THE TEMPERATURE DROP CALCULATION METHOD FOR Oil-GAS-WATER MIXTURE TRANSPORTATION BURIED PIPELINE

摘要

The mixture produced from the oil well is oil-gas-water three-phase, which belongs to complex multiphase flowing in the oil gathering pipeline. It is affected by liquid output, gas outlet, water-cut, pressure drop, annual periodicity change and time delay of soil temperature and so on, therefore, the computation of oil-gas-water three-phase temperature drop is very complex. At present, both domestic and oversea scholars have already studied a lot on multiphase flow temperature calculation without the consideration of annual periodicity change and time delay of soil temperature. This paper firstly considers the annual periodicity change and time delay of soil temperature and deduces a new calculation formula for temperature drop in mixture transportation buried pipeline, which makes use of acknowledge in engineering thermodynamics, hydrodynamics and gas-liquid two-phase flow, and which bases on energy balance, steady-state mass. At the same time, we have built a scientific testing installation in certain measuring space of Daqing oilfield in China, and have obtained about 500 groups testing datum. According to the contrasting analysis between the calculating datum and the testing datum, the results indicate the relative error of temperature drop is between -20% and +20%. We conclude that this formula is very applied for the temperature drop computation for oil-gas-water mixture transportation buried pipeline during high water-cut.Finally, we analyze the temperature drop influencing factors in Oil-gas-water Mixture Transportation Buried Pipeline.