煤矿区煤层气开发利用新技术现状及发展趋势

Current situation and development trend of coalbed methane development and utilization technology in coal mine area

“十二五”以来,我国煤矿区煤层气开发利用技术取得了巨大的进步,虽然我国煤矿数量由近20000对直线下降到了不足5800对,但煤层气产量仍由2010年的88亿m 3提高到了2018年的184亿m 3,利用率亦提升了10%,科技对产业的贡献巨大;但是也出现了单井排采产量低、气源分散性高等新的问题。因此,全面梳理了近10 a煤矿区地面抽采技术装备、井下抽采技术装备和煤矿区高、低浓度煤层气利用技术装备的科技创新及应用效果等,阐述了煤矿区煤层气开发利用在三级瓦斯地质分析技术、碎软低渗煤层地面井分段压裂顶板技术、煤层群分层控压联合排采技术、采动区地面L型顶板水平井技术、井下千米定向长钻孔技术、碎软煤层井下护孔钻进技术、智能化钻机远控钻孔技术、井下水力化压裂/割缝增渗技术等煤层气抽采技术及其配套装备最新进展和中高浓度煤层气深冷液化、低浓度煤层气分级压缩提浓、超低浓度煤层气蓄热氧化利用等煤层气利用装备的最新进展及技术指标。在此基础上,针对我国目前面临的深部开采、西部煤炭资源开发及高强度集约化开采等新特点,分类整理了束缚煤层气产业发展的技术瓶颈和发展趋势,提出了煤炭开采与煤层气开发协同规划和联合开发的技术思路等。

Since the 12th Five Year Plan,the development and utilization technology of coalbed methane in China’s coal mining areas has made great progress.Although the number of coal mines in China from nearly 20000 to less than 5800,the production of coalbed methane has increased from 8.8 billion m 3 in 2010 to 18.4 billion m 3 in 2018,the utilization rate has also increased by 10 percentage,and the technology has made a great contribution to the coalbed methane industry.However,there are also new problems such as low single well production and high gas source dispersion.Therefore,this paper comprehensively reviews the scientific and technological innovation and application effect of surface extraction technology and equipment,underground extraction technology and equipment,and high and low concentration coalbed methane utilization technology and equipment in coal mine areas in recent 10 years.This paper expounds the development and utilization of coalbed methane in the coal mine areas,including three-level gas geological analysis technology,roof fracturing technology of ground wells in broken soft and low-permeability coal seams,layered and pressure controlled combined mining technology of coal seams,L-shaped Roof Horizontal Well Technology in mining area,kilometer long Directional Borehole technology under the well,underground hole protection drilling technology of broken soft coal seam,remote control drilling technology of intelligent drilling machine,technology of hydraulic fracturing/slotting and permeability increasing in well water and so on,and the latest progress and technical indicators of utilization equipment for coalbed methane,such as cryogenic liquefaction of medium and high concentration coalbed methane,classified compression and concentration of low concentration coalbed methane,thermal storage and oxidation utilization of ultra-low concentration coalbed methane,etc.On this basis,according to the characteristics of deep mining,western mining and high-intensity intensive mining,the paper classifies the technical bottlenecks and development trends that restrict the development of coalbed methane industry,and puts forward the development ideas of collaborative planning and joint development of coal mining and coalbed methane development.