Dynamic models and equations of hydrocarbon migration and accumulation in graben basins:A case study of the Maichen Sag, Beibuwan Basin

The quantitative research of hydrocarbon migration and accumulation dynamics has become a trend and important direction of petroleum geological research with the gradual development of oil and gas exploration and increasingly complex exploration conditions. This paper concentrates on the commercial quantity of hydrocarbon to establish a new method, which can calculate the dynamics and resistance of hydrocarbon migration and accumulation quantitatively, by selecting several dynamic and resistance parameters in macro level. Considering the episodic accumulation features in graben basins and the different processes of hydrocarbon generation, migration and accumulation, the paper utilizes this method to analyze the relationship between accumulation dynamics and resistance during the critical episodic accumulation stage and to establish four dynamic models including the overpressure drive dynamic model, the continuous migration dynamic model, the lateral seal dynamic model and the buoyancy driven dynamic model accompanied with their equations. An example from the Maichen Sag of Beibuwan Basin has been given in this paper to illustrate the features of accumulation dynamics and resistance distribution by compiling their isogram maps through calculating these parameters and to judge the direction and distance of hydrocarbon migration and accumulation quantitatively. And then, the best prospective traps have been given at last.