松辽盆地东部盆地群下白垩统泥页岩源盖层特征

发布时间：2018-05-26 07:46

  本文选题：东部盆地群 + 下白垩统　； 参考：《东北石油大学》2017年硕士论文

【摘要】：松辽盆地东部盆地群下白垩统泥页岩是一套有利的勘探目的层,在通化盆地通D1井页岩和致密砂岩中均见到良好的油气显示,预示着该地区具有常规油气和非常规油气勘探的前景,因此,研究该地区下白垩统泥页岩具有长远的意义。目前,泥页岩的定义尚未统一,本文中的泥页岩是一个统称,主要包括泥岩和页岩。由于泥页岩这一特殊的概念,在已有的资料基础上,搜集和实测了东部盆地群下白垩统泥页岩大量的地化数据和岩石学特征数据,本文试图通过泥页岩的岩石学特征、地化特征和封闭能力三个方面,研究泥页岩“源”和“盖”的特征。结果表明,研究区下白垩统泥页岩主要发育于滨浅湖相和半-深湖相。北部下白垩统沉积水体较浅,泥页岩厚度变化大、粉砂质含量高;南部沉积水体较深,泥页岩厚度变化较小,粉砂质含量低。通过泥页岩XRD、扫描电镜和液态氮吸附实验发现,研究区下白垩统泥页岩脆性矿物含量(≥40%)较高,有利于在外力作用下形成裂缝,总脆度受到石英矿物含量的影响,与Barnett等北美页岩气储层矿物含量具有很好的对比性。下白垩统泥页岩中有裂缝发育,其中有机质孔发育受控于有机质热演化程度,当Ro0.8%时,研究区下白垩统泥页岩有机质孔开始发育,随着有机质热演化程度的增加,有机质孔增多,但具有一定的临界值,当Ro≥4.0%时,有机质孔减少。发育的孔喉类型主要为微孔-中孔,不具有连通性,不会影响其封闭能力,但确有利于产生的页岩气吸附在泥页岩中。通过地化数据的分析,研究区下白垩统泥页岩具有一定的生烃能力,且南部泥页岩品质好于北部。北部有机质丰度达到了中等偏差,干酪根主要为Ⅱ2-Ⅲ型,目前处于成熟-高熟阶段,易于生气;南部泥页岩有机质丰度较高,达到中等偏好的水平,干酪根主要为I-Ⅱ2型,目前处于低熟-成熟阶段,易于生油和生气。与国内外泥页岩地化特征对比,下白垩统泥页岩样品大部分落在了TOC=1.0%~24.0%、Ro=0.4%~1.8%的范围内,具有生成页岩气的潜力。研究区下白垩统直接盖层和区域盖层的岩性不仅仅是泥页岩,同时还有火山岩和凝灰岩,但本文以讨论泥页岩为主,主要包括粉砂质泥岩、泥岩、页岩和泥质粉砂岩。发与盖层的成岩阶段主要处于中成岩阶段A1亚期-中成岩阶段A2亚期,排替压力较大,封闭性主要处于中-好、好和好-中三个等级,封闭能力较好。根据源控论和盖层保存条件控制成藏理论,结合研究区下白垩统泥页岩岩石学特征、地化特征和封闭特征的讨论结果,表明该研究区南部更具有勘探开发的价值。
[Abstract]:The Lower Cretaceous shale is a favorable exploration target layer in the eastern Songliao Basin, and good oil and gas display is found in TongD1 well shale and tight sandstone in Tonghua Basin. It indicates that there are prospects for conventional and unconventional oil and gas exploration in this area, so it is of long-term significance to study the Lower Cretaceous shale in this area. At present, the definition of shale is not uniform, the shale in this paper is a general term, mainly including mudstone and shale. Because of the special concept of shale, based on the existing data, a large number of geochemistry and petrological data of the Lower Cretaceous shale in the eastern basin group were collected and measured. This paper attempts to analyze the petrological characteristics of the shale. The characteristics of shale "source" and "cap" are studied in three aspects: geochemical characteristics and sealing capacity. The results show that shales of Lower Cretaceous are mainly developed in littoral shallow lacustrine facies and semi-deep lacustrine facies in the study area. The lower Cretaceous sedimentary water body in the north is shallow, the shale thickness changes greatly, and the silty sand content is high, while the sedimentary water body in the south is deeper, the shale thickness is small, and the silty sand content is low. By means of XRD, SEM and nitrogen adsorption experiments, it is found that the lower Cretaceous shale has a higher brittle mineral content (鈮，

本文编号：1936380