影响超声成像效果的模拟实验  

Simulation Experiment in Affectting Ultrasonic Imaging Result.

作　　者：胡学红[1] 李长文[1] 魏海云[1] 

机构地区：[1]江汉测井研究所

出　　处：《测井技术》2002年第6期467-470,共4页Well Logging Technology

基　　金：中国石油天然气集团公司资助项目"声学成像测井地质响应的实验研究"(970 30 2 )

摘　　要：换能器的工作频率及类型、测量距离、扫描间隔、仪器偏心及倾斜、目的层的波阻抗差异等因素都会不同程度地影响声波的传播 ,最终影响成像效果。针对这些影响因素研制了一套超声成像多维扫描系统 ,在实验室进行了大量的声成像模拟实验。实验结果表明 ,换能器频率的选择必须在成像分辨率和泥浆适应性之间进行折中 ,相同尺寸和频率的曲面型换能器比平面型换能器成像效果明显要好 ;采样间距越小 ,扫描速度越慢 ,其超声成像分辨率越高 ;应通过实验建立各种典型地质特征的声波成像解释图版 ,为实际应用提供参考和对比 ;通过对图像进行滤波、平衡、增强等处理以及根据超声换能器的声波辐射特征对图像进行高分辨率精细处理 ,以改进和提高信号的处理质量。实验分析结果有助于改进井下超声换能器的设计 。Propagation of sonic wave and results of ultrasonic imaging logging are affected, in some degree, by these factors, such as working frequency, types of transducers, measuring distances, scanning intervals, tool eccentricity and slope, interface wave impedance difference, etc. On the basis of many sonic imaging simulation experiments in lab, we developed a set of ultrasonic imaging multi-dimension scanning tool. We must trade off the transducer′s working frequency between imaging resolution and mud adaptability. The same size and curve-type transducer is much better than the plane transducer in imagings. The smaller the sampling intervals, the slower the scanning speed, and hence the higher the ultrasonic imaging resolutions. Sonic imaging interpretation charts for various typical geologic characteristics should be set up to provide reference and comparison for actual applications. The obtained images should be filtered, balanced and enhanced; and the images with higher resolutions should also be finely processed so to improve the sonic signal quality. These experimental results are helpful to improvement of downhole ultrasonic transducer and imaging tool′s resolutions.

关 键 词：超声成像测井 换能器 频率 分辨率 测量 模拟实验 

分 类 号：P631.814[天文地球—地质矿产勘探]