Pemodelan Fasies 3 Dimensi Reservoar Batupasir ‘X’, Parasekuen ‘Y’, Formasi Talang Akar, Lapangan ‘Z’, Sub Cekungan Palembang Selatan, Cekungan Sumatera Selatan

Abstrak

This study focuses on the 'Z' Field, located within the working area of PT. Pertamina Hulu Rokan Zone 4 in the South Palembang Sub-Basin of the South Sumatra Basin. The primary reservoir under investigation is the 'X' Sandstone interval of the Upper Talang Akar Formation. Notable declines in oil production, coupled with a rising water cut, have prompted the need for targeted development initiatives. Before the implementation of these efforts, it is critical to understand the reservoir's geometry and distribution. To achieve this, we conducted research aimed at constructing a 3D facies model of the 'X' Sandstone Reservoir. The methodology integrated an analysis of well-log data with 3D seismic data to provide a comprehensive view of the reservoir characteristics. The modeling approach utilized Truncated Gaussian with Trends (TGS) and Sequential Indicator Simulation (SIS) techniques. Our findings indicate that the facies within the Talang Akar Formation comprise tidal channels, tidal flats, and sand sheets, suggesting a depositional environment that ranges from a tide-dominated estuary to shallow marine settings. Additionally, the Talang Akar Formation is organized into 15 parasequences and encompasses two system tracts. Chronostratigraphically, the 'X' Sandstone Reservoir is located in Parasequence 9 and features a variety of facies, including sandstone, shaly sandstone, shale, and coal. The 3D facies model reveals a blanket sand geometry with a coarsening-upward vertical pattern, highlighting the complexity of the reservoir's architecture.