Determination of density pattern of fracture in Asmari Formation in Marun oilfield

Marun oilfield is located in the middle part of Dezful Embayment and is situated along the Aghajari، Ahvaz and Ramin anticline. Given the important role of fracture characteristics for improving production، so the aim of this research is to investigate the density pattern of fracture in Asmari formation in Marun oilfield. For this purpose، results of image log، core data، graphic well log، methods of inscribed circle analysis and curvature changes geometry of anticline were analyzed. Asmari formation is the main reservoir rock in Marun oilfield that divided into five zones. Limestone and dolomite are the main lithology of zones 1، 2 and 3 which has a high density of fractures (especially in zones with 90% dolomite). Also there is less fracture density (micro fracture) in the 4 and 5 Asmari zone due to an increase of shale and marl layers and due to less break ablity has a less distribution of fractures. The result show that there are a good conformity existed between the results of inscribed circle analysis، image log، core data، curvature and the presence of fractures in Marun anticline. The data indicate that highest density of fracture density concentrates in the southern limb in the central region of anticline and also in the north limb in the northeast region of the anticline. So، finally using these parameters، it is recommended that further development and production wells be drilled in the north eastern part of the oil filed as well as center part of southern flank of the anticline.