【作者】 孔凡军；

【导师】 汤达祯；

【作者基本信息】 中国地质大学（北京） ， 矿产普查与勘探， 2006， 博士

【摘要】 本文运用改造型盆地油气成藏系统评价思路,结合孔雀河斜坡具体地质特点,从剥蚀量恢复和残存地层厚度分析研究入手,重塑孔雀河斜坡及邻区古构造面貌,以已知油气藏解剖为切入点,以成烃—成藏研究为主线,深入研究烃源岩特征、烃源岩热演化、油气地化特征、成藏期次,恢复研究区成藏过程,建立成藏模式,总结成藏主控因素,明确了下步勘探方向。 孔雀河斜坡存在寒武系—下奥陶统、中上奥陶统、侏罗系三套烃源岩,其中寒武系—下奥陶统烃源岩有机质丰度高,干酪根类型好,为该区重要的烃源岩。通过烃源岩埋藏史和热演化史研究认为,寒武系—下奥陶统烃源岩经历了复杂的热演化过程,总体上具备成熟度高,生烃早的特征,即加里东早期开始大面积成熟生烃,加里东晚期整个孔雀河斜坡都已进入成熟生烃范围,至海西期进入高—过成熟阶段。天然气、原油碳同位素、原油生物标志化合物及成熟度对比分析表明,目前已发现油气藏主要来源于寒武—下奥陶统烃源岩。孔雀河斜坡及邻区发现的油气赋存形式为湿气和凝析油,与现今的高成熟—过成熟的烃源岩不相匹配。根据天然气形成温度、天然气的碳同位素组成、天然气的轻烃组成分析认为,孔雀河斜坡及邻区的原油和天然气主要为原油裂解气成因。早期生成的油气可能以原油裂解气的形式保存在地层中,成为晚期成藏的有效烃源灶。通过典型油气藏解剖,结合构造演化分析认为,孔雀河斜坡经历了加里东期至海西早期为油气成藏系统的形成与破坏期,海西晚期至印支期为油气成藏系统的重建与破坏期,燕山期至喜山期为油气成藏系统的调整成藏期三个阶段的成藏史。根据油气的成因和油气注入时期,归纳总结出本区存在早期原生型古油气成藏、晚期混合型油气成藏、混源型油气成藏三种成藏模式。根据油气注入时期和注入方式可以划分为早期原生型古油气成藏模式和“古藏新源”型次生油气成藏模式。重点指出以早期原生型古油气藏为基础,后期原油或裂解气纵向调整而形成的“古藏新源”型次生油气藏是该区下步勘探的重要对象。对改造型盆地油气勘探具有重要指导作用。明确龙口背斜构造带、维马—开屏背斜构造带为下步勘探的有利区带。更多还原

【Abstract】 In combination with special geological features of Kongquehe slope, the idea of reservoir-forming system evaluation which is based on reformed-basin is introduced. Starting from an analysis of denudation thickness and remaining formation thickness, the palaeostructural features of Kongquehe slope and its neighboring areas are reconstructed. Taking the known reservoir dissection as cut-in point and considering the study of hydrocarbon generation and reservior formation as main line, this paper makes a further study on source rock characteristics, thermal evolution, O&G geochemical behavior and episodes of petroleum accumulation;then restores the petroleum accumulation process in the study area;establishes petroleum accumulation patterns;sums up the major control factors and makes clear the future exploration tendency.There are three sets of source rocks in Kongquehe Slope: Cambrian-Lower Ordovician, Middle-Upper Ordovician and Jurassic. Among them Cambrian-Lower Ordovician is the most important source rock and it has high standard of organic matter abundance and belongs to good kerogen type. According to researches of burial history and thermal evolution history of hydrocarbon source rock, the source rock in Cambrian-Lower Ordovician experienced complicated thermal evolution and is generally characterized by high maturity and early-stage hydrocarbon-generation, which can be specified: a large area of Kongquehe entered into hydrocarbon-generation in early-Caledonian;whole area of Kongquehe slope into hydrocarbon-generation in Later-Caledonian, and into high-over maturity period in Hercynian.Through comparative analysis of natural gas, crude oil carbon isotope, crude oil biomarker and maturity, the newly found hydrocarbon reservior mainly comes from Cambrian-Lower Ordovician. The occurrence shapes of hydrocarbon in Kongquehe slope and its adjacent area are wet gas and condensed oil, which is not in accordance with source rock in high-over maturity period nowadays. According to formation temperature, isotopic constitution and lighter hydrocarbon analysis of natural gas, it is believed that the crude oil and natural gas there derives from oil-cracked gases. Hydrocarbon generated in early stage may be preserved in stratum in the form of oil-cracked gases and dispersed organic matter, and turns into effective hydrocarbon kitchen in late petroleum accumulation.In combination with the analysis of typical hydrocarbon reservoir and structure evolution, the petroleum accumulation system of Kongquehe slope can be divided into three periods: from Caledonian to early-Hercynian, it is a period of formation and destruction;from late-Hercynian to Indosinian, it is a period of reconstruction and destruction;from Yanshanian to Xishaninan, it is an adjustment reservoir-forming period.Based on hydrocarbon generation and hydrocarbon charging period, hydrocarbon accumulation can be divided into three patterns: prototype palaeo-hydrocarbon in early period, mixed type in late period, and mixed source type. In accordance with hydrocarbon charging period and charging patterns, there are two types: prototype palaeo-hydrocarbon in early period, which is found to be the basic pattern, and palaeo-hydrocarbon type with secondary hydrocarbon reservior, which is believed to be the key object of further exploration and plays an important guiding role in reformed-basin exploration, hi the end, this paper points out anticline structural zones of Longkou and Weima-Kaiping are advantageous exploration zones.更多还原