天然气工业2026，Vol.46Issue(4)：84-94,11.DOI:10.3787/j.issn.1000-0976.2026.04.007
热解作用下不同煤岩类型孔隙结构差异演变模式
Differential evolution patterns of pore structures under pyrolysis for different coal lithotypes
摘要
Abstract
Deep coalbed methane(CBM)is of important strategic significance to energy security and low-carbon development.However,the differential pore development patterns of different coal lithotypes throughout the complete thermal evolution path have not been figured out,which restricts the occurrence mechanism study and reservoir evaluation of deep CBM.Taking the low-maturity coal of the Haerwusu Mine in the Junggar Coalfield of the Ordos Basin as the simulation sample,this paper analyzes the differential variation characteristics and controlling factors of coal pore structures at different evolutionary stages by means of field emission scanning electron microscopy(FESEM),high-pressure mercury intrusion porosimetry(MIP),low-temperature nitrogen(N2)adsorption,and low-temperature carbon-dioxide(CO2)adsorption,and other characterization techniques.Based on this,a pore structure evolution model is established.The following results are obtained.First,the coal pore volume exhibits a bimodal distribution of micropores and macropores,with mesopores having the smallest pore volume,and micropores being the main contributors to specific surface area.With increasing thermal evolution degree,the volume and specific surface area of micropores generally show a trend of first decreasing and then increasing,those of mesopores display a sharp decrease followed by basic stability,and those of macropores exhibit a phased variation of first increasing and then decreasing.Second,different macroscopic coal lithotypes show significant difference in maceral.In bright coal and semi-bright coal,macropores and micropores are relatively developed,while in dull coal,pore evolution shows lag characteristics.Third,coal lithotype and thermal evolution degree are the primary factors controlling coal pore volume and specific surface area.Fourth,the models of four thermal evolution stages of coal reservoir pores are established.It is revealed that the evolution process of pore structures in coal reservoirs is the competitive outcome of primary pore alteration and secondary pore formation.In conclusion,the research results are beneficial for deepening the understanding of the geological evolution patterns of pores in different coal lithotypes,and further provide a reference for evaluating the carriers and mature intervals of free gas and adsorbed gas enrichment in deep coal seams,as well as for deep CBM accumulation research,exploration,and evaluation.关键词
热模拟/孔隙结构/低温氮吸附/CO2吸附/高压压汞/扫描电镜/哈尔乌素煤矿Key words
Thermal simulation/Pore structure/Low-temperature nitrogen adsorption/CO2 adsorption/High-pressure mercury intrusion/Scanning electron microscopy(SEM)/Haerwusu Mine分类
能源科技引用本文复制引用
田永净,王存武,张月,康世龙,陈朝辉,郑兰圣龙,申建..热解作用下不同煤岩类型孔隙结构差异演变模式[J].天然气工业,2026,46(4):84-94,11.基金项目
国家自然科学联合基金重点支持项目"深部煤炭地下气化产物调控与气化腔封存CO2地质响应机制"(编号:U24B2042)、山西省科技重大专项项目"深层煤层气地质工程一体化开发技术研究与应用"(编号:202501080301004)、山西省重点研发项目"深部煤层气地质-工程一体化高效联动开发技术与工程示范"(编号:202202080301010). （编号:U24B2042）
