Sikuen Stratigrafi Formasi Talang Akar Lapangan “Dr”, Sub–Cekungan Jambi,Cekungan Sumatera Selatan

Abstract

The area of this study include to PT. Energi Mega Persada Tbk work area. The area of this study is located in Jambi Sub - Basin, South Sumatera Basin. This study is emphasized to examine the sequence stratigraphy of Talang Akar Formation. The data that is used in this study include core, mudlog, 3D seismic, well log, and palynomorf fossil. The result of those data analysis and data correlation are lithofacies, electrofacies, depositional environment, and stratigrahys sequences of Talang Akar Formation. From data analysis, the facies’ that develop in Talang Akar Formation are A, B, C, D, E, F, G, H, I, J, K, L, and M. Those facies’are deposited in fluvial – deltaicenvironment at Late Oligocene until Early Miocene. From the well correlation and seismic interpretation, the sediment distribution pattern of Talang Akar Formation become thicker and deeper in the west side and the highland is located relatively in the east of the study area. At the area of study Talang Akar formation is very influenced by structure. From the lithofacies and electrofacies analysis, there are six kinds of stratigraphy sequencesthat develop in the study area. System tracts LST-1 (braided channel) just developed at sequence-1. The other sequences developed TST 1 – 4 (floodplain meandering channel), TST 5 – 6 (marsh delta plain), HST 1 – 4 (crevasse splay meandering channel) and HST 5 – 6 (floodplain delta plain). . Keywordsi: Sequence stratigraphy, facies,depositional environment, Talang Akar Formation, Jambi Sub - Basin. Daerah penelitian termasuk ke dalam wilayah kerja PT. Energi Mega Persada Tbk. Daerah penelitian berada di Sub – Cekungan Jambi, Cekungan Sumatera Selatan. Studi ini difokuskan untuk membahas sikuen stratigrafi Formasi Talang Akar. Dalam penelitian ini, data yang digunakan adalah core, mudlog, seismik 3 dimensi, well log, dan fosil palinomorf. Hasil dari analisis dan korelasi data tersebut adalah litofasies, elektrofasies, sikuen stratigrafi, dan lingkungan pengendapan dari Formasi Talang Akar. Dari analisis data tersebut didapatkan bahwa fasies yang berkembang pada Formasi Talang Akar adalah fasies A, B, C, D, E, F, G, H, I, J, K, L, dan M. Fasies tersebut diendapkan di lingkungan fluvial – deltaic pada umur Oligosen Akhir sampai Miosen Awal. Berdasarkan korelasi antar sumur dan interpretasi seismik, distribusi sedimen Formasi Talang Akar lebih menebal dan mendalam pada sisi barat dengan tinggian yang berada relatif pada bagian timur daerah penelitian. Pada daerah penelitian Formasi Talang Akar sangat dipengaruhi oleh struktur serta berdasarkan analisis litofasies dan elektrofasies terdapat 6 sikuen yang berkembang pada daerah penelitian. System tracts LST-1 (braided channel) hanya berkembang pada sikuen-1. Pada sikuen lainnya berkembang TST 1 – 4 (floodplain meandering channel), TST 5 – 6 (marsh delta plain), HST 1 – 4 (crevasse splay meandering channel) dan HST 5 – 6 (floodplain delta plain). Kata kunci : Sequence stratigraphy, facies, depositional environment, FormasiTalang Akar, Sub Cekungan Jambi.