The Sequence and Depositional System of Weizhou Formation in the Weixinan Sag, Beibuwan Basin

Under the guidance of the sequence stratigraphy theory, with high-resolution 3-D seismic data and seismic sedimentology methods, the sequence stratigraphy and the depositional system distribution of the main target Weizhou Fm in the western part of Beibuwan Basin have been studied. It is revealed by the study results that the sequence stratigraphic framework in this area is con-trolled by the double (multi) faults, and the Weixinan low uplift is very important for the distribution of depositional system. During the sedimentation period of Weizhou Fm, the provenance comes from three directions, and wide range of typical delta lobes are well developed, of which delta front bar and distal sands are potential favorable exploration targets. On the basis of this study result, the model for prediction of favorable sand is put forward.