Reservoir Quality Analysis of the Sarvak Fractured Reservoir with Petrophysical and Geophysical Data in an Oilfield of Persian Gulf

In this research, the image log techniques along with full set logs and geophysical data have been used to investigate reservoir quality of the Sarvak Formation reservoir in an oilfields of Persian Gulf. Image log analysis on 4 selected wells (A, B, C, and D) of studied oilfield show that the structural dip of the Sarvak Formation Reservoir base on 129 readings are 11 degree toward N69W with strike of N27E and S27W. Moreover, two main fractures type are recognized in the studied reservoir. The first has been seen in wells named A, B and, C that have the dip of 81 degree toward N38E with Strike of N25S/S52E base on 489 readings. The second one is related to well name D and has the dip of 64 degree toward N58W with Strike of S32W/N32E base on 110 readings. Also, geophysical data in studied oilfield show 2 main faults with North-South trends and 11 local faults with Northwest- Southeast trends. The correlation of fracture trends identified in image logs with faults’ trends of oilfield indicate that the trend of theses fractures correlate well with the trend of local faults. Models of porosity, permeability, fractured density with openness of fractures of the Sarvak Reservoirs indicate that the effects of local faults in fractures of oilfields are important and caused the increase in quality of reservoirs in wells B, C, and D. Based on image log data, the maximum and minimum of in-situ horizontal stress in oil reservoir have been estimated from N32W and S55W respectively.