Elastic Property Modeling Related to Pore Type Analysis in Carbonate Reservoir

Abstract

The reservoir has a significant role as a place of hydrocarbon accumulation in a petroleum system. Therefore, during exploration, a good understanding of the reservoir characterization becomes important to recognize the hydrocarbon migration path. There are several types of reservoirs which are commonly found; one of them renowned as carbonate reservoir. This type of reservoir is hard to be understood due to the heterogeneity of its pore type as a result of intense cementation and diagenesis. Information of pore type can be obtained based on core analysis or rock physics analysis. There are some rock physics approaches commonly used such as Kuster-Toksöz, Self Consistent Approximation (SCA), and Differential Effective Moduli (DEM). On the other hand, there are also other approaches but less famous. Parameters such as spherical porosity(ɸS), pore shape parameters –pore shape factor (S) and relative pore shape factor(ΔS) – are sensitive to identify pore type which may be developed in a carbonate reservoir. A positive value of ɸS and ΔS is the characteristic of carbonate rocks with the domination of stiff pore (high aspect ratio). These characteristics also can be informed by a value of S > 1. On the opposite, a negative value of ɸS and ΔS is the characteristics of carbonate rocks dominated by soft pore (low aspect ratio) that also can be informed by a value of S < 1. These parameters offer a simpler approach about pore type analysis and easier compared to Kuster-Toksöz in rock physics modeling. This research will use synthetic data to comprehend each parameters and real data to validate a hypothesis based on synthetic data. The results obtained in this study can be used as a first step to do seismic inversion based on the elastic property which is sensitive enough for this condition.