沁水盆地南部15号煤层和顶板K2灰岩水文地球化学演化特征  

Hydrogeochemical evolution of No.15 coal seam and limestone K2 in southern Qinshui basin

作　　者：李忠城[1] 吴建光[1] 王建中[1] 吴翔[1] 卢国军[1] LI Zhongcheng;WU Jianguang;WANG Jianzhong;WU Xiang;LU Guojun(China United Coalbed Methane Corporation Ltd.,Beijing 100015,China)

机构地区：[1]中联煤层气有限责任公司,北京100015

出　　处：《煤田地质与勘探》2020年第3期75-80,共6页Coal Geology & Exploration

基　　金：国家科技重大专项项目(2017ZX05064)。

摘　　要：针对煤层气井产水量大、降压困难、产气效果不佳等问题,基于沁水盆地南部煤矿15号煤层顶板K2灰岩水以及15号煤层气井水矿化度和离子数据,利用统计、对比方法,系统研究两者的水化学成分特征、类型、成因机理,建立了地层水演化模型,系统阐述灰岩和煤层水在补给区、径流区、滞流区发生的各种反应和作用。研究结果表明:K2灰岩水和15号煤层水会发生离子交换、混合作用及CO2作用,在补给区和强径流区,K2灰岩水水型以Ca-Mg-HCO3-SO4型为主,煤层水水型以Na-HCO3-SO4型为主;缓径流区K2灰岩水一般为Na-Ca-Cl-HCO3型,而煤层水以Na-Cl-HCO3或Na-HCO3型为主;滞流区K2灰岩水和煤层水水型相同,为Na-HCO3或Na-Cl-HCO3水型。研究结果为15号煤的煤层气开发提供可靠的水文地质依据。Based on the water test data of No.15 coal roof K2 limestone and No.15 coalbed methane well in the southern Qinshui basin,the characteristics,types and the genetic mechanism of water chemical composition were systematically studied by statistical and comparative methods.The evolution model was built to systematically describe the various reactions and effects of limestone and coalbed water in the recharge zone,runoff zone and detention zone.The results show that the K2 limestone water and the No.15 coal seam water will undergo ion exchange,mixing and CO2 action.The K2 limestone water is mainly Ca-Mg-HCO3-SO4 type in the recharge zone and the strong runoff zone,and the water type of the coal seam is Na-HCO3-SO4 type;K2 limestone water in slow-flow area is generally Na-Ca-Cl-HCO3 type,while coalbed water is mainly Na-Cl-HCO3 or Na-HCO3 type;K2 limestone water is the same as the coal seam water in detention area,and it is Na-HCO3 or Na-Cl-HCO3 water type.The study aims to provide a reliable hydrogeological basis for the development of No.15 coalbed methane.

关 键 词：K2灰岩水 15号煤层气井产出水 水类型 水演化模型 沁水盆地南部 

分 类 号：P641.3[天文地球—地质矿产勘探]