高含水、高粘、高凝点原油低温管输粘壁现象研究

一些高含水原油在低于凝点输送时，水包油乳状液中的水滴会以凝胶的形式粘在管道内壁，称“粘壁现象”，原油输送过程中粘壁现象会造成管道局部或全部堵塞，造成能源浪费。通过室内环道实验，研究了高含水、高粘、高凝点原油在管道内低温输送时的粘壁规律。发现含水率、剪切率是影响原油粘壁速率和粘壁温度的主要因素，水包油乳状液的含水率越低、剪切率越小粘壁现象越严重。提出粘壁温度判别式，建立粘壁速率模型，据此建立高含水时压降计算软件。

Wall sticking of high water-cut,highly viscous,and high gel-point crude oil transported at low temperatures

Some crude oils with high water cut have the capability to flow below the oil gel point, while the oil particles adhere to the pipe wall in the form of paste, also called "wall sticking". Wall sticking is a serious problem during the pipeline transportation, leading to partial or total blockage of the pipeline and energy wastage. In this paper, a series of laboratory flow loop experiments were conducted to observe the wall sticking characteristics of crude oil with high water cut, high viscosity and high gel point at low transportation temperatures. The effects of shear stress and water cut on the wall sticking rate and occurrence temperature were investigated. Experimental results indicated that the wall sticking rate and occurrence temperature were lower under stronger shear stress and higher water cut conditions. A criterion of wall sticking occurrence temperature(WSOT) and a regression model of wall sticking rate were then established. Finally, the software was developed to calculate the pressure drop along the pipelines of crude oils with high water-cut. It was able to predict the wall sticking thickness of gelled oil and then calculate the pressure drop along the pipelines. A typical case study indicated that the prediction results obtained from the software were in agreement with actual measured values.