Estimating the Reservoir Permeability and Fracture Density Using Petrophysical Logs in Marun Oil Field (SW Iran)

摘要

Surveying the pores, permeability, and fractures in an oil field using petrophysical data and its relative logs has significant importance in precise schematization of how to prevent from mud loss and from reservoir rock damages. The authors completed a survey and determination was done using neutron logs and density. Then S_(wirr) rate and permeability were measured using experimental methods. In these processes, the gained results from permeability are qualitative and cannot show the exact rate and the only application of these methods is for estimating the permeability. For exact measurement, the processes such as well testing or coring should be exploited. For studying on fractures, the image logs were used and because of oil-based mud in this field, for assessing the fractures, the oil-based microimager tool was used. The studied reservoir layer is Asmari formation, which is one of the most important reservoir rocks in Southwest Iran. The lithology of this formation is carbonate and sandstone, which has medial and good porosity. For permeability estimating, some zones were chosen that are relatively sandstones and clean. The permeability range of them is between 80 and 400 md, and has good and medial permeability development. The observed cracks are between 2,820 and 3,000 m depth, which have different slopes and have low-level aggregation in lower zones, based on fracture assessing.