三塘湖盆地中二叠统原油的来源及其分布特征

在对三塘湖盆地中二叠统原油物性、生物标志物特征分析的基础上,开展了油岩生物标志物参数的对比和成藏主控因素的分析。研究认为,中二叠统芦草沟组原油属于自生自储、源内成藏。条湖组原油主要来自芦草沟组烃源岩,属于近源成藏;部分原油(马49井等)来自下二叠统-上石炭统,属于源外成藏。中二叠统的源岩油藏分布主控因素主要体现在源和裂缝两个方面,有效源岩(主要体现在源岩成熟度上)控制了油藏的分布;裂缝(构造裂缝为主)则是控制油藏产能的关键。因此,三塘湖盆地的原油勘探应围绕源和裂缝这两个方面进行,上述认识对油田中二叠统原油的勘探具有积极的指导意义。

Study on the source and distribution of Middle Permian oils in the Santanghu basin

This contribution discusses the biomarker parameters and the main control factors of reservoir formation of Permian series in the Santanghu basin, based on analyses of physical properties and biomarkers of oil＇s. Through this study, it is suggested that reservoirs of Lucaogou Formation of the Middle Permian 〈http：//dict.cnki.net/dict_result.aspx？searchword=%e4%b8%ad%e4%ba%8c%e5%8f%a0%e7%bb%9f%e8%8a%a6%e8%8d%89%e6%b2%9f%e7%bb%84＆tjType=sentence＆style=＆t=loucaogou＋formation＋of＋middle＋permian〉 are in-source, and Our results suggest that crude oils of Tiaohu Formation are mainly from source rocks of the Middle Permian Lucaogou Formation, with minor contributions （Ma 9 well, etc） from Lower Permian-Upper Carboniferous. Main control factors of formation and distribution of natural gas reservoirs in Middle Permian series are mainly embodies in both source and fractures. The effective source rock （main source-control factor is maturity of source rock） controls the distribution of oil reservoirs, and the fractures （mostly structural fractures） control reservoir productivity. Therefore, the oil exploration in the Santanghu basin should be centered on these two aspects. This understanding is useful for the exploration of Permian oil in this oil field.