【作者】 周铁锁；

【导师】 柳益群；

【作者基本信息】 西北大学 ， 矿产普查与勘探， 2008， 硕士

【摘要】 吐哈盆地是中国西部最重要的含油气盆地之一,二叠系在新疆各个盆地中广泛发育,并且是重要的烃源岩层。吐哈盆地台北凹陷北部的博格达山前构造带发育二叠系深湖相泥岩,具有较高的生烃潜能。但由于构造复杂、地震品质差且很少有钻井钻遇二叠系,因此对该区带二叠系油气勘探潜力评价受到极大限制,同时也制约了台北凹陷二叠系生烃前景评价。本文试图根据博格达南缘二叠系发育情况,为本区的油气勘探前景提供新的研究资料。本文从地质构造背景、研究区二叠世沉积环境、烃源岩评价地化指标以及盆地的热演化特征四个方面探讨了博格达南缘台北凹陷山前带二叠系油气勘探潜力,并进一步推测台北凹陷二叠系生烃前景。从构造背景入手,结合岩性特征、沉积特征以及地球化学数据分析,探讨了本区二叠纪构造-沉积格局及沉积环境特征。认为早二叠世吐哈盆地及邻区发育了一系列的裂谷盆地,研究区为一槽型深水盆地:中二叠世,研究区在继承早二叠世裂谷型深水盆地的基础上,逐渐向坳陷盆地演化。晚二叠世,博格达地区发生隆升,从此,本区由裂谷-坳陷盆地转变为前陆盆地。通过系统分析有机质丰度、有机质类型以及有机质成熟度,对研究区二叠系烃源岩进行了综合评价。下二叠统烃源岩残留面积小、热演化程度高。中二叠统的烃源岩分布广、丰度高、类型好、而且均已成熟,为本区重要烃源岩层。上二叠统梧桐沟组有机质总体具丰度低,类型差及成熟度较低等特征,综合评价为较差烃源岩。在进行区域热事件以及热演化趋势研究的基础上,采用古温标法(镜质体反射率、磷灰石裂变径迹、包裹体测温等)进行热史研究。研究表明,盆地热演化经历二叠纪的急速升温过程,三叠纪-早白垩世的缓慢降温过程以及第三纪-现今的基本稳定阶段。二叠系烃源岩自印支期末开始生烃,燕山期至喜山期大量生烃排烃。更多还原

【Abstract】 The Tulufan-Hami basin is one of the most important oil/gas enriched large basins in the west of China. The Permian which is the important hydrocarbon mother rock exists in all of the basins in xinjiang.There is Permian lake facies mudstone which has big potence to produce hydrocarbon in the front structural belt of Bogeda mountain in the north of Taibei depression. It is difficult to evaluate the exploration foreground of the north structural belt and Taibei depressed basin,because the seismic data is bad and the tectonic is complex and there is less well in which the Permian can be reached In this article , some new messages of the foreground of exploration can be supplied according to the situation of the existence of Permian. The potence of producing hydrocarbon of the Permian in the south of Bogeda mountain is talked by the analysis of geological background and the character of lithology and sediment and the geochemical character of the mother rock and the trait of thermal evolution of the basin. According to that the potence to produce hydrocarbon of the Permian in Taibei depressed basin can be presumed.The tectonic-sedimentary and the depositional environment framework is talked by the analysis of the tectonic background, the trait of lithology and sediment the data of geochemistry. The conclusion is that:There is a deep basin which belongs to some of the rifted basin in Tulufan-Hami basin and its adjacent area in the region of interest in Early Permain ; The deep basin turned into depression basin in Middle Permain;Then the depression basin turned into foreland basin in Late Permain when the mountain turned up in the Bogeda region.The hydrocarbon mother rock of the Permain has been evaluated by the analysis of the Abundance,the Type and the Maturity of organic material. The conclusion is that:There is little hydrocarbon mother rock of early Permain remained of which the thermal evolution is deep; The mother rock of Middle Permain which is good in the Abundance,the Type and the Maturity is widespread. The mother rock of Late Permain of which the Abundance and the Maturity are low and the type is bad is evaluated as bad hydrocarbon mother rock..The thermal history is reaserched using the palaeotemperature scale means(i?o, fission track and inclusion thermometry) by the analysis of the regional thermal event and the tendency of thermal evolution. It is proved that the basins have experienced fast heating course in Permian, slowly cooling course in Triassic-Early Crataceous and primary steady course in Tertiary to nowadays; The hydrocarbon mother rock of the Permain began to produce hydrocarbon in late Indo Chinese epoch and bleeded off hydrocarbon in big mass in Yanshan-xishan epoch.更多还原