A low cost and pipe conformable microwave-based water-cut sensor

Efficient oil production and refining processes require the precise measurement of water content in oil (i.e., water-cut [WC]) which is extracted during oil production as a by-product. Traditional laboratory water fraction measurements are precise but incapable of providing real-time information, while recently reported inline WC measurements are either incapable of sensing the full WC range (0-100%), restricted to a limited selection of pipe sizes, bulky, intrusive or extremely expensive. This work presents a novel planar microwave sensor for entirely non-intrusive in situ WC sensing over the full range of operation. Its planar configuration has enabled the direct implementation of this sensor on the pipe surface using two low cost methods i.e. copper tape and 3D printed mask. The innovative ground plane design makes this WC sensor usable for the wide range of pipe sizes present in the oil industry. The viability of this sensor has been confirmed through EM simulations as well as through characterization of two types of prototype. The proposed design offers very fine resolution due to its wide sensing range (> 110%) in the frequency band of 90-190MHz and repeatability of 0.1%.