A high-efficiency oil layer cleaning agent and its preparation method

Abstract

This invention belongs to the field of cleaning agent technology, specifically relating to a high-efficiency oil layer cleaning agent and its preparation method. The high-efficiency oil layer cleaning agent, by weight percentage, consists of the following raw materials: sodium perfluorobenzenesulfonate 0.2-0.3%; trifluorotoluene polyurethane ether 0.1-0.2%; rapid penetrant T 0.1-0.2%; the balance being water; wherein the structural formula of sodium perfluorobenzenesulfonate is as follows:; the structural formula of trifluorotoluene polyurethane ether is as follows: where m=5-20, n=5-50; and the structural formula of rapid penetrant T is as follows: This invention combines strong temperature and salt resistance with low foaming and easy operation, enabling deep, rapid, and thorough cleaning of heavy oil stains; the oil removal rate of the cleaning agent of this invention can reach up to 97.5%.

Description

Technical Field

[0001] This invention belongs to the field of cleaning agent technology, specifically relating to a high-efficiency oil layer cleaning agent and its preparation method. Background Technology

[0002] Once oilfield development enters the high water-cut or even ultra-high water-cut stage, the formation water cut generally reaches over 60%, and in some cases exceeds 90%. The remaining oil is highly dispersed, with approximately 60%-70% remaining in the reservoir pores, resulting in low recovery rates and increased extraction costs. Simultaneously, changes in formation temperature and pressure, along with fluid flow, cause heavy components such as paraffin and colloids in the crude oil to precipitate and adsorb onto the core and inorganic scale surfaces, forming complex blockages that reduce reservoir permeability and exacerbate extraction difficulties. Therefore, highly efficient reservoir cleaning agents are urgently needed to address these problems.

[0003] Existing oil reservoir cleaning agents have many drawbacks: acidic cleaning agents can only remove inorganic scale, are ineffective against oil scale, and are highly corrosive, easily damaging equipment; organic solvent-based cleaning agents can dissolve oil scale, but they are flammable, explosive, highly toxic, difficult to degrade, costly, and unsuitable for large-scale applications; conventional surfactant-based cleaning agents have poor penetration, low oil washing efficiency, weak temperature and salt resistance, are easily depleted in complex oil reservoirs, and cannot provide long-term cleaning.

[0004] Existing products struggle to balance efficient oil washing, unclogging, environmental friendliness, and low cost, and also lack compatibility with oilfield extraction systems and ease of application. To address these shortcomings, the development of an oil reservoir cleaning agent that combines efficient oil washing, rapid unclogging, temperature and salt resistance, environmental friendliness, ease of use, and controllable cost is of significant practical importance and promising application prospects for resolving oil reservoir blockage, improving the utilization rate of remaining oil, and promoting efficient later-stage oilfield development. Summary of the Invention

[0005] This invention addresses the shortcomings of existing technologies by providing a highly efficient oil layer cleaning agent and its preparation method. This invention combines strong temperature and salt resistance with low foaming and ease of operation, enabling deep, rapid, and thorough cleaning of heavy oil stains; the cleaning agent of this invention can achieve an oil removal rate of up to 97.5%.

[0006] The first objective of this invention discloses a high-efficiency oil layer cleaning agent, which, by weight percentage, is composed of the following raw materials: Sodium perfluorobenzenesulfonate 0.2-0.3%; Trifluorotoluene polyurethane 0.1-0.2%; Rapid penetration agent T 0.1-0.2% Water balance; The structural formula of the sodium perfluorobenzenesulfonate is as follows:

[0007] The structural formula of the trifluorotoluene polyurethane ether is as follows:

[0008] Where m = 5 - 20, n = 5 - 50; The structural formula of the rapid penetration agent T is as follows: .

[0009] The second objective of this invention is to provide a method for preparing the aforementioned oil layer cleaning agent, the method specifically comprising the following steps: (1) Preparation of sodium perfluorobenzenesulfonate ① Add 2,2'-benzidine disulfonic acid and isopropanol / water mixed solvent (V:V=1:1) to the first reactor, and add sodium hydroxide solution while stirring until completely dissolved, and adjust the pH to 8-9; ② In the above reactor, add triethylamine and cool to 10°C or below; ③ Add perfluorooctanoic acid chloride slowly in batches, controlling the temperature to not exceed 10℃, and continue the reaction for 30 minutes or more after the addition is complete; ④ After the reaction is complete, remove part of the solvent by vacuum distillation, cool to crystallize, filter, and dry to obtain sodium perfluorobenzenesulfonate.

[0010] Preferably, the molar ratio of triethylamine, perfluorooctanoyl chloride and 2,2'-benzidine disulfonic acid in step (1) is 1.8-2.6:1.6-2.4:1.

[0011] Preferably, the mass ratio of isopropanol / water mixed solvent to 2,2'-benzidine disulfonic acid in step (1) is 10-15:1.

[0012] (2) Preparation of trifluorotoluene polyurethane ① In a high-pressure reactor, add 4-aminotrifluorotoluene and catalyst, purge the pipeline and reactor with nitrogen, evacuate, heat to 80-90℃, stop evacuating, add propylene oxide, continue stirring and heat to 110-160℃, then gradually reduce the pressure. When the pressure no longer decreases, cool the reaction system to 80-90℃. ② Slowly introduce ethylene oxide. After the introduction is complete, raise the temperature to 120-170℃. Then, gradually decrease the pressure. When the pressure no longer decreases, cool the reaction system to room temperature and neutralize the pH to 7-8 with phosphoric acid to obtain trifluorotoluene polyurethane.

[0013] Preferably, the molar ratio of propylene oxide, ethylene oxide and 4-aminotrifluorotoluene in step (2) is 5-20:5-50:1.

[0014] Preferably, the catalyst in step (2) is one of sodium hydroxide, potassium hydroxide, and potassium carbonate, with a mass ratio of 0.005-0.01:1 to 4-aminotrifluorotoluene.

[0015] (3) Preparation of oil layer cleaning agent Water, sodium perfluorobenzenesulfonate, trifluorotoluene polyurethane, and rapid penetrant T are added sequentially to the second reactor and stirred until homogeneous to obtain a high-efficiency oil layer cleaning agent.

[0016] Compared with the prior art, the present invention has the following advantages and beneficial effects: The high-efficiency oil layer cleaning agent of this invention belongs to the category of composite cleaning agents. Among them, sodium perfluorobenzenesulfonate has extremely low surface tension and excellent chemical stability, which significantly changes the wettability of the rock, changing it from oil-wet to water-wet, which is beneficial for oil washing. During the oil washing process, it can also effectively prevent the crude oil being washed off from forming a stable emulsion with the working fluid, ensuring a smooth oil washing process. Trifluorotoluene polyurethane can firmly encapsulate the stripped oil droplets to form a stable emulsion and prevent oil stains from re-adhering. At the same time, its low-foaming properties ensure the smooth operation of the system. The fast penetrant T has a double-tailed chain structure and an extremely fast penetration speed. It quickly inserts itself between the oil stains and the substrate like a "molecular wedge", "splitting" the continuous oil film into small pieces, making the oil stains easier to peel off. It can significantly improve the wettability of the cleaning fluid on solid surfaces, allowing the liquid to spread rapidly on the oil stain surface. The three components combine to create a three-stage synergistic effect of penetration, stripping, and emulsification: the fluorocarbon surfactant, with its ultra-low tension, opens channels and penetrates into micropores; the rapid penetrant T then splits and strips away the oil film; and trimethylolpropane polyether stabilizes and emulsifies the oil, preventing back-adhesion. This system combines strong temperature and salt resistance with low foaming and ease of operation, enabling deep, rapid, and thorough cleaning of heavy oil stains. The cleaning agent of this invention can achieve an oil removal rate of up to 97.5%. Detailed Implementation

[0017] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0018] The technical solution of the present invention will be further described below with reference to specific embodiments: Example 1

[0019] (1) Add 0.05 mol of 2,2'-benzidine disulfonic acid and 172 g of isopropanol / water mixed solvent (V:V=1:1) to the reactor, and add sodium hydroxide solution while stirring until completely dissolved, and adjust the pH to 8-9; (2) Add 0.09 mol of triethylamine to the above reactor and cool it to 10°C; (3) Add 0.08 mol of perfluorooctanoyl chloride slowly in batches, control the temperature at 10℃, and continue the reaction for 30 min after the addition is complete; (4) After the reaction is complete, part of the solvent is removed by vacuum distillation, the crystals are cooled, filtered, and dried to obtain sodium perfluorobenzenesulfonate.

[0020] Example 2 (1) Add 0.05 mol of 2,2'-benzidine disulfonic acid and 258 g of isopropanol / water mixed solvent (V:V=1:1) to the reactor, and add sodium hydroxide solution while stirring until completely dissolved, and adjust the pH to 8-9; (2) Add 0.13 mol of triethylamine to the above reactor and cool it to 5°C; (3) Add 0.12 mol of perfluorooctanoyl chloride slowly in batches, control the temperature at 5°C, and continue the reaction for 60 min after the addition is complete; (4) After the reaction is complete, part of the solvent is removed by vacuum distillation, the crystals are cooled, filtered, and dried to obtain sodium perfluorobenzenesulfonate.

[0021] Example 3 (1) Add 0.05 mol of 2,2'-benzidine disulfonic acid and 236 g of isopropanol / water mixed solvent (V:V=1:1) to the reactor, and add sodium hydroxide solution while stirring until completely dissolved, and adjust the pH to 8-9; (2) Add 0.11 mol of triethylamine to the above reactor and cool it to 5°C; (3) Add 0.1 mol of perfluorooctanoyl chloride slowly in batches, control the temperature at 6℃, and continue the reaction for 40 min after the addition is complete; (4) After the reaction is complete, part of the solvent is removed by vacuum distillation, the crystals are cooled, filtered, and dried to obtain sodium perfluorobenzenesulfonate.

[0022] Example 4 (1) In a high-pressure reactor, add 0.1 mol of 4-aminotrifluorotoluene and 0.08 g of sodium hydroxide, purge the pipeline and reactor with nitrogen, evacuate, heat to 80°C, stop evacuating, add 0.5 mol of propylene oxide, continue stirring and heat to 110°C, then gradually reduce the pressure. When the pressure no longer decreases, cool the reaction system to 80°C. (2) Slowly introduce 0.5 mol of ethylene oxide. After the introduction is complete, raise the temperature to 120°C. Then, gradually decrease the pressure. When the pressure no longer decreases, cool the reaction system to room temperature. Neutralize the pH to 7-8 with phosphoric acid to obtain trifluorotoluene polyurethane.

[0023] Example 5 (1) In a high-pressure reactor, add 0.1 mol of 4-aminotrifluorotoluene and 0.16 g of potassium hydroxide, purge the pipeline and reactor with nitrogen, evacuate, heat to 85°C, stop evacuating, add 1 mol of propylene oxide, continue stirring and heat to 140°C, then gradually reduce the pressure. When the pressure no longer decreases, cool the reaction system to 85°C. (2) Slowly introduce 2 mol of ethylene oxide. After the introduction is complete, raise the temperature to 150°C. Then, gradually reduce the pressure. When the pressure no longer decreases, cool the reaction system to room temperature. Neutralize the pH to 7-8 with phosphoric acid to obtain trifluorotoluene polyurethane.

[0024] Example 6 (1) In a high-pressure reactor, add 0.1 mol of 4-aminotrifluorotoluene and 0.14 g of potassium carbonate, purge the pipeline and reactor with nitrogen, evacuate, heat to 90°C, stop evacuating, add 2 mol of propylene oxide, continue stirring and heat to 160°C, then gradually reduce the pressure. When the pressure no longer decreases, cool the reaction system to 90°C. (2) Slowly introduce 5 mol of ethylene oxide. After the introduction is complete, raise the temperature to 170°C. Then, gradually reduce the pressure. When the pressure no longer decreases, cool the reaction system to room temperature. Neutralize the pH to 7-8 with phosphoric acid to obtain trifluorotoluene polyurethane.

[0025] Examples 7-11, Comparative Examples 1-3 Water, sodium perfluorobenzenesulfonate, trifluorotoluene polyurethane, and rapid penetrant T were added sequentially to the reactor and stirred until homogeneous to obtain a high-efficiency oil layer cleaning agent.

[0026] The dosage of each component is shown in Table 1.

[0027] Table 1. Composition of Examples 7-11 and Comparative Examples 1-3

[0028] Test Example 1: Oil Washing Efficiency Test The oil washing efficiency was tested using the method described below, and the test results are shown in Table 2.

[0029] (1) Take the sludge and sand from the bottom of a heavy oil storage tank at a certain joint station, place it in an 80℃ oven, and let it stand for 7 days to age. (2) Take 5g of aged oily mud sand and place it in a 100ml Erlenmeyer flask. Add 50g of the present invention (Examples 7-11 and Comparative Examples 1-3), mix thoroughly, place in an 80℃ oven, and let stand for 48h. (3) Use clean cotton gauze to remove the crude oil floating in the sample solution and the crude oil adhering to the bottle wall after standing. Pour out the sample solution and rinse the oil sand 2 to 3 times with distilled water until there is no foam. Carefully pour out the solution. Place the conical flask in a 105℃ constant temperature oven to dry to constant weight and weigh it. (4) Use petroleum ether to wash the oil sand dried in step (3) until the petroleum ether is colorless. Place the conical flask with all the crude oil washed out in a 120°C oven and dry for 2 hours before weighing.

[0030] (5) Calculate the washing efficiency η × 100% η is the oil washing efficiency; m is the mass of the aged oil sand, in grams; m1 is the mass of the conical flask, in grams; m2 is the total mass of the conical flask and oil sand after washing, in grams; m3 is the total mass of the conical flask and the washed formation sand, in grams.

[0031] Table 2 Results of the wash-oil ratio test

[0032] As can be seen from Table 2: The difference between Example 7 and Comparative Example 1 is that Comparative Example 1 did not add the fast penetrant T, and the oil washing rate decreased by 6.2%.

[0033] The difference between Example 9 and Comparative Example 2 is that Comparative Example 2 did not add trifluorotoluene polyurethane, and the wash oil rate decreased by 4.2%.

[0034] The difference between Example 11 and Comparative Example 3 is that Comparative Example 3 did not add sodium perfluorobenzenesulfonate, and the wash oil rate decreased by 4.3%.

[0035] Therefore, the sodium perfluorobenzenesulfonate, trifluorotoluene polyurethane, and rapid penetration agent T in this invention all contribute to improving the wash oil yield.

[0036] The difference between Example 7 and Comparative Example 3 is that the total mass of the active ingredients is the same, but Comparative Example 3 did not add sodium perfluorobenzenesulfonate, and the wash oil rate decreased by 1.6%.

[0037] Therefore, the various components of this invention, such as sodium perfluorobenzenesulfonate, trifluorotoluene polyurethane ether, and rapid penetrant T, have a synergistic effect on improving the oil washing rate. It is not a simple compound, and the oil washing effect is 1+1+1>3.

[0038] In summary, this invention combines excellent temperature and salt resistance with low foaming and ease of operation, enabling deep, rapid, and thorough cleaning of heavy oil stains. Therefore, it has broad market application prospects.

[0039] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details of the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

Claims

1. A high-efficiency oil layer cleaning agent, characterized in that, The high-efficiency oil layer cleaning agent is composed of the following raw materials by weight percentage: Sodium perfluorobenzenesulfonate 0.2-0.3%; Trifluorotoluene polyurethane 0.1-0.2%; Rapid penetration agent T 0.1-0.2% Water balance; The structural formula of the sodium perfluorobenzenesulfonate is as follows: ； The structural formula of the trifluorotoluene polyurethane ether is as follows: ； Where m = 5 - 20, n = 5 - 50; The structural formula of the rapid penetration agent T is as follows: 。 2. The method for preparing the oil layer cleaning agent according to claim 1, characterized in that, The preparation method specifically includes the following steps: (1) Preparation of sodium perfluorobenzenesulfonate ① Add 2,2'-benzidine disulfonic acid and isopropanol / water mixed solvent (V:V=1:1) to the first reactor, and add sodium hydroxide solution while stirring until completely dissolved, and adjust the pH to 8-9; ② In the above reactor, add triethylamine and cool to 10°C or below; ③ Add perfluorooctanoic acid chloride slowly in batches, controlling the temperature to not exceed 10℃, and continue the reaction for 30 minutes or more after the addition is complete; ④ After the reaction is complete, remove part of the solvent by vacuum distillation, cool to crystallize, filter, and dry to obtain sodium perfluorobenzenesulfonate; (2) Preparation of trifluorotoluene polyurethane ① In a high-pressure reactor, add 4-aminotrifluorotoluene and catalyst, purge the pipeline and reactor with nitrogen, evacuate, heat to 80-90℃, stop evacuating, add propylene oxide, continue stirring and heat to 110-160℃, then gradually reduce the pressure. When the pressure no longer decreases, cool the reaction system to 80-90℃. ② Slowly introduce ethylene oxide. After the introduction is complete, raise the temperature to 120-170℃. Then, gradually decrease the pressure. When the pressure no longer decreases, cool the reaction system to room temperature and neutralize the pH to 7-8 with phosphoric acid to obtain trifluorotoluene polyurethane. (3) Preparation of oil layer cleaning agent Water, sodium perfluorobenzenesulfonate, trifluorotoluene polyurethane, and rapid penetrant T are added sequentially to the second reactor and stirred until homogeneous to obtain a high-efficiency oil layer cleaning agent.

3. The method for preparing the oil layer cleaning agent according to claim 2, characterized in that, The molar ratio of triethylamine, perfluorooctanoyl chloride and 2,2'-benzidine disulfonic acid in step (1) is 1.8-2.6:1.6-2.4:

1.

4. The method for preparing the oil layer cleaning agent according to claim 2, characterized in that, The mass ratio of isopropanol / water mixed solvent to 2,2'-benzidine disulfonic acid in step (1) is 10-15:

1.

5. The method for preparing the oil layer cleaning agent according to claim 2, characterized in that, The molar ratio of propylene oxide, ethylene oxide and 4-aminotrifluorotoluene in step (2) is 5-20:5-50:

1.

6. The method for preparing the oil layer cleaning agent according to claim 2, characterized in that, The catalyst mentioned in step (2) is one of sodium hydroxide, potassium hydroxide, and potassium carbonate, with a mass ratio of 0.005-0.01:1 to 4-aminotrifluorotoluene.

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