内蒙古二连盆地岩性油藏形成的相对早期性特征

在对内蒙古二连盆地3大凹陷成藏条件和埋藏史、热史分析研究基础上,结合储层成岩流体包裹体特征分析,利用流体包裹体均一化温度定量分析方法确定了二连盆地油藏的成藏期,并将二连盆地岩性油藏与构造油藏的成藏期进行了对比研究。研究表明,二连盆地3大主力凹陷岩性油藏的成藏期多在白垩纪的早、中期,相对于二连盆地构造油藏的形成期具有明显的早期成藏的特征。岩性圈闭形成的早期性和岩性油藏的相对早期充注可能是产生岩性油藏相对早期形成的主要因素。岩性油藏的相对早期成藏有利于后期多期捕集油气,形成大油藏。

Characteristics of Relatively Earlier Formation of the Lithologic Oil Accumulation in Erlian Basin,Inner Mongolia

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.