Microwave-enabled chipless sensor for real-time non-contact water-cut measurements
Bushra Kamal, Sarah Vestrum, Mabkhot BinDahbag, Zahra Abbasi, Hassan Hassanzadeh
Abstract
Accurate water-cut measurement is critical for monitoring and increasing the efficiency of the oil and water production rates and assessing crude oil quality. The accurate measurement aids in the quality control of production operations, monitoring the condition of oil wells, minimizing process energy consumption, and oil fields automation. In this paper, we report the development of a unique measurement technique for water-cut measurement based on planar microwave sensors. The developed technique is a real-time, non-contact, non-invasive, and low-power water-cut measurement technique. The platform of the proposed sensor is a passive split-ring resonator (SRR)-based sensor with a defected ground gap coupled transmission line as the reader, and the resonance frequency of the sensor is 890 MHz. The dimensions of the tag and reader are 45 × 21.4 mm and 57.3 × 95.8 mm, respectively. The sensor monitors the variation in the water content of crude oil based on the shift in the resonance frequency that occurs within a resonator as a result of variation in the effective permittivity of the emulsions. The experiments were conducted first with pentane/water and hexane/water mixtures of known effective permittivities, which validated the proof of concept for the sensor. The experiments were further advanced to more complex emulsions of bitumen/water and heavy oil/water. The results revealed that the frequency shift of the resonance peak changes by 69.75 MHz for the bitumen and 70.5 MHz for the heavy oil in the full water-cut range. The proposed microwave sensor offers real-time monitoring of water-cut and aids in quality control for production surveillance. The non-contact nature and high resolution of the proposed sensor design enables water-cut monitoring of a small volume of sample ∼1.424 mL with a standard deviation of 0.001 in the full range.