CO2-ECBM通过将CO2注入煤层提高煤层气采收率并实现CO2地质封存受到业界的高度关注。为了探索CO2-ECBM在沁水盆地南部SZN区块大量低单井产量井技术适应性，实现低效老井区产量提升以及CO2封存的双重收益，基于区内地质条件及储层非均质性等特征分析，提出了老井低效煤层气井区CO2-ECBM可注入性、可增产性、可封存性三大类选址关键地质原则。在此基础上，阐释了研究区关键地质选址原则下煤厚、渗透率、煤层倾角、构造曲率、地下水流场、地温场、埋深、顶底板岩性、断层等地质约束条件，指出煤层厚度适宜且煤层结构简单、平均产气量较高、煤层倾角小于5°、处于平缓近等轴褶皱构造部位(构造曲率低于2.5×10-4)、距离断层1 km以外、相对较低地应力及主地应力差、煤层地下水径流与CO2注入流场协同、煤层顶底板以致密泥岩类为主等CO2-ECBM潜在工程有利区评价参数和指标，优选出SZN区块北部Z-1～Z-100、中部Z-160～Z-170、南部Z-180～Z-240区等作为CO2-ECBM潜在有利区。通过对比分析，在有利区基础上进一步优选出煤体结构以碎裂-原生为主、物性条件较好且采出程度较低的7个备选井组。采用煤层剩余含气量、渗透率、现今产水量、15 m内砂岩厚度、井距等CO2-ECBM井组优选参数，基于灰色关联分析方法，厘定了CO2-ECBM注入井组实施先后序列为T-7>T-2>T-1>T-3>T-6>T-4>T-5，即T-2与T-7为最优先注入井组。

CO2-ECBM has attracted great attention from the natural gas industry,as it enhances the CBM recovery rate by injecting CO2 into coal seams and achieves the geological storage of CO2.In order to explore the technical adaptability of CO2-ECBM to a large number of existing low single well production wells in SZN block in the south of Qinshui Basin,and to enhance the gas production of low effective old wells and seal CO2 underground as well,some research have been conducted based on the geological settings and the anisotropy of physical properties in coal seams in the study area.This study proposes three key geological principles of location selection:injectability,stimulation and storage of selected wells in low efficiency old well area CO2-ECBM.On this basis,the paper explained the principle of the key geological conditions,such as the coal seams thickness,permeability,the dip angle of coal seams,structure curvature,groundwater flow field,geothermal field,burial depth,lithology of the roof and floor,faults,etc.The result show that appropriate coal seam thickness and simple seam structures,high gas production,less than 5 degree of dip angle,a flat fold which has approximate axis (structural curvature is less than 2.5×10-4),1 km away from the fault,relatively low ground stress and small difference of primary stresses,the cooperation of groundwater runoff and CO2 injection flow field in coal seam,and the roof and floor of the coal seam with a dense mudstone lithology are the evaluation parameters and indexes of potential engineering favorable areas of CO2-ECBM.Results Z-1~Z-100 in the north,Z-160~Z-170 in the middle and Z-180~Z-240 in the south are the favorable areas for CO2-ECBM.Through the above comparative analysis,on the basis of favorable areas,seven alternative well groups with good physical properties and low recovery degree are further selected.The implementation sequence of injection well group is T-7>T-2>T-1>T-3>T-6>T-4>T-5 by grey correlation analysis,and T-2 and T-7 are the most preferred injection well groups.