特种油气藏2026，Vol.33Issue(1)：22-32,11.DOI:10.3969/j.issn.1006-6535.2026.01.003
准噶尔盆地深层煤岩气赋存特征及游离气饱和度定量表征方法
Occurrence characteristics of deep coal-measure gas in Junggar Basin and a quantitative characterization method for free gas saturation
摘要
Abstract
In view of the inadequate understanding of the pore structure refined characterization and gas occurrence mechanism in deep coal-measure gas reservoirs of the Junggar Basin,a quantitative characterization method for free gas saturation was proposed based on pore types and gas occurrence space.A correspondence was established be-tween different pore types in coal rock(micropores,mesopores and macropores)and different gas occurrence states(adsorbed gas,free gas).The adsorption space do minated by micropores and the free gas space composed of meso-pores-macropores are quantitatively delineated,overco ming the limitation of traditional methods lacking targeted linkage between pore types and gas occurrence states.By integrating measured gas content,isothermal adsorption,o-verburden porosity-permeability and other experimental data,targeted corrections were made for the bias in free gas content caused by dynamic adsorption-desorption-diffusion changes in measured total gas,as well as for the com-pression effect on free space under reservoir conditions.This achieved accurate quantification of in-situ free gas space and the space occupied by in-situ free gas,and ultimately established a calculation model for free gas satura-tion.This method,for the first time,systematically couples pore types with gas occurrence states and introduces free gas saturation as a key evaluation parameter.Application results show that in Dimei Well and Caimei Well areas,free gas saturation is below 35%,belonging to the model of moderate gas generation capacity-relatively strong stor-age space-relatively low free gas saturation;in Qixin Well area,despite lower pore development,free gas saturation is mostly above 75%,belonging to the model of strong gas generation capacity-moderate storage space-high free gas saturation.This method effectively reveals the controlling mechanism of different pore types on gas occurrence,deep-ens the understanding of gas occurrence and production mechanisms.The combined evaluation model of gas genera-tion capacity-gas storage capacity-free gas saturation can provide a basis for optimizing future development plans and improve the production efficiency of coal-measure gas.关键词
煤岩气/气体赋存/吸附空间/游离空间/游离气饱和度/生气能力/储气能力Key words
coal-measure gas/gas occurrence/adsorption space/free gas space/free gas saturation/gas generation capacity/gas storage capacity分类
能源科技引用本文复制引用
杨潇,胡正舟,潘拓,姚卫江,陈国辉,谢菲,付基友..准噶尔盆地深层煤岩气赋存特征及游离气饱和度定量表征方法[J].特种油气藏,2026,33(1):22-32,11.基金项目
中国石油攻关性应用性科技专项"深地煤岩气赋存特征及成藏机理研究"(2023ZZ18YJ02) （2023ZZ18YJ02）
