延川南区块深部煤层气井排采速率适配性研究  

Study on drainage rate adaptation of deep CBM wells in South Yanchuan Block

作　　者：刘加东 LIU Jiadong(Oil and Gas Engineering Service Center of Sinopec East China Oil and Gas Branch Company, Taizhou 225300, Chin)

机构地区：[1]中石化华东油气分公司采油气工程服务中心,江苏泰州225300

出　　处：《煤炭科学技术》2018年第5期192-196,共5页Coal Science and Technology

摘　　要：为研究排采管理对深部煤层气井产能影响,根据生产动态特点,将排采阶段划分成排水降压、控套压、降压提产、稳定产气4个阶段,通过归一化数据分析得出了排水降压和降压提产2个阶段压降速率对产能的影响规律。研究结果表明:排水降压阶段以疏通地层,扩大煤层降压面积为目的,日降液面过快或过慢均不利于后期高产,日降液面应控制在1.0~1.5 m,既可以将煤粉携带至井筒,又可避免煤层渗透性因应力敏感而急剧下降;降压提产阶段产气量不断增加,产液量逐渐降低,日降液面越少越有利于后期稳产,日降液面应控制在1.0 m以内,后期稳定产量在1 000~1 200 m^3/d。In order to study the drainage management effect on the productivity of deep coal bed methane well,according to its dynamic characteristics,the production process could be divided into four stages,namedly water drainage,controlling casing pressure,reducing pressure for production increase and stable gas production. The author then came to the conclusion on the influence of pressure drop rate of water drainage and reducing pressure for production increase stage on the productivity through normalized data analyse. The research results indicated that the purpose of water drainage stage was to dredge the formation,and to expand the coal seam area of pressure reduction. It was neither conducive for the gas production if the daily level dropped too fast or too slow,and the speed should remain at 1.0 ~ 1.5 m,which could not only carry coal to the wellbore,but also could avoid coal seam permeability sharply decline as a result of sensitive stress response. In the gas production stage,the gas production rate increased and the liquid production rate decreased gradually. The lower the daily level dropped,the more conducive for the stable production in the coming days. The daily drop level should be controlled within 1.0 m,and the stable production in the later stage was from 1 000 to 1 200 m^3/d.

关 键 词：煤层气 排采管理 排水降压 降压提产 

分 类 号：P618.11[天文地球—矿床学]