Fractures are considered as the most important feature in the fractured reservoirs, especially in the carbonate heterogeneous reservoirs. However, fractures diagnosis is not valuable, unless they could be applied to determine the porosity and permeability systems. The main purpose of this study is to find a quick and inexpensive method for identification of fractured zones and then fracture parameters such as fracture density (FVDC) and fracture aperture (FVAH) in these zones using petrophysical logs. Practically, raw conventional logs cannot be used as inputs for fracture parameters estimation, while some log preprocessing methods increase the relation between conventional logs and fracture parameters. The results show that, some parameters such as pore system, lithology and reservoir fluids effected on the petrophysical logs as the main factors. However, fracture parameters can be determined using conventional logs which corrected by statistical methods and logs energy. Hence, logs preprocessing is the most important step in such studies due to low initial relationship between conventional logs and fracture parameters. Results indicate that the zones with high fracture density and aperture are easily detectable by conventional logs. On the other hand, the behavior of these logs is a function of fracture parameters in the fractured intervals, especially in the zones with high fracture aperture. Also, results indicate that fractured and non-fractured zones are easily detectable using a combination of logs energy and lithology heterogeneity with high accuracy. RHOB, NPHI, GR, DT, PEF, PHIE, CAL and resistivity logs which have been applied in this study, are the best logs that may be used in the identification of fracture parameters. Based on their responds in the fractured zones and correction on responds, they can be used to fractures detection which show great correlation with image logs results. The results for 6 studied wells, show the excellent prediction ability in the fracture zones after logs preprocessing.

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