油田掺水集油系统的高频防垢
High Frequency Antiscaling in A Watered Oil Gathering System
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摘要: 对于大庆油田生产的高含蜡、高粘度、高凝固点的石蜡基原油, 采用双管掺水集油。为解决掺水造成的水质污染与结垢, 从80年代开始采用化学投药进行阻垢, 虽阻垢效率达90%以上, 但因费用高、在90C热水中有降解作用、腐蚀管道、污染环境、加药工艺复杂, 且只能防垢不能清垢, 所以也不是理想的方法。基于以上原因, 提出一种新的高频防垢技术, 其防垢机理是当掺水介质进入高频电场后, 与高频电磁波发生极化作用和空化作用, 极化作用使分子的极性增强, 在分子热运动过程中分子的排列顺序改变, 钙镁离子不能正常结晶, 垢晶松散, 垢粒易被破碎; 空化作用使介质在高频电场下产生旋流。使其表面张力下降, 延缓水垢沉积附壁的速度, 使结垢分子与金属壁之间的亲和力减弱, 对已沉积在金属壁上的老垢亦有疏松和软化作用, 从而达到对掺水集油系统的阻垢和清垢的目的。要想得到最佳防垢、清垢效果, 必须合理地选择流程, 并使主机与副机的阻抗相匹配。Abstract: In Daqing Oil Field, dual string watered gathering is adoped for the paraffinic base oil with high wax content, high viscosity and high pour point. Chemical additive method has been in use since the 80's to prevent scaling due to watering. Although it has a performance of 90%, this method is not a good solution because of the following disadvantages: high cost, degradation at 90 C water, corrosion to pipeline, pollution to environment, complicated dosing process, prevention without scale cleaning. Therefore, introduced is the high frequency antiscaling method, the concept of which is that the watered medium in high frequency field sees polarization and cavitation with the effect of high frequency electromagnetic waves. Polarization results in high polarity, molecular rearrangement, incapability of crystallisation between calcium and magnesium ions, loose scale crystal, and brittle scale particals. Cavitation, on the other hand, contributes to scale prevention and removal by convoluting and decreasing the surface tension of the medium in high frennencv electric field, lagging scale deposit, breaking the affinity between scale and metallic wall, and loosening and softening the existing seale. Best seale prevention and removal can be achieved only by reasonable process selection and impendence matching between main and associate machines.