Structural relationship analyses of the Rudak and Milatun fields

The reservoirs of southwestern Iran, fractures play an important role in hydrocarbon production. Identification of the fractures patterns and their distributions play an important role in exploration, production and development of the oil fields. The Rudak and Milatun oil fields are are located in the southern part the Dezful Embayment'soil fields. The Rudak and Milatun oil fields are located 40 Kilometer away from Kazerun city. The outcrop of the Milatun oil field consists of the Ghachsaran, Mishan, Aghajari and Bakhtyari Formations and they contain Asmari and Khami reservoir horizons. Rudak oil field on the surface outcrop consists of the Mishan, Aghajari and Bakhtyari Formations which contain the Asmari, Kazhdomi and Khami reservoir horizons.Investigation of the relationship between, geometry and fractures is not possible without detailed structural analysis .Therefore, various methods based on the geometry and fracture patterns were used for structural analysis. These methods consist of the satellite image investigations, field observations, relative fracture frequency(RFF) and some other geometric methods such as inscribed circle and calculation of the fold axis curvature. In the Milatun oil field the fractures near the north and south of the present exploration well show high fracture densities. In the Rudak oil field the fractures are mainly concentrated around the wells I and II. This shows that the area around well Ι has more fracture concentration more than well ΙΙ. In general, the outer curves of the fold have highfracture prone.Fractures in the superficial formations are consists of extension fractures, tension fractures and shear fractures that the later one display high frequency. These fractures can also help us to observe the bend in the eastern, central and western parts of anticlines. Since there is a thrust fault on the southern limbs of the anticlines, Rudak and Milatun anticline are detachment folds. Based on the morphotectonic evidences and sub-surface 3D models, it was find out that the activity of the Milatun anticline is more than Rudak anticline. Each of the anticlines hase different reproductive nucleation. They have been linked during their growth nucleation and it was found that and their linkage is oblique type. Finally, tear fault model and conjugate zone model for the oil fields were appropriate which indicate that they are independent structures.