摘要
数字岩心技术在油田开发中得到了越来越多的应用,CT图像处理的准确性是数字岩心技术在石油行业应用的关键。针对同一砂岩进行了三次不同分辨率的CT扫描实验,对获得的三组图像数据分别基于三种图像滤波算法进行处理;并对比分析了各种方法的处理效果,总结出不同分辨率岩石CT图像的最优处理方式。结果表明,随着分辨率增加,CT图像中噪声点总量增加,相边界灰度梯度减小;三种滤波算法中中值滤波和非局部均值滤波在边界信息保护方面效果最好,各向异性扩散滤波除噪能力最强;岩石CT图像在较低分辨率下非局部均值滤波和中值滤波的处理结果均比较理想,对于中等分辨率图像各向异性扩散滤波效果最佳,高分辨率下需要使用非局部均值滤波与各向异性扩散滤波综合处理才能取得理想效果。
Digital core analysis, which based on X-ray imaging and image processing, is becoming a useful tool to obtain essential parameters for the oil and gas industry. By improving the image quality, including removing im-age noise and preserving the edge feature at same time, image processing ensures accurate results of the modeling and analysis. CT images with different resolutions differ obviously, however, little research neieher focused on tire differences between these images nor optimized the image processing of them. A sandstone sample scanned at resolu-tion of 3.57 μm, 0. 70 μm and O. 39 gem and features of each dataset were analyzed. Three filtering algorithms were compared which then used to processing the three image datasets. Results of different filters were directly illustrated and compared by segmented images, experiment and analyzing show that there are clear noises in CT im-age of higher resolution; Non-local means fiherand median filter do well in preserving the edge features and aniso-tropic diffusion filter does well in denoising. According to the segmented images, non-local means filter and median filter performs well in low resolution image （3.57 μm）, where the noise is insignificant, median resolution image （0. 7 μm） can be well processed by anisotropic diffusion filter; high resolution image （0. 39 μm） needs to be pro- cessed by the sequence of non-local means filter and anisotropic diffusion filter.
出处
《科学技术与工程》
北大核心
2014年第2期1-4,共4页
Science Technology and Engineering
基金
国家自然科学基金(51234007、51304232)
教育部科学技术研究重大项目(311009)
山东省自然科学基金(ZR2011EEQ002)
高等学校博士学科点专项科研基金资助课题(20120133120017)资助
关键词
数字岩心
岩石CT图像
滤波算法
优化处理
digital core
CT image of rock
filtering algorithm
optimization of image processing
