Brief discussion of risk exploration directions of buried hills in Jiyang Depression

Jiyang Depression is rich in petroleum resources. However， as the exploration degree intensifies， the exploration difficulty of the Paleogene conventional petroleum reservoirs is increasing. Therefore， exploring new fields and ensuring the effective supplement of resources is urgent. The strata in Jiyang Depression is well developed， and the pre-Paleogene buried hill is widely distributed， with a great thickness and significant exploration potential. However， the exploration results are unsatisfactory due to the early formation of deep buried hills， complex geological evolution history， and poor quality of deep seismic data. In recent years， with continuous breakthroughs in experimental technologies， deepening research on basic geology， and massive seismic data processing methods， the exploration of buried hills has yielded many promising leads. This has led to an understanding of petroleum exploration in buried hills characterized by multiple periods of structures contributing to hills， multiple sets of source rocks supplying hydrocarbons in conjunction， multi-element control of advantageous reservoir formation， and various modes of orderly controlling the reservoir. The risk direction and exploration targets for deep buried hills were clarified， and the ways for further petroleum potential exploration in Jiyang Depression were pointed out through an in-depth dissection of the discovered reservoirs， coupled with the exploration experience of neighboring areas. Specifically， the risk exploration directions for each stratum were as follows： fault-fractured bodies， fault-dissolved bodies， and other enclosures within the buried hills of the Archean； concealed fault block traps and internal grain beaches， as well as lithologic traps formed by layer-following dissolution of the lower Paleozoic； deep coal-measure gas reservoirs with a burial depth of greater than 2 000 meters of the upper Paleozoic； lithologic traps controlled by fractures and sand bodies of the Mesozoic.