The Research Of The Phase Flowrate Measurement With Ultrasonic Method In Multi-phase Flow Downhole

The ultrasonic method to measure multi-flow in oil well is analyzed and researched in the paper. The experimental tool is designed. With the tool, the experiments are proceeded at the different states of oil-water-gas ratio. The experimental results are fit well with the theory analysis. Most of oil fields have produced in middle-final stage in china.. Generally, Oil gas and water appear at meantime and the fluid is babble flow with continues water in the oil well. The fluid comes to be complex flow regime, the total flowrate can not be measured correctly with the spinner flowmeter due to unfitting the fluid changing.The reflected character and Doppler effect are used in ultrasonic method to measure the phase flowrate. With the method, the oil flowrate and gas flowrate can be measured directly in the case of continues water. When the distribute oil babbles or gas babbles flow up in the continues water, the angle between the direction of fluid flowing and the beam of ultrasonic wave is less than 90°, the beam of wave is reflected by the babbles and the frequency deviation is generated between emitted wave and reflected wave due to Doppler effect. The vertical flowing velocity of fluid is related with the amount of frequency deviation. The holdup of oil phase or gas phase is related with the intensity of reflected wave. The experimental results show, he oil phase flowrate can be measured with ultrasonic method in oil-water two phase flow. The 0.1m~3/d alter volume of oil phase can be distinguished. When the total flowrate of fluid is less than 60m~3/d, the oil phase flowrate can be measured directly; When the total flowrate of fluid is more than 60m~3/d, the oil phase flowrate can be obtained by amount of frequency deviation and holdup. The gas phase flowrate can be measured with ultrasonic method in oil-gas-water three phase flow. The response of the tool is not related with the holdup of water or oil, when total flowrate and gas flowrate are both stable. When the total flowrate of fluid is less than 100m~3/d, the gas phase flowrate can be measured directly; When the total flowrate of fluid is more than 100m~3/d, the gas phase flowrate can be obtained by amount of frequency deviation and holdup.The theory analysis and experimental results show, the oil flowrate and gas flowrate can be measured directly in the case of continues water. The paper presents a new method to measure multi-flow downhole.