IDENTIFICATION OF POTENTIAL STRATIGRAPHIC TRAPS IN TALANGAKAR FORMATION SANDSTONE, CENTRAL ARJUNA SUB-BASIN, NORTHWEST JAVA BASIN

• Main Author: Apriliani Pritama, Renky
• Format: Theses
• Language: Indonesia
• Subjects: Geologi, hidrologi & meteorologi
• Online Access: https://digilib.itb.ac.id/gdl/view/84478
• Institution: Institut Teknologi Bandung

In the YM Field, the sandstone of the Talangakar Formation is the main objective that looking for hydrocarbons. The Talangakar Formation (TAF) sandstone of Late Oligocene has contributed 15% of total oil production in the Arjuna sub-basin, while 80% of the contribution comes from the sandstone of the Middle Miocene Upper Cibulakan Formation and 5% comes from other formations. The difficulty of finding prospects/leads in the sandstone of the Talangakar Formation in this field makes sequence stratigraphic analysis using biostratigraphic data as well as well and seismic data an effort to find potential new stratigraphic traps. The data used in this study is the result of the analysis of the core rock data of one well, the results of biostratigraphy analysis of a well, wireline log data of three wells, and 2D seismic data of 25 lines. The study phase was carried out by determining the lithofacies and association facies of the core rock data, assisted by biostratigraphy data to determine age and depositional environment. Next, identify the parasequences and sequences markers from the electro facies pattern analysis result on each well. Sequences stratigraphy correlation was carried out, after that to determine the direction and distribution pattern of depositional facies. The results of the study showed that the sequences in the Talangakar Formation from old to young are sequence-1 (SB1/32ma to SB2/28ma), consist of Lowstand System Track-1 (LST-1), Transgressive System Tract-1 (TST-1), Highstand System Tract-1 (HST-1); sequence-2 (SB2/28ma to SB3/23ma) consist of Lowstand System Track-2 (LST-2), Transgressive System Tract-2 (TST-2), and Highstand System Track-2 (HST-2); sequence-3 (SB-3/23ma to SB-4/21.5ma) consist of Transgressive System Tract-3 (TST-3) and Highstand System Tract-3 (HST-3). The direction of deposition and distribution of sequences stratigraphic units in the Talangakar Formation originates from the south to the north of the Central Arjuna sub-basin with the sand prone area being architectural facies such as tidal bars, sand flats and river mouth bars in tidal dominated estuarine systems. Potential prospects/leads can be mapped in overlay of structure maps, facies analysis maps and RMS (Root Mean Square) amplitude attribute anomaly maps in sequence SB 1 (LST-1) with tidal bar depositional facies, sequence MFS-1 (TST-1) with sand flat depositional facies, sequence SB-2 (TST-2) with sand flat depositional facies and sequence SB-3 (TST-3) with tidal bar depositional facies.