Experiment Research On The Mechanism Of Gas Fluid Two-phase Slug Flow

Slug flow is the most common flow regime of oil-gas-water combined pipelines, which has liquid slug intermittent flow separated by long bubbles. For the alternation of gas-liquid two-phase causes intensive fluctuations between liquid holdup and pressure in the pipelines, which makes pipeline transporting gas-liquid mixture to endure impact under pulsed stress. At the same time, the long liquid slug leaving the end of pipeline causes intensive fluctuations of liquid level of oil and gas treatment equipment in the lower reaches and affects normal production. Especially during transportation of oil gathering in ocean oil and gas field, the special and harmful flow regime will be found in the ascension pipe system, which brings about several problems in design and production. Therefore, the research on the flow characters and change law in various slope pipeline of slug flow plays an important role and application value in finding a good way to control slug flow effectively.In the special laboratory, we studied gas-liquid two-phase flow in different oblique angle and pipe diameter by multiphase flow equipment, got some flow parameters , such as, condition and pressure drop of slug flow happening, analyzed it, announced the law, established the calculation formula of forecasting pressure drop in different oblique angle and pipe diameter by data. All of this supply important theoretical basis for calculating and controlling slug flow. The main work can be seen form the following:(1) Collecting the slug flow papers in the world. It summaries the research progress of slug flow's forming mechanism, characteristic parameters and its measurement. And it introduces how to calculate liquid holdup and pressure drop, and deduces important calculation.(2) During consulting design data of experiment equipment, I know their work principle, data acquisition and calculation principle, and adjust and correct the steps and instrument that need to be improved in the multiphase flow equipment. Basing on the practical investigation to State Key Laboratory of Multiphase Flow in Xi'an Communication University, I study some ways to measure characteristic parameter of multiphase flow and get ready to devote to research.(3)In the special Laboratory of Daqing Petroleum Institute, air and waiter are considered to be flow media in different oblique angle and pipe diameter to be tested, and data can be obtained form collecting and finishing. Analysis of pressure gradient and liquid holdup variation law in slug flow covers its inner law and determines the influential factors of slug flow'pressure drop.(4)According to the experiment result, I deduce and fit of pressure drop calculation of slug flow in test section, and get its calculation and derivation method.