Pore type characterization of kais carbonate reservoir using differential effective medium

Abstract

The Kais Formation is a hydrocarbon reservoir that produces in the Salawati Basin. However, the success in drilling has diminished so a new concept of exploration is needed to characterizing the pore type. Carbonate reservoirs are classified into three pore types based on pore geometry, namely interparticle pore, stiff pore, and crack pore. The pore geometry of carbonate reservoir is very complicated which is compared to siliciclastic rock. The process has greatly affects heterogeneity and pore geometry complexity are cementation, dissolution, and fracturing. These processes modify the pore geometry which correlates with rock porosity. The modification of pore geometry will change the rock elastic properties. It can be identified from the P-wave velocity (Vp). The change in P-wave velocity (Vp) has an effect of 40 %, as a result of modification of the pore geometry. Therefore, studies of rock physical properties that take into account the complexity of pore geometry are very important in characterizing carbonate rocks. Differential Effective Medium (DEM) is one of the elastic rock modeling methods which calculates the geometry aspect of the pore by including porosity into the parent material. The aim of this study is to characterize pore type using DEM in the three different wells; MEI-1 well, MEI-2 well, and APR-1 well. The result of this study shows that MEI-1 and APR-1 well is dominated by interparticle and crack pore, while MEI-2 well is dominated by interparticle and stiff pore.