Calculation method of equivalent permeability of dual-porosity media considering fractal characteristics and fracture stress sensitivity

Abstract In the petroleum industry, accurate calculation of equivalent permeability dual medium is very important for estimation reserves and design oil gas production. At present, there are many methods to calculate medium. These have their own advantages disadvantages, suitable different characteristics physical problems, but they cannot under reservoir conditions. Thus, emergence fractal theory provides a theoretical basis us study law fluid transport in randomly distributed pores fractures. Many scholars deduced analytical solution model double-porosity media, dimension rock matrix fracture network has been widely used dual-porosity media. It proven that pore considering properties can be realistically applied. this work, aperture surface tortuosity introduced establish dual-permeability closure effect. Taking Yanchi Chang 8 area Ordos Basin as an example, comparing results numerical simulation model, proposed two-porosity stress effect more accurate. The sensitivity analysis each parameter shows reduced aperture. significantly influenced by inclination, aperture, diameter. rougher tortuous capillary path forces particles move longer distances, thereby reducing network.