龙马溪组页岩干酪根表征初探及干酪根吸附特征研究

doi:10.13809/j.cnki.cn32-1825/te.2023.05.011

Abstract

Abstract:

Adsorbed gas represents a primary mode of shale gas occurrence and is a major source of shale gas production in the later stages of development. It primarily resides within the organic kerogen and clay minerals of shale formations, with organic kerogen being the dominant host. Consequently, the study of organic kerogen characteristics and its adsorption mechanisms is crucial for understanding shale gas development. In this paper, the kerogen of Longmaxi Shale in the Sichuan Basin is taken as the research object. The microstructure of kerogen is expressed by combining methods through the solid-state NMR experiment, Fourier transform infrared spectroscopy experiment, X-ray photoelectron spectroscopy experiment, and the molecular structure model of kerogen is constructed. The adsorption mechanism and characteristics of CH₄ in kerogen of Longmaxi Shale are analyzed by magnetic levitation weight experiment, molecular simulation methods of the Grand Canonical Monte Carlo（GCMC）, and Molecular Dynamics（MD）. The results show that the molecular formula of the kerogen of shale experimental sample of Longmaxi Formation is C₂₃₇H₂₁₉O₂₁N₅S₄. The excess adsorption gas volume of CH₄ in kerogen increase first and then decreased with the increase of pressure. Under the same pore size and pressure, the excess adsorption gas volume and total gas volume of CH₄ decrease with the increase in temperature. The C and S atoms in kerogen are the main cause of CH₄ adsorption. The CH₄ near the kerogen pore wall presents an adsorption state, while the CH₄ far from the kerogen pore wall presents a free state. As the pore size increase, the distance between the two peaks of CH₄ density gradually increases, and the peak value decreases gradually.

Key words: shale kerogen, molecular structure, adsorption characteristics, molecular simulation, Longmaxi Formation

CLC Number:

TE377

Dali HOU,Xin HAN,Hongming TANG, et al. Primary research on expression of kerogen in Longmaxi Shale and its adsorption characteristics[J]. Petroleum Reservoir Evaluation and Development, 2023, 13(5): 636-646.

Figures/Tables 18

Fig. 1

Fig. 2

Fig. 3

Table 1

Table 2

Skeleton parameters of shale kerogen in Longmaxi Formation, Changning area"

骨架参数	物理意义	定义	小数
$f a l$	脂化度	$f a l M + f a l A + f a l B + f a l H + f a l D + f a l O$	0.153 6
$f a r$	芳香度	$f a r A + f a r H + f a r B + f a r C + f a r O$	0.673 6
$X B P$	桥周比	$f a r B / f a r A + f a r H + f a r C + f a r O$	0.160 0
BI	脂肪分支系数	$f a l D + C H - O / f a l$	0.140 0
δ	芳香取代度	$1 - f a r H / f a r$	0.270 0

Table 2

Fig. 4

Fig. 5

Table 3

Fig. 6

Fig. 7

Fig. 8

Fig. 9

Fig. 10

Fig. 11

Fig. 12

Fig. 13

Fig. 14

Fig. 15

References 29

[1]	张金川, 徐波, 聂海宽, 等. 中国页岩气资源勘探潜力[J]. 天然气工业, 2008, 28(6): 136-140.
	ZHANG Jinchuan, XU Bo, NIE Haikuan, et al. Exploration potential of shale gas resources in China[J]. Natural Gas Industry, 2008, 28(6): 136-140.
[2]	刘伟新, 卢龙飞, 叶德燎, 等. 川东南地区奥陶系五峰组—志留系龙马溪组页岩气异常压力封存箱剖析与形成机制[J]. 石油实验地质, 2022, 44(5): 804-814.
	LIU Weixin, LU Longfei, YE Deliao, et al. Significance and Formation mechanism of abnormally pressured compartments of shale gas in the Ordovician Wufeng-Silurian Longmaxi formations, southeastern Sichuan Basin[J]. Petroleum Geology & Experiment, 2022, 44(5): 804-814.
[3]	胡凯. 川西南威远地区五峰—龙马溪组页岩储层特征及甜点分布规律研究[J]. 非常规油气, 2021, 8(5): 34-44.
	HU Kai. Reservoir and sweet pot distribution characteristics of shale gas in Wufeng-Longmaxi Formation, southwest of Sichuan Basin[J]. Unconventional Oil & Gas, 2021, 8(5): 34-44.
[4]	CURTIS J B. Fractured shale-gas systems[J]. AAPG Bulletin, 2002, 86(11): 1921-1938.
[5]	LIU Y, LIU S M, ZHANG R, et al. The molecular model of Marcellus shale kerogen: Experimental characterization and structure reconstruction[J]. International Journal of Coal Geology, 2021, 246: 1-18.
[6]	王擎, 程枫, 潘朔. 油页岩干酪根化学键浓度与能量密度研究[J]. 燃料化学学报, 2017, 45(10): 1209-1218.
	WANG Qing, CHENG Feng, PAN Shuo. Chemical bond concentration and energy density of oil shale kerogen[J]. Journal of Fuel Chemistry and Technology, 2017, 45(10): 1209-1218.
[7]	黄亮. 基于分子模拟的页岩气多组分竞争吸附机理研究[D]. 北京: 中国石油大学(北京), 2020.
	HUANG Liang. Molecular simulation study on competitive adsorption mechanism of multi-components in shale gas reservoir[D]. Beijing: China University of Petroleum(Beijing), 2020.
[8]	WANG X Y, HAN X X, YOU Y L, et al. Molecular characterization of Dachengzi oil shale kerogen by multidimensional solid-state nuclear magnetic resonance spectroscopy[J]. Fuel, 2021, 303(6): 1-9.
[9]	CHAREONSUPPANIMIT P, MOHAMMAD S A, ROBINSON R L, et al. High-pressure adsorption of gases on shales: Measurements and modeling[J]. International Journal of Coal Geology, 2012, 95: 34-46. doi: 10.1016/j.coal.2012.02.005
[10]	闫建萍, 张同伟, 李艳芳, 等. 页岩有机质特征对甲烷吸附的影响[J]. 煤炭学报, 2013, 38(5): 805-811.
	YAN Jianping, ZHANG Tongwei, LI Yanfang, et al. Effect of the organic matter characteristics on methane adsorption in shale[J]. Journal of China Coal Society, 2013, 38(5): 805-811.
[11]	RAJPUT V, ERTEKIN T. Thermodynamically-consistent modeling of adsorption in liquid-rich shales[C]// Paper SPE-169589-MS presented at the SPE Western North American and Rocky Mountain Joint Meeting, Denver, Colorado, USA, April 2014.
[12]	翟常博, 邓模, 曹清古, 等. 川东地区上二叠统龙潭组泥页岩基本特征及页岩气勘探潜力[J]. 石油实验地质, 2021, 43(6): 921-932.
	ZHAI Changbo, DENG Mo, CAO Qinggu, et al. Basic characteristics and exploration potential of shale gas in Longtan Formation of Upper Permian in eastern Sichuan Basin[J]. Petroleum Geology & Experiment, 2021, 43(6): 921-932.
[13]	李腾飞, 田辉, 肖贤明, 等. 样品粒径对高过成熟度页岩低压气体吸附实验结果的影响[J]. 天然气地球科学, 2020, 31(9): 1271-1284.
	LI Tengfei, TIAN Hui, XIAO Xianming, et al. The effect of particle size on low pressure gas adsorption experiments for high-maturity shale[J]. Natural Gas Geoscience, 2020, 31(9): 1271-1284.
[14]	CHEN L, LIU K Y, JIANG S, et al. Effect of adsorbed phase density on the correction of methane excess adsorption to absolute adsorption in shale[J]. Chemical Engineering Journal, 2020, 420: 1-13.
[15]	KATTI D, THAPA K, KATTI K S. Modeling molecular interactions of sodium montmorillonite clay with 3D kerogen models[J]. Fuel, 2017, 199: 641-652. doi: 10.1016/j.fuel.2017.03.021
[16]	许晨曦, 薛海涛, 李波宏, 等. 页岩气在矿物孔隙中的微观吸附机理差异性研究[J]. 特种油气藏, 2020, 27(4): 79-84. doi: 10.3969/j.issn.1006-6535.2020.04.012
	XU Chenxi, XUE Haitao, LI Bohong, et al. Microscopic adsorption mechanism difference in the mineral pore of shale gas reservoir[J]. Special Oil & Gas Reservoir, 2020, 27(4): 79-84. doi: 10.3969/j.issn.1006-6535.2020.04.012
[17]	任俊豪, 任晓海, 宋海强, 等. 基于分子模拟的纳米孔内甲烷吸附与扩散特征[J]. 石油学报, 2020, 41(11): 1366-1375. doi: 10.7623/syxb202011006
	REN Junhao, REN Xiaohai, SONG Haiqiang, et al. Adsorption and diffusion characteristics of methane in nanopores based on molecular simulation[J]. Acta Petrolei Sinica, 2020, 41(11): 1366-1375. doi: 10.7623/syxb202011006
[18]	BABATUNDE K A, BEGASH B, MOJID M R, et al. Molecular simulation study of CO₂/CH₄ adsorption on realistic heterogeneous shale surfaces[J]. Applied Surface Science, 2021, 543(3): 1-11.
[19]	石钰, 杨晓娜, 李树刚, 等. 含水量对干酪根中多组分气体吸附和扩散的影响: 分子模拟研究[J]. 西安石油大学学报(自然科学版), 2021, 36(4): 50-57.
	SHI Yu, YANG Xiaona, LI Shugang, et al. Effect of moisture on adsorption and diffusion of multi-component gas in kerogen: A molecular simulation study[J]. Journal of Xi'an Shiyou University(Natural Science Edition), 2021, 36(4): 50-57.
[20]	石油地质勘探专业标准化委员会. 沉积岩中干酪根分离方法: GB/T 19144—2010[S]. 北京: 中国标准出版社, 2010: 1-3.
	Professional Standardization Committee of Petroleum Geology Exploration. Isolation method for kerogen from sedimentary rock: GB/T 19144—2010[S]. Beijing: Standards Press of China, 2010: 1-3.
[21]	国家能源局. 透射光—荧光干酪根显微组分鉴定及类型划分方法: SY/T 5125-2014[S]. 北京: 石油工业出版社, 2014.
	National Energy Administration.Method of identification microscopically the maceral of kerogen and indivision the kerogen type by transmitted-light and fluorescence: SY/T 5125—2014[S]. Beijing: Petroleum Industry Press, 2014.
[22]	JACOB H. Classification, structure, genesis and practical importance of natural solid oil bitumen (“migrabitumen”)[J]. International Journal of Coal Geology, 1989, 11(1): 65-79. doi: 10.1016/0166-5162(89)90113-4
[23]	谢国梁, 刘树根, 焦堃, 等. 受显微组分控制的深层页岩有机质孔隙: 四川盆地五峰组—龙马溪组有机质组分分类及其孔隙结构特征[J]. 天然气工业, 2021, 41(9): 23-34.
	XIE Guoliang, LIU Shugen, JIAO Kun, et al. Organic pores in deep shale controlled by macerals: Classification and pore characteristics of organic matter components in Wufeng Formation-Longmaxi Formation of the Sichuan Basin[J]. Natural Gas Industry, 2021, 41(9): 23-34.
[24]	王笑奇. 长宁地区五峰—龙马溪组页岩气成藏过程及富集机制研究[D]. 徐州: 中国矿业大学, 2021.
	WANG Xiaoqi. Study on shale gas accumulation process and enrichment mechanism of Wufeng-Longmaxi Formation in Changning area[D]. Xuzhou: China University of Mining and Technology, 2021.
[25]	吴小奇, 周小进, 陈迎宾, 等. 四川盆地川西坳陷上三叠统须家河组烃源岩分子地球化学特征[J]. 石油实验地质, 2022, 44(5): 854-865.
	WU Xiaoqi, ZHOU Xiaojin, CHEN Yingbin, et al. Molecular characteristics of source rocks in Upper Triassic Xujiahe Formation, western Sichuan Depression, Sichuan Basin[J]. Petroleum Geology & Experiment, 2022, 44(5): 854-865.
[26]	邹雨, 王国建, 卢丽, 等. 纳米孔隙中页岩气扩散模拟实验和数学模型分析[J]. 石油实验地质, 2021, 43(5): 844-854.
	ZOU Yu, WANG Guojian, LU Li, et al. Simulation experiment and mathematical model analysis for shale gas diffusion in nano-scale pores[J]. Petroleum Geology & Experiment, 2021, 43(5): 844-854.
[27]	李鹏飞. 基于分子模拟研究深部煤储层孔隙结构和吸附特征——以大宁—吉县地区煤层为例[D]. 太原: 太原理工大学, 2019.
	LI Pengfei. Pore structural characterization and adsorption properties of deep coal reservoir based on molecular simulation: A case study from Daning-Jixian District coalbed[D]. Taiyuan: Taiyuan University of Technology, 2019.
[28]	鲁中灯, 刘岩, 陈祖林, 等. 烃源岩抽提物中藿烷分子碳同位素分析新方法及指示意义[J]. 石油实验地质, 2022, 44(2): 288-294.
	LU Zhongdeng, LIU Yan, CHEN Zulin, et al. An improved method and indications for the compound specific isotopic analysis of hopanes in source rock extracts[J]. Petroleum Geology & Experiment, 2022, 44(2): 288-294.
[29]	陈彦鄂, 张志荣, GREENWOOD Paul. 油气包裹体分子组成的热释—色谱—质谱分析[J]. 石油实验地质, 2021, 43(5): 915-920.
	CHEN Yan'e, ZHANG Zhirong, GREENWOOD Paul. Pyrolysis-gas chromatography-mass spectrometry analyses of oil-bearing fluid inclusions composition[J]. Petroleum Geology & Experiment, 2021, 43(5): 915-920.

碳官能团	面积分数/%
脂甲基	2.31
芳甲基	1.41
脂C（2）碳	2.90
亚甲基	2.47
次甲基，季sp³碳	0.77
氧—亚甲基	1.37
氧—次甲基	1.43
氧—脂肪环	2.70
氧—芳香环	1.45
质子化芳香碳	48.95
桥联芳香碳	9.13
支链芳香碳	5.36
氧—芳香碳	2.47
羧基，羰基	17.29

元素	归属	结合能/eV	面积分数/%
C1s	C—C，C—H	284.6	55.90
	C—O，C—OH	285.4	20.40
	C=O	287.1	6.60
	O—C=O	288.5	17.10
F1s	F^-	684.4	100.00
N1s	吡啶	398.8	6.50
	吡咯	400.2	64.60
	季氮	401.7	24.50
	氮氧化物	403.0	2.30
S2p	噻吩型硫	162.4	30.16
	亚砜型硫	165.4	33.47
	砜型硫	168.6	36.37

Primary research on expression of kerogen in Longmaxi Shale and its adsorption characteristics

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