高含水期原油低温集输黏壁特性实验

Experiment on wall sticking characteristics during the low-temperature gathering and transportation of crude oil in the period of high water cut

高含水期油井可在原油凝点以下进行低温集输,但当集输温度低于其黏壁温度时,会发生原油在壁面黏附积聚的情况,影响油田实际生产运行。基于大量的油田现场实验,利用可视化实验装置,通过停三管伴热降低油水进站温度的方法,分析华北油田高阳区块油水两相流在不同进站温度下的管输流动特性,得到了进站温度与压降间的关系,并发现黏壁温度下压降突增的现象,从而得到油田现场测定高含水期油井原油黏壁温度的方法,并测得高阳区块3口典型油井的黏壁温度,其实际生产条件下的黏壁温度均低于原油凝点3~4℃,且油井液量越大,含水率越高,黏壁温度越低。提出的黏壁温度测试方法,对华北油田高含水期油井实现低温集输具有指导意义。

In the oil wells with high water cut,low-temperature gathering and transportation can be implemented below the freezing point of crude oil.When the gathering temperature is lower than its wall sticking occurrence temperature,however,the crude oil will be adhered and accumulated on the wall,which will impact the actual operation of the oilfield.In this paper,the pipeline flow characteristics of oil-water two-phase flow in Gaoyang Block of Huabei Oilfield at different inlet temperatures were investigated by stopping the heating of three pipes to decrease the inlet temperature of oil and water.This study was carried out using the visual experiment device based on a great number of field experiments.The relationship between the inlet temperature and the pressure drop was obtained and the sudden pressure drop at the wall sticking occurrence temperature was discovered.In this way,the method for the on-site determination of wall sticking occurrence temperature of crude oil in the oil wells with high water cut was developed,and the wall sticking occurrence temperatures of three typical oil wells in Gaoyang Block was measured.It is indicated that the wall sticking occurrence temperature under actual production conditions is 3-4℃lower than the freezing point of crude oil.What’s more,the higher the liquid production rate of oil well is,the higher the water cut is and the lower the wall sticking occurrence temperature is.In conclusion,this proposed method for measuring wall sticking occurrence temperature is of guiding significance to the low-temperature gathering and transportation of oil wells with high water cut in Huabei Oilfield.