Research On The Flow-rate Measurement System Of Oil-gas-water Three-phase Flow Based On LMS Adaptive Time Delay Estimation And ARM

In recent years, TDE (time-delay estimation) technology is widely used in oil wellflow-rate measurement, and thus conducting much more study on it has become animportant topic in the field of modern petroleum industry. In this paper, considering thatmost of the current TDE technologies for flow-rate measuring have the problems ofslow-speed and low-precision, an improved algorithm based on LMS adaptive time-delayestimation algorithm was proposed, which named LMS based on Second Correlation fortime-delay estimation. Then the improved algorithm has been transplanted to a customizedARM system, constituting a flow-rate measurement system. It provides a feasible methodfor accurate measuring flow-rate of oil-gas-water three-phase flow.Firstly, Due to the slow convergence speed and gentle weight vector of adaptivetime-delay estimation algorithm based on LMS, the time-delay estimation algorithm ofLMS based on Second Correlation has been presented in this dissertation. On the basis ofimplementation process of Second Correlation, this algorithm completes the firstcross-correlation and auto-correlation adaptively using LMS algorithm, and then the twooptimal weight vectors are correlated to get the time-delay estimation. Since correlatingthe optimal weight vector, the convergence speed of this algorithm is improved definitely,and the new algorithm achieves a better accuracy of time-delay estimation.Secondly, in order to realize the ameliorated algorithm based on hardware and meetthe need of oil-gas-water three-phase flow-rate measuring, a Flow-rate MeasurementSystem based on ARM and TDE has been presented in this dissertation. S3C610isselected as the CPU of this system which expands interfaces of sampling, storage, displayand transmission. At the same time, the programs based on Linux operating system aredesigned, such as TDE algorithm subroutine, signal acquisition and processing subroutine.Finally, the implementation process of measuring flow-rate of oil-gas-waterthree-phase flow by the Flow-rate Measurement System based on ARM and TDE has beengiven, and the test had been finished on the field simulation well experimental platform inDaqing Oilfield. The experiments used the measurement data of oil-gas-water three-phase flow in different conditions to make experimental validations for the time-delay estimationalgorithm of LMS based on Second Correlation and the Flow-rate Measurement Systembased on ARM and TDE, and then the estimation results were analyzed in detail.