基于工业CT扫描的岩芯裂缝结构表征

The Characteristics of the Core Fracture Structure Based on The Industrial CT Scanning

为了研究泥页岩中裂缝的发育特征,利用工业CT技术对句容盆地的页岩岩芯进行扫描,并使用数字处理技术对页岩的CT扫描图像进行分析,通过VGStudio MAX对CT扫描数据进行重建体模型及裂缝提取,更好的在三维尺度上研究不同矿物组成成分的页岩中裂缝的结构和发育情况及工业CT扫描图的区别.结果发现岩芯中主要存在两组不同走向及倾角的裂缝,-组高角度裂缝,倾角约为70°-90°;一组低角度裂缝,倾角约为30°-40°.依此推测句容盆地在志留纪鲁丹阶以后至少经历两次构造运动.对比不同的矿物组成成分的页岩研究发现,当岩石样品的矿物组成密度差别越大时,工业CT扫描就会越清晰;当岩石样品颗粒度越大时,扫描的效果就会越明显.

In order to study the characteristics of fractures in the shale,we used the industrial CT to scan the shale core in the Jurong basin,and analyzed the CT scanning data of shale by the digital processing technology. We established the model of CT scanning data and extracted the fracture by VGStudio MAX software. In this way we could study the differences between the structure of fractures in the shale which is composed of different mineral composition and the various CT image. The research results show that there are two groups of fractures with different strike and dip of fracture developed. The dip of one group with high angle was approximately 70°~90°;the other group with low angle was approximately 30°~40°. Jurong basin may have experienced at least two tectonic events after the Rhuddanian. The comparison of the shale composed of different composition indicated that the greater density differences of mineral component,the industrial CT scanning image will be more clear, and that the larger size of mineral grain, the effect of scanning will be more obvious.