准确确定出煤层气直井低产的原因并提出针对性的增产技术对策，是减少盲目投资、提高产气效益的关键之一。以柿庄南区块为研究对象，从煤储层地质资源条件、钻井工艺、压裂工艺、排采工作制度等4个方面分析了煤层气低产原因。在此基础上，通过实验室酸化解污试验、压裂参数优化模拟研究、解除煤粉堵塞工艺原理分析、降低泵挂深度增产原理分析等方法，提出了不同低产原因下的针对性技术对策。结果表明：钻井污染严重的井可采用酸化解污+常规水力压裂方式实现增产；煤体结构以原生结构+碎裂煤为主，压裂参数不合理造成的煤层气低产井，优先采用重复压裂技术；煤体结构以碎粒或糜棱煤为主的低产井，需根据顶/底板岩性及围岩补给情况，确定顶/底板压裂的可行性；泵挂深度在煤层5 m以上的且曾经有较高产气量的低产井，可通过加深泵挂实现增产；排采应力敏感的低产井，优化二次压裂泵注参数，实现裂缝转向的目的；井筒内煤粉堵塞、泵效低造成的低产井，优先选用冲洗泵等循环洗井装置洗井提高泵效，实现正常产液来提高产气量；井筒附近煤粉堵塞引起产水量、产气量急剧下降的低产井,优先选用氮气等解堵技术实现增产。现场部分增产技术的应用验证了理论分析的可靠性。该研究成果为煤层气低产井区二次改造方案设计提供了借鉴。

One of the keys to reduce blind investment and improve gas production efficiency is to accurately determine the causes for low production of CBM vertical wells and proposetargeted technical measures to increase production.This article takes the Shizhuang south block as the research object，and analyzes the reasons of low-yield of CBM from four aspects:geological and coal reservoir conditions，drilling technology，fracturing technology and drainage work system.On this basis，the corresponding technical countermeasures for reasons of the different low gas production were putted forward by means of acid decontamination experiment，optimized simulation of fraction parameters，analysis on the process principle of solving powder blockage and increasing production principle of reducing pump depth.The results showed that:low-yield wells due to serious drilling pollution can be improved in gas production by using acid decontamination and conventional hydraulic fracturing.The coal body structure is mainly composed of primary structure fragmented coal，and low-production CBM wells caused by unreasonable fracturing parameters are preferred to be repeated fracturing technology； low-yield wells with mainly coal or militic coal in the structure of the coal body need to determine the feasibility of top/bottom fracturing according to the top/bottom lithology and surrounding rock recharge；If the pump is more than 5 m above the coal seam and the low-yield wells has a relatively high gas production before，the gas production can be increased by deepening the pump hanging； the low-productivity wells that are sensitive to production and recovery are optimized for the secondary fracturing pump injection parameters to achieve the purpose of fracture turning.If low-yield wells caused by coal blockage，low pump efficiency in wellbore are preferred to use circulation washing device such as flushing pump to improve pump efficiency and realize normal liquid production to improve gas production.Nitrogen solution technology is preferred for increasing production in low-yield wells where the amount of water and gas production decreases dramatically by coal seam blockage near wellbore.The application of part of the on-site production increasing technology verified the reliability of the theoretical analysis.The research results provide a reference for the design of the secondary reconstruction scheme of the low-production coalbed methane well area.