四川威远地区九老洞组页岩微观非均质性

发布时间：2018-01-26 20:05

本文关键词： 微观非均质性微观孔隙九老洞组威远地区　出处：《断块油气田》2017年01期 　论文类型：期刊论文

【摘要】：目前,国内外对于页岩非均质性的研究刚刚起步,相关理论还不成熟。文中利用X射线衍射手段,结合观察九老洞组页岩样品的薄片和扫描电镜,在微米级—纳米级的尺度下,从矿物组分、微观孔隙和微裂缝3个方面来评价页岩的微观非均质性。从矿物组分的角度来看,主要矿物为石英,其次为斜长石和黏土矿物,样品矿物组分和含量上没有明显的差异性。在厘米以上尺度,页岩岩性和矿物组分纵向非均质性较弱;而在微观尺度下,矿物组分对孔隙发育和分布状态影响较大,非均质性明显,而且随着观测倍数增大,页岩微观非均质性将会越来越明显。从微观孔隙的角度来看,主要发育粒间孔、粒内孔、晶间孔和有机质孔等类型。在微观尺度下,页岩孔隙类型、分布和孔径大小差别较大,非均质性明显。从微裂缝的角度来看,在2 711~2 815 m的页岩岩心,下部裂缝较上部发育,表明在毫米级—厘米级的裂缝非均质较为明显。微米级—纳米级的微裂缝尺度变化较大,微裂缝可分为黏土转化缝、成岩收缩缝和异常高压缝,微裂缝形态多样,其发育特征和配置关系在微观尺度下具有强非均质性。
[Abstract]:At present, the research on shale heterogeneity has just started at home and abroad, and the relevant theory is not mature. In this paper, X-ray diffraction method is used to observe the shale samples of Jiulaodong formation and scanning electron microscope (SEM). The microcosmic heterogeneity of shale is evaluated on the scale of micron-nanometer scale from three aspects: mineral composition, micro-pore and micro-fracture. From the point of view of mineral composition, the main mineral is quartz. Secondly, plagioclase and clay minerals have no obvious difference in mineral composition and content. The longitudinal heterogeneity of shale lithology and mineral composition is weak on the scale above cm. On the micro scale, the mineral components have a great influence on the pore development and distribution, and the heterogeneity is obvious, and with the increase of the observation multiple. The microcosmic heterogeneity of shale will become more and more obvious. From the point of view of micropore, there are mainly intergranular pore, intragranular pore, intergranular pore and organic pore. The distribution and pore size differ greatly, and the heterogeneity is obvious. From the point of view of micro-fracture, the lower fracture is more developed than the upper one in the shale core of 2711 ~ 2 815 m. The results show that the heterogeneity of the cracks in the millimeter-centimeter scale is obvious, and the microcracks in the micron-nanometer scale vary greatly. The micro-cracks can be divided into clay transformation joints, diagenetic shrinkage joints and abnormal high-pressure fractures. The microfractures are diverse in shape and have strong heterogeneity in microcosmic scale.
【作者单位】：中国石化胜利油田分公司勘探开发研究院;
【基金】：国家自然科学基金项目“页岩油、气甜点构成要素比较研究”(41472123)
【分类号】：P618.13
【正文快照】： 0引言四川盆地非常规油气资源丰富,盆地页岩气勘探开发主要位于下志留统龙马溪组和下寒武统九老洞组。其中,下志留统龙马溪组页岩受关注较多,其微观特征已有较多研究[1￣2]。九老洞组页岩有机质丰度高、厚度大、生烃条件好,有利于页岩气藏的形成[3],但因勘探程度低和资料少,九

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