Analisis Fasies dan Penentuan Zona Reservoir Non Konvensional Pada Formasi T Berdasarkan Data Bawah Permukaan di Lapangan X, Cekungan Sumatra Tengah

Abstract

This research was conducted in Field X, Block Y, administratively located in Siak Regency, Riau Province, Indonesia with an area of ±79 mil^2. This study contains facies analysis and determination of unconventional reservoir zones with the aim of determining facies, depositional environments, petrophysical parameters and potential zones of unconventional reservoirs in the research area. The method carried out consists of detailed analysis of T Formation based on well data, cores and biostratigraphy, well correlation (lithoststratgraphic correlation), well facies analysis, petrophysical analysis which includes identification of shale volume, effective porosity and water saturation, well-seismic tie, seismic attribute analysis, facies analysis and depositional environment based on facies classification Darman et al (2017), as well as reservoir quality analysis for reservoir quality ranking based on those defined based on petrophysical parameters. Subsurface mapping is carried out based on 3D seismic data, well data, core data and biostratigraphic data (on several wells) to determine the distribution of facies and unconventional reservoir zones in the Upper T Layer and Lower T Layer. Based on all the analyses that have been done, it was found that there are four facies in the T Formation, namely Tidal bar, Distributary Channel, Abandoned Channel and Mouth bar. By the direction of sediment deposition of the Southwest-Northeast. Facies in the Upper T Layer, namely Tidal bar and Distributary Channel are declared as facies that have great potential as unconventional reservoirs and are marked as 1st and 2nd reservoir ranks with distribution from Southeast to Northwest which is in the Southwest from Field X.