【作者】 宋占东；

【导师】 查明；

【作者基本信息】 中国石油大学 ， 地质资源与地质工程， 2009， 博士

【摘要】 近年来国内许多盆地相继发现火成岩油气藏。这类油气藏资源潜力巨大,成藏条件独特,成为油气勘探的又一重点。但火成岩与烃源岩的形成、演化生烃的关系研究相对较少,两者之间相互关系的研究对油气勘探意义重大。本文首先从岩石化学入手,研究火成岩的形成与构造运动之间的关系。阳信洼陷火成岩以玄武岩、玄武安山岩和粗面玄武岩类为主,为大陆拉张背景下裂谷环境的产物。火成岩的岩石化学特征分区明显,对应盆地演化的4个转型期,即中生代与孔店组沉积时期、孔店组与沙四段沉积时期、沙三段与沙二段沉积时期、东营组与馆陶组沉积时期。演化历史表明构造运动控制着火成岩的形成和演化,火成岩的岩石化学特征是盆地构造运动的良好示踪剂。洼陷地层层序发育不仅受构造运动的控制,也受到火成岩的影响。阳信洼陷含火成岩地层层序具有火山沉积特征,其主控因素为构造运动、火山作用、沉积物供给与湖平面变化等。火山活动使湖盆可容空间变化复杂,呈现非均一性变化特征。火成岩对可容空间的迅速充填,是导致湖盆体系域构成和层序边界与正常沉积地层差别明显的主要原因。火山活动以及相伴生的热液为烃源岩提供了大量矿物质和养料,使湖盆生物繁盛,导致周围泥质岩富含有机质而形成优质烃源岩(TOC>5%)。阳信洼陷的优质烃源岩都发育在阳信次洼(火成岩发育区),有机碳含量明显高于温家次洼(非火成岩发育区)。火成岩区的烃源岩具有多种生烃机制:①火成岩提供的大量过渡金属元素可作为烃源岩生烃的催化剂;②火山矿物橄榄石、沸石等的蚀变作用可在较低的温度下促使烃源岩生烃;③火山环境中含有的大量硫元素参与烃源岩的形成、演化,可使烃源岩进入生烃门限之前形成大量低熟油气;④火山环境中含有大量氢气和甲烷,可作为外部氢源促使烃源岩生烃;⑤火成岩带来的大量的高温热能,使附近的烃源岩受到烘烤和对流加热作用,促使源岩中有机质快速生烃和异常成熟。阳信洼陷烃源岩成熟度参数研究表明,阳信次洼的生烃门限深度比温家次洼浅了大约400m,并且烃源岩有一个低熟油和两个成熟油等三个生烃高峰,由此建立了火成岩区烃源岩三段式生烃模式。阳信洼陷火成岩与烃源岩呈互层分布格局,其油气分布具有平面上连续、垂向上相互重叠以及成熟油与低熟油混杂等的特点。更多还原

【Abstract】 In recent years, many igneous reservoirs have been found successively in many basins in China. Production potentials of igneous reservoirs is huge, their accumulating conditions are unique, and have been hydrocarbon exploration key. However, the study on the source rocks forming, hydrocarbon-generating characteristics around the igneous rocks is relatively few. The study of mutual relations between igneous rocks and source rocks is very important to hydrocarbon exploration.This dissertation researches the relationships of the igneous rock forming and the tectonic movement by using petrochemistry. The types of igneous rocks of Yangxin sag, Humin depression, includes basalt, basaltic andesite and trachybasalt, and the igneous rocks had been formed under the background of continental rift environment. The petrochemistry characteristics is well correlation with the 4 transition period of the basin evolution. Namely, the Mesozoic-Kongdian Formation, Kongdian-the Fourth Member of Shahejie Formation, the Third-the Second Member of Shahejie Formation and Dongying-Guantao Formation depositional transition periods. The correlation showed that the tectonic movement controlled igneous rocks forming and its evolution. The petrochemistry characteristics is a better tracer to tectonic movement.The sequences of Yangxin sag were controlled by both tectonic movement and igneous rocks distribution. The sequences contain igneous rocks with volcanic sedimentary characteristics, and their main control factors include tectonic volcanism, sediment supply and lake level change and so on. Volcanic activity effected on accommodation space of the lake basin cannot be neglected, and volcanic cone distribution made accommodation space complicated. The evolution of accommodation space presents uniformity. Because igneous rocks filled rapidly, the difference of the system tract and sequence boundary with normal deposition formation is obvious. The main periods of volcanic activity reflected well correlation with the main pull periods of tectonic movement. The forming stages of Paleogene igneous rocks of Yangxin sag were consistent with the sequences evolution.Volcanic activity brought large quantity of CO2, volcanic minerals, transitional metals and nutriments. These factors caused aquatic organisms were prosperous than before any times and any other places, which leaded to the shales around igneous rocks being rich in organic carbon of the source rocks. The shales were basically excellent source rocks with high hydrocarbon potentials (TOC>5%).The hydrocarbon generating mechanisms of source rocks around igneous rocks were diversification. There are lots of hydrocarbon generating catalysts in volcanic activities environment, and they are transition metal, volcanic minerals (including peridot, zeolite), more sulfur elements, much hydrogen and methane gas, respectively. At the same times the magmas and thermal-waters brought heat to the source rocks, and caused organic matter in the source rocks mature and hydrocarbon-generating earlier.Under the action of catalysts and heats, hydrocarbon generating threshold of the source rocks in igneous rocks area is shallower about 400m than the western region of Yangxin sag-Wenjia subsag. The hydrocarbon generating model of the source rocks in igneous rocks region showed that there are three hydrocarbon generating peaks, ie one low mature oil peak and two mature oil peaks respectively.更多还原