基于GC-MC-ICPMS的地质体中单体烃硫同位素分布特征及其石油地质意义

有机硫化物是石油中重要的杂原子化合物，包含丰富的地球化学信息。传统有机硫同位素具有均一化的特点，气相色谱-多接受电感耦合等离子体质谱仪(GC-MC-ICPMS)可测定单体烃硫同位素、实现元素硫分子级示踪。本课题采用GC-MC-ICPMS等技术，以塔里木、渤海湾盆地代表性原油、烃源岩为研究对象，揭示不同成因类型原油、烃源岩中有机硫同位素组成与分布特征、分馏效应及其地化意义。重点通过不同沉积环境、不同有机质类型与成熟度烃源岩/原油中单体烃硫同位素的调查，结合热模拟实验，揭示控制单体烃硫同位素的主要因素与机制；开发基于GC-MC-ICPMS的有机硫同位素古环境、油源及岩性识别指标；结合传统地化指示，判识塔里木海相油气源及其岩性、揭示海相、咸水相优质烃源岩形成与生烃机制。期待通过本项目的研究，解析塔里木海相、渤海湾盆地咸水相油气勘探中存在的科学难题。在国内外高水平杂志上发表SCI 论文4 篇。

Organic sulfur compounds are important heteroatomic compounds in petroleum, coal and the other Fossil fuels, which contain a wealth of geochemistry information. The traditionally measured results of kerogen S and oil phase OSCs by GC-ir-MS showed a 34S homogenisataion, organic sulfur isotopes have the characteristics of homogenization, which result in great limitations of their application. The development of instrumentation and methods capable of measuring accurate δ34S values in individual OSCs at the picomole level using a gas chromatograph coupled to a multi-collector inductively coupled plasma mass spectrometer (GC-MC-ICPMS) could realize of elemental sulfur molecular level tracing, and the application potential of sulfur isotope could be greatly expanded. In this study, GC-MC-ICPMS would be used and combined with Conventional geochemical approaches to reveal the composition and relative distribution, fractionation effection and geochemical significance of organic sulfur isotopes in representative crude oils and source rocks, including marine crude oils from the Tarim Basin, saline lacustrine oils from the Dongpu Depression, brackish and fresh-water lacustrine oils from the Dongying Dpression in the Bohai Bay Basin. The emphasis will be put on the investigation of compound specific sulfur isotopes in potential source rocks and the related oils with varied paleo-environment (i.e., marine, saline lacustrine, brackish lacustrine, fresh-water lacustrine and paludal facies), lithology including carbonate and mud shale, kerogen type, thermal maturity. In combination with thermal model experiment, the dominant controlling factors and mechanisms affecting compound specific sulfur isotopes will be disclosed. Meanwhile, new indices such as facies and lithology, oil-source rock and maturity indicating parameters are expected to be explored and established. Particularly, the marine oil sources and the lithology of the predominant source rocks in the Tarim Basin will be re-investigated by the new oil-source rock indicating parameters of organic sulfur isotopes, in combination with oil-source rock correlations by traditional parameters under considering the impact of thermal maturity etc on the parameters. Additionally, the formation mechanisms of high quality source rocks in marine and saline-brackish lacustrine as well as hydrocarbon generation mechanisms will be revealed. The aim of this study is to disclose some puzzling questions about the origin and formation mechanisms of the Tarim marine oils and the formation and hydrocarbons generation mechanism of sulfur-enriched and OM-enriched saline-brackish source rocks in the Bohai Bay Basin. Four manuscripts about this work would be expected to be published in internal and international journals with a relatively high level.