Publications

The offshore North Sumatra Basin (NSB) is a relatively immature petroleum province with supergiant potential. It has strong parallels to the mature, onshore part of the NSB, which has been a major hydrocarbon province for more than a century. Conservative estimates of hydrocarbons originally in place indicate that reserves of more than 6.0 billion barrels of oil equivalent have already been discovered in the NSB. However, despite prolific success in the onshore NSB, the offshore NSB is remarkably under-explored. 130 offshore exploration wells have been drilled through 2011, (including fewer than 40 deepwater wells) in an area that is roughly the size of the offshore Kutei or Natuna basins, the greater North West Shelf of Australia, or the US Gulf Coast and Shelf petroleum provinces. In the past decade, only 4 offshore wells have been drilled in total. As a result of the lack of offshore exploration activity and the maturity of the onshore trend, the creaming curve for the NSB has remained remarkably flat for the past three decades. However, comparison with other prolific basins in southeast Asia indicates that the offshore NSB has significant growth potential. This potential has been confirmed by recent exploration efforts, which have highlighted exciting possibilities in at least 5 plays on recently acquired and re-processed 3D seismic surveys in the offshore NSB. Many of these plays are offshore extensions of proven plays in the onshore NSB. These plays have potential reservoirs in syn-rift Oligocene clastics (Parapat Formation), Oligocene- * Zaratex N.V Miocene carbonate build-ups (Tampur and Peutu Formations), and Miocene-Pliocene turbidites (Bampo, Baong, Keutapang, and Seurula Formations). Gas, oil, and condensate are generally accepted to have been generated from highly prolific, albeit low richness, terrestrial and marine shales (Bampo, Belumai, Peutu, and Baong Formations), and charged from deep basinal kitchens located adjacent to structural highs. Hydrocarbons are interpreted to have filled structural, stratigraphic, and combination traps.