新疆三塘湖盆地马朗凹陷条湖组凝灰岩油藏油源分析

通过系统采集新疆三塘湖盆地马朗凹陷二叠系芦草沟组和条湖组各套烃源岩岩心样品以及条湖组凝灰岩段原油样品，研究各套烃源岩的基本地球化学特征、烃源岩和 原油饱和烃生物标志化合物特征、抽提物/原油以及族组分的稳定碳同位素特征等，探讨了凝灰岩油藏的原油来源。结果表明：芦草沟组二段烃源岩的质量最好；各套泥质烃源岩可溶有机质生物标志化合 物特征具有明显的差异，主要表现在Pr/Ph、 γ蜡烷含量、β-胡萝卜烷含量以及规则甾烷ααα20RC₂₇、ααα20RC₂₈、ααα20RC₂₉相对含量等方面；条湖组凝灰岩油藏中原油具有低Pr/Ph、高γ蜡 烷含量、高β-胡萝卜烷含量以及规则甾烷ααα20RC₂₇、ααα20RC₂₈、ααα20RC₂₉中ααα20RC₂₉最高和ααα20RC₂₇最低(谱图呈上升直线型)、原油及族组分稳定碳同位素较轻的特点；油源对比 显示凝灰岩油藏的原油主要来自芦草沟组二段烃源岩，但也有凝灰岩自身有机质的贡献。

Oil-source Analysis of Tiaohu Formation Tuff Reservoirs in Malang Sag,Santanghu Basin in Xinjiang

Geochemical characteristics of source rocks, biomarker characteristics of source rocks and crude oil saturated hydrocarbons, stable carbon isotope characteristics of source rock extracts or crude oil and their family components are researched based on source rock samples of Permian Lucaogou and Tiaohu formations, as well as crude oil samples of tuff in Malang Sag of the Santanghu Basin in Xinjiang. The sources of the crude oil in the tuff are made clear in this paper. It indicates that the second member of Lucaogou Formation has the best quality. There are significant differences among soluble organic matter biomarkers of various sets of source rocks, mainly in Pr/Ph, gammacerane content, β-carotane content and peaks of steranes of ααα20RC₂₇, ααα20RC₂₈ and ααα20RC₂₉. Crude oils of tuff in Tiaohu Formation are characterized by low Pr/Ph, high gammacerane content, high β-carotane content, and dominated by ααα20RC₂₉(upward type of steranes of ααα20RC₂₇,ααα20RC₂₈ and ααα20RC₂₉). Also there is light stable carbon isotope of crude oils and their family components. The oil-source correlation shows that the crude oil of the tuff reservoirs is mainly from source rocks of the second member of Lucaogou Formation, and is also from the reservoirs’ organic matters.