Method Of Digital Core Construction And Pore Network Extraction

Digital core and pore-scale modeling are both effective methods on studying flow mechanism in porous media.Therefore,we conducted an all-round study in the field of model-building for both of them.We first got micro-CT image of core by CT scanning,denoising micro-CT image by median filter,obtaining binary image by OTSU algorithm so as to obtain pore data of the core.An effective means--Markov Monte Carlo(MCMC)for constructing digital core has been studied systematically in this paper.Based on the binary images,digital cores was established,We assessed digital cores by analyzing pore structure of these digital cores,The results show that the digital cores constructed by MCMC method can reflect pore structure of real cores,which shows the MCMC algorithm is suitable for model-building.On the base of the algorithm developed by Palagyi and Kuba for medial axis construction,we proposed an analysis method for spatial topological structure of digital core,in which we first built the medial axis space in digital core,and then deleting medial axis generated by irregular matrix surface and unfair parts caused by boundary.merging its redundant nodes,which ensured extract a topologically and geometrically equivalent pore network from its corresponding digital core.On this foundation,we located the pores and throats and statisticed their properties,including radius,length,volume and shape factor that characterized geometric features,and analyzed topological structure of pore structure.The key algorithms and programming method are detailedly explained.And the approach to 3D-visualize digital core and pore network is also approved with detailed instructions.Digital core and pore network work,fundamental research platform for all the pore-scale study of flow through porous media,have important scientific and academic value and promising application prospect.