Abstract:

Based on the hydrocarbon accumulation conditions of Erlian basin, integrated analyses including burial history, thermal history and characteristics of diagenetic fluid inclusions of oil reservoir in three main depressions are conducted, and in terms of quantitative analysis of homogenization temperature of fluid inclusions, the formation stages of the oil accumulations are determined. The results indicate that most of the lithologic oil accumulation of the three main depressions in Erlian basin eventually formed in Early to Mid Cretaceous, and compared with most structural oil accumulation in the basin the lithologic ones represent the characteristic of relatively earlier formation period. Early generation of lithologic traps coupled with early hydrocarbon charges make the early formation of oil accumulation possible. These two factors may also be the main elements for relatively earlier lithologic accumulation formation which is favorable for the forming of giant oil accumulations.

Key words: Erlian basin, relatively earlier formation, lithologic reservoir, fluid inclusion