Characterization of clastic reservoirs in the North West Java basin has many challenges due to the presence of Clay which influences the reservoir. Until now, there are differences in whether the calculation of the fine fraction is calculated by shale volume (Vsh) or clay volume (Vcl), which are currently considered the same. The first is rock type and the next is naming which uses grain size or mineral type as the basis for naming rocks. Inaccurate Vcl quantification can provide errors in porosity and saturation calculations due to the impact of clay density and conductivity if the equations used depend on the conductivity of the clay

Alternative models are offered to evaluate reservoir composition in the form of sand, silt and clay, which may be applicable in some local areas and not applicable in other areas. One of the fundamental things is the availability of a mixture model between the volume of Sand, Silt and Clay because dispersed Clay has an impact on the calculation of porosity and effective water saturation, especially when evaluating low resistivity and contrast (LRLC) reservoirs

In this research, we discuss the use of the Sand Silt Clay ratio model which is commonly used in the Malaysian Basin to see whether this model can be used in other basins. To validate the results, they were compared with the results of core analysis in the form of grain size distribution and the results of X-ray diffraction (XRD) analysis in the research area.

The proposed technique helps in calculating the effective porosity and maximum volume of Clay as an important parameter in petrophysical analysis besides being used for formation characterization and sedimentology purposes. The proposed model will help minimize uncertainty as a suitable approach for improving accuracy in mineralogy, porosity, saturation calculations, and ultimately in volumetric calculations.