超深稠油高温高压井筒降黏举升摩阻实验研究

新疆深层稠油在井筒举升过程中，由于温度的降低，原油会逐渐失去流动性。稠油降黏是有效降低井筒举升摩阻的途径。根据现场掺降黏剂工艺，建立了室内高温高压井筒流动模拟实验装置，实验研究了温度、压力及流速对稠油井筒举升流动摩阻的影响，得到了不同降黏方式井筒举升摩阻梯度分布，在已有井筒压降计算模型的基础上，构筑了室内井筒流动模拟装置与实际井筒之间的压降换算关系，得到了不同降黏方式塔河原油在实际井筒中压力分布。实验表明：原油在垂直井筒中举升摩阻随压力和流速的增加而增大，随着温度的升高而降低，但流速越大，井筒流动摩阻增加趋势渐缓。在井下3000m处掺降黏剂使稠油更易举升至井口，降黏效果：复合降黏剂＞油溶性降黏剂＞掺稀降黏。

Research on lift friction of ultra-deep heavy oil with viscosity reduction in wellbore under high temperature/pressure

The ultra-deep heavy oil in Xinjiang will lose its fluidity gradually with the decrease in temperature during the fluid lifting in wellbore. Heavy oil viscosity reduction is the effective way to reduce the lift friction in wellbore. The high temperature and high pressure wellbore simulation experiment set was built according to the practical process of blending viscosity reducer. In the experiments, the effects of temperature, pressure and flow rate on the friction drug of wellbore lift were studied. And the friction gradient distribution in the wellbore with different ways of viscosity reduction were measured. Moreover, the mathematical relation of pressure drop between the wellbore flow simulation device and the actual wellbore was built and the pressure distribution in the actual wellbore was experimental obtained. Experimental results show that the pressure drop during the crude oil lifting in wellbore increased with the increase in pressure and flow rate while decreased with temperature increasing, the increasing trend of the flow friction of heavy crude oil in wellbore decreased with increase in flow rate. The effect of viscosity reduction is: compound viscosity reducer>oil-soluble viscosity reducer> mixing light oil.