Signal Processing in Liquid Level Detection with Acoustic Method Based on Spectral Subtraction
Haiwen Wang, Lin Li-xing, DU Zhong-wei, Min Zhang · Journal of Oil and Gas Technology · 2012
In liquid level detection with acoustic method,the liquid level reflected wave signal was very complex due to the influence of the noises from the annulus between tubing and casing,and the real liquid level was covered which made it difficult to be identified.The reason of noises that influenced the liquid level detection was analyzed,and the spectral subtraction was used to process the liquid level signal.After process with the spectral subtraction,the liquid level which was difficult to be identified was to appear obviously.The result shows that the process of liquid level signal using spectral subtraction can eliminate the influence of background noises,and improve the identification capacity of liquid level to obtain the accurate liquid level value.