Improvement of petrophysical evaluation of the Asmari reservoir by using of well log tomography method in an oil field from southwest of Iran

In this study, the Asmari reservoir in 39 wells in one of the oil fields of southwestern Zagros, located in the Dezful region, was investigated using well log tomography of Gamma ray logs and core porosity data. For this purpose, two-dimensional and three-dimensional models of gamma and core porosity logs in 4 reservoir zones of Asmari Formation have been designed by Petrel software. Among the slice of Gama log and porosity data, 2 slice were selected from the upper and lower sections of the zones, and a total of 8 tomographic sections from 10 key wells were prepared and compared with each other. The results of gamma logs and porosity tomography models are very close and compatible with each other and show that there is an inverse relationship between gamma values and porosity in the slices made by Asmari Formation in the studied wells. Also, with increasing dolomitization in the zones, the petrophysical characteristics have changed and the amount of porosity has increased. Based on the well log tomography model of the studied oil field, it was found that zone 2 with the lowest gamma value and the highest dolomite value, has higher porosity than other zones and can be the main target of production wells in the field. Since drilling wells is expensive and time consuming, it is possible to achieve very close and accurate results of well drilling using well log tomography. Therefore, tomography studies can be very useful before increasing excavations in the area for general information.