The reservoiring period has traditionally been analyzed from the matching of source rock,reservoir rock, cap rock,migration,accumulation and preservation parameters,on the basis of trap formation history,hydrocarbon generating history of source rocks and dew point pressure method.Considering that most of the petroliferous basins in China are superimposed basins,which are characterized by multiple source rocks,multi-stage hydrocarbon generation,accumulation and destruction,fluid history analysis method was introduced in late 1990s.Utilization of several new methods,such as reservoir geochemistry,fluid inclusion,illite K-Ar dating,reservoir bitumen and tracing of oilgas-water contacts,has converted the traditional qualitative(period determining)study to quantitative or senti-quantitative study,thus the formation time of pools can be relatively accurately calculated.In view of the complexity of the formation of reservoirs in superimposed basins,attentions should still be paid to basic geologic studies.Traditional methods,such as trap formation period and hydrocarbon generating history,are the basis of application of new technologies.Future trends of reservoiring period studies are combining geochemistry method with geologic setting study, traditional method with new methods,and qualitative method with quantitative method.
