Study comparative rock typing methods to classify rock type carbonate reservoir Field "s" East Java

Challenges in the characterization of the carbonate reservoir are related to rock type and porosity. The permeability cannot be determined only by porosity. So the method that can be used to classify rock type and estimates the permeability is rock typing method. This study uses several rock typing methods that are Flow Zone Indicator (FZI), Winland R35, Pore Geometry Structure (PGS), and Lucia method. Core data from three wells have been applied in this study as reference wells. The objective is comparing those four methods and choose the best method for this study. There are two assessments in comparing. First, comparing the core permeability with predicted permeability on each method of rock typing. The result is the Winland R35 method has a better correlation between predicted permeability and core permeability, which have the value of the gradient is 0,9772, R ² is 0,9369 and RMS error is 62,14 mD. Second is by spreading the seismic parameters data to see the separation of each class in each method of rock typing. From this assessment, Lucia has a better distribution of seismic parameters. This assessment is more important than the first assessment. Therefore, Lucia is the best rock typing method in this study.