Seismic Sedimentology Applied to Qinan Sag, China

Xiaomin Zhu and Yanlei Dong
CUP Beijing, Beijing, China

Seismic sedimentology has great potential in improving exploration and production in mature basins in eastern China. Advantages include high-resolution (reservoir-level) imaging of facies images from 3D seismic data and interpretation of lithofacies and reservoir properties for reservoir distribution and quality, which are especially useful for study of subtle stratigraphic traps in complex non-marine basins in China.

We applied seismic sedimentology to study Qikou Sag in Huanghua Depression, eastern China. A series of stratal slices were made among four maximum flooding surfaces in Sha-1 section with 90-degree phase 3D seismic data on Recon software platform. These stratal slices provide sequential imagery of depositional systems of Sha-1 sequence, depicting a depositional history of braided-fan delta with braided channels and inter-channel facies. More specifically, SI subsequence was the main episode of braided-fan delta development, with widespread channel images on stratal slices; single sandstones are as thick as 30 m and sandstone content as high as 40% in well. To SIII episode, however, the sediment supply was reduced notably, channel images shrink on stratal slices, indicating a significant retreat of braided-fan delta system in the area.

AAPG Search and Discovery Article #90078©2008 AAPG Annual Convention, San Antonio, Texas