Linking between Sedimentary Facies and Petrophysical Rock Type: A Case Study

Rock typing is a technique of grouping rocks that have similar properties, which properties can be in the form of sedimentary, petrophysical, and reservoir parameters. Classification based on sedimentary parameters is called sedimentary rock type (SRT), while grouping based on petrophysical parameters is called petrophysical rock type (PRT). The purpose of this study is to determine the relationship between SRT and PRT in the research area. The method used to determine sedimentary rock type is to use the facies concept approach, while the method used to determine petrophysical rock type is the Hydraulic Flow Unit Method, Global Hydraulic Element, Winland R35, and Pore Geometry Structure. In this study, determined the relationship between sedimentary rock type with petrophysical rock type, where some facies that have certain characteristics will have a certain type of petrophysical rock type pattern. Thoroughly bioturbated mudstone facies which have low porosity and permeability have two petrophysical rock types with initial sequence (RT 1 and RT 2) with the HFU, GHE, and Winland R35 methods, while with the PGS method there are RT 4 to RT 7. These facies have low rock type variations, it can be concluded that these facies are homogeneous