高凝原油低温集输多相流流型试验研究

Experimental research on multiphase flow regime for low-temperature gathering process of high freezing point crude oil

由于多相流流型直接影响多相流动的传热特性及摩擦阻力,因此高凝原油低温集输多相流流型研究对原油安全集输及节能降耗有至关重要的意义。课题组在大庆油田现场,进行环状集输流程改造,以油井产出的油气水混合物为试验介质,在内径为67mm的水平管内,通过目测及摄影法等研究手段,进行了高凝原油低温集输多相流流型试验研究。试验原油凝点为38℃,试验环路掺水量1.5m3/h,含水质量分数84.6%,油相折算速度0.02m/s,水相折算速度0.13m/s,气相折算速度0.048m/s,实验温度为35.6～43.3℃。试验研究结果表明,在试验参数范围内,油气水多相流流型划分为分层流、油柱管芯流、满管油柱间断流三种。与温度高于原油凝固点时油气水多相流流型相比,输送温度在原油凝固点以下时,油气水三相流流型有较大差异。

Owing to the direct effect of multiphase flow pattern to friction and heat transfer characteristics, experimental research on multiphase flow pattern for Low-temperature Gathering process of high freezing point crude oil has a crucial importance for improveing energy efficiency and secure transportion. Circle oil transportation process was transformed at Daqing oilfield. Experimental medium was the oil-gas-water produced by the wells. Researchs on the multiphase flow for low-temperature gathering process of high freezing point crude oil by means of visual observation, photography in horizontal pipe with an inner diameteris of 67 mm. Under the conditons of 38.0 ＊C oil freezing point, 1.5 m3/h mixed water, 84.6~ quality water fraction, 38 ＊C freezing point, 0.02 m/s the oil phase convert velocity, 0.13 m/s the water phase convert velocity and 0.048 m/s the gas phase convert velocity, temperature range from 35.6 to 43.3 ＊C, the results show that the flow pattern can be classified as three kinds that are stratified flow, oil column in the pipeline center flow, and full pipe oil column intermediate flow. Compared to oil gas and water multiphase flow above the freezing point of crude oil, when the transportation temperature is lower than the oil freezing point, oil-gas-water multiphase flow have great difference.