用插值法提高声波时差的计算精度

To Improve the Accuracy of Calculations for Acoustic Slowness with Interpolation

乔文孝．用插值法提高声波时差的计算精度．测井技术，１９９７，２１（２）：１２５～１２８从声波全波列测井中提取纵波、横波、偶极子波和斯通利波时差时，无论是采用相似法还是相关法以及ＳＴＣ法，所计算的时延的精度不会优于一个时间采样间隔ＤＴ，所造成的时差测量误差达１０％～３０％。本文提出改进现有方法的时域插值法和频域插值法，使时延的计算误差小于ＤＴ／４，甚至更小。为说明方法的可靠性，给出了ＤＳＩ资料中斯通利波波形处理的例子。

While extracting the slowness of P,S,dipole, and Stoneley waves from acoustic full waveform logging data, no matter whether semblance, cross correlation, or slowness time coherence method is employed, the accuracy of the delay time involved in these techniques is no better than one sampling interval—? DT ,which results in a relative error of slowness of 10%～30%.The interpolation methods for time domain and frequency domain presented in this paper improve the conventional methods considerably, and can decrease the computational error of the delay time to less than DT/4 ,or even less. An example of the processing of Stoneley waveforms measured by DSI is supplied in this paper as well, in order to demonstrate the reliability of this technique.