论文部分内容阅读
利用高温气相色谱(HTGC)、高温气相色谱-质谱(HTGC-MS)技术,结合气相色谱-同位素质谱(GC-IRMS)和有机岩石学分析,对松辽盆地烃源岩的氯仿抽提物及原油中烷烃,尤其是高分子量(C+40)烷烃组成及分布特征进行了研究.结果表明,嫩江组烃源岩氯仿抽提物正烷烃分布在nC14~nC63之间,低分子量(C-21)、中分子量(C21-40)正烷烃以双峰群分布为主,且在nC30~nC37之间有高丰度的C29~C35藿烷系列化合物;高分子量烷烃化合物以nC45~nC47为中心呈小峰群突起,并有丰富的异构烷烃、烷基环己烷和烷基环戊烷系列化合物;单体烃(nC22~nC44)碳同位素相对偏重,源岩中的有机质显微组分类型丰富.显示嫩江组烃源岩生源输入具有多样性,低等水生植物、蓝细菌以及陆生高等植物都是可能的生油母质.青山口组烃源岩氯仿抽提物烷烃组分主要由正烷烃构成,最高碳数可达nC61,正烷烃分布以单峰型为主,中、高分子量化合物呈连续递减趋势;C29~C35藿烷系列化合物以及高分子量异构烷烃、烷基环己烷和烷基环戊烷系列化合物丰度相对较低;单体烃(nC22~nC44)碳同位素相对偏轻,烃源岩有机质显微组分以腐泥组为主.反映青山口组烃源岩生源输入单一,藻类体可能是主要的生油母质.烃源岩中C+40相对含量及分布在低熟-成熟阶段变化不大,进入高成熟阶段C+40相对含量减少、正烷烃奇偶优势降低.原油中C+40相对含量主要与源岩性质有关,并对原油黏度有显著影响.
By using HTGC, HTGC-MS, GC-IRMS and organic petrology analysis, the effects of the chloroform extract of the source rocks in the Songliao Basin The composition and distribution characteristics of alkanes, especially high molecular weight (C + 40) alkanes in crude oil were studied.The results showed that the n-alkanes of the chloroform extract of Nenjiang Formation were distributed between nC14 ~ nC63, while the low molecular weight ), While the middle molecular weight (C21-40) n-alkanes are mainly bimodal with C29 ~ C35 hopane series compounds with high abundance between nC30 ~ nC37. High molecular weight alkane compounds with nC45 ~ nC47 as the center Small peak group protrudes, and is rich in isoparaffins, alkylcyclohexane and alkylcyclopentane series compounds; carbon isotopes of monomer hydrocarbons (nC22 ~ nC44) are relatively biased, the types of organic matter in source rocks are abundant It shows that the input of source rocks of Nenjiang Formation is diversified, and the lower aquatic plants, cyanobacteria and terrestrial higher plants are possible parent materials.The alkane fraction of the chloroform extract of source rocks in Qingshankou Formation is mainly composed of n-alkanes Composition, the highest carbon number up to nC61, n-alkanes distribution to a single peak-based, High molecular weight compounds showed a continuous decreasing trend; C29 ~ C35 hopane series of compounds and high molecular weight isoparaffin, alkylcyclohexane and alkylcyclopentane series of compounds relatively low abundance; monomer hydrocarbons (nC22 ~ nC44) carbon The isotopes are relatively light, and the organic matters in the source rocks are dominated by sapropelic units, which indicates that the source rocks of the Qingshankou Formation have a single source of input, and the algae may be the main parent material. And distribution in the low-maturity-maturity stage changed little, and the relative content of C + 40 in the stage of high maturity decreased and the even-odd advantages of n-alkane decreased.The relative content of C + 40 in crude oil was mainly related to the source rocks and had a significant effect on the viscosity of crude oil .