MIGRATION-ACCUMULATION OF GAS UNDER THE ABNORMAL HIGH GEOTEMPERATURE AND SUPERPRESSURE CIRCUMSTANCE IN YINGGEHAI BASIN

Yinggehai basin developed in the Cenozoic is an abnormal high geotemperature and superpressure basin that belongs to the passive continental margin in the north of the South China Sea. The high geotemperature and superpressure system is mainly located in the diapir belt of the Yinggehai depression in the middle of the basin, so the intrusion of heat flow in the diapir belt, especially the movement of heat fluids of the late Pliocene and the distribution of abnormal high geotemperature and superpressure control the migration-accumulation of gas and CO₂.Based on close relationships between the distribution of abnormal high geotemperature and superpressure in the basin and the characteristics of migration-accumulation of gas, we can analyse and predict the regulation of migration-accumulation of gas so as to provide a decision-making for gas exploration plan.