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1、2016年9月,第22卷,第3期,543-548页高校地质学报Sep2016,Vol.22,No.3,pp.543-548GeologicalJournalofChinaUniversitiesDOI:10.16108/j.issn1006-7493.2015225基于核磁共振不同煤岩类型储渗空间精细描述1,21,21,21,21,2刘玉龙,汤达祯,许浩,赵俊龙,李冰洋1.中国地质大学(北京)能源学院,北京100083;2.中国地质大学(北京)煤层气开发利用国家工程研究中心煤储层实验室,北京100083摘要:为了深入探究不同煤岩类型储渗空间的特征及其差异性,选取了韩城矿区4种不同煤岩类
2、型的中煤阶样品,采用低场核磁共振技术,实现了对韩城矿区不同煤岩类型孔裂隙的识别和有效孔隙度差异性的精细描述和定量表征,并在此基础上基于离心前后累计振幅曲线求取了孔裂隙系统划分的阀值T2C1和T2C2,实现了对不同煤岩类型孔径结构分布的重构。实验结果表明:不同煤岩类型煤样的T2谱形态差异较大,从光亮煤到暗淡煤,T2谱由双峰大孔隙型逐渐过渡到双峰小孔隙型,且T2C截止值和有效孔隙度均呈现出逐渐降低的趋势;并由求取的阀值T2C1和T2C2计算得到的三大孔裂隙系统孔径分布可知,从光亮煤到暗淡煤,储层的孔裂隙结构由渗流孔型逐渐向综合型和扩散孔型过渡。关键词:煤岩类型;储渗空间;低场核磁共振;有效
3、孔隙度;划分阀值中图分类号:P618.13文献标识码:A文章编号:1006-7493(2016)03-0543-06DescriptionoftheStorage-PermeabilityUndertheControlofMacrolithotypesBasedontheNuclearMagneticResonance1,21,21,21,21,2LIUYulong,TANGDazhen,XUHao,ZHAOJunlong,LIBingyang1.SchoolofEnergyResources,ChinaUniversityofGeosciences(Beijing),Beijing1
4、00083,China;2.CoalReservoirLaboratoryofNationalEngineeringResearchCenterofCoalbedMethaneDevelopment&Utilization,ChinaUniversityofGeosciences(Beijing),Beijing100083,ChinaAbstract:Inordertoexplorethecharacteristicsofstorage-permeabilityandtheheterogeneitywithinthecoalmacrolithotypes,themedium-high
5、ranksamplesofdifferentmacrolithotypesinHanchengminingarea,werestudiedusingthelowfieldnuclearmagneticresonancetechnique,finedescriptionandquantitativecharacterizationofpore-fracturesystemandthedifferenceintheeffectiveporositywithindifferentmacrolithotypesinHanchengminingareahavebeenobtained.Based
6、onthecumulativeamplitudecurvesbeforeandaftercentrifugation,thethresholdT2C1andT2C2,whichcandividethepore-fracturesystem,wasobtained,andthereconstructionofproesizedistributionofdifferentmacrolithotypeswasestablished.Theexperimentalresultsshowthatdifferentmacrolithotypesofcoalsampleshavesignifican
7、tlydifferentT2spectrum,whichshowsfromthebrightcoaltothedullcoal.TheT2spectrumfromthedoublemacroporetypeisgraduallytransformedtothedoublemicroporetype,andbothofT2Ccutoffvalueandeffectiveporosityshowagraduallydecreasingtrend.T