页岩中有机质孔隙非均质性的微观结构及电镜—拉曼联用研究

鲍芳; 俞凌杰; 芮晓庆; 张庆珍; 范明; 马中良

doi:10.11781/sysydz202105871

页岩中有机质孔隙非均质性的微观结构及电镜—拉曼联用研究

doi: 10.11781/sysydz202105871

鲍芳^{1, 2,},
俞凌杰^{1, 2},
芮晓庆^{1, 2},
张庆珍^{1, 2},
范明^{1, 2},
马中良^{1, 2}

1.
中国石化油气成藏重点实验室, 江苏无锡 214126
2.
中国石化石油勘探开发研究院无锡石油地质研究所, 江苏无锡 214126

基金项目:

国家自然科学基金 42072156

详细信息

作者简介:
鲍芳(1981-), 女, 博士, 高级工程师, 从事岩石矿物微区分析技术研究。E-mail: baofang.syky@sinopec.com

中图分类号: TE122.23
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- 被引次数: 0
出版历程
- 收稿日期: 2021-07-07
- 修回日期: 2021-08-29
- 刊出日期: 2021-09-28

Microstructure and SEM-Raman study of organic matter pore heterogeneity in shale

BAO Fang^{1, 2
,},
YU Lingjie^{1, 2},
RUI Xiaoqing^{1, 2},
ZHANG Qingzhen^{1, 2},
FAN Ming^{1, 2},
MA Zhongliang^{1, 2}

1.
SINOPEC Key Laboratory of Petroleum Accumulation Mechanisms, Wuxi, Jiangsu 214126, China
2.
Wuxi Research Institute of Petroleum Geology, SINOPEC, Wuxi, Jiangsu 214126, China

摘要

摘要: 页岩中有机质孔隙的发育特征及其影响因素对我国页岩气勘探开发具有重要意义。扫描电镜下观察发现页岩中有机质的孔隙发育常见非均质性，但现阶段由于缺乏有效的微区研究方法，有机质孔隙发育的影响因素仍存在较大的争议。选取四川盆地平桥地区下志留统龙马溪组黑色页岩，利用氩离子抛光-扫描电镜、FIB-SEM三维分析技术，从二维和三维层面对页岩中有机质孔隙的非均质性特征进行了分析。不依赖于有机质显微组分类型，只考虑有机质的孔隙发育程度，将不同孔隙发育程度的有机质分为3个级别，并利用大面积背散射成像（MAPS）分析方法对这三种有机质的面积占有率和对孔隙的贡献度分别进行了定量分析；采用扫描电镜-激光拉曼联用技术分析其拉曼光谱，利用拉曼参数的差别探讨了影响有机质孔隙发育非均质性的主要因素。不同孔隙发育程度有机质的D峰与G峰强度比不同，说明不同有机质的芳香结构有序度有较明显的区别，表明影响有机质孔隙发育的主要因素为原始有机质的组成。该方法能够在微区观察有机质孔隙的同时，原位分析有机质显微组分的分子结构特征，明确有机质孔隙发育的主要影响因素。
- 扫描电镜 /
- 拉曼光谱 /
- 非均质性 /
- 孔隙 /
- 有机质 /
- 页岩
Abstract: The characteristics and influencing factors of pore development in organic matters of shale are of great significance for shale gas exploration and production in China. The pore development in organic matters of shale has been found to be heterogeneous with SEM observation. However, due to the lack of effective approach for micro-scale research, the influencing factors of pore development of organic matter are still controversial. Black shale samples of the Longmaxi Formation of Pingqiao area of the Sichuan Basin were selected by this study and the heterogeneity of development and distribution of pores in organic matters were analyzed in detail from two-dimensional and three-dimensional levels by the means of Ar ion polishing SEM and FIB-SEM observation. The organic matters with different pore development degrees were divided into three levels, and the area occupancy and contribution to the pores of these three levels of organic matter were studied by MAPS. In this paper, the Raman spectrum of three levels of organic matter with different pore development were obtained by SEM-Raman. The main factors affecting the heterogeneity of pore development of organic matter were discussed in view of the differences of Raman parameters. The results showed that the intensity ratio of D peak to G peak of organic matter was different, which indicated that the order degree of aromatic structure of different organic matter was significantly different, proving that the main factor affecting the pore development in organic matter could be the composition of original organic matter. This method can be used to observe the pores of organic matter in micro area and analyze the molecular structure characteristics of organic matter macerals in-situ, and further clarifies the main influencing factors of pore development of organic matter.
- scanning electron microscope (SEM) /
- Raman spectra /
- heterogeneity /
- porosity /
- organic matter /
- shale

HTML全文

图 1 四川盆地平桥页岩气田下志留统龙马溪组页岩岩心样品中不同类型孔隙特征的扫描电镜照片

Figure 1. SEM photographs of different types of pores in core samples from Lower Silurian Longmaxi Formation, Pingqiao shale gas field, Sichuan Basin

下载: 全尺寸图片幻灯片

图 2 四川盆地平桥页岩气田下志留统龙马溪组页岩岩心样品中不同孔隙发育特征有机质的扫描电镜照片

Figure 2. SEM photographs of organic matter with different pore development in core samples from Lower Silurian Longmaxi Formation, Pingqiao shale gas field, Sichuan Basin

下载: 全尺寸图片幻灯片

图 3 四川盆地平桥页岩气田下志留统龙马溪组页岩岩心样品不同孔隙发育程度有机质的FIB-SEM三维重构图

a.一级孔隙发育有机质；b.二级孔隙发育有机质；c.三级孔隙发育有机质
1.三维重构图；2.有机质与孔隙的三维分布图；3.有机质孔隙的三维分布图；4.有机质孔隙孔径分布图

Figure 3. FIB-SEM three-dimensional reconstruction of organic matter with different pore development in core samples from Lower Silurian Longmaxi Formation, Pingqiao shale gas field, Sichuan Basin

下载: 全尺寸图片幻灯片

图 4 四川盆地平桥页岩气田下志留统龙马溪组页岩岩心样品不同孔隙发育程度有机质的MAPS分析

Figure 4. MAPS analysis of organic matter with different pore development in core samples from Lower Silurian Longmaxi Formation, Pingqiao shale gas field, Sichuan Basin

下载: 全尺寸图片幻灯片

图 5 四川盆地平桥页岩气田下志留统龙马溪组页岩岩心样品不同孔隙发育程度有机质的拉曼光谱图

Figure 5. Raman spectra of organic matter with different pore development in core samples from Lower Silurian Longmaxi Formation, Pingqiao shale gas field, Sichuan Basin

下载: 全尺寸图片幻灯片

图 6 不同孔隙发育程度有机质的峰强度比(D/G)分布

Figure 6. Peak intensity ratio (D/G) of organic matter with different pore development degrees

下载: 全尺寸图片幻灯片

图 7 四川盆地平桥页岩气田下志留统龙马溪组页岩岩心样品孔隙发育不均匀有机质颗粒的扫描电镜图

Figure 7. SEM photographs of organic matter with uneven pore development in core samples from Lower Silurian Longmaxi Formation, Pingqiao shale gas field, Sichuan Basin

下载: 全尺寸图片幻灯片

图 8 四川盆地平桥页岩气田下志留统龙马溪组页岩岩心样品孔隙发育不均匀有机质颗粒的拉曼面分布

Figure 8. Raman surface distribution of organic matter with uneven pore development in core samples from Lower Silurian Longmaxi Formation, Pingqiao shale gas field, Sichuan Basin

下载: 全尺寸图片幻灯片

表 1 四川盆地平桥页岩气田下志留统龙马溪组页岩岩心样品不同孔隙发育等级有机质的参数

Table 1. Parameters of organic matter with different pore development in core samples from Lower Silurian Longmaxi Formation, Pingqiao shale gas field, Sichuan Basin

有机质孔隙发育等级	有机质孔隙度/%	主要孔径/nm	有机质面积占有率/%	对有机质孔隙度的贡献率/%
一级	＜1	＜30	2.96	0.32
二级	1~5	50~200	9.09	5.47
三级	＞5	10~50	87.95	94.2

下载: 导出CSV

表 2 四川盆地平桥页岩气田下志留统龙马溪组页岩岩心样品不同孔隙发育程度有机质的拉曼光谱主要参数

Table 2. Raman parameters of organic matter with different pore development in core samples from Lower Silurian Longmaxi Formation, Pingqiao shale gas field, Sichuan Basin

有机质等级	拉曼位移(D)/cm^-1	拉曼位移(G)/cm^-1	峰强度(D)	峰强度(G)	位移差(G-D) /cm^-1	峰强度比(D/G)
一级	1 334.55	1 598.66	1 924.65	2 989.03	264.11	0.64
	1 334.49	1 591.04	1 476.41	2 338.54	256.55	0.63
	1 336.88	1 590.74	1 412.40	2 440.46	253.86	0.58
	1 335.68	1 587.40	1 741.07	2 995.10	251.72	0.58
	1 331.32	1 586.21	3 205.41	5 497.34	254.89	0.58
二级	1 329.34	1 578.43	503.47	604.30	249.09	0.83
	1 330.87	1 584.22	810.34	934.69	253.35	0.87
	1 331.07	1 580.11	535.46	602.32	249.04	0.89
	1 332.09	1 580.84	426.77	504.77	248.75	0.85
	1 333.85	1 562.69	246.02	301.29	228.84	0.82
三级	1 323.37	1 569.11	259.55	238.14	245.74	1.09
	1 329.39	1 579.27	422.78	425.96	249.88	0.99
	1 326.28	1 571.22	396.95	393.02	244.94	1.01
	1 331.25	1 580.72	691.97	680.96	249.47	1.02
	1 342.30	1 580.34	266.25	266.57	238.04	1.00

下载: 导出CSV

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