海拉尔盆地巴彦呼舒凹陷西部陡坡带原油地球化学特征及油源

巴彦呼舒凹陷西部陡坡带原油的族组分、饱和烃色谱特征和生物标志化合物等资料的分析表明，西部陡坡带原油类型分为稠油和正常油；沉积环境为缺氧的咸水或者半咸水湖泊强还原环境；饱和烃色谱分布完整，未遭受生物降解；原油的全油碳同位素组成都比较轻，δ¹³ C值在−32‰左右；原油中含有伽马蜡烷、β-胡萝卜烷；三环萜烷含量较低，五环萜烷的含量较高；均以ααα-构型规则甾烷为主，且C₂₉ 甾烷的含量最高。油源对比表明，西部陡坡带南屯组和铜钵庙组的成熟原油来源于凹陷南屯组成熟源岩,南屯组低熟原油主要来自于本地区南屯组低成熟的源岩。

Geochemical features and source analysis of crude oils from the western slope of Bayanhushu sag, Hailaer Basin

Date analyses of the group-type fractions, saturated hydrocarbon chromatograms and biomarkers of crude oils from the western slope of Bayanhushu sag, Hailaer Basin showed that they are composed of heavy and normal oils and their depositional environment is an anoxic saline- or brackish-lake strongly-reducing environment. The saturated hydrocarbon chromatograms of the oils are distributed fully, indicating non-biodegradation. Carbon isotopes of the bulk crude oil are relatively lighter, with δ¹³ C values around−32‰. The oils contain gammacerane, β-carrotane, relatively lower tricyclic terpanes but higher pentacyclic hopanoids, and steroids composed mainly of ααα-regular steranes with the dominance of C₂₉ steranes. The oil-source correlation showed that the mature oil of Nantun and Tongbomiao Formation in the western slope is derived from mature source rock of Nantun Formation depocenter, while the low-maturity oil of Nantun Formation originates mainly from the low-maturity source rock of the Nantun Formation.