基于小波变换的声波法测油井动液面信号去噪

摘要

In liquid level detection with acoustic method, the reflected acoustic signal is complex due to the influence of the noises in the annulus between tubing and casing, and the real liquid level is difficult to be identified. The noises that influence the liquid level detection are analyzed, and wavelet threshold denoising is used to filter the noises in the acoustic signal of liquid level detection with acoustic method. The result shows that the wavelet denoising method is able to eliminate the noises effectively in the a-coustic signal of liquid level detection, and the result is better with the increase of wavelet decomposition level.%由于受到油套环空中各种噪声的影响,用声波法测油井动液面过程中,得到的反射声波信号异常复杂,常常出现液面反射位置不容易辨识的情况.该文分析了噪声产生的原因,将小波阈值去噪的方法用于声波法测油井动液面信号的噪声去除.结果显示,利用小波去噪方法处理油井动液面信号能够有效地去除噪声,随着小波分解层数的增加,利用小波方法去噪的效果越好.