一种基于工业CT技术的岩芯样品孔隙度测量分析方法  

THE APPLICATION OF INDUSTRIAL COMPUTATION TOMOGRAPHY (CT) TO THE ANALYSIS OF CORE SAMPLE POROSITY

作　　者：陈超[1] 魏彪[1] 梁婷[2] 何鹏[1] 冯鹏[1] 王静[1] 

机构地区：[1]重庆大学光电工程学院光电技术及系统教育部重点实验室,重庆400044 [2]长安大学地球科学与国土资源学院,陕西西安710054

出　　处：《物探与化探》2013年第3期500-507,共8页Geophysical and Geochemical Exploration

基　　金：国家"深部探测技术与实验研究专项"(SinoProbe-03-01-4F)

摘　　要：岩芯(石)或地质样品的孔隙度,对于成矿流体的研究有着极其重要的意义。针对现有测量与分析计算岩石孔隙度方法难于确保反映岩石样品内部的、原始的、原位的信息或特征等不足,笔者利用工业CT无损检测技术能以图像的形式,直观呈现物体内部密度分布或结构状况这一特点,基于岩芯(石)样品的工业CT切片图像,采用边缘检测和阈值分割等数字图像处理方法,对某矿区ZK992钻井10件岩芯样品的孔隙度做了计算分析研究工作。通过二阶B样小波模极大值法对岩芯CT图像ROI进行边缘检测和改进的类间方差最大法对岩芯CT图像ROI进行阈值处理,分别获得了10件岩芯样品的孔隙度(1.22%～5.79%),基此得出了随着钻进深度的增大,岩芯样品的孔隙度呈现先递增后递减的趋势。研究结果表明,所测得的岩芯样品的孔隙度结果,与经验值基本吻合。这既可为成矿流体的研究提供参考价值,又可为岩石孔隙度测量分析提供一种新的手段或方法。The porosity of core samples or geological samples plays a great role in the research on ore-forming fluid. Considering the de- fects of traditional rock porosity measuring or calculating methods which are hardly capable of obtaiing the internal and original informa- tion of rock samples, the authors utilized the industrial computed tomography technology to analyze the porosity of core samples, which can intuitively present object density distribution or structure in the form of digital images. Based on CT images of core samples, the authors used modern digital image processing method composed mainly of edge detection and threshold segmentation to carry out meas- uring and analyzing porosity of core samples from ZK992 well in a certain mining area. The ROI edge of CT images was first detected in the way of wavelet modulus maxima method based on quadric B-spline wavelet, then the ROI of CT images were segmented in the way of an improved Otsu method. The authors not only obtained the porosity values of 10 core samples that range between 1.22% and 5.79% but also drew the conclusion that porosity of core samples increases first and then decreases as sample location becomes deeper. The result of the research shows that the porosity values measured by this method are in accord with the values by experience. This study offers referable value for research on ore-forming fluid and provides a new method or means for measuring and analyzing rock po- rosity.

关 键 词：工业CT技术 岩石孔隙度 图像边缘检测与分割 小波模极大值法 类间方差最大法 

分 类 号：P631[天文地球—地质矿产勘探]