This invention provides a method and
system for designing
complex fracture networks in three-dimensional fracturing of
shale oil systems. The method includes: first, identifying the original three-dimensional seepage paths of reservoir samples, including natural fractures and pores, using core observation and microscopic identification. Then, using CT and NMR techniques, the number and morphology of fractures are quantitatively characterized and delineated, forming digital characterization units of the pore-fracture
network structure. Next, appropriate fracturing processes are selected based on different original fracture matching relationships, including controlled near-to-far expansion,
broadband expansion, and pressurized expansion processes. A CO2-based pre-fracturing acid
initiation process is added. Finally, based on optimized and reasonable three-dimensional fracturing parameters for the well group, a refined three-dimensional geological model, a geostress model, and a numerical
simulation model of the actual well group are established. This three-dimensional fracturing network design method has advantages such as high accuracy, comprehensive parameters, convenience, and ease of operation.