Fractures and diagenesis effect on the reservoir quality: An example from Albian-Cenomanian carbonate unit of the Natih Formation, Jabal Akhdar area, Oman

Reservoir rocks in the Middle East, including the Sultanate of Oman, are mainly carbonates that display various types of diagenetic environments and, therefore, different alterations. This proposal aims to study and understand the fractures and diagenetic features of the Albian-Cenomanian carbonate unit of the Natih Formation that crops out in the Jabal Akhdar area, Oman, and their influences on reservoir quality. Moreover, the outcropped carbonate rocks can serve as analogs for heterogeneous reservoir rocks in the subsurface of the Sultanate of Oman. The study goals can be better achieved, and predictive conceptual models can be developed when the diagenetic alterations and fracture distribution that influence reservoir quality are linked to depositional facies and stratigraphic sequence framework (systems tracts and key sequence stratigraphic surfaces) of the carbonate succession. Particular emphasis will be placed on the cemented (mineral-fill) and open fractures and their role in developing, redistributing, and destroying secondary porosity. The study will, thus, be conducted employing an integrated approach, which involves the analysis of field geometries, petrography, reconstruction of conceptual tectonics modeling, fracture system characterization micro-thermometry (fluid inclusions), and geochemical (major and minor elements as well as stable and radiogenic isotopes) analyses of the diagenetic minerals and host carbonate rocks.