Bulletin of Scientific Contribution

ABSTRAK

Lapangan Barumun Tengah adalah lapangan yang baru dikembangkan semenjak ditemukannya potensi hidrokarbon pada sumur eksplorasi BT-1 pada lapisan batupasir A dan B tahun 1984. Pengambilan data baru berupa sumur pengembangan dan seismik 3D dapat digunakan untuk melihat pola sebaran lateral dan geometri batupasir yang sesuai dengan model lingkungan pengendapan yang diajukan, sehingga diperlukan studi lebih lanjut untuk memahami tipe fasies, distribusi lateral, geometri dan kualitas reservoir pada reservoir batupasir A. Kelompok Sihapas berumur Awal Miosen menindih tidakselaras terhadap Formasi Pematang. Formasi ini mengandung batupasir dengan ukuran butir medium-coarse dan batulempung yang diendapkan pada delta plain- delta front. Ketebalan pada Formasi Lower Sihapas di sumur BT-1 adalah 130 kaki dan terdapat 4 batupasir individu berukuran 40kaki, 8kaki, 30kaki, dan 10kaki masing-masing. Sedangkan pada sumur BT-2 ketebalan Lower Sihapas 150kaki dengan 4 batupasir individu juga masing-masing 53kaki, 23kaki, 5kaki, 22kaki. Berdasarkan deskripsi litofasies, maka dapat diinterpretasikan asosiasi fasies yang terdapat pada sumur BT-3 terdiri dari dua asosiasi fasies (genetic unit).

Kata kunci: Fasies,Formasi Menggala, Sumatera Tengah

ABSTRACT

Barumun Tengah is one of newly developed field since the discovery of hidrocarbon potential in BT-1 Well on Sand A and B in 1984. Newly well and seismic data taken was able to determinate the geometry and lateral distribution of the sand facies. But the new integrated study to understand the facies type is needed. The Early Miocene Sihapas group was deposited unconformitely the Older Pematang Group, Consist of medium to coarse sandstone and shale deposited in delta plain to delta front environment. Thickness of the sand in BT-1 sand is aproximately 130 ft in total with 4 separated sandstone layer, from bottom to top 40ft, 8 ft, 30ft, and 10ft. while thickness in BT-2 Well 53ft, 23ft, 5ft, and 22ft respectively.  Based on litofacies description, there are two genetic unit can be found.

Keyword: Facies, Menggala Formation, Central Sumatera

Asquith, G., dan Krygowski, D., (2004): Basic Well Log Analysis, AAPG Methods in Exploration 16, 245 p., Tulsa, Oklahoma – Amerika Serikat.

Cameron, N.R. (1983) : The stratigraphy of the Sihapas Formation in the North West of the Central Sumatra Basin. Proceedings Indonesian Petroleum Association, 12th Ann. Convention 1983-1, Jakarta.

Eubank, R.T. dan A.C. Makki (1981) : Structural geology of the Central Sumatra back-arc basin. Proceeding Indonesian Petroleum Association, 10th Annual Convention.

Heidrick, T.L., K. Aulia, B. Mertani, dan Yarmanto (1996) : Petroleum geology of Indonesian basins, II: Central Sumatra basin. Pertamina BPPKA.

Heidrick, T.L. dan K. Aulia (1993) : A structural and tectonic model of the Coastal Plains Block, Central Sumatra basin, Indonesia. Proceeding Indonesian Petroleum Association, 22nd Annual Convention, Jakarta.

Koning, T. dan F.X. Darmono (1984) : The Geology of The Beruk Northeast Field, Central Sumatra, Proceedings Indonesian Petroleum Association, Thirteenth Annual Convention, Jakarta.

Mertosono, S. dan G.A.S. Nayoan (1974) : The Tertiary basinal area of Central Sumatra. Proceeding Indonesian Petroleum Association. 3rd Annual Convention, Jakarta.

Moulds, P.J. (1989) : Development Of The Bengkalis Depression, Central Sumatra and Ins Subsequent Deformation – A Model for Other Sumatran Grabens, Proceedings Indonesian Petroleum Association, Eighteenth Annual Convention vol.1, Jakarta.

Posamentier, H.W., dan Walker, R.G. (2006): Facies Models Revisited, Society for Sedimentary Geology Special Publication 84, Tusla, Oklahoma.

Wain, A.S. dan Jackson, B.A. (1995) : New Pematang Depocentres on The Kampar Uplift, Central Sumatra, Proceedings Indonesian Petroleum Association , Twenty Fourth Annual Convention vol.1, Jakarta.

Williams, H.H. dan R.T. Eubank (1995) : Hydrocarbon habitat in the rift graben of the Central Sumatra Basin, Geological Society of London Special Publication, London. Twenty Fourth Annual Convention vol.1, Jakarta.

Zuo, G., Lu, F., Fan, G., dan Shao, D. : Study of Hydrocarbon Detection Methods in Offshore Deepwater Sediments, Gulf of Guinea, Search and Discovery Article, 2012, California.