摘要
针对原油在管道集输过程中在管壁结蜡危害的问题,首先分析了管道结蜡沉积机理,在此基础上,综合考虑了蜡分子浓度梯度、管壁处剪切应力、油流温度梯度以及粘度等因素建立结蜡沉积速率模型,根据实际油田地区情况,结合当地季节土壤温度,做了含水率、集油温度、流量等对结蜡速率的影响,研究表明含水率在65%左右,也就是在转相点附近管道结蜡速率最高,主要是原油粘度影响较大;集油温度越高,结蜡速率越低,是由于温度的高低决定了分子的扩散和热运动大小;流量越大,结蜡速率越低,是因为剪切应力破坏了管壁结蜡沉积强度。针对结蜡对管道堵塞腐蚀的影响,选取PIG清管技术进行处理,能够有效的降低管道输送压力,降低管道穿孔风险,在保障年输量的条件下,节约电量高达4.32×105 k W?h,年运行费用减少了123.89×104元。实验结果有助于指导该地区原油集输管道工程设计。
Aimed at hazards of paraffin deposit rate in crude oil gathering and transferring process, firstly wax deposition mechanism was analyzed.On this basis, considering the wax molecule concentration gradient and wall shear stress, flow, temperature gradient, viscosity and so on, the wax deposition rate model was established. According to actual oil field condition, combined with the local seasonal soil temperature, effect of moisture content, oil temperature and flow rate on the paraffin deposit rate was investigated. The results show that, when the moisture content is about 65%, which is near the phase inversion point, the wax precipitation rate is the highest, which is mainly caused by greater viscosity of crude oil; The higher the oil temperature, the lower the wax precipitation rate, which is due to that the temperature can affect the molecular diffusion and heat movement; The lower the flow rate, the higher the wax precipitation rate, which is due to that the shear stress can damage wall wax deposition. In order to decrease effect of the paraffin deposit rate on pipe blockage and corrosion, the PIG pigging technology can be used, it can effectively reduce the pipeline pressure and the pipeline perforation risk; Under the condition of ensuring annual throughput, 4.32＆#215;105 kW＆#183;h power can be saved, annual operation cost can be decreased by123.89＆#215;104 Yuan. The results help guide for engineering design of crude oil pipeline in the region.
出处
《当代化工》
CAS
2015年第6期1388-1391,共4页
Contemporary Chemical Industry
基金
国家科技重大专项
项目号:2009ZX05038-002
