Abstract:

After the Baiyun Movement (13.8 Ma), Baiyun Sag in the Pearl River Mouth Basin happened a massive regressive event, the sea level regressed near the shelf slope-break zone and the delta propelled furthest towards the basin, which was very beneficial to the development of deep-water fan. By means of the drilling and logging analysis and the well-seismic calibration of B6 well in the deep water area of the continental slope and some wells in the shelf margin, it was concluded that reservoir of slope fan with larger thickness (20 m to 40 m) in argillaceous siltstone, corresponded to the low frequency, short axis and high amplitude in the seismic reflection, and strong wave hollow in the negative polarity display of the seismic profiles. Through the establishment of sequence stratigraphic framework, it was summarized that the main depositional setting of the SQ13.8 was “shelf margin delta-bypass area-slope fan”. On the restraint of the stratigraphic framework, through synthetic seismic records to establish the well-seismic relationship, we identified and interpreted SF-5 reservoir in slope fan zone, and determined the SF-5 reservoir mainly distributed in the moundy which is in the flank of continental slope of the shelf slope break zone, its plane distribution looks like a broom and it has feature of the slope fan. The high quality reservoir of SF-5 mainly distributed in the middle and west working areas, was banded in the north west-south east direction.

Key words: northern South China Sea, Baiyun deep-water area, slope fan, synthetic seismic record, sequence stratigraphic framework, reservoir distribution