Orthogonal computations and analysis of flow performances for the Berea sandstone perforation tunnel

The engineering expressions of the axial and radial flow were given out based on the dimensional analysis of the influence factors on the perforation tunnel flow performance. To reduce computation cost, the orthogonal calculation scheme was designed in terms of the main influence factors and their value ranges. The flow rate of Berea sandstone tunnel with damaged zone was numerically simulated by using ANSYS/FLOTRAN. The axial and radial flow were obtained, which are used to fit the constants of the flow engineering expressions with the least square polynomial fitting. The final engineering expressions of the axial and radial flow show that the order of the influence on flow is: original permeability, thickness of damage zone, perforation depth, decreasing degree of permeability, perforation diameter.