摘要
盐湖相烃源岩单体烃硫同位素分布特征和影响因素研究薄弱。采用气相色谱-电感耦合等离子体质谱,结合色谱/质谱、微量元素以及碳氧同位素技术,对东濮凹陷北部盐湖相烃源岩进行了分析。结果表明,不同单体含硫化合物的δ^(34)S值有较大差异,以δ^(34)S=25.00‰为界,将烃源岩分成了两类,第一类:δ^(34)S>25.00‰,主要为卫城地区的烃源岩,总体具有单体烃硫同位素随分子量、烷基化程度增加而降低的特征;第二类:δ^(34)S<25.00‰,主要为文留地区的烃源岩,单体烃硫同位素变化特征与卫城烃源岩相反。观察到二苯并噻吩的硫同位素与成熟度相关参数——饱和烃含量、三环萜烷/五环萜烷等有明显的正相关性、与“非烃+沥青质”含量有明显的负相关性,反映成熟度的控制作用,随成熟度增加,硫同位素有变重的趋势;观察到硫同位素与沉积环境相关参数伽马蜡烷/C_(31)藿烷、C_(35)/C_(34)藿烷有明显的正相关性,与方解石、黏土矿物等含量和微量元素比值有很好的线性关系,反映原始沉积环境的控制作用,强还原、封闭的蒸发环境有助于有机质的硫化作用,从而使硫同位素变重。概括而言,烃源岩单体烃硫同位素有重要的沉积环境与成熟度指示意义,具有油—岩对比、成因类型划分的应用潜能。
The researches about compound specific sulfur isotopes of saline lacustrine source rocks are rare.Using the technology of gas chromatography with multicollector inductively coupled plasma mass spectrometry(GC-MC-ICP MS),combined with gas chromatography/mass spectrometry(GC/MS),carbon and oxygen isotopic and trace elements to analyze the source rocks(oil sands)from saline lacustrine northern of Dongpu Depression.The analysis results show that the sulfur isotopic values of individual hydrocarbon in source rocks(oil sands)are small,but theδ^(34)S values of different sulfur compounds are quite different(5.16‰to 44.73‰).Boundary withδ^(34)S=25.00‰the source rocks(and oil sands)can be divided into two categories,the first type withδ^(34)S>25.00‰is mainly Weicheng source rock characterized by the sulfur isotope of individual hydrocarbon decreases with the increase of methyl.And theδ^(34)S<25.00‰is the second type,which characteristics are opposite to Weicheng source rocks.The sulfur isotopes of dibenzothiophenes have obvious positive correlation with the content of saturated hydrocarbon,tricyclic terpane/pentacyclic terpane,and negative correlation with content of“nonhydrocarbon+asphaltene”.The sulfur isotopes of hydrocarbons have obvious positive correlation with gammacerane/C_(31)hopane and C_(35)/C_(34)hopanes,excellent correlation with contents of minerals and ratios of trace elements,indicating that the isotopes of organic sulfur compounds in the closed evaporation environment becomes heavier,and the values in the open terrestrial input environment becomes lighter.The analysis shows that the sulfur isotopes of individual hydrocarbon are significantly controlled by the original sedimentary environment of source rock.Strong reduction and closed evaporation environment are conducive to the sulfuration of organic matter,which makes the sulfur isotope heavier.The sulfur isotopes are also affected by maturity,while the sulfur isotope tends to become heavier with the increase of maturity.Generally speaking,isotopes of organic sulfur compounds have important significance of indicating sedimentary environment and maturity,and the potential of oil-oil and oil-rock correlation.
作者
柯昌炜
李素梅
张洪安
徐田武
张云献
曾凡纲
张树海
张韩静
KE Changwei;LI Sumei;ZHANG Hongan;XU Tianwu;ZHANG Yunxian;ZENG Fangang;ZHANG Shuhai;ZHANG Hanjing(State Key Laboratory of Petroleum Resources and Prospecting,China University of Petroleum,Beijing 102249,China;College of Geosciences,China University of Petroleum,Beijing 102249,China;SINOPEC Zhongyuan Oilfield Company,Puyang,Henan 457001,China;School of Environment&Natural Resources,Renmin University of China,Beijing 100872,China)
出处
《现代地质》
CAS
CSCD
北大核心
2021年第2期301-314,共14页
Geoscience
基金
国家自然科学基金项目(41673055,42073064)
国家科技重大专项(2016ZX05006-004)。
关键词
东濮凹陷
盐湖相
有机硫同位素
微量元素
沉积环境
Dongpu depression
saline lacustrine
isotopes of organic sulfur compounds
trace elements
sedimentary environment
