The Characterization Analysis Of Oil-air-water Three-phase Flow Regime Based On Dynamic Image Processing

The transportation of oil, gas and water is the key point in oil industry devel- opment and gathering transportation project. Multiphase transportation technolo- gy has the characteristics of reducing pipeline investment and working cost and so on, so it is increasingly used in gathering pipeline nets and oil pipeline transportation nets in oil fields, in which flow pattern identification is the means. Therefore, it is of great significance to perform an investigation on oil/gas/water three-phase flow in pipelines. Different flow regimes have their unique flow and heat-transferring characteristics. As a result, it is of great academic value and of practical meaning.High-speed photography method is applied to the flow regime characterization. It achieves a visual, non-contact measurement, and does not interfere with the normal operation of the production equipment. Moreover, in the high speed oil-air-water three-phase flow, we can adjust the frequency of snapping to be more clear flow regime images. Therefore, it expands the scope of the application for online flow regime identification. Based on a large amount of experimental data, image texture analysis, chaotic characteristics and complexity measures theory are used in flow regime characterization. Three-phase flow regime characterization method is discussed systematically from the aspects of theory and experiment.The experiment of oil-air-water three-phase flow was carried out on the large mu- ltiphase flow pipe at Northeast DianLi University .Firstly, dynamic images of the oil-air-water three-phase flow regime in different conditions are captured by digital high speed video systems in the vertical upward pipe. Secondly, flow regime images noises are removed and images are enhanced by using image processing technology. Then four kinds of texture feature parameters of oil-gas-water three-phase flow dynamic image are extracted in the second histogram. Processed results show that the extracted texture features parameters of flow patterns can reflect the flow characteristics of oil-gas-water three-phase flow. Flow structure and complexity degree can be depicted in the developing process of flow pattern. Finally, the gray time series are composed of gray mean extracted by dynamic flow patterns image, and fractal characteristic parameters are extracted in the theory of chaos and fractal. By analyzing the rules of fractal characteristic parameters with the changes of oil-air-water three-phase flow parameters, we could get the dynamics structure inversion characters of oil-air-water three-phase flow, and they provided an efficient, supplementary diagnostic tool to reveal the flow regime transition mechanism of oil-air-water three-phase flow.