利用井壁超声图象判别岩性的数学模型研究

On a Mathematical Model for Lithologic Recognition Using Ultrasonic Images of the Side wall

本文从数字超声电视测井的成象原理出发,研究了根据井壁超声图象的灰度和回波时间数据计算井壁反射系数的方法.实测图象表明,在比较规整的井段可用该方法求得的反射系数判别井壁岩性;在不规整的井段或在由于仪器偏心而造成数据畸变时,筛选、除去失真数据后进行判别,因此该判别原理可适应于一般井段.文中的分析结果为研制从井壁超声图象中进行计算机岩性判别提供了基本的数学模型.

Based on the principle of imagery by a digital ultrasonic logging system, a method for computing the reflection coefficient of the side wall according to the degree of greyness and the echo time data is presented. Actual logging images show that in regular wall sections, it is possible to determine the lithologic character with the reflection coefficients obtained by this method. However, in irregular wall sections or in the case of signal distortion due to eccentricity of the instrument, the data sieving method has to be used to eliminate the distorted data.