基于分子模拟的新型油溶性降黏剂的制备及性能优化

为了解决胜利油田稠油黏度高、开采困难等问题，通过分子模拟指导，以马来酸酐、甲基丙烯酸十八酯、N-乙烯基吡咯烷酮及苯乙烯进行四元共聚，获得了适合原油特性的降黏剂。以降黏率为考察指标，探讨了单体投料比例、最佳反应条件等对降黏效果的影响。结果表明，马来酸酐、甲基丙烯酸十八酯、N-乙烯基吡咯烷酮及苯乙烯投料摩尔比为4∶13.5∶8∶3、引发剂加量为1%（质量分数）、链转移剂用量为0.5%（质量分数）、80℃反应8h时，合成的降黏剂效果最好，且在降黏剂用量为0.3%（质量分数）时，可将原油黏度从1100mPa·s（50℃）降至403mPa·s，降黏率达到63.3%，原油凝点可从38.5℃降低至33.2℃，通过红外及氢谱等进行了表征，与预想分子结构一致。

Preparation and performance optimization of a new viscosity-reducing agent for crude oil based on molecular simulation

This article provides a method to design a viscosity reducing agent, which builds a crude oil model through molecular simulation and calculates the type of monomer suitable for the viscosity reduction of the crude oil. Viscosity reducing agent was obtained by quaternary copolymerization of styrene with maleic anhydride, octadecyl methacrylate, and N-vinylpyrrolidone. The influence of various factors on the viscosity reduction was determined, and the optimal reaction conditions and monomer feeding ratio were obtained by measuring the viscosity reduction rate of crude oil, infrared spectrum and hydrogen spectrum. The results show that the feed ratio is 4∶13.5∶8∶3, and the reaction is performed at 80℃ for 8 hours. The amount of initiator is 1%(wt), the amount of chain transfer agent is 0.5% (mass fraction). The viscosity of crude oil can be reduced from 1100mPa·s (50℃) to 403mPa·s with a viscosity reduction rate of 63.3% by adding 0.3% (mass fraction) viscosity reducer. After testing the viscosity-temperature curve, it is found that the viscosity-reducing agent can effectively reduce the freezing point of crude oil from 38.5℃ to 33.2℃.The characterization by infrared spectrum and hydrogen spectrum indicates that it has the expected molecular structure.