Signal-to-noise ratio variance impact on the image reconstruction of electrical resistance tomography in solutions with high background conductivity

Abstract

Electrical Resistance Tomography (ERT) has the potentialities of non-intrusive techniques and high temporal resolution which are essential characteristics for multiphase flow measurements. However, high background conductivities, such as saline water in oil extraction, impose a limitation in ERT image reconstruction. Focusing on the operational limits of an ERT tomography system operating in different conductivity backgrounds from 0.010 to 4.584 S/m, the impact on the image reconstruction was assessed via signal-to-noise variance. The signal-to-noise ratio (SNR) variance had a strong correlation ( p-value = 5.40 × 10−15) with the image reconstruction quality at the threshold of 30 dB, reaching a correlation value of r = −0.92 in the range of 0.010–0.246 S/m. Regarding the position error of the phantom, p-value = 1.30 × 10−5 and r = −0.66 were attained. The global results revealed that the correlation of the mean of the SNR ( p-value = 5 × 10−4 and r = 0.55) was kept unaltered through the whole conductivity range, showing that such a statistical index can induce bias in establishing the operational limits of the hardware.