准噶尔盆地南缘烃源岩热演化生烃史及油气源分析

发布时间：2018-04-02 22:20

  本文选题：热演化史　切入点：生烃史　出处：《西安石油大学》2017年硕士论文

【摘要】：准噶尔盆地南缘勘探程度较低,尚未有规模性的发现,按照成藏地质条件的类比,准南前陆冲断带下组合是准南前陆盆地可能取得重大战略突破的潜在领域。本文在调研准南复杂构造带成藏研究成果的基础上,综合利用地质、钻井、地震、分析化验等基础资料,以单井实测地温、Ro数据为约束,以单井和三维盆地模拟为技术手段,以烃源岩的成烃演化分析为研究重点,通过对准南多套烃源岩的空间分布、热演化以及生烃史的分析,结合现今油气来源及分布特征,进行有效烃源岩及有效生烃区划分,从烃源岩热演化生烃史的角度去解释准南缘不同构造带或地区的油气来源、成藏匹配条件及油气分布的差异,深化准南前陆盆地烃源岩对油气分布规律的控制作用的认识,以期为下一步的勘探部署提供了指导性建议。通过以上研究主要取得以下几点创新性认识:1、准南地温梯度较低,仅为1.5~2.2℃/100m,地温梯度整体低于18℃/km,现今地表热流值低于35mW/m2,往南部山前带地温梯度逐渐降低,远低于准噶尔腹部、西北缘和东部。低地温有利于烃源岩生烃潜力的保持和晚期生烃。2、根据实测数据检验和单井、三维盆地模拟,结合油气源对比结果,认为准南前陆发育三套有效烃源岩,分别为二叠系、中-下侏罗统以及白垩系清水河组烃源岩。由于热演化程度低,安集海河组烃源岩为无效烃源岩,准南四棵树凹陷原油应来自于侏罗系烃源岩,而非之前认为的来自于E烃源岩。3、准南不同区带构造-埋藏史、热演化史差异巨大,可划分为四种类型:Ⅰ晚期抬升剥蚀型(齐古断褶带)、Ⅱ持续埋藏型(乌奎背斜带)、Ⅲ晚期缓慢埋藏型(前陆斜坡带)、Ⅳ早期浅埋晚期快速埋藏型(四颗树凹陷带)。4、根据已发现的来自于侏罗系烃源岩的油气分布,表明侏罗系烃源岩为准南地区的主力烃源岩,并且广泛分布。准南侏罗系来源油气分布具有中段富气,西段油气共存,东段富油的特征,从西向东,烃源岩成熟度具有先增加后减小的规律,天然气的成熟度也具有同样的变化规律,表明烃源岩成熟度对油气组成和油气成熟度具有明显的控制作用。
[Abstract]:The southern margin of Junggar basin is low in exploration degree and has not yet been found on a large scale. According to the analogy of reservoir forming geological conditions, the sub-assemblage of the quasi-southern Foreland thrust belt is the potential area for the major strategic breakthrough in the quasi-southern Foreland basin.On the basis of investigating and researching the reservoir formation of the complex tectonic belt in the southern part of China, this paper synthetically utilizes the basic data such as geology, drilling, earthquake, analysis and laboratory analysis, taking the Ro data measured by single well as the constraint, and taking the simulation of single well and three dimensional basin as the technical means.Based on the analysis of hydrocarbon generation evolution of source rocks, through the analysis of spatial distribution, thermal evolution and hydrocarbon generation history of several sets of source rocks in South China, the effective source rocks and effective hydrocarbon generation areas are divided according to the present source and distribution characteristics of oil and gas.From the point of view of hydrocarbon generation history of thermal evolution of source rocks, this paper explains the source of oil and gas in different structural zones or areas in the southern margin of the quasi southern margin, the matching conditions of oil and gas accumulation and the difference of oil and gas distribution, and deepens the understanding of the controlling effect of source rocks on the distribution of oil and gas in the quasi southern Foreland basin.In order to provide guidance for the next exploration deployment.Through the above research, we have mainly obtained the following innovative understandings: 1: 1, the quasi-southern geothermal gradient is relatively low, only 1.5% 2.2 鈩，

本文编号：1702379