Medial Access Path Search (MAPS) for pore-network extraction

Over the past few decades, pore-network models (PNMs) have emerged as a pivotal tool in the investigation of fluid flow within porous media. The crux of PNM lies in the extraction of the topological structure of porous media, as abstracted from geological scans, commonly referred to as the pore network. Conventional methods for pore-network extraction rely on pixel-based techniques and necessitate high-quality images to accurately capture pore information. In recent times, the flashlight search medial axis (FSMA) algorithm has been introduced, offering a novel approach to extract pore networks within continuous spatial domains. This innovation enables the algorithm to operate independently of specific pixels, thereby significantly reducing computational complexity. Building upon the foundational principles of the FSMA algorithm, this paper presents an efficient search algorithm in conjunction with string methods. This algorithm facilitates the precise determination of pore and throat center locations within porous media using a minimal number of computational points and can accurately compute the positions of pore medians. Furthermore, this algorithm can effectively circumvent the issue of dead-end pores encountered in the FSMA algorithm, a feature of paramount importance in the study of multiphase flow within porous media.