我国煤层普遍具有低孔、低渗特征，采用化学增透方法溶蚀割理、裂隙中的充填矿物，增强裂隙连通性，可提高煤层渗透率和煤层气井产量。针对盐酸、土酸等常规酸体系的腐蚀和二次沉淀等问题，提出使用螯合剂进行储层改造的技术思路。以山西沁水盆地成庄矿3号煤层为研究对象，采用化学滴定、静态溶蚀、表面形貌观察、岩心酸化流动、标准试片腐蚀速率评价和压汞等试验方法，探究了EDTA、HEDTA、GLDA和MGDA 4种螯合剂在不同pH条件下对煤中矿物的溶蚀效果，以及在驱替过程中煤岩心的渗透率动态变化过程，最后比较了螯合剂与常规盐酸对N-80型试片的腐蚀速率，并明确了所优选的螯合剂对煤孔隙结构影响规律及其增透作用机理。结果表明：4种螯合剂中，HEDTA对Ca²⁺和Fe³⁺的螯合能力最强；5%GLDA浸泡后的煤样基质产生了微裂缝和孔隙，有利于煤层气的解吸和运移；向煤岩心中注入约80倍孔隙体积（PV）的5%GLDA后，其渗透率增加68.75%；压汞结果表明，经过GLDA处理后的煤样总孔隙度由5.91%增至28.8%，这主要是由于10～100 nm和>1 000 nm孔径范围内的孔隙增加；5%GLDA对N-80型试片的腐蚀速率仅为5%HCl腐蚀速率的7.53%，因此无需额外添加缓蚀剂，可有效降低酸化作业成本。环保型螯合剂通过酸化作用和螯合作用能有效溶蚀煤层中的无机矿物（方解石、铁白云石等），生成稳定、可溶的螯合物，从而提高煤层的渗透率，同时降低对储层的二次伤害，研究成果可为低渗煤层气高效勘探开发提供新的技术思路。

China’s coal seams are characterized of low porosity and low permeability. To improve the production of coalbed methane (CBM) wells, chemical stimulation was proposed to enhance the connectivity of coal fractures and cleats by dissolving the cementing inorganic minerals, hance increase coal permeability. Considering the drawbacks of conventional acid such as severe corrosion and second precipitation, the possibility of using chelating agents for reservoir reconstruction was proposed. Taking coal samples from No.3 coal seam, Chengzhuang coal mine, Qinshui basin as research object, chemical titration, static dissolution experiment, micromorphology observation, core-flooding experiment, evaluation of corrosion rate of N-80 coupons and mercury intrusion porosimetry experiment were conducted. The corrosion effects of four chelating agents, EDTA, HEDTA, GLDA and MGDA, on minerals in coal under different pH conditions and the dynamic change process of permeability in coal cores during the process of expulsion were investigated, and finally the corrosion rates of chelating agents and conventional hydrochloric acid on the N-80 specimens were compared, and the influence law of the preferred chelating agents on the pore structure of coal and their permeability-enhancing action mechanism were clarified. Results showed that among the four chelating agents, HEDTA has the strongest chelating ability to Ca²⁺ and Fe³⁺; the coal dissolution rate decreases with the increase of the concentration of chelating agent under acidic conditions; the coal matrix soaked with 5% GLDA produces micro-cracks and pores, which is beneficial to the desorption and migration of coalbed methane; after injecting 80PV of 5% GLDA into the coal, its permeability increased 68.75%; the total porosity of the coal sample increased from 5.91% to 28.8% due to the increase of pore volume with diameter of 10-100 nm and >1000 nm; the corrosion rate of 5% GLDA to N-80 coupon is only 7.53% of that of 5% HCl, no additional corrosion inhibitor is needed, which is more cost-effective. The environmentally friendly chelating agent can effectively dissolve the inorganic minerals (calcite, iron dolomite, etc.) in the coalbed through acidification and chelation to generate stable and soluble chelating compounds, which can improve the permeability of the coal bed and reduce the secondary damage to the reservoir. These findings can provide valuable ideas for efficient exploration and development of low-permeability coalbed methane.