Acidizing is used to increase the permeability and fluid flow inside the reservoirs. In this regard, various laboratory and numerical studies have been conducted to investigate the effect of acidizing on the hydraulic behavior of the joints. However, due to the joint displacement, the fluid flow pattern and the flow rate change, which has not been studied or reported in past studies based on acidized joints with the stated conditions, which is the main purpose of this research. In this regard, various samples of natural jointed rocks were prepared through an indirect tension method on Asmari limestone, which is a reservoir rock in oil fields located in southern Iran, and after acidification through a developed acidifier machine, the amount of flow rate in the initial conditions has been measured. The roughness of the joint surfaces before and after acidizing was taken by a laser scanner and the mechanical aperture at different points of joint surface was calculated. A numerical code based on the finite element method in the MATLAB environment has been developed to evaluate the effect of the cutting rate at different amounts of displacement, on the hydraulic behavior of the joints in the pre and post acidification process, and the results have been calibrated with the laboratory data in the initial cutting conditions at different acidizing times. The results showed that the flow rate increases by increasing the cutting rate in both pre and post acidizing conditions. Also, the fluid flow pattern becomes more channelized by increasing the cutting rate. The variation of discharge rate through shear displacement along Y direction, has a greater slope rather than the X direction. In the post-acidizing condition, the variation of discharge rate has a lesser slope than that of the pre-acidizing condition. In some cases, the course of fluctuation in the post-acid-digestion process does not follow the general pattern of discharge changes. In some cases, the trend of discharge rate in the post-acidizing process does not follow the general pattern of discharge rate variation.
