THE CENOZOIC EVOLUTION AND PETROLEUM RESPONSE ESTIMATION IN THE QUTANG-LIBAO REGION OF THE HAIAN DEPRESSION, THE NORTH JIANGSU BASIN

The Qutang-Libao region lies in the south of Haian depression, the north Jiangsu.It is a Neozoic depression controlled by NE-and EW-oriented big faults. Periodic fault activities controlled deposition and sediment in the Qutang subdepression in the north and the Haibei subdepression in the south, resulting in 3 combinations of hydrocarbon generation, reservation and capping. Primary hydrocarbon terrane including the Taizhou Fm. and the Member 1 and 3 of Funing Fm. came into threshold of oil yielding after the Sanduo Fm.subsided and then entered peak era when the Member 2 of Yanchen Fm.subsided. It is estimated applying the TSM basin modelling that, Votal hydrocarbon yielding of the Qutang subdepression is about 230.54×10⁶t,and that of the Haibei subdepression is about 149.21×10⁶t.The hydrocarbon expelling period took place during depression development, accounting for 95% of the total discharging amout (88.837×10⁶t).Fractures of different level generated in different period affect hydrocarbon scale.Fault belt of multiple faults near deep depression is the main target for exploration.Nose uplift in exterior slope and fault step belt may be favorable accumulation zone.