Petroleum Reservoir Evaluation and Development >
2022 , Vol. 12 >Issue 3: 455 - 461
DOI: https://doi.org/10.13809/j.cnki.cn32-1825/te.2022.03.007
Molecular simulation of adsorption law for shale kerogen
Received date: 2021-09-06
Online published: 2022-06-24
Shale gas is unconventional natural gas, mainly CH4, occurring in organic shale. The adsorbed gas is the main source for later production of shale gas. Therefore, studying the adsorption mechanism of shale plays an important role in shale gas development. By using type Ⅱ kerogen molecules, a type Ⅱ kerogen model is established. Then, Monte Carlo method and molecular simulation method are used to study the micro adsorption behavior and mechanism of CH4 in type Ⅱ kerogen. Experimental data are used to verify this model, and the effects of pore size, temperature and pressure on the adsorption behavior are investigated. The findings are as follows: ① The higher the pore size, the greater the excess adsorption capacity of CH4. The higher the temperature, the lower the excess adsorption capacity of CH4. With the increase of pressure, the absolute adsorption amount of CH4 increases rapidly at first and then gently, and the excess adsorption amount of CH4 increases first and then decreases. ② The adsorption heat of CH4 decreases with the increase of pore size. The adsorption of CH4 in kerogen is physical adsorption. ③ When the pore size is smaller than 1 nm, CH4 is the adsorption phase in kerogen; when the pore size is larger than one nanometer(1 nm), CH4 is the coexistence of adsorption phase and free phase in kerogen.
Key words: molecular simulation; shale gas; kerogen; adsorption; adsorption mechanism
Jinghui LI , Xin HAN , Sijing HUANG , Yangyang YU , Xianyu QIANG , Kangfu GU , Dali HOU . Molecular simulation of adsorption law for shale kerogen[J]. Petroleum Reservoir Evaluation and Development, 2022 , 12(3) : 455 -461 . DOI: 10.13809/j.cnki.cn32-1825/te.2022.03.007
[1] | 张东晓, 杨婷云. 页岩气开发综述[J]. 石油学报, 2013, 34(4):792-801. |
[1] | ZHANG Dongxiao, YANG Tingyun. An overview of shale gas production[J]. Acta Petrolei Sinica, 2013, 34(4): 792-801. |
[2] | 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. |
[2] | 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. |
[3] | 王瑞, 杨晨曦, 茹瀚昱, 等. 页岩和煤在容量法等温吸附实验中的误差对比[J]. 非常规油气, 2021, 8(3):43-48. |
[3] | WANG Rui, YANG Chenxi, RU Hanyu, et al. Comparison of error in methane isotherm adsorption by volumetric method for shale and coal[J]. Unconventional Oil & Gas, 2021, 8(3): 43-48. |
[4] | CURTIS J B. Fractured shale-gas systems[J]. AAPG Bulletin, 2002, 86(11): 1921-1938. |
[5] | ZHANG T W, ELLIS G S, RUPPEL S C, et al. Effect of organic-matter type and thermal maturity on methane adsorption in shale-gas systems[J]. Organic Geochemistry, 2012, 47: 120-131. |
[6] | WANG S, FENG Q H, ZHA M, et al. Molecular dynamics simulation of liquid alkane occurrence state in pores and slits of shale organic matter[J]. Petroleum Exploration and Development Online, 2015, 42(6): 844-851. |
[7] | WANG T Y, TIAN S C, LI G S, et al. Selective adsorption of supercritical carbon dioxide and methane binary mixture in shale kerogen nanopores[J]. Journal of Natural Gas Science and Engineering, 2018, 50: 181-188. |
[8] | AMBROSE R J, CLARKSON C R, YOUNGBLOOD J E, et al. Life-cycle decline curve estimation for tight/shale reservoirs[C]// Paper SPE-140519-MS presented at the SPE Hydraulic Fracturing Technology Conference, The Woodlands, Texas, USA, January, 2011. |
[9] | 刘冰, 史俊勤, 沈跃, 等. 石墨狭缝中甲烷吸附的分子动力学模拟[J]. 计算物理, 2013, 30(5):692-699. |
[9] | LIU Bing, SHI Junqin, SHEN Yue, et al. A molecular dynamics simulation of methane adsorption in graphite slit-pores[J]. Chinese Journal of Computational Physics, 2013, 30(5): 692-699. |
[10] | 陈磊, 黄鼎斌, 李仲珍, 等. 微狭缝中甲烷吸附特性的分子动力学模拟[J]. 热科学与技术, 2016, 15(2):92-96. |
[10] | CHEN Lei, HUANG Dingbin, LI Zhongzhen, et al. Study on methane adsorption in graphite slit-pores by molecular dynamics simulation[J]. Journal of Thermal Science and Technology, 2016, 15(2): 92-96. |
[11] | 田守嶒, 王天宇, 李根生, 等. 页岩不同类型干酪根内甲烷吸附行为的分子模拟[J]. 天然气工业, 2017, 37(12):18-25. |
[11] | TIAN Shouceng, WANG Tianyu, LI Gensheng, et al. Molecular simulation of methane adsorption behavior in different shale kerogen types[J]. Natural Gas Industry, 2017, 37(12): 18-25. |
[12] | 卢双舫, 沈博健, 许晨曦, 等. 利用GCMC分子模拟技术研究页岩气的吸附行为和机理[J]. 地球科学, 2018, 43(5):1783-1791. |
[12] | LU Shuangfang, SHEN Bojian, XU Chenxi, et al. Study on adsorption behavior and mechanism of shale gas by using GCMC molecular simulation[J]. Earth Science, 2018, 43(5): 1783-1791. |
[13] | 唐鑫, 朱炎铭, 郭远臣, 等. 四川盆地龙马溪组页岩储层孔隙及伊利石甲烷吸附特征[J]. 天然气地球科学, 2018, 29(12):1809-1816. |
[13] | TANG Xin, ZHU Yanming, GUO Yuanchen, et al. Molecular simulation of methane adsorption within illite minerals in the shale of the Longmaxi Formation based on a grand canonical Monte Carlo method and pore size distribution[J]. Natural Gas Geoscience, 2018, 29(12): 1809-1816. |
[14] | XIONG J, XIANGJUN LIU X J, LIANG L X, et al. Adsorption of methane in organic-rich shale nanopores: An experimental and molecular simulation study[J]. Fuel, 2017, 200: 299-315. |
[15] | HAMZA J, MAYTHAM I, KOVSCEK A R. Experimental investigation and Grand Canonical Monte Carlo simulation of gas shale adsorption from the macro to the nano scale[J]. Journal of Natural Gas Science and Engineering, 2017, 48: 119-137. |
[16] | KATTI D R, THAPA K B, KATTI K S. Modeling molecular interactions of sodium montmorillonite clay with 3D kerogen models[J]. Fuel, 2017, 199: 641-652. |
[17] | 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. |
[17] | XU Chenxi, XUE Haitao, LI Bohong, et al. Microscopic adsorption mechanism difference in the mineral pore of shale gas reservoir[J]. Special Oil & Gas Reservoirs, 2020, 27(4): 79-84. |
[18] | 邹才能, 董大忠, 王社教, 等. 中国页岩气形成机理、地质特征及资源潜力[J]. 石油勘探与开发, 2010, 37(6):641-653. |
[18] | ZOU Caineng, DONG Dazhong, WANG Shejiao, et al. Geological characteristics, formation mechanism and resource potential of shale gas in China[J]. Petroleum Exploration and Development, 2010, 37(6): 641-653. |
[19] | UNGERER P, COLLELL J, YIANNOURAKOU M. Molecular modeling of the volumetric and thermodynamic properties of kerogen: Influence of organic type and maturity[J]. Energy & Fuels, 2015, 29(1): 91-105. |
[20] | 马青华, 张学梅, 郝静远, 等. 页岩气临界吸附量的初步研究[J]. 非常规油气, 2020, 7(6):76-80. |
[20] | MA Qinghua, ZHANG Xuemei, HAO Jingyuan, et al. Preliminary Study on Critical Adsorption Capacity of Shale Gas[J]. Unconventional Oil & Gas, 2020, 7(6): 76-80. |
[21] | GIBBS J W. The collected works of J. Willard Gibbs, Volume I: Thermodynamics[M]. New Haven Yale University Press, 1928. |
[22] | 熊健, 刘向君, 梁利喜. 甲烷在官能团化石墨中吸附行为的影响因素研究[J]. 中国矿业大学学报, 2017, 46(2):356-364. |
[22] | XIONG Jian, LIU Xiangjun, LIANG Lixi. Investigation on the influence factors of the methane adsorption in functionalized graphite[J]. Journal of China University of Mining & Technology, 2017, 46(2): 356-364. |
[23] | GASPARIK M, BERTIER P, GENSTERBLUM Y, et al. Geological controls on the methane storage capacity in organic-rich shales[J]. International Journal of Coal Geology, 2014, 123: 34-51. |
[24] | 范德赞, 杜建芬, 张玲玲. 页岩气在Ⅱ型干酪根有机质中吸附的分子模拟[J]. 原子与分子物理学报, 2018, 35(4):537-543. |
[24] | FAN Dezan, DU Jianfen, ZHANG Lingling. Molecular simulation of shale gas adsorption onto Ⅱ kerogen organic matter[J]. Journal of Atomic and Molecular Physics, 2018, 35(4): 537-543. |
/
〈 | 〉 |