Seismic sedimentology analysis of fluvial-deltaic systems in a complex strike-slip fault zone, Bohai Bay Basin, China: Implications for reservoir prediction

Abstract

The Miocene fluvial-deltaic system in the Bohai Bay Basin exhibits difficulties in favourable reservoir prediction in a complex strike-slip fault zone in the Tanlu fault system. On the basis of 3D seismic data and 12 wells, we utilize two different RGB colour-blending methods from various datasets. The first method is derived from the 3D stacked, −90° phase seismic volume, and the second method is generated from the root mean square (RMS) volume attribute, which is extracted from −90° phase seismic data. Combined with the linear combination analysis of user control, we attempt to better quantify reservoir thickness and evolution of the fluvial-deltaic system in the Guantao Formation. The results show that stratal slices of the second RGB colour-blending method have a much greater ability to characterize sedimentary facies evolution and to analyse sand-thickness variations, which can effectively decrease the disadvantageous influence of multiple fault blocks on stratal slice views. In the vertical section, the linear combination analysis and the first RGB colour-blending method, however, have greater utility and resolution, which can be used to characterize the sand body by the width of seismic events or display the various sand thicknesses in different colours. The high-resolution anatomy of the fluvial-deltaic system in the Bohai Bay Basin not only explains current exploration effects but also effectively predicts thick sandstones with the most production potential in this complex region. This study may also have great significance for other complex areas or strata.