Research On Measurement Method Of Gas Holdup Of Horizontal Gas-Liquid Two-Phase Flow Based On Array Optical Fiber Sensing

Shale gas is a clean source of energy that plays an important role in many countries’ energy strategies.In the critical period of energy transition,shale gas development opens up a new way to solve the country’s energy problems.Therefore,the development and exploitation of shale gas are particularly important.In the process of shale gas exploitation,it is not easy to grasp the downhole mining dynamics in real time,so it is an important problem to realize the real-time monitoring of the flow condition and gas holdup of the downhole gas-liquid two-phase flow.Based on the array optical fiber sensing technology,this dissertation intends to carry out the research on the flow pattern identification and gas holdup measurement technology of horizontal gas-liquid two-phase flow under the state of gathering flow.Specific research contents are as follows:Firstly,on the basis of analyzing the flow characteristics and flow parameters of horizontal gas-liquid two-phase flow,the simulation model of horizontal total-flow gas-liquid two-phase flow is established by using FLUENT simulation software,and the simulation experiments under different working conditions are carried out to obtain the flow pattern distribution of gas-liquid fluid in full-collecting horizontal measurement tube.At the same time,the development process and flow law of the transient flow pattern in the horizontal fully integrated flow channel are understood,and the optimal axial spatial position of the fluid in the full-collecting horizontal measurement tube is determined,so as to provide a basis for the design of the array fiber probe structure.Then,according to the above characteristics of horizontal gas-liquid two-phase flow,the optical fiber probe sensor array structure for gas holdup measurement is designed.According to the effective measurement area and the area of repeated interference area as performance metrics,the designed array structure is optimized and the performance sequence is obtained.The two former arrays in the performance sequence are modeled by using ZEMAX optical simulation software,and the optical simulation tracking response and gas holdup measurement and analysis experiments are carried out under different flow patterns,to select the optimal array structure with better measurement effect.Finally,according to the above optimal results,the optical fiber probe array sensor is developed,the flow pattern response and gas holdup measurement experiment platform is built,and the physical measurement experiment is carried out.The response data is collected by the data analysis system and the data is zero-processed to obtain the flow pattern measurement and gas holdup measurement results.The measurement results are compared with the preset results to verify the accuracy of the measurement system.