The Research Of Digital Core Network Extraction Based On Micro-CT Images

Digital core modeling technology is a new numerical simulation method, and itcurrently plays an increasingly important role in the research of rock physicalproperties. Common rock physics modeling method requires some particularassumptions, which simplifies the rock structure and can’t reflect the real complexinternal structure of the rock. Moreover, the rock physics experiment of this methodhas some disadvantages such as long test cycling, high resulting noise and difficultpreservation. Digital core modeling technology is established by real rock samples. Itcan describe the rock internal structure faithfully. At the same time, the core data canbe preserved permanently by digitizing the core, making it easy to invoke and veryreusable, which solves the deficiencies of the traditional rock physics experimenteffectively. The reservoir parameters based on digital core such as sound, electricity,nuclear magnetic and seepage are more accurate, providing a foundation for theanalog computation of geometric characteristics and topology of the complex rockpore. The pore network model based on digital core is the basic research platform ofPorous micro seepage theory. It can reflect the connectivity between3D porous mediapore-body accurately. By the research of micro properties, for instant, thedevelopment scale of the reservoir rock pore space, the fluid seepage influence of thespatial distribution, the fluid distribution rule and interaction mechanism, we canunderstand the relation between the microscopy and the macroscopy, by which we canfind the right direction and required technical means for improving the recoveryefficiency of oil and gas, providing a powerful technical guidance for the siteproduction.This paper uses two different pieces of sandstones as the research subject. Firstly,we use Micro-CT to acquire the data of rock samples, and filter and segment theobtained core fault image; Secondly, this paper introduces the basic principle ofbuilding digital core by simulated annealing method, process simulation and CTscanning method. Among these methods, the X-ray CT scanning method is the mostaccurate and direct method for building digital core, so we use this method to modeldigital core of the two core samples. Finally, the ball algorithm is applied to extractthe pore network model of the two cores based on digital core. This paper implement many methods, instantly, eliminating the redundant side structure caused by theroughness of the rock skeleton wall during the modelling process, searching pore andthroat position and determining their shapes and sizes, making the established porenetwork model and digital core having the properties of equivalent topology structureand geometric features.The Digital core and pore network modeling is a new method to study thereservoir rock seepage properties etc. numerical simulation in microscopic scale. It’scurrently the research hot spot in the micro seepage field and it has importantscientific significance, academic value and application prospect.