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

This paper studied conductance-based method for water cut measurement to dynamically monitor the horizontal oil-producing wells. Existing conductance tools cannot obtain the response values corresponding to the water phase in horizontal wells due to the characteristics of the ring-shaped electrode structure and the horizontal well structure. In order to tackle this issue, this paper designed a novel Combined Conductance Sensor (CCS), which mainly consists of the Ring-Shaped Conductance Probe (RSCP) and the novel Clock-like Conductance Probe Array (CCPA). Specifically, we first established the structure model of CCS, optimized the geometry of CCPA by analyzing the uniformity of electric field distribution generated by the exciting electrodes of CCPA and then analyzed the local sensitivity field region of the optimized CCPA. Then we studied the flow pattern distribution of the horizontal oil-water two-phase flow and analyzed the response characteristics and the linear relation between RSCP and CCPA. In addition, this research developed the CCS-based tool and conducted the experiments about different inclined angles in horizontal and slightly inclined pipes. Extensive experiments demonstrated that the developed CCS can cover the three-quarter scale of water cut measurement(25%-100%) in horizontal and slightly inclined pipes, and the experimental results verified the validity of CCS for the water cut measurement. Comparing to the existing methods, the proposed CCS is more suitable for water cut measurement with the advantages of simple structure and low cost for the horizontal oil wells with the characteristics of the low production, which could be used widely in the actual logging.