Distribution of Glutinite Bodies and Prediction of Favorable Sandbodies of the 4th Member of Shahejie Formation in Tuonan Area

Large scale glutinite bodies deposits are developed in the 4th member of Shahejie Formation of the south of Niuxintuo area, and the geological conditions of accumulation are superior. Good results have been achieved in previous exploration of this area. However, the sand bodies in this area are thick, multiple sets superimposed in multiple periods and rapid lateral changes. The distribution pattern of favorable reservoir sand bodies is unclear, making identification and characterization difficult, and the exploration is very challenging. In order to further deepen exploration and form continuous reserves, the study on the genesis and distribution of glutinite bodies was carried out. Research shows that the formation and distribution of glutinite bodies are mainly controlled by factors such as boundary types and paleogeomorphology. They have the distribution features of planar zonation, vertical stage, backward development and long-term inheritance. Under the guidance of research understanding, the favorable sandbodies were identified and characterized through methods such as sequence tectonic interpretation, seismic attribute analysis and wave impedance inversion. It is considered that the down-dip part of the slope is located in the favorable facies belt of the middle fan of the nearshore subaqueous fan. It is prone to form lithologic and tectonic-lithologic traps due to occlusion of faults and fan-root dense conglomerate and obliterated laterally. It is a favorable area for future exploration and evaluation. This paper aims to summarize the geological laws, explore technical methods suitable for the exploration of glutinite bodies in this area and offer referenceable experience for the exploration of oil and gas reservoirs in other similar areas.