Divergent Strike-Slip Structure Interpretation - A Successful Case study from Qingxi, Bohai Bay Basin

Geologically, Qingxi is at the eastern edge of Dongying sag, Bohai Bay Basin, China. Controlled by both extensional and strike-slip stresses, structure and stratigraphic distribution this area is so complicated that few systematic research was carried out on fault system and structural pattern. We present an integrated study based on seismic and geological data. In which, Structural feature and stress mechanism were clarified by cross section and horizontal slices analysis. Formation period of strata in complicated blocks were determined by the well-log cobweb; tectonic-stratigraphic framework was established through three-factor synthetic seismogram, guided by logging-seismic spectrum analysis, fischer curve and coupling coefficient. Faults of different sizes were depicted through reasonable application of seismic attributes in multiaspects. Finally, structural map of target layer E2s31 was drawn. Qingxi is divided into four break zones by three large EW strike faults, and stratum gradually rises from south to north, while NS strike-slip faults and EW faults cutting each other forms checkerboard-shaped blocks in the high belt in the west and the large EW strike faults converges to form an brush structure in the high belt in the east.