多孔介质中甲烷水合物边界的CT图像识别技术

采用X射线计算机断层扫描(X-CT)技术观测多孔介质中天然气水合物的生成和分解过程,具有实时、直观和无损等优点。由于颗粒物边缘图像容积效应和X-CT分辨率的限制,多孔介质体系中不同物质的边界域难以确定,从而影响对多孔介质中水合物赋存状态的准确判断。利用Matlab平台图像处理软件中的开闭运算、多值化、梯度图像提取和边缘检测等方法,对实验获得的多孔介质中甲烷水合物的CT图像进行优化处理,获得了更清晰的图像,可有效地提高多孔介质中不同物质边界域的识别效果,有利于准确判断甲烷水合物在多孔介质中的赋存状态。 

Identification Technology of the CT Images for Distinguishing the Boundary Condition of Methane Hydrate in Porous Media

X-ray tomography technology(X-CT) can be used to observe the formation and decomposition processes of natural gas hydrate in porous medium, with the advantages of real-time, intuitive and lossless. However, the boundary region condition of different materials in sediment system is difficult to be determined due to the volume effect of particle edge image and low resolution, resulting in reducing the identification accuracy of gas hydrate occurrence in sediments. The Matlab platform image processing software was used for optimum processing of the CT images obtained from the experiment of methane hydrate in porous media. The results show that a more clear and distinguishable image can be obtained after optimizing the CT image with opening and closing operation, multi-value, gradient edge detection and image extraction methods, which can effectively help enhancing recognition for different boundary conditions of materials and improving the identification of methane hydrate occurrence in porous media.