STRUCTURAL SYSTEMS AND OILFIELD GEOLOGICAL HAZARDS IN THE BOHAI GULF BASIN

The Bohai Gulf basin is an important petroleum base of China.Many structural systems of different structural orders are developed in the basin,such as the en-echelon,brush and network structural systems.According to the dynamic setting,characteristics,harm and distribution of geological hazards,the oilfield geological hazards occurring in the basin may be divided into several types such as well casing damage,induced earthquakes,sand blasting and water and oil spouting at the surface and ground cracks,and the characteristics and distribution of various oilfield geological hazards in the Bohai Gulf basin are discussed.The authors think that the formation,distribution and evolution of oilfield geological hazards in the Bohai Gulf basin are controlled by the structural systems and structural stress fields of different orders.The conversion or turning zones of present stress fields such as the converging end of the brush structural system are usually areas where oilfield geologic hazards take place frequently and intensively.