Maturation Level of Organic Matter and Hydrocarbon Generation by Probable Source Rocks in the South Sumatra Basin: Results of Basin Analysis

MARDIANZA, Andi¹; Galushkin, Yurii²
¹Geology and Gephysic, Gubkin Russian State Univ. of Oil and Gas, Moscow, Russian Federation.
²Lomonosov Moscow State University, Moscow, Russian Federation.

Numerical reconstruction of the burial, thermal and maturation histories for sedimentary sections of six wells: Lambak, Gambir-1, Tepus-1, Tepus-2, Petanang-1, and Pandan-b1 in the South Sumatra Basin were carried out with use of the GALO system of basin modeling. The present-day sedimentary sections, measured values of temperatures and vitrinite reflectance and calculations of variations of tectonic subsidence of the Basin served as control factors of our modeling. High temperature regime of sedimentary rocks during their subsidence in the Basin resulted in early maturation of organic matter and relatively shallow depths of "oil window" (1.3 - 3.5 km in present-day section). The Lower Miocene and Oligocene rocks realized their hydrocarbon potential to considerable extent, whereas the Middle and Upper Miocene rocks were characterized by moderate and little hydrocarbon generation. As whole, hydrocarbon generation by source rocks together with maturation level of the rocks in the South Sumatra Basin changes strongly due to thermal influence of numerous fracture, hydrothermal and igneous activity resulted local step-like increase in Ro with depth.

AAPG Search and Discovery Article #90155©2012 AAPG International Conference & Exhibition, Singapore, 16-19 September 2012