南华北盆地偃龙地区二叠系泥页岩微观孔隙特征及其影响因素分析

发布时间：2018-06-22 14:55

本文选题：南华北盆地 + 二叠系　；参考：《地质力学学报》2017年06期

【摘要】：运用氩离子抛光—场发射环境扫描电子显微成像测试技术,对南华北盆地偃龙地区ZK1614井二叠系海陆交互相—陆相的泥页岩样品进行观察并获取二次电子及背散射信息。结合X射线能谱信息和JMicro Vision软件灰度识别功能,对样品矿物组成及微观孔隙特征进行定性分析和定量表征,并探讨了孔隙发育分布的影响因素。研究发现:样品主要发育的孔隙以无机矿物孔为主,孔隙类型有粒内孔、粒间孔、少量有机质孔及微裂隙;样品面孔率介于0.92%~5.53%之间,整体来看,面孔率大小与孔隙数量正相关;孔径大小介于50~2000 nm间,不同区段的孔面积对数指标与单位面积孔数量对数指标呈两段式线性关系,孔径较小时两者负相关,孔径较大时两者正相关。不同矿物对孔隙的发育有不同的控制作用,脆性矿物主要影响裂隙的发育,对孔隙的发育有一定的抑制作用;粘土矿物因构造应力、矿物相变及脱水等作用形成大量孔隙,对孔隙的发育起一定的促进作用。研究区燕山期、喜山期因构造活动形成了大量尺度较大的裂隙,裂隙的发育使岩层的渗流性能增加,促进了有机酸和地层水对矿物的溶蚀作用,相应的促进了孔隙的发育。此外,随着埋藏深度的增加,孔隙体积随着压实作用的增大而逐渐减小。
[Abstract]:Using argon ion polishing and field emission environment scanning electron microscopic imaging technique, the mud shale samples of well ZK1614 in South North China Basin were observed and the secondary electron and backscatter information were obtained. Based on the X-ray energy spectrum information and the gray recognition function of JMicro Vision software, the mineral composition and micropore characteristics of the samples were qualitatively analyzed and quantitatively characterized, and the influencing factors of pore development and distribution were discussed. It is found that the main pores developed in the samples are inorganic mineral pores, the types of pores are intragranular pores, intergranular pores, a few organic pores and microcracks, and the sample face rate is between 0.92% and 5.53%. Overall, the pore size is positively correlated with the number of pores. The aperture size is between 50nm and 2000nm. The logarithmic index of pore area in different regions is linear in two segments. The aperture is negatively correlated when the aperture is small, and positive correlation is found when the aperture is larger. Different minerals have different controlling effects on the development of pores, brittle minerals mainly affect the development of fractures and inhibit the development of pores, clay minerals form a large number of pores due to tectonic stress, mineral phase transition and dehydration, etc. Play a certain role in promoting the development of pores. During the Yanshanian and Himalayan periods, a large number of large scale fractures were formed in the study area. The development of the fractures increased the seepage performance of the strata, promoted the dissolution of organic acids and formation water to minerals, and promoted the development of pores. In addition, with the increase of burial depth, the pore volume decreases with the increase of compaction.
【作者单位】：河南理工大学资源环境学院;
【基金】：国家自然科学基金(41102059) 河南省高校科技创新团队支持计划(17IRTSTHN025)
【分类号】：P618.13

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