is to prepare petroleum sulfonates for oil displacement using catalytic slurry clarified oil as the main raw material. These petroleum sulfonates have low production costs, stable interfacial tension, and are suitable for weakly alkaline oil displacement systems.
[0008] The above-mentioned objective of this invention is achieved through the following technical solution:
[0009] A petroleum sulfonate surfactant for oil displacement includes a feedstock oil, a diluent, and a sulfonating agent; wherein the molar ratio of the sulfonating agent to the aromatics in the feedstock oil is 1.0 to 1.5:1.
[0010] Furthermore, the feedstock is a mixture of catalytic cracking slurry oil and low-aromatic dewaxing oil.
[0011] Furthermore, the diluent is an organic alcohol. Preferably, the organic alcohol is n-propanol or n-butanol. The amount of diluent added is 1% to 5% of the mass of the feed oil.
[0012] Furthermore, the sulfonating agent is chlorosulfonic acid or sulfur trioxide.
[0013] Furthermore, the low-aromatic dewaxing oil is preferably a ketone-benzene dewaxing oil.
[0014] The above-mentioned method for preparing petroleum sulfonate surfactants involves sulfonating, neutralizing, and aging catalytic cracking slurry to prepare petroleum sulfonate surfactants for oil displacement.
[0015] Furthermore, the above preparation method specifically involves: mixing catalytic cracking slurry oil and ketone-benzene dewaxing oil in a certain proportion as feedstock oil. Based on the total weight of the feedstock oil (100%), it contains 10wt%-90wt% catalytic cracking slurry oil and 10wt%-90wt% low-aromatic dewaxing oil. Adding 1%-5% of a diluent by weight of the feedstock oil, and using chlorosulfonic acid or sulfur trioxide as a sulfonating agent, a sulfonation reaction is carried out. The molar ratio of chlorosulfonic acid to aromatics in the feedstock oil is 1.0-1.5:1. After the sulfonation reaction, petroleum sulfonic acid is obtained. The petroleum sulfonic acid is neutralized with alkali to pH 8-10 to obtain petroleum sulfonate. The petroleum sulfonate undergoes an aging reaction to obtain a petroleum sulfonate surfactant.
[0016] Furthermore, the alkaline solution is a sodium hydroxide solution. The alkaline solution is a sodium hydroxide solution with a mass concentration of 20% to 40%.
[0017] Furthermore, the sulfonation reaction conditions are as follows: the sulfonation reaction is carried out at 50–70°C for 30–60 min.
[0018] Furthermore, the aging reaction conditions are: aging temperature of 50-60℃ and aging time of 30-60min.
[0019] The advantages of this invention compared to the prior art are:
[0020] This invention uses clarified oil from catalytic cracking slurry as the main raw material, combined with other low-aromatic dewaxed oils and additives, to carry out a sulfonation reaction to obtain petroleum sulfonate products. The preparation method provided by this invention not only increases the added value of the by-product catalytic slurry, but also broadens the source of petroleum sulfonate raw materials.
[0021] The petroleum sulfonate surfactant obtained by the preparation method provided by this invention can reduce the oil-water interfacial tension to 10. -3 With a strength of mN / m, the product performance meets the requirements for tertiary oil recovery composite flooding. This product can be used alone as an oil displacement agent or in combination with other additives as a tertiary oil recovery flooding agent. Detailed Implementation
[0022] The present invention is described in detail below through specific embodiments, but this does not limit the scope of protection of the present invention. Unless otherwise specified, the experimental methods used in the present invention are all conventional methods, and the experimental equipment, materials, reagents, etc. used can all be obtained commercially.
[0023] This invention synthesizes petroleum sulfonates for oil displacement using a mixture of catalytic cracking slurry and low-aromatic dewaxing oil as raw materials. Research and development were conducted to achieve ultra-low oil-water interfacial activity in the oil displacement agent product. The synthesized petroleum sulfonate product meets industry standards for both active component content and oil-water interfacial activity. This not only broadens the source of raw materials and provides effective technical support for the industrial production of petroleum sulfonate surfactants in target oilfields, but also comprehensively utilizes byproducts from the catalytic cracking unit, achieving efficient utilization of the catalytic cracking slurry.
[0024] This invention provides a new approach for the high-value utilization of catalytic cracking slurry, which utilizes catalytic cracking slurry through sulfonation, aging, and neutralization to prepare petroleum sulfonate surfactants for oil displacement.
[0025] This invention provides a petroleum sulfonate surfactant for oil displacement, comprising feedstock oil, diluent, and sulfonating agent; wherein the molar ratio of the sulfonating agent to the aromatics in the feedstock oil is 1.0 to 1.5:1.
[0026] The feedstock is a mixture of catalytic cracking slurry oil and low-aromatic dewaxing oil.
[0027] The diluent is an organic alcohol. Preferably, it is n-propanol or n-butanol. The amount of diluent added is 1% to 5% of the weight of the feed oil.
[0028] The sulfonating agent is chlorosulfonic acid or sulfur trioxide.
[0029] Low-aromatic dewaxing oil is preferably ketone-benzene dewaxing oil.
[0030] The specific preparation method is as follows: catalytic cracking slurry oil and ketone-benzene dewaxing oil are mixed in a certain proportion as feedstock oil. Based on the total weight of the feedstock oil as 100%, it contains 10wt%-90wt% catalytic cracking slurry oil and 10wt%-90wt% low aromatic dewaxing oil. 1%-5% of diluent by weight of the feedstock oil is added. Chlorosulfonic acid or sulfur trioxide is used as a sulfonating agent to carry out a sulfonation reaction. The molar ratio of chlorosulfonic acid to aromatics in the feedstock oil is 1.0-1.5:1. After the sulfonation reaction, petroleum sulfonic acid is obtained. Petroleum sulfonic acid is neutralized with alkali solution to pH 8-10 to obtain petroleum sulfonate. The petroleum sulfonate undergoes an aging reaction to obtain petroleum sulfonate surfactant.
[0031] The alkaline solution is a sodium hydroxide solution. The alkaline solution has a mass concentration of 20% to 40% sodium hydroxide.
[0032] The sulfonation reaction conditions are as follows: the sulfonation reaction is carried out at 50-70℃ for 30-60 minutes.
[0033] The aging reaction conditions are: aging temperature of 50-60℃ and aging time of 30-60min.
[0034] The preparation method is further illustrated below through examples.
[0035] Example 1
[0036] Weigh a certain amount of feedstock oil (based on the total weight of the feedstock oil, which contains 50 wt% catalytic cracking slurry and 50% low-aromatic dewaxed oil, with a mass ratio of 1:1 between the catalytic cracking slurry and the low-aromatic dewaxed oil) into a three-necked flask. Place the flask in a constant temperature water bath and heat it to 60°C. Add chlorosulfonic acid to the dropping funnel in proportion, and add the chlorosulfonic acid dropwise under stirring to carry out the sulfonation reaction for 40 minutes. The molar ratio of chlorosulfonic acid to aromatics in the feedstock oil is 1.5:1. After the sulfonation reaction is completed, neutralize the petroleum sulfonic acid with 40% NaOH solution to a pH value of 8-9. Then, age the product at an aging temperature of 50°C for 40 minutes to obtain the petroleum sulfonate product.
[0037] The interfacial tension test results of the petroleum sulfonate product prepared in Example 1 on the oil-water interface are shown in Table 1. The interfacial tension was tested using a spin-drop interfacial tensiometer. The surfactant was prepared from formation water reinjection wastewater from the oilfield to a concentration of 0.05 wt%–0.3 wt%. The interfacial tension was the stable equilibrium value after 2 hours of testing. The experimental data show that when the petroleum sulfonate product concentration is 0.1–0.3 wt% and the alkali concentration is 0.4–1.2 wt%, the interfacial tension between oil and water can reach 10. -3 mN / m; can meet the interfacial tension requirements of weak base composite systems.
[0038] Table 1. Effect of petroleum sulfonate products prepared in Example 1 on the oil-water interfacial tension in oilfields.
[0039]
[0040] Example 2
[0041] Weigh a certain amount of feedstock oil (based on the total weight of the feedstock oil, which contains 60 wt% catalytic cracking slurry and 40 wt% low-aromatic dewaxed oil, with a mass ratio of 3:2 between the catalytic cracking slurry and the low-aromatic dewaxed oil) into a three-necked flask. Place the flask in a constant temperature water bath and heat it to 60°C. Add chlorosulfonic acid to the dropping funnel in proportion, and add the chlorosulfonic acid dropwise under stirring to carry out the sulfonation reaction for 40 min. The molar ratio of chlorosulfonic acid to aromatics in the feedstock oil is 1.5:1. After the sulfonation reaction is completed, neutralize the petroleum sulfonic acid with 30% NaOH solution to a pH value of 8-9. Then, age the product at an aging temperature of 55°C for 50 min to obtain the petroleum sulfonate product.
[0042] The interfacial tension test results of the petroleum sulfonate product prepared in Example 2 on the oil-water interface are shown in Table 2. The interfacial tension was tested using a spin-drop interfacial tensiometer. The surfactant was prepared from formation water reinjection wastewater from the oilfield to a concentration of 0.05 wt%–0.3 wt%, and the interfacial tension was the stable equilibrium value after 2 hours of testing. The experimental data show that with a petroleum sulfonate product concentration of 0.05–0.3 wt% and an alkali concentration of 0.2–1.2 wt%, the interfacial tension between oil and water can reach 10. -3 mN / m can meet the interfacial tension requirements of a weak base composite system.
[0043] Table 2. Effect of petroleum sulfonate products prepared in Example 2 on oil-water interfacial tension in oilfields.
[0044]
[0045]
[0046] Example 3
[0047] Weigh a certain amount of feedstock oil (based on the total weight of the feedstock oil, which contains 40 wt% catalytic cracking slurry and 60 wt% low-aromatic dewaxed oil, with a mass ratio of 2:3 between the catalytic cracking slurry and the low-aromatic dewaxed oil) into a three-necked flask. Place the flask in a constant temperature water bath and heat it to 60°C. Add chlorosulfonic acid to the dropping funnel in proportion and add it dropwise under stirring to carry out the sulfonation reaction for 40 minutes. The molar ratio of chlorosulfonic acid to aromatics in the feedstock oil is 1.5:1. After the sulfonation reaction is completed, neutralize the petroleum sulfonic acid with 30% NaOH solution to a pH of 8-9. Then, age the product at an aging temperature of 50°C for 40 minutes to obtain the petroleum sulfonate product.
[0048] The interfacial tension test results of the petroleum sulfonate product prepared in Example 3 on the oil-water interface are shown in Table 3. The interfacial tension was tested using a spin-drop interfacial tensiometer. The surfactant was prepared from oilfield formation water reinjection wastewater at a concentration of 0.05 wt%–0.3 wt%, and the interfacial tension was the stable equilibrium value after 2 hours of testing. The experimental data show that with a petroleum sulfonate product concentration of 0.05–0.3 wt% and an alkali concentration of 1.0–1.2 wt%, the interfacial tension between oil and water can reach 10. -3 mN / m; can meet the interfacial tension requirements of weak base composite systems.
[0049] Table 3. Effect of petroleum sulfonate products prepared in Example 3 on oil-water interfacial tension in oilfields.
[0050]
[0051]
[0052] The embodiments described above are merely preferred embodiments of the present invention, and not all feasible embodiments of the present invention. Any obvious modifications made by those skilled in the art without departing from the principles and spirit of the present invention should be considered to be included within the scope of protection of the claims of the present invention.
Claims
1. A petroleum sulfonate surfactant for oil displacement, characterized in that, It includes feedstock oil, diluent, and sulfonating agent; wherein the molar ratio of the sulfonating agent to the aromatics in the feedstock oil is 1.0 to 1.5:1; the feedstock oil is a mixture of catalytic cracking slurry oil and low-aromatic dewaxing oil.
2. The petroleum sulfonate surfactant for oil displacement as described in claim 1, characterized in that, The diluent is an organic alcohol; the amount of diluent added is 1% to 5% of the raw oil mass.
3. The petroleum sulfonate surfactant for oil displacement as described in claim 1, characterized in that, The sulfonating agent is chlorosulfonic acid or sulfur trioxide.
4. The petroleum sulfonate surfactant for oil displacement as described in claim 1, characterized in that, Low-aromatic dewaxing oil is ketone-benzene dewaxing oil.
5. The method for preparing a petroleum sulfonate surfactant for oil displacement as described in claim 1, characterized in that, Petroleum sulfonate surfactants for oil displacement are prepared by sulfonation, neutralization, and aging of catalytic cracking slurry.
6. The method for preparing a petroleum sulfonate surfactant for oil displacement as described in claim 1, characterized in that, Specifically, the following steps are taken: catalytic cracking slurry oil and ketone-benzene dewaxing oil are mixed in a certain proportion as feedstock oil. Based on the total weight of the feedstock oil as 100%, it contains 10wt%-90wt% catalytic cracking slurry oil and 10wt%-90wt% low-aromatic dewaxing oil. 1%-5% of diluent by weight of the feedstock oil is added, and sulfonation reaction is carried out using chlorosulfonic acid or sulfur trioxide as sulfonating agent. The molar ratio of chlorosulfonic acid to aromatics in the feedstock oil is 1.0-1.5:
1. After the sulfonation reaction, petroleum sulfonic acid is obtained. The petroleum sulfonic acid is neutralized with alkali solution to pH 8-10 to obtain petroleum sulfonate. The petroleum sulfonate undergoes an aging reaction to obtain petroleum sulfonate surfactant.
7. The method for preparing a petroleum sulfonate surfactant for oil displacement as described in claim 6, characterized in that, The alkaline solution is a sodium hydroxide alkaline solution.
8. The method for preparing a petroleum sulfonate surfactant for oil displacement as described in claim 6, characterized in that, The sulfonation reaction conditions are as follows: the sulfonation reaction is carried out at 50-70℃ for 30-60 minutes.
9. The method for preparing a petroleum sulfonate surfactant for oil displacement as described in claim 6, characterized in that, The aging reaction conditions are: aging temperature of 50-60℃ and aging time of 30-60min.
10. The method for preparing a petroleum sulfonate surfactant for oil displacement as described in claim 7, characterized in that, The alkaline solution is a sodium hydroxide solution with a mass concentration of 20% to 40%.