Hu F.,Jilin University |
Hu F.,Key Laboratory for Evolution of Past Life and Environment in Northeast Asia |
Hu F.,Key Laboratory of China Universities of Jilin Province |
Liu Z.-J.,Jilin University |
And 11 more authors.
Jilin Daxue Xuebao (Diqiu Kexue Ban)/Journal of Jilin University (Earth Science Edition) | Year: 2012
Sequence boundaries of the Dunhua Basin have been identified by the well-logging and seismic marks. Sequence interface on the well-logging curves has obvious chop value. The amplitude and frequency changed greatly above and beneath the interface. Seismic data indicate that above the sequence interface is marked by onlap, and beneath it is marked by truncation. The system tracts of each sequence have been divided by the overlay manners of subsequence sets, and the Paleocene Hunchun Formation in Dunhua basin can be divided into two third-class sequences, SQ1 and SQ2; the Tumenzi Formation of Neogene can be divided into four third-class sequences, SQ3 to SQ6.and each third-class sequence includes four whole system tracts. According to the cores and logging characteristics, two sedimentary facies of fan-delta and lacustrine have been identified, which can be further divided into 5 kinds of subfacies and 10 kinds of microfacies. The sedimentary evolution played an important role on source rock development, and the semi-deep lake sedmentary facies is the best favorable environment for source rock. The later stage of Hunchun Formation (SQ2) and early stage of the Tumenzi Formation (SQ3) is the main developing stage of source rock in Dunhua Basin, and the region southwestern slope of the basin to Jingbohu area is the best position for source rock. The organic abundance of developed source rock is high and the type is II1, among which, the quality of source rock in Highstand System Tract (HST) is the best, secondly is the Transgressvie System Tract (TST).