【作者】 杨晓敏；

【导师】 田世澄； 束青林；

【作者基本信息】 中国地质大学（北京） ， 矿产普查与勘探， 2009， 博士

【摘要】 中国东部断陷盆地中坳隆相间的构造格局造就了大量四周被生烃洼陷环绕的披覆含油气背斜构造。论文以渤海湾盆地沾化凹陷中勘探开发程度较高的孤岛披覆背斜油藏为例,通过对其在多洼陷、多套烃源岩供烃条件下形成的混源油的地球化学特征、分布的研究,结合物理、数值模拟和包裹体分析测试结果,以揭示混源油的来源、定量匹分、优势运移路径和富集机理,明确勘探方向和不同区带勘探潜力。建立了3个洼陷以甲藻甾烷、三芳甲藻甾烷、4-甲基甾烷、δ¹³C等为标志的烃源岩地球化学判识标准,有效实现了孤岛凸起及其周缘原油来源的精细分析。馆陶组原油分别来自渤南洼陷、孤北洼陷及孤南洼陷。其中,周缘西北渤南区及凸起主体的油气来自渤南洼陷沙四上段（Es₄^s）与沙三段（Es₃）烃源岩形成的“混源油”,北部孤北区油气来自孤北洼陷Es₃烃源岩,南部孤南区油气主体来自孤南洼陷Es₃烃源岩,西南部斜坡过渡区油气除少量仅来自渤南洼陷外,主体为来自渤南洼陷和孤南洼陷的混源油。在明确了不同区块油气来源的基础上,通过两端元混源模拟实验,建立了混源油定量判识模版,实现了孤岛凸起及其周缘地区油藏混源比的定量匹配,确定该区已探明资源量中渤南洼陷贡献最大,其Es₃供油占62%,Es₄^s占10%;孤南洼陷次之,其Es₃占10%,沙一段（Es₁）约占8%;孤北洼陷贡献最少,仅Es₃提供油源,约占10%。通过对输导要素及其组合关系的落实,建立了新的输导体系分类。厘定了断层纵向开启的必要条件为东营期V_f（断层活动速率）≥3.4m/Ma或馆陶期V_f≥1.9m/Ma,或者为断层泥比率SGR≥0.40。反之,断层封闭利于封堵油气。通过埋藏史和流体包裹体综合分析,确定研究区内存在东营组（Ed）沉积期、馆陶组末-明化镇组（Nm）沉积早期和Nm沉积末期3期排烃和成藏。油气运移模拟清晰再现了3个砂岩发育层在三个油气运聚高峰时的优势运移路径,其中孤岛凸起西南缘、东北近孤南断层处和北部近孤北断层处是向凸起供烃的主要通道。成藏史分析表明,Ng沉积期间及之前,油气主要来自渤南洼陷Es₄烃源岩;Nm沉积期间则来自渤南洼陷和孤南洼陷的Es₃烃源岩;至平原组沉积期,随着Es₁低成熟油的生成及孤北洼陷Es₃进入生油门限,孤岛凸起区油气运移路径复杂性强,油气构成具有明显的多源、混源特点,发育主断裂带陡坡带和缓坡带2类成藏模式。更多还原

【Abstract】 As a result of structural framework with sag-uplift alternation, many oil-bearing drape anticline structures arrounding hydrocarbon generation sags were formed in faulted basins in eastern China. In this paper, the chemical characteristics and distribution of source-mixed oils were studied, and the sources of mixed oils, relative quantity from different sources, hydrocarbon migration pathway and accumulation mechanism were disclosed taking Gudao drape anticline of Zhanhua depression as an example using physical simulation, numerical modelling and inclusions analysis. This studies make clear where and what the petroleum exploration targets are in the future, further, to give guidances for rapid, high efficient hydrocarbon exploration and development of similar geological structures or areas.In this study, geochemical distinguishing marks, such as dinophyceae sterane, triaromatic dinophyceae steroid, 4-meth sterane,δ¹³C, and so on, are summarized systimatically among different sources in Bonan, Gunan and Gubei sub-depressions for oil-source correlation in Gudao draping anticline and its circumambience. Correlation results show that there are three types of oil and come from Bonan, Gunan and Gubei sub-depressions respectively. Additionally, oils in different areas around Gudao swell were analyzed. The northwestern area’s oil comes from Bonan sag’s source rocks of the 4th member of Shahejie formation（Fm.） （Es₄） and the 3rd member of Shahejie Fm. （Es₃）, and northern area from Gubei sag’s source rocks of Es₃; and southern one from Gunan sag’s of Es₃ and the 1st member of Shahejie Fm. （Es₁）, southwestern slope area from Gunan sag and Bonan sag besides some deep strata’s oil only from Bonan sag’s source rock. According to maturity and geochemical signatures, these oils in southwestern slope area are divided into two types and four kinds.Two-end mixed source oils experiments based on subtle oil-source correlation results provides a great many of quantificational distinguishing models for discovered reserves in Gudao swell and its circumambience. Experiments shows that about 62% of discovered reserves comes from Es₃ source rock of Bonan sag, and about 10% from Es₄ source rock of Bonan sag, and about 10% from Es₃ source rock of Gunan sag, and about 8% from Es₁ source rock of Gunan sag, and about 10% from Es₃ source rock of Gunan sag.A new classification on oil and gas transport system was put forward after ascertainment of transport factors and assembled relationship. As an important factor for hydrocarbon migration, faults were studied considering those action for oil migration or seal ability. Studies indicates faults are open and migrates oil and groundwater when fault activity speed （V_f）≥3.4m/Ma in Dongying Fm. or V_f≥1.9m/Ma in Guantao Fm., or SGR≥0.40 in any stratum. On the contrary, faults are close and be closed reserves.Analysis by buried history and fluid inclusion shows that there three times of hydrocarbon accumulation at the end of sedimentation of Dongying Fm., during the sedimentation of from the end of Gutao Fm. to early Minghuazhen Fm. and the end of sedimentation of Minghuazhen Fm.. Hydrocarbon migration simulation shows clearly superior migration routes of three sand-rich strata during three main stages of hydrocarbon migration and accumulation. Southwestern part, northeast partnear Gunan fault and northern part near Gubei fault are the main entrances into Gudao swell.In studied area, pools charaterized by many sources and mixed source oils are widely exist beacause of structural pattern alternated with sags and swells, oil and gas reserves types and accumulation efficiency are controlled by transport system’s type in different structural belts, and complex and episodic accumulation process is affected by multistage migration based on abnormity pressure’s episodic discharge. For those reason, two hydrocarbon accumulation models, i.e. actic region hydrocarbon accumulation model near main fault belts and gentle slope hydrocarbon accumulation model are summarized.更多还原