Reservoir Characterization and Rock Typing of Carbonate Reservoir in the Southeast of Iraq

Abstract

Flow unit and reservoir rock type identification in carbonates are difficult due to the intricacy of pore networks caused by facies changes and diagenetic processes. On the other hand, these classifications of rock type are necessary for understanding a reservoir and predicting its production performance in the face of any activity. The current study focuses on rock type and flow unit classification for the Mishrif reservoir in Iraq's southeast and the study is based on data from five wells that penetrate it. Integration of several methods was used to determine the flow unit based on well log interpretation and petrophysical properties. The flow units were identified using the Quality Index of Rock and the Indicator of Flow Zone. The Winland correlation was used to determine the pore throat size. The Lucia classification was based on fabric rock number, and cluster analysis detects rock types using well log data within the Mishrif Formation. Four rock types have been specified by the combination of these approaches grainstone-packstone, packstone-wackestone, Wackestone-Mudstone and Mudstone.