Abstract:

As a universal low temperature gathering and transportation boundary condition,the wall sticking occurrence temperature (WSOT) has been widely promoted and applied in the oilfield in the late stage of high water cut development. When the oil gathering temperature is higher than the WSOT, the pipeline operates smoothly, otherwise the pressure drop of most pipelines increases significantly, but some of the pipeline pressure drop changes are not obvious. Through the field cooling experiment, it was found that in the process of the oil gathering temperature gradually decreasing to 6,8,10 ℃ and 12 ℃ below the gel point, the wellhead back pressure has experienced four stages of smooth operation, small fluctuation, low frequency large fluctuation and high frequency large fluctuation, and there are several "restart" processes in the pipeline when the gathering temperature is too low. At the same time, the gas injection experiment under different gas?oil ratio was further carried out, and the results show that when the gas?oil ratio is 40,80,160 m³/t, the pipeline can run stably at the gathering temperature 3,4 ℃ and 6 ℃ lower than the WSOT.

Key words: Low temperature gathering and transportation, Below the wall sticking occurrence temperature, Gas?containing crude oil, Field gas injection experiment

摘要：

黏壁温度作为普适性低温集输边界条件，其在高含水率开发后期的油田中得到了广泛推广及应用。当集输温度高于黏壁温度时，集输管线运行平稳；当集输温度低于黏壁温度时，绝大部分集输管线的压降显著升高，部分集输管线的压降变化不明显。现场降温试验结果表明，当集输管线进入计量间温度逐渐降低至凝点以下6、8、10、12 ℃时，井口回压存在运行平稳、小幅波动、低频大幅波动和高频大幅波动四个阶段的变化，且当集输温度过低时，集输管线内存在多次“再启动”过程。不同气油比条件下的现场集油管线掺气降温试验结果表明，当气油比分别为40、80、160 m³/t时，集输管线可以在进入计量间温度低于黏壁温度3、4、6 ℃的工况下进行低温集输。

关键词: 低温集输, 黏壁温度, 含气原油, 现场掺气试验