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沉积环境对优质页岩储层发育的控制作用——以渝东南地区龙马溪组为例
供稿: 赵迪斐;郭英海;白万备;冶正阳;曹磊;李刚;王雪莲 时间: 2018-07-18 次数:

作者:赵迪斐郭英海白万备冶正阳曹磊李刚;王雪莲

作者单位:中国矿业大学资源与地球科学学院煤层气资源与成藏过程教育部重点实验室河南理工大学资源环境学院

摘要:为深入探讨优质页岩储层的发育机理,借鉴沉积控相、相控储层的研究思路,以渝东南地区龙马溪组页岩储层为例,利用氩离子抛光-场发射扫描电镜(AIP-FESEM),有机碳丰度(TOC)测试,X射线衍射(XRD),镜质组反射率(Ro)测试,显微镜观测,主量微量元素测试等技术手段,通过对储层特征、沉积环境的系统研究,综合讨论沉积环境对优质页岩储层发育的控制作用。结果表明:龙马溪组页岩储层可以划分为下-底部、中-上部两段,分别对应鲁丹阶与埃朗阶,两段储层的有机质特征、矿物组分、力学脆性特征、储层物性等差异显著,鲁丹阶页岩有机质和脆性矿物含量更高,储层性质更优;对比分析显示,龙马溪组储层有机特征主要受控于水体氧化还原环境,但龙马溪组下部具有更好的有机质富集与保存条件,主要受益于鲁丹段深水陆棚相内低速率的欠补偿沉积环境与全球海平面上升所形成的大面积缺氧水体;储层脆性矿物组分受控于沉积-成岩的共同作用,储层底部高脆性矿物含量段富含来自特殊沉积环境的生物成因石英、陆源碎屑石英与形成于储层成岩作用的自生石英;鲁丹阶对应的底部储层TOC和石英含量更高,有利于储集空间发育;鲁丹阶储层更加发育的富笔石水平层理等特殊...更多

基金:国家自然科学基金面上项目(41772130);国家重点基础研究发展计划(973)项目(2012CB214702);煤层气资源与成藏过程教育部重点实验室(中国矿业大学)开放基金资助项目(2015-007);中国矿业大学大学生创新训练项目(201560);

关键词:页岩气;龙马溪组;优质储层;沉积环境;沉积条件;

Abstract:In order to explore the development of high quality shale reservoirs, the controlling mechanism of sedimentary environment on high quality shale reservoir was discussed. Reservoir features, sedimentary environment and its controlling on development of high quality shale reservoir were systematic studied. Experimental methods of argon ion polishing-field emission scanning electron microscopy ( AIP-FESEM) , TOC test, X-ray diffraction ( XRD) , vitrinite reflectance test, microscope, and main/trace elements test were conducted on samples of shale reservoirs of Longmaxi formation. The results showed that shale reservoirs of Longmaxi formation could be divided into two parts ( i. e. lower-bottom part and middle-upper part) corresponding to Rhuddanian stage and Aeronian stage. The two parts were significant differences in organic matter, mineral compositions, mechanical brittleness and reservoir physical properties, etc. Shale reservoirs of Rhuddanian stage have better reservoir properties, higher TOC and brittle mineral content compared with that of Aeronian stage. The comparative analysis shows that the organic characteristics in Longmaxi formation are mainly controlled by the redox environment of water. However, the lower part of the Longmaxi formation has better organic matter enrichment and preservation conditions, which mainly benefits from the large area hypoxia water formed by the low sedimentary rate of Rhuddanian stage and the global sea level rise. The brittle mineral components of the reservoir are controlled by sedimentation-diagenesis. The high brittle mineral content in the bottom of the reservoir is rich in biological genesis quartz, terrigenous clastic quartz from the special sedimentary environment, and the autogenous quartz formed in the progress of reservoir diagenesis. The bottom reservoir has higher TOC content and quartz content, which is conductive to reservoir development. The special sedimentary structures, such as the horizontal bedding of the Rhuddanian stage reservoir, have favorable influence on enhancing the permeability of reservoir and improving the mechanical properties while fracturing. The sedimentary environment controls the types and characteristics of material compositions in the reservoir. Favorable sedimentary environment and sedimentary conditions of the Rhuddanian stage reservoirs in the Longmaxi formation are the key factors to affect the development of the bottom high quality reservoirs.

DOI:10.16186/j.cnki.1673-9787.2018.04.6

分类号:P618.13

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