Extraction Method Of Fractured And Vuggy Characteristics In Digital Rock Of Carbonate Reservoir

Fractures and vugs are well developed in carbonate rock, and are also the main factor affecting the seepage, so to establish a set of methods studying on extraction and identification of fractures and vugs in carbonate reservoir is very important. In this paper, the author starts from geometry and topology characteristics of the fractured space, fracture extraction methods, including new methods to describe and identify fractured space, methods to extract the skeleton of pore space based on the characteristics of the fractured space, new segmentation method of the pore space.First, the author analyzed the description methods of common micro-scale pore space, proposed “Pointillize ” method of medial surface and points on it of the fractured space; secondly the author proposed a new path compression algorithm which can realize the fractured space identification process, and identified and quantified the related geometry parameters; then, based on the spatial neighborhood theory and simple point elimination algorithm while keeping the invariant topological features, the author established a new set of pore space skeleton extraction method taking fractured characteristic into consideration, and specified the detailed skeleton extraction process to reserve surface point and edge points.Finally, based on fracture characteristics, the author proposed a new segmentation method of the pore space, developed the pore network model, carried out flow simulation and then studied on digital core visualization during auxiliary observational studies. The new segmentation method segments the pore space in two parts. For fractured space, select the Euclidean distance of the medial surface points as the threshold value of the segmentation, for matrix pore space, the author followed the traditional segmentation method and connect the splited matrix and fractured space with the edge point. In the mercury injection simulation of the digital rock, the author extract the skeleton information as a flow path of the mercury. This method is more accurate and efficient than traditional euclidean distance based method.The author also provides a visualization platform based on real-time volume rendering methods to meet the real-time observation needs of the fractured digital rock feature. This thesis created a set of theory and methods on carbonate digital rock identification and extraction, which laid a theoretical foundation for the efficient development of fractured and vuggy reservoir.