Author/Authors :
Aghli، Ghasem نويسنده Department Geology, Chamran, University , , Fardin، Hashem نويسنده National South Iranian Oil Company (NISOC), Studies office, Ahvaz , , Mohamadian، Ruhangiz نويسنده National South Iranian Oil Company (NISOC), Studies office, Ahvaz , , Saedi، Ghasem نويسنده National South Iranian Oil Company (NISOC), Studies office, Ahvaz ,
Abstract :
Assessment of the reservoir structure and determination of theinsitu stress direction arenecessary in oil production optimization and
field development. Today, the application of reservoir software and Image logsplay a central role in resolving this problem. Electric
and ultrasonic imaging tools record vast amounts of high-resolution data within the borehole wall. This enables the geoscientists to
describe in detailthe structuralfracture networksvery essential for stratigraphic and structural analysis and improved reservoir
characterization. A Six Arm Electrical Borehole Imaging (EMI) tool has recently been developed. This tool represents further
advancement in the evolution of electric borehole imaging. The electrode arrays mounted on six independent arms provide excellent
pad contact and produce very high resolution images for stratigraphic and structural analysis. Furthermore,the results of this study
indicate that EMI is a powerful technique for identifying thedominant porosity and defining the relationship between fractures and
permeability. In this study, data from two wells(well No.3 with FMI and well No.6 EMI image log) were utilized. The results of the
Velocity Deviation Log and images indicate that the production in the Asmari reservoir of this field is a combination of fractures and
rock matrix. Besides, the fractures and porous zones have effectively impacted the reservoir rock properties so that two general patterns
of tectonic fractures associated with longitudinal and diagonal wrinklingcan be identified. Longitudinal patterns are the dominant ones
and often form the open fractures. They are mainly oriented in the N45-90W direction and are chiefly observed in the upper Asmari
zones.Induced fractures and breakouts have been observed in the two wells, indicating a maximum horizontal stress orientation of
65°N in well No.6 and 295°N in well No.3. The stress direction in the western section of this oil field is therefore different from the
eastern one and does not follow the general Zagros trend.
