Reservoir properties and seal efficiency in the Zubair Formation in Euphrates Subzone, Southern Iraq

摘要

The lower cretaceous Zubair Formation in Euphrates Subzone south of Iraq is divided into threemembers. These members are divided depending on the variation in lithology. The upper and lower members, which consist mainly of shale is known as Upper Zubair Formation and Lower Zubair Formation, respectively. The middle Zubair Formation consists mainly of sandstone. Intra-formation Zubair-shale are primarily seals, as well as source rock. The gained hard and software data are loaded into GeoFrame system. A trial is done to perform the formation evaluation for Zubair Formation on available data for nine wells. The created project contains all the operation of the reservoir properties. The quality of a sealing rock from both upper and lower is determined by the minimum permeability and effective porosity (less than 80 mD and 9 %, respectively). The sealing rock of Zubair Formation is mainly the shale rocks, which is an organic-rich elastic rock that may suppose to be efficient. On the other hand, the reservoir sand facies have good petrophysical properties. The average of effective porosity was 18 %; however, the permeability is at least 250 mD. The geological setting may supports the horizontal migration of oil to the western area along Abo-Jir fault to the stable shelf successions.