Improving sand flow rate measurement of commercial ASDs and comparison with ultrasonic spectral analysis and filtering

Abstract

Production of sand in gas wells is associated with various issues such as the erosion of pipes, disruption of the gas processing plant and reduced production capacity. Sand production can jeopardise the integrity of the pipes/equipment. Measuring the sand flow rate helps better sand control and management. Currently, there are many concerns about the accuracy of sand flow rate measurement using a commercial acoustic sand detector (ASD). This study suggests a relationship which substantially improves the accuracy of sand flow rate measurement using an ASD. This study also investigates using a simple ultrasonic sensor for sand flow rate measurement in which a fast Fourier transform (FFT) is used to convert data into the frequency domain. When a Savitzky–Golay filter is used on the FFT response, the smoothed output shows that there is a close relationship between the peak value of smoothed FFT signal in the 10–50 kHz frequency range, and the sand flow rate. This relationship provides a more accurate measurement of sand flow rate than is presently available using an ASD.