CN-121991669-A - High-efficiency paraffin removal and prevention agent for heavy crude oil and preparation method thereof

Abstract

The invention provides a high-efficiency paraffin inhibitor for heavy crude oil and a preparation method thereof, belonging to the technical field of oilfield chemistry, and comprising the following steps of S1, carrying out surface modification on hollow mesoporous silica microspheres through KH-570 to obtain a carrier with methacrylate double bonds on the surface; the method comprises the steps of S2, preparing a composite carrier with a surface grafted copolymer layer, S3, preparing an amphoteric functional composite carrier, and S4, carrying out D-limonene loading on the amphoteric functional composite carrier to obtain the high-efficiency paraffin inhibitor for heavy crude oil. The invention can solve the problems of difficult combination of paraffin removal and paraffin prevention, insufficient sustained release of active components and poor dispersion stability in complex oil phase in the prior art.

Inventors

• Chen cen
• ZHANG LEI
• LI LE
• ZHANG LONGLONG
• CHENG JIAN

Assignees

• 西安三维科技发展有限责任公司

Dates

Publication Date

20260508

Application Date

20260410

Claims (10)

1. 1. The preparation method of the high-efficiency paraffin inhibitor for heavy crude oil is characterized by comprising the following steps of: Step S1, dissolving CTAB in water, adding ethanol, adjusting pH, adding solid silica spheres, performing ultrasonic dispersion, dripping TEOS to perform heating stirring reaction, and then performing etching and acid extraction by a sodium carbonate solution to obtain hollow mesoporous silica microspheres; s2, dispersing the carrier in a mixed solvent of anisole and DMF, and carrying out graft copolymerization with GMA and ODMA in the presence of an initiator to obtain a composite carrier with a surface graft copolymerization layer; s3, dispersing the composite carrier in a mixed solvent of isopropanol and DMF, reacting with N, N-dimethylaminoethylenediamine, and reacting with 1, 3-propane sultone to obtain an amphoteric functional composite carrier; And S4, carrying out vacuum drying on the amphoteric functional composite carrier, and loading D-limonene by adopting a vacuum adsorption and pressurized impregnation mode to obtain the high-efficiency paraffin inhibitor for heavy crude oil.
2. 2. The method for preparing the high-efficiency paraffin inhibitor for heavy crude oil according to claim 1, wherein the preparation of the solid silica spheres comprises the following steps: Mixing absolute ethyl alcohol, deionized water and ammonia water, stirring at 30-32 ℃ and 390-430rpm, dripping TEOS at the speed of 0.45-0.51g/min, continuing to react for 3.9-4.3h after dripping, centrifuging, washing with ethanol and drying to obtain solid silica spheres.
3. 3. The method for preparing the high-efficiency paraffin inhibitor for heavy crude oil according to claim 1, wherein in the step S1, the pH is regulated to be 10.4-10.6, the ultrasonic dispersion time is 28-32min, the temperature of heating and stirring is 44-46 ℃, and the speed is 580-630rpm.
4. 4. The method for preparing the high-efficiency paraffin inhibitor for heavy crude oil according to claim 1, wherein in the step S1, the concentration of the sodium carbonate solution is 0.075-0.09mol/L, the etching temperature is 79-82 ℃ and the etching time is 7.2-8.5h.
5. 5. The method for preparing the high-efficiency paraffin inhibitor for heavy crude oil, as claimed in claim 1, wherein the carrier comprises the following components in parts by weight: 1.8-2.2 parts of hollow mesoporous silica, 65.9-71.1 parts of anhydrous toluene and 2.8-3.4 parts of KH-570.
6. 6. The preparation method of the high-efficiency paraffin inhibitor for heavy crude oil, as claimed in claim 1, is characterized in that the composite carrier of the surface graft copolymer layer comprises the following components in parts by weight: 0.9-1.1 parts of carrier, 2.2-2.8 parts of GMA, 3.8-4.4 parts of ODMA and 0.09-0.11 part of AIBN.
7. 7. The preparation method of the high-efficiency paraffin inhibitor for heavy crude oil, which is disclosed in claim 1, is characterized in that the amphoteric functional composite carrier comprises the following components, by weight, 1.4-1.6 parts of composite carrier of a surface graft copolymer layer, 22.6-24.5 parts of isopropanol, 0.9-1.1 parts of N, N-dimethylamino ethylenediamine and 0.7-0.9 parts of 1, 3-propane sultone.
8. 8. The method for preparing the high-efficiency paraffin inhibitor for heavy crude oil according to claim 1, wherein in the step S4, the amphoteric functional composite carrier is dried to constant weight at 58-62 ℃ under vacuum, and is kept for 2.0-2.5h after being vacuumized to 18-25 Pa.
9. 9. The method for preparing the high-efficiency paraffin inhibitor for heavy crude oil, as claimed in claim 1, wherein in the step S4, the weight portion of the D-limonene is 32.0-35.3, the pressure of the pressurized impregnation is 1.4-1.6MPa, and the time is 9-11h.
10. 10. The high-efficiency paraffin inhibitor for heavy crude oil is characterized by being prepared by adopting the preparation method of the high-efficiency paraffin inhibitor for heavy crude oil according to any one of claims 1-9.

Description

High-efficiency paraffin removal and prevention agent for heavy crude oil and preparation method thereof Technical Field The invention relates to the technical field of oilfield chemistry, in particular to a high-efficiency paraffin inhibitor for heavy crude oil and a preparation method thereof. Background During the process of exploitation, gathering, transportation and storage of heavy crude oil and high-wax-content crude oil, along with temperature reduction, pressure fluctuation and local shearing condition change, the phase balance among normal alkane, isoparaffin, partial resin and colloid components in the crude oil is destroyed, the paraffin components are gradually separated out and grown up and overlap joint occurs, and finally an adhesive wax layer is formed on the wall surfaces of a shaft, an oil pipe, a gathering pipeline and a storage tank. Once the wax layer is formed, the flow resistance, the pumping pressure and the energy consumption are increased, the effective flow section is reduced, the error of a testing instrument is increased, and even the well is stopped. For heavy crude oil, wax crystals tend to form a dense framework more easily due to higher high molecular weight hydrocarbons, gums and asphaltenes in the system, further increasing the difficulty of peeling and redeposition of the formed wax layer. Aiming at the problem of wax deposition, the prior art generally adopts three means of mechanical paraffin removal, thermal cleaning paraffin removal and chemical paraffin removal and paraffin control agents. Mechanical paraffin removal and thermal cleaning paraffin removal can restore local channels in a short time, but require frequent operation, have high field cost, often can only treat the formed deposited paraffin layer, and have no continuous inhibition effect on subsequent redeposition. Chemical paraffin removal and prevention agents become an important technical route for oilfield sites because of convenient filling and continuous action, but the chemical agents have the problems of different paraffin removal and prevention emphasis, larger site adaptability difference and the like. Patent application document CN103805279a discloses a paraffin removal and prevention agent which takes aromatic hydrocarbon solvent, weighting agent and anionic surfactant as main components, and the scheme realizes short-time paraffin removal by means of rapid dissolution of wax and asphaltene by solvent, and has a certain removal effect on a low-temperature condensed wax layer. However, the free solvent system has the problems of volatile loss, rapid instantaneous consumption and short duration of action when the active ingredients are fully exposed to the oil phase, and meanwhile, the technical emphasis is biased to the dissolution of the deposited wax layer, and the long-term inhibition capability on wax crystal nucleation, growth and redeposition is limited. An oilfield crude oil wax inhibitor and a preparation method thereof are disclosed in a patent application document with publication number of CN109370553A, and the scheme adopts the compound components such as ethylene-vinyl acetate copolymer, pinene, surfactant and the like to improve the wax crystal structure and the fluidity of high-wax-content crude oil. The polymer type wax-proofing system has positive significance for wax crystal morphology adjustment and viscosity reduction, but the main action stage is still in the wax crystal formation and growth process, and the aged wax layer which is firmly adhered to the metal surface is generally lack of strong enough quick stripping and cleaning capability, so that the polymer type wax-proofing system has limitations in continuous scenes of cleaning before preventing. The patent application document with the publication number of CN114763469A discloses an oil-soluble paraffin removal and prevention agent and a preparation method thereof, wherein the scheme combines oil solubility and paraffin removal and prevention performance, has certain applicability to a paraffin-containing thick oil system, but active components of the paraffin removal and prevention agent are still mainly present in a medium in a free dispersion mode and are easy to be influenced by a shaft temperature gradient, a flow rate and a residence time to generate local concentration attenuation, and when the paraffin removal component and the paraffin prevention component lack of space distribution and interface tissues, the quick weakening of an existing paraffin layer, the inhibition of secondary aggregation of paraffin crystals and the dispersion stability in a complex oil phase environment are difficult to be simultaneously considered. Therefore, there is a need to provide a high-efficiency paraffin inhibitor for heavy crude oil and a preparation method thereof, so as to solve the problems in the prior art. Disclosure of Invention In view of the above, the invention provides a high-efficiency paraffin inhibitor for heavy