Abstract: Qingxi oilfield, located in western Jiuxi basin of Gansu province, is composed of a number of deep fractured hydrocarbon reservoirs. Fractures are not only the primary petroleum-storage spaces,but also major percolation flow channel in this area. The major oil zone is situated in well-developed fractural zones which are generally high production areas in the oilfield. About these fractures,lots of techniques have been applied currently to study such as full diameter core's X-CT scanning,NMR analysis,fractural interpretation/identification by image log,3D seismic phase-interference data processing and seismic attribute extraction analysis,etc. These techniques can be used to study fractures by fractural static characterization fractural evaluation around wellbore and fractural distribution prediction, and to determine fracture developed zones and their distributions.

Key words: Jiuxi basin, Qingxi oilfield, reservoir, fracture, image log, fractural zone