鄂尔多斯盆地庆阳气田山1段地层水地球化学特征及成因

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中图分类号：P618.13 文献标识码：A 文章编号：2097-5465（2026）02-0015-13

Abstract：ThisstudyinvestigatestheoriginandsourcesofformationwaterthroughgeochemicalanalysisoftheShan-1Memberin theQingyangGasField，OrdosBasin，providingabasisforresearchongas-waterdistributionandtheoptimizationoffavorable exploration targets.The results show that the formation water exhibits high salinity，weaklyacidic pH ，and an ionic composition dominated by Ca2+ ， Na++K+ ，and Cl- . The water type is mainly CaCl2 ， followed by MgCl2 ，with minor N& 12 S 4 type， indicating generally poorpreservationconditions，withonlylocalwellareasfavorableforhydrocarbonacumulationandpreservationThegeochemicalparametersofteformationwaterareharacterzedbylowsoum-chlodecoeficient，lowdesulfurzationcficient， lowmetamorphiccoeficient，medium-to-lowmagnesium-calciumcoefcient，andhighcationexchangecapacity，sugestingpoor formationsealing，intensewater-rockinteractions，andrelativelydepmetamorphisminlocalareas，typicalofhydrocarbonasociatedwater.Thedistributionofgasandwaterisjointlycontroledbynear-sourceaccumulation，structuralfeatures，faults， reservoirheterogeneity，andhydrocarbongenerationintensity.Furthermore，comparativeanalysisofClwithotherion concentrations reveals Ca2+ enrichment，slight Na + depletion，and Mg2+ depletion in the study area.Diagenetic processes include albitizationanddisslutionoffeldspar，adsorptionbyclayminerals，isomorphismofsiderite，andchloritizationofvolcanic fragments，biotite，andtufaceousmaterials，aswellasdolomitizationofcalcite.Comprehensiveanalysisindicatesthatthe formationwateroiginisloselyassociatedwithwaterrockinteractionsandevaporatioconcetrationprocesss，claifngitas burial-metamorphictypeformationwaterwithoutaunifiedgas-waterinterface.Thefidingsprovidescientificsupportforidentifying favorable natural gas exploration areas.

Keywords：Geochemistry；originof formation water；the Shan1 member of Qingyang gas field；Ordos Basin

0 引言

地层水作为油气成藏体系的重要组成部分，始终与烃源岩及油气相伴生，为油气的生成、运移和聚集提供动力及介质条件，参与天然气成藏演化过程，对于油气藏的形成与保存起关键作用[1]。（剩余15277字）