Abstract:

Based on the effects of pressure, temperature, light oil, solvent and surfactant on the mobility of heavy crude oil, a method was proposed for improving oil mobility. The research results indicate that various active agents and light oil used to reduce the viscosity of crude oil have obvious influences on the flow ability of heavy oil. Adding a small amount of mixed aromatics can significantly reduce the viscosity of crude oil bulk and also reduce the adding amount of light oil. While adding the solvent oil-soluble active agent, the lower viscosity of crude oil can be obtained. While the light oil is limited, adding emulsion viscosity-reducer is still a cheap and effective method. However, if the viscosity of crude oil is particularly high and the salinity of formation water is up to 15×10⁴mg/L, and alkaline earth metal is as high as 2×10⁴ mg/L, the active agents for reducing viscosity of heavy oil must be of salt resistance. Moreover, it is necessary to add the stable agents and friction-reducing agents for adjusting the oil-water ratio. So crude oil and formation water can be well mixed and simultaneously flow in the low-friction wellbore. The high water production and low oil production resulted from the instability of oil-water emulsion can be effectively avoided under the action of salt.

Key words: heavy crude oil, flow ability, viscosity-reduction method, oil and water stabilizer, active agent, salt resistance

摘要：

探讨了压力、温度、掺入剂等外加因素对高矿化度稠油流动性的影响，提出了改善原油流动的方法。稠油掺入稀油降黏所用的“稀油”对改变原油的流动性的影响十分明显，加入少量混合芳烃能使原油本体黏度大大降低，同时也大幅度减少稀油的用量。如果加入油溶性活性剂，则效果更好。当稀油资源受到限制时，加入乳化降黏剂更是廉价有效的方法。如果原油黏度特别高及储层水的矿化度高达15×10⁴mg/L、且碱土金属也高达2×10⁴mg/L时，稠油降黏所用的活性剂必须耐盐，并且须加入油水稳定剂和降摩阻剂。这样调整油水的流度比能使原油和水同步上升，使原油在地层和井筒中的摩擦力降低，有效地避免由于油水乳状液在盐的作用下的不稳定性所引起的地层含水率升高、产油量降低的问题。

关键词: 稠油, 流动性, 降黏法, 油水稳定剂, 活性剂, 耐盐性