ANALISIS KORELASI SIKUEN STRATIGRAFI PADA FORMASI AIR BENAKAT, BERDASARKAN DATA DESKRIPSI CORE DAN LOG SUMUR, LAPANGAN MINYAK “X”, LAPISAN “HJ”, CEKUNGAN SUMATRA SELATANLISIS LAIN DIDAERAH X - Hisar Josua Apriano Simatupang (Jurnal Eksakta Kebumian, 2021)
Abstrak Lapangan minyak “X” merupakan wilayah kerja dari KSO Pertamina EP – SE BWP Meruap yang berada pada Cekungan Sumatra Selatan. Penelitian ini difokuskan pada Formasi Air Benakat. Penelitian ini menerapkan fasies dan sikuen stratigrafi dengan metode korelasi, kalibrasi dan analisa, yang akan memberikan hasil berupa (1) Penentuan fasies dan litologi (litofasies, elektrofasies) (2) Penentuan marker / korelasi sikuen stratigrafi (3) Pemodelan peta isopach lingkungan pengendapan dan (4) Runtunan paleogeografi serta penampang yang mewakili setiap kronologi lingkunngan pengendapan yang berlanjut. Data yang digunakan dalam penelitian ini meliputi integrasi dari: 6 data well logs, 1 data batuan inti (drilling core), 1 Side Wall Core (SWC).Interpretasi lingkungan pengendapan, dan korelasi marker sikuen stratigrafi pada lapangan minyak “X”, lapisan “HJ” antara lain ditentukan oleh analisis data well log. Pada area penelitian, litologi yang diperoleh berupa sandstone, shaly sand dan claystone disertai oleh analisa elektrofasies well log yang dilakukan terhadap enam sumur dan core berupa litofasies. Pola log gamma ray berhubungan dalam penentuan fasies, pada lapisan penelitian diperoleh dominan pola log berupa serrated, bell shape, funnel shape dan blocky. Berdasarkan asosiasi fasies yang didapatkan, lingkungan pengendapan pada lapisan “HJ” berupa upper shoreface, middle shoreface, lower shoreface, estuarine channel dan tidal mudflat. Beserta parasikuen pada area penelitian dibagi menjadi dua (2) parasikuen. Kata kunci: Cekungan Sumatra Selatan, Formasi Air Benakat, Fasies, Lingkungan Pengendapan, Sikuen Stratigrafi, Abstract The "X" oil field is the working area of ​​the KSO Pertamina EP - SE BWP Meruap located in the South Sumatra Basin. This research is specifically focused within the Air Benakat Formation. This study uses facies and stratigraphic sequences by applying basic correlation method, calibration and analysis, which will give results in the form of (1) Determination of facies and lithology (lithofacies, electrofacies) (2) Determination of marker / sequence stratigraphy corelation (3) Depositional environment isopach mapping(4) Paleogeographic sequences and cross section that represents each ongoing chronology of each depositional environment within. The data used in this study includes integration of 6 well logs data, 1 drilling core data, 1 Side Wall Core (SWC) data. Interpretation of depositional environments, and sequence stratigraphical markers on oil field “X”, "HJ" stratum, among others, are determined by analysis of well log data. In the study area, the lithology obtained consisted of sandstone, shaly sand and clay stone which was obtained by electrofacies log analysis carried out by six well logs and core obtaining lithofacies. Gamma ray log patterns are crucial for determining facies within the “HJ” stratum, dominant log patterns consists of serrated, bell shape, funnel and blocky. Based on the associations obtained, the depositional environment in the "HJ" stratum consists of the upper shoreface, middle shoreface, lower shoreface, estuarine channel and tidal mudflat. Along within the parasequence in the study was divided into two (2) parasequences. Keywords: South Sumatra Basin, Air Benakat Formation, Facies, Depositional Environment, Sequence Stratigraphy