Study on water fraction of oil–gas–water three-phase flow based on electrical methods

Abstract

Oil–gas–water multiphase flows are widely used in petrochemical, biochemical, food chemical, mineral engineering and energy engineering. In this paper, the double-ring conductivity probe and the double-helical capacitance probe were extended to the water fraction measurement of oil–gas–water multiphase flow in the vertical pipe. The test pipe section of the multiphase flow of oil–gas–water in the vertical riser was designed. In the experiment, the self-designed double-ring conductivity probe and the corresponding signal processing circuit were used to measure the water fraction in the oil–gas–water three-phase flow. In this paper, the dynamic calibration of oil–gas–water three-phase flow was carried out under the working condition of high water fraction. Under uniform bubbly flow, with the increase of water fraction, the measurement error of the double-ring conductivity probe decreased, which can be controlled within 8% under working conditions with a water fraction of more than 90%. The results of water fraction were performed for different flow patterns in oil–gas–water multiphase flow. Under the bubbly flow pattern, the error reaches the maximum and the error is only related to the water fraction when the water fraction is about 85%. Under the slug flow pattern, the two measurement results of the double-ring conductivity probe and the double-helix capacitance probe were compared. It is found that the double-ring conductivity probe can clearly and accurately reflect the change of the flow pattern in the pipe.