Fasies Dan Lingkungan Pengendapan Serta Proses Diagenesis Batuan Karbonat Interval ‘M’, Formasi Baturaja, Lapangan ‘AHAN’, Sub Cekungan Palembang Selatan, Cekungan Sumatra Selatan

Anindito Hafizh Akyela Nugroho, Ir. Moch. Indra Novian, S.T., M.Eng., IPP. ; Ir. Jarot Setyowiyoto, M.Sc., Ph.D., IPU, ASEAN Eng.

2026 | Skripsi | TEKNIK GEOLOGI

Batuan karbonat pada interval ‘M’ Formasi Baturaja, Lapangan ‘AHAN’, Sub cekungan Palembang Selatan, Cekungan Sumatra Selatan, memiliki tingkat heterogenitas yang tinggi sehingga memerlukan kajian fasies dan diagenesis untuk memahami karakteristik reservoarnya. Penelitian ini bertujuan untuk mengidentifikasi fasies, lingkungan pengendapan, proses diagenesis, serta lingkungan diagenesis batuan karbonat pada interval penelitian. Analisis dilakukan melalui integrasi data batuan inti, petrografi sayatan tipis, elektrofasies, dan biostratigrafi. Hasil penelitian menunjukkan keberadaan fasies yang merepresentasikan lingkungan reef slope - near reef. Fasies yang berkembang terdiri atas bioclastic wackestone - packstone dan bioclastic packstone. Proses diagenesis yang teridentifikasi mencakup dissolution, sementasi, kompaksi, dolomitisasi, dan neomorfisme, dengan neomorfisme sebagai proses yang paling dominan. Berdasarkan karakteristik diagenesis tersebut, lingkungan diagenesis diinterpretasikan berada pada zona vadose, freshwater phreatic, mixing dan burial.

Carbonate rocks within the ‘M’ interval of the Baturaja Formation, AHAN Field, South Palembang Sub-basin, South Sumatra Basin, exhibit a high degree of heterogeneity, necessitating detailed facies and diagenetic investigations to better understand their reservoir characteristics. This study aims to characterize the facies, depositional environment, diagenetic processes, and diagenetic environments of the carbonate succession within the study interval. The analysis integrates core descriptions, petrographic examination of thin sections, electrofacies interpretation, and biostratigraphic data. The results reveal the presence of two facies representing a reef slope to near reef depositional environment. These facies comprise bioclastic wackestone - packstone and bioclastic packstone. Diagenetic analysis identifies several diagenetic processes, including dissolution, cementation, compaction, dolomitization, and neomorphism, with neomorphism constituting the most pervasive diagenetic processes throughout the interval. Based on the observed diagenetic characteristics, the diagenetic environments are interpreted to have developed within vadose, freshwater phreatic, mixing, and burial diagenetic environments.

Kata Kunci : Fasies, lingkungan pengendapan, proses diagenesis, lingkungan diagenesis, Formasi Baturaja.