Abstract: Petroleum accumulation period is a section of time. The formation an oil/gas pool tends to being resuled from multiple charging The presence of hydrocarbon inclusion is the direct evidence for oil-gas migration and accumulation. The petroleum accumulation period can be determined based on the time corresponding to fuid inclusion homogenization lemperature which can be plotted by continuous and discontinuous distribution types of histograms. The continuous distribution type indicates continuous charging and just one-period accumulation. The discontinuous type means discontinuous changing and multi-period accumulations. In terms of accumulation history partly described by accumulation period, the Cenozoic petroleum accumulation history is relatively short, moet belong to one -period accumulation, while Palcozoic petroleum accumulation history is comparatively long, and there could be multi-period accumulations. This paper suggests that most of paleo oiVgas reservoirs is destroyed, only could those pools that are continuously charged with oil and gas or formed in late period preserve, but they may not necessarily be characterized by multi-period accumulations. Only by study of the accumulation or charging history can they be evaluated.

Key words: petroleum accumulation period, charging period, fuid inclusion, oil-gas pool age, late-period accumulation