ABSTRACT: The utilization of paleo heatflow to define a source rock maturity: case study at Ngimbang-01, North East Java Basin, Indonesia

Koesoemadinata, R. P.¹, A. H. P. Kesumajana¹, and Ory Sadjati²
(1) Institute of Technology Bandung, Bandung, Indonesia
(2) PERTAMINA, Jakarta, Indonesia

Present day heatflow value, interpreted as a constant along geological time, is often used in modeling to define a source rock maturity. This assumption is actually inaccurate as heatflow in reality is not constant but trancient instead, and is related to each basins's tectonic history. In order to get heatflow history approaching reality, evaluation on temperature history need to be conducted, followed by converting the temperature to vitrinite reflection data (Ro). In this paper, the convertion is done using Easy%Ro method (Sweeney and Burnham, 1990). Consequently, the resulting Ro data is calibrated with the direct measured Ro.

Investigation carried out at Ngimbang-01 well, North East Java Basin, shows that the source rock is interpreted as having matured in 34 million years ago using heatflow history approaching reality, whereas by using heatflow which is constant along all the geological time, the maturity is interpreted to have started 16 million years ago.

AAPG Search and Discovery Article #90913©2000 AAPG International Conference and Exhibition, Bali, Indonesia