The Assessment of Carbonate Heterogeneity, Using Seismic Inversion of Two-Dimension Seismic Multi Vintage: A Case Study of North West Java']Java Basin

Seismic inversion two dimension (2D) multi vintage has been done to characterize heterogeneity of carbonate of Baturaja formation, North West Java Basin. Baturaja formation is tight carbonate but is proven to produce hydrocarbon. The research data consisted of seismic data multi vintage and well data. Inversion multi vintage data has limitation in different phase, amplitude and time thus we performed pre-conditioning data in order to balancing the differences. This research was using the Constrained Sparse Spike Inversion (CSSI) method. CSSI is a model based inversion to make an initial model and applied sparse spike inversion to get acoustic impedance value. Heterogeneity was the mainly carbonate rock properties focused in this research, seen by its porosity. Carbonate porosity is the secondary porosity, since it was not depended on diagenesis, though there were several factors that influenced it. The aim of this research is to prove that the tight carbonate reservoir in the target zone can produce hydrocarbons and to know its relationship with the heterogeneity of porosity. The result of this research showed that the fracture porosity affected the permeability of rock. The compression on tight carbonate will fracture the rock, so the fracture will increase the permeability of rock. A good permeability of rock can be used as a hydrocarbon migration pathway. This research will add knowledge about carbonate rock properties and to help fulfilling next proposed drilling in Baturaja formation.