煤层气集输系统颗粒杂质分布及应对措施

受煤层气田地质情况和抽采方式等影响,煤层气在从井口到外输的气田集输过程中常夹带有粉尘和水分等杂质,影响地面集输系统安全运行。为了解集输管道内杂质现状,利用管道内颗粒物在线检测方法,检测了井口、阀组和集气站等多处集输节点的粉尘质量浓度和粒径分布、游离水和水蒸气含量等数据,发现了液体杂质的含量较大,并分析得到杂质在集输管道内的沉积现象。从不同区块的井口、压缩机后等位置捕集杂质并进行成分分析,得到了固体杂质的成分和液体杂质的物性,发现压缩机前后杂质成分差异较大。针对地面集输系统的分离设备存在的问题,提出了现场在用过滤元件的改进措施,通过实验室测试和现场试验证明了改进后的过滤元件具有低阻高效的特点,适用于低压低成本特点的煤层气田地面集输系统。

Distribution characteristics and solutions on particulate matter in coalbed methane gathering system

Particulate matter such as dust and free water is often entrained into coalbed methane (CBM)，which affects the safety of the operation in gathering system.The on-line detection method for particulate matter was used to find out the distribution characteristic of the impurity in gas gathering system.Dust concentration and particle size distribution，free water and water vapor concentration can be obtained at the gathering nodes，including wellhead，manifold，gas gathering station and central treatment plant.It was found that the content of liquid impurities was large，and the impurities deposition phenomenon was obtained.The impurities were also captured for chemical composition analysis，which could affect the composition of solid impurities and the property of liquid impurities.Particulate matters were obvious different before and after the compressor.To deal with the problems of separation equipment，the improvement measure of existing filter element was proposed.The test in the laboratory and field proved that the improved element had lower resistance and higher efficiency.The improved filter element could effectively reduce the operation cost and is suitable for the CBM system with a low pressure characteristic.