Experimental measurement of oil–water two-phase flow by data fusion of electrical tomography sensors and venturi tube

Abstract

Oil–water two-phase flows are commonly found in the production processes of the petroleum industry. Accurate online measurement of flow rates is crucial to ensure the safety and efficiency of oil exploration and production. A research team from Tsinghua University has developed an experimental apparatus for multiphase flow measurement based on an electrical capacitance tomography (ECT) sensor, an electrical resistance tomography (ERT) sensor, and a venturi tube. This work presents the phase fraction and flow rate measurements of oil–water two-phase flows based on the developed apparatus. Full-range phase fraction can be obtained by the combination of the ECT sensor and the ERT sensor. By data fusion of differential pressures measured by venturi tube and the phase fraction, the total flow rate and single-phase flow rate can be calculated. Dynamic experiments were conducted on the multiphase flow loop in horizontal and vertical pipelines and at various flow rates.

Multiple Measurement Vector-Based Complex-Valued Multifrequency ECT

“…In gas/oil/water multiphase flows, the water content over 40% is normally very challenging for conventional ECT, as the admittance obtained from an ECT measurement unit is mainly determined by the conductivity of the water, rather than the permittivity of MUT. To address this issue, Liu et al implemented Electrical Resistance Tomography (ERT) as a supplementary method to deal with multiphase flows with a high water content [7]. However, ERT sensors require direct contact with the conductive media, which is not suitable for long-term metering in oil wells, since the wax or deposits might stick to the electrodes and block the conductive path between electrodes.…”

Numerical Analysis of a Two-Phase Flow (Oil and Gas) in a Horizontal Separator used in Petroleum Projects

“…There are few corporate and public studies on the two-phase separators in the relevant literature. Some of them address operating performance associated with multiphase separators Zhang et al (2007), Liu et al (2017) while the others suggest separator design guidelines, Engineering Design Guidelines (2011). In comparison with the vertical separators, the horizontal separators have been studied extensively, due to the fact that these types of separators have much more advantages than the vertical separators.…”

A Novel Combined Conductance Sensor for Water Cut Measurement of Low-Velocity Oil-Water Flow in Horizontal and Slightly Inclined Pipes

“…The high speed camera method [5] has high resolution, has no interference to the flow and presents the intuitional visual performance, but the performance of it is restricted by the bottom-hole opaque and oil contamination. The full-bore tomographic method has electrical capacitance tomography [6], [7] and electrical resistance tomography [8], [9]: the electrical capacitance tomography utilizes the different permittivity of the fluid phase to carry on image reconstruction for the information obtained by the array capacitance sensors in different places of the full bole, but for using this method in the practical application, the oil phase needs to be continuous; the electrical resistance tomography utilizes the different conductivity of the fluid phase to carry on image reconstruction for the information obtained by the array impedance sensors in different places of the full bole, but this method is severely affected by the temperature and mineralization degree. The full-bore tomographic method, mainly including ECT and ERT techniques, could measure multiple parameters and has potential advantages in describing the downhole conditions, notwithstanding their advantages, these tomographic methods need more sensors, more complex manufacturing processes, high cost and complicated tomographic algorithms which would limit their actual application in oil-field logging [10], [11].…”