济阳坳陷C-P煤系原生气藏成藏机理研究

发布时间：2018-05-18 15:27

  本文选题：济阳坳陷 + C-P煤系　； 参考：《中国矿业大学》2015年硕士论文

【摘要】：本文以济阳坳陷为研究区,以石炭二叠系煤系原生气藏为研究对象,探讨了煤系煤层气气藏、煤型气气藏和煤层气-煤型气叠合型气藏等典型共伴生原生气藏的形成机理。本文利用沉积学和成藏动力学的方法,系统探讨了煤系原生气藏的沉积地质背景、成藏要素特征、成藏过程以及煤型气气藏和叠合型气藏的成藏模式,并对有利区沾化凹陷孤北地区进行了详细剖析和潜力预测,主要研究成果如下:太原组潮坪相和山西组分流间湾微相是本区烃源岩发育的主要沉积环境类型。烃源岩以镜质组为主,母质类型基本上为以生气为主的Ⅲ型干酪根,石炭系煤的生烃潜力优于石炭系泥岩、二叠系煤和泥岩,沾化凹陷烃源岩总体质量较其他三个凹陷要好。上、下石盒子组曲流河河道亚相发育,形成了煤型气气藏的主要储层;砂岩孔隙以次生孔隙为主,Ⅰ类储层主要出现在沾车地区,惠民和东营凹陷以Ⅱ和Ⅲ类储层为主。山西组分流河道微相砂岩是形成叠合型气藏的砂岩储层,成条带状分布,从沾化和车镇凹陷延伸到惠民和东营凹陷,储层物性较上、下石盒子组要差,以Ⅲ和Ⅳ类储层为主。煤储层的饱和吸附量随着深度的增大呈现先增大后减小的变化,临界深度出现在800~1500m范围内。济阳坳陷上古生界主要受印支、燕山、喜山三期构造运动影响,北西向断裂是影响煤系地层分布及煤型气运聚成藏的主要因素。印支期,上古生界经历了第一次埋深阶段,最大埋深能达到3000m,但由于印支运动的强烈抬升,有机质刚进入生烃门限即告终止,生烃作用微弱。燕山期,煤系烃源岩埋深显著分异,但普遍小于2500m,由于地幔热流机制的调整,局部地区仍发生二次生排烃过程,由于燕山期末强烈的地壳抬升剥蚀,煤层生成的烃类不容易保存。喜山期,分为喜山早期和晚期,但烃源岩演化主要发生在喜山早期,烃源岩埋深普遍大于3000m,发生显著的二次生排烃过程,是最主要的生排烃阶段。从成藏过程分析,济阳坳陷煤系原生气藏总体属于间断式多次成藏模式。从成藏主控因素分析,煤型气藏成藏模式属于断裂控藏的“由远及近”模式;叠合型气藏成藏模式属于沉积控藏的自生自储模式。孤北地区具有优越的煤系原生气藏成藏条件,义155井气藏在下石盒子组中发现煤型气,属于断裂控制的向斜成藏;孤北古1井气藏在上石盒子组奎山段发现煤型气,属于断裂控制的潜山断鼻构造气藏,下石盒子组和山西组也有油气显示,有形成煤型气气藏和叠合型气藏的前景。
[Abstract]:Taking Jiyang depression as the study area and taking the primary gas reservoir of Carboniferous Permian system as the research object, this paper discusses the formation mechanism of the typical coexisting primary gas reservoir, such as the coal measure gas reservoir, the coal-type gas reservoir and the coalbed gas-coalbed gas superposition gas reservoir. By means of sedimentology and reservoir dynamics, this paper systematically discusses the sedimentary geological background, the characteristics of reservoir forming elements, the process of reservoir formation, and the reservoir forming model of coal type gas reservoir and superimposed gas reservoir in coal measure primary gas reservoir. The main results are as follows: the tidal flat facies of Taiyuan formation and the interdistributary bay microfacies of Shanxi formation are the main sedimentary environment types of hydrocarbon source rock development in this area. The source rocks are mainly vitrinite, the parent material type is basically type 鈪，

本文编号：1906374