Research On Gas-Liquid Phase Velocity Measurement Of Oil-Gas-Water Three-Phase Flow Based On Independent Component Analysis And Time Delay Estimation

It's of great importance to measure the oil-gas-water multi-phase flow since it has a wide range of application in modem petroleum industry, the measurement technology for multi-phase flow has been one of the hot issues in the multi-phase flow research field, to measure the velocity is one of the main topics. Accurate measurement of oil-gas-water three-phase flow velocity parameter can open out the mechanism of multi-phase flow, set up model of multi-phase flow, and also provide essential foundations for forecast, design, and optimized control of flow process. But it is difficulty to measure the velocity because of the complexity and randomness in the oil-gas-water multi-phase flow process. On this condition this dissertation has studied gas-liquid phase velocity measurement of oil-gas-water multi-phase flow in a deep-going way based on Independent Component Analysis (ICA) and Time Delay Estimation.Firstly, this dissertation presented gas/liquid phase information extraction of oil-gas-water three-phase flow algorithm based on ICA as for the mixing property of the three-phase flow conductance signal. This algorithm applied ICA to obtain separated-phase information of fluid, and adopted Pearson correlation coefficient as the basis of gas/liquid phase information identification. This dissertation established a theoretical model of gas/liquid phase information extraction of oil-gas-water three-phase flow, demonstrated feasibility of this algorithm, applied simulation data and measured Data for experimental verification.Secondly, aiming at the low-accuracy of time delay estimation calculated by cross correlation, this dissertation presented Generalized Second Correlation for time delay estimation. On the basis of Fourier Transform of Second Correlation, this algorithm used weighting function to avoid causing spreading of the peak of the correlation function, approached a delta function centered at the correct delay, and then located the maximum peak in the output which represents the estimated time delay.Finally, realization process of gas-liquid phase velocity measurement of oil-gas-water three-phase flow based on ICA and Time Delay Estimation was given, and dynamic test had finished on the field simulation well experimental platform in Daqing Oilfield. After gas/liquid phase information extraction of oil-gas-water three-phase flow conductance signal which sampled by seven-electrode conductance probe, Generalized Second Correlation was applied for time delay estimation of gas/liquid phase signal, and then gas/liquid phase velocity were obtained. This dissertation found some multi-phase flow regularities by analysing the velocity results of dynamic test.