Measurements of electrical capacitance in the flow of reservoir fluid with gas bubbles
DOI:
https://doi.org/10.24425/ather.2025.154922Abstract
The paper discusses tests of an electric capacitance sensor designed and built to measure gas fraction in a reservoir fluid flow. These tests were conducted under conditions typical for oil field testing and productivity monitoring. In such an application, the electrical permittivity of the liquid and gas components is of the same order of magnitude, which poses a significant challenge in capacitance metering of the phase content. The studied two-electrode capacitance sensor is a novel design. It uses a commercial, high-resolution ΔΣ capacitance-to-digital converter. The sensor was experimentally tested on the flow of reservoir fluid (from Lubiatów-Międzychód-Grotów field in Poland) heated to 40–50°C to reproduce field conditions during actual gas and oil extraction. The gas fraction in the reservoir fluid was generated by the injection of air or methane bubbles. Fluid velocities during the testing ranged from 1 to 3.1 m/s, and the void fraction reached 4.4%. After calibration, the examined capacitance sensor was able to detect a void fraction as low as 1%. The measured capacitance differences due to gas content were dependent on the spatial distribution of voids in the inter-electrode space. This effect was confirmed by photographs of the flow patterns and numerical simulations of the electric field distributions.References
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