3D Seismic Sedimentology of Nearshore Subaqueous Fans – A Case Study from Dongying Depression, Eastern China - Advances in Data, Methods, Models and Their Applications in Geoscience - page 134

4.2 The distribution characteristics of effective reservoir in nearshore subaqueous fan
The synthetic seismogram calibration results show significantly higher dimension values of
12000-15500 in the GS pseudo-acoustic 3D seismic inversion for the effective sand-
conglomerate reservoir but lower dimension values<12,000 for the ineffective reservoir in
the lower Es 4 Formation (Fig.8). Accordingly, quantifying the thickness and the distribution
of the effective sand-conglomerate reservoir in the lower Es 4 Formation can be relatively
easy (Fig.8).

Fig. 8. The effective reservoirs range of values in the GS 3D seismic inversion data for the
blue zone (see location in Fig.5b)

5. Conclusions

1. Nearshore subaqueous fans of Paleogene age are well developed in the lower Es4

Formation of the Dongying Depression, in the Bohai Bay Basin, eastern China. Research
and oil and gas exploration in the northern Dongying Depression have demonstrated
that the sand-conglomerate in the mid sub-fan is not only the main part of the
nearshore subaqueous fan, but also the effective oil and gas reservoir in the region.

2. Statistical analyses on different lithology and effective reservoir and logging parameters

show that the acoustic (ac), natural gamma (gr), spontaneous potential (sp) can be used
as characteristic curves for seismic inversion calculation. Any combinations of two logs
can distinguish the effective from the ineffective sand -conglomerate reservoirs with a
thicknesses greater than 6 m.