Application of Digital Rock Physics and FIBSEM Imaging to Unconventional Reservoir Characterization in the Najmah Formation

An attempt has been made to characterize the reservoir properties of the low porosity carbonates of the Najmah Formation through digital rock studies and FIBSEM(focused Ion beam electron microscope) imaging to determine the Microstructural characters of mineral matrix, Organic matter distribution, Pore network and organic matter pore type, pore size and permeability variation in the kerogen rich Kimmeridigian stratigraphic interval. It is possible that intergranular clay pores in highly thermally mature rocks were originally filled with organic matter and that during progressive thermal maturation, transformation of organic matter to hydrocarbon s removed much of the porefilling organic matter. Segmented three dimensional focused ion beam electron microscope (FIBSEM) volume from Najmah Formation brings out the distribution of Connected porosity disconnected porosity and organic material. It has been observed that although the TOC content of the rocks are very good (>21%), and good maturity index (VR0>1)only few samples show good connected porosity within the organic matter. These intervals can be considered as the potential sweet spots in the Najmah Formation after integration with petrophysical and geomechanical parametres.