摘要
酸化是一种改善煤渗透性的常用化学改造方法,目前对酸化煤研究主要集中在矿物组成、孔隙结构和渗透性等方面,而对酸化煤吸附性能研究尚有不足。选择盐酸(HCl)作为改造试剂,探讨了酸化煤的孔隙和吸附演化特征。结果表明,HCl对碳酸盐矿物的溶蚀作用,导致孔隙结构的变化。HCl对大孔具有扩孔效应,表现为孔体积增大,而孔面积减小。介孔表现为扩孔和转化的双重效应,具体为孔体积和孔面积均减小。Langmuir常数表现为VL减小而pL增大。孔隙结构的变化进一步影响煤的吸附能力,即大孔和介孔面积的降低减少了气体的吸附位点,削弱了吸附能力。本研究从矿物成分和孔隙结构的角度阐明了HCl对吸附能力的靶向控制效应,促进煤层气的解吸,为HCl在储层改造和煤层气增产中的应用提供了理论依据。
Acidification is a commonly used chemical modification method to improve coal permeability.Current research on acidified coal mainly focuses on mineral composition,pore structure,and permeability,while studies on its adsorption properties remain insufficient.This study selected hydrochloric acid(HCl)as the modification reagent to explore the pore and adsorption evolution characteristics of acidified coal.Results indicate that HCl’s dissolution of carbonate minerals leads to changes in pore structure.HCl has a pore-enlargement effect on macropores,manifested as increased pore volume but decreased pore area.Mesopores exhibit a dual effect of enlargement and transformation,specifically characterized by decreases in both pore volume and pore area.The Langmuir constants show a decrease in VL and an increase in pL.The changes in pore structure further affect the coal’s adsorption capacity;specifically,the decrease in the macropores and mesopores area decreases the gas adsorption sites,weakening the adsorption capacity.This study,from the perspectives of mineral composition and pore structure,clarifies the targeted control effect of HCl on adsorption capacity,promotes coalbed methane(CBM)desorption,and provides a theoretical basis for the application of HCl in reservoir stimulation and CBM production enhancement.
作者
任威
张利军
乔磊
REN Wei;ZHANG Lijun;QIAO Lei(Shanxi Gaohe Energy Co.,Ltd.,Changzhi,Shanxi 047100)
出处
《中国煤炭地质》
2025年第7期38-42,58,共6页
Coal Geology of China
基金
国家科技重大专项子课题“潞安矿区单一低渗煤层井上下联合开发技术集成与示范”(2016ZX05067/003)。
关键词
盐酸
孔隙结构
吸附常数
解吸效率
煤层气
HCl
pore structure
adsorption constant
desorption efficiency
coalbed methane(CBM)
