Multiphase Flow Experimentation System Design Based On Fuzzy-logic Control

Offshore oil and gas resources is of great amount.Its development directly relates to the future of the world’s energy industry.China has abundant offshore resources,yet the development ability is insufficient as it is still in its initial stage.Adequate technical strength is needed before the development of offshore resources.The theory of multiphase flow in well bore is one of the main branches,playing an important role in the exploitation of marine oil and gas.In the process of oil and gas resource exploitation,oil-gas, oil-water, oil-water-gas and other multiphase flow in the wellbore are inevitable.Analysis of the dynamic characteristics of different media in the wellbore is helpful to improve the transport process of oil and gas resources in mining.Multi phase flow experimental device of wellbore is generally small,mostly built indoor.Research on oil development technology can not be separated from the support of these kind of experimental devices.Wuhan experimental base of Turpan gas lift center developed a set of experimental apparatus for the study of multiphase flow in wellbore theory.The device can be divided into oil, gas and water three-phase pipelines.Its experimental pipe section is adjustable from 0 to 90 degree s.Its auxiliary device is separating and recovering and cooling circulation devices.This system can simulate different kind of three-phase flow, such as bubble flow, annular flow and mist flow and so on.To achieve higher measurement accuracy,metering branch pipe with different diameter is designed.The experimental device of oil-water measurement precision of 0-20m3/h in the range to ±0.5%.Gas metering accuracy is 0-35m3/h in the range to ±1%,ensuring the requirements of the experiment.The hardware of the control system of oil-gas-water three phase flow experiment device is composed of industrial control computer and PLC.This structure is conducive to the rapid and stable transmission of system data and easy for expanding,bringing convenience to the use of the device.The upper control software of the control system is designed by Kingview 6.55.Its rich control mode and visual design mode make the development process of human computer interaction interface more convenience.Aiming at the problem of controlling the instability and overshoot of the air flow heating device in the multiphase flow experiment device. The traditional PID control method can not effectively improve the control effect.As a summary of expert experience,fuzzy PID controller can be used to improve the control effect of traditional PID.The control algorithm is applied to the SIEMENS S7-300 series PLC,and the control process is analyzed and compared in the Simulink platform through several groups of off-line and on-line simulation,improving the control effect.