Geochemical Characteristics and Development Significances of Constant and Trace Elements from Coalbed Methane Co-Produced Water:A Case Study of the Shizhuangnan Block,the Southern Qinshui Basin  

作　　者：Yang Li Shuheng Tang Jian Chen Songhang Zhang Zhaodong Xi 

机构地区：[1]Key Laboratory of Universities in Anhui Province for Prevention of Mine Geological Disasters,Anhui University of Science and Technology,Huainan 232001,China [2]School of Earth and Environment,Anhui University of Science and Technology,Huainan 232001,China [3]National Key Laboratory of Petroleum Resources and Engineering,China University of Petroleum,Beijing 102249,China [4]School of Energy Resource,China University of Geosciences,Beijing 100083,China [5]Key Laboratory of Marine Reservoir Evolution and Hydrocarbon Enrichment Mechanism,Ministry of Education,Beijing 100083,China [6]Key Laboratory of Strategy Evaluation for Shale Gas,Ministry of Land and Resources,Beijing 100083,China

出　　处：《Journal of Earth Science》2024年第1期51-61,共11页地球科学学刊（英文版）

基　　金：supported by Open Foundation of the Key Laboratory of Universities in Anhui Province for Prevention of Mine Geological Disasters(No.2022-MGDP-07);National Natural Science Foundation of China(No.42102216);National Key Laboratory of Petroleum Resources and Engineering,China University of Petroleum,Beijing(No.PRE/open-2302);the NSFC-Shanxi Coal-Based Low Carbon Joint Fund of China(No.U1910205);National Natural Science Foundations of China(No.41972173)。

摘　　要：As an unconventional natural gas resource,coalbed methane(CBM)development releases a large amount of CBM wells co-produced water.Geochemical characteristics of the co-produced water provide an essential foundation for the production dynamics of CBM reservoirs if the impacts of fracturing fluids and other aquifers can be ignored.In the Shizhuangnan Block of the southern Qinshui Basin,constant and trace elements in CBM co-produced water from the wellheads were collected and determined,which is applied to assess water source,fracturing fluid effect,and CBM production.Based on principle component analysis and hierarchical clustering analysis,the water samples are divided into four categories.It suggests that different characteristics affected by water-rock interaction,reservoir environment,aquifer recharge,and hydraulic fracturing result in the various ratios of Na^(+)/Cl^(-),alkalinity(HCO_(3)^(-)+CO_(3)^(2-))/Cl^(-)and other specific rules.Moreover,Cl^(-)is selected as a dividing line for complete fracturing fluid flow back,associated with organic-bound chlorine complexes in the original coal seam water.Compared to constant elements,there is a significant correlation between Li and Sr concentrations and CBM productivity,so templates regarding trace elements can be used to distinguish various sources of the co-produced water.

关 键 词：coalbad methane CBM co-produced water hydraulic fracturing Qinshui Basin 

分 类 号：TE37[石油与天然气工程—油气田开发工程]