摘要
煤矿区地面瓦斯废弃井改造再利用,可进行采动区瓦斯抽采,具有保障回采工作安全生产,瓦斯资源有效利用,减少瓦斯逸散对环境压力等经济环保多重效益。针对这一目的,结合采动区地面井和废弃井的特点,提出废弃井“一井多用”瓦斯抽采技术思路。通过分析试验工作面开采工艺、覆岩结构及废弃井的基本情况等条件,研究并提出了废弃井优选及判识、地面井改造工艺、防护装置安设、抽采系统布置及抽采控制技术等,改进了废弃井改造射孔造缝段长度确定方法。研发了基于油套环空动态调节、组合套管双重防护及筛管分级优化的安全防护方法,形成了废弃井“一井多用”地面井瓦斯抽采技术。选取晋城矿区岳城煤矿作为试验对象,完成了3口废弃井(井号为YC-50、YC-52、YC-54)再利用改造试验,其地面井瓦斯抽采量累计分别为257.88万、172.50万、129.60万m^(3)。YC-50井改造运行后,地面井抽采范围内工作面上隅角瓦斯体积分数最大值从0.77%降至0.40%,降幅48.05%;YC-52井改造运行后,采煤工作面上隅角瓦斯体积分数降幅为52.38%,有效保障了回采工作面安全生产,实现了废弃井“一井多用”目标,取得了良好的经济与社会效益。研究成果为其他区域废弃井改造利用提供了借鉴,建议今后从地面预抽井设计阶段便考虑“一井多用”方案,开展相关技术研发,以提升设计井质量和接续再利用问题,以降本增效。
Gas drainage from mining area could be realized through the reconstruction and reuse of abandoned surface gas wells in the coal mine area,which has multiple economic and environmental benefits such as ensuring the safe production of mining,the effective utilization of gas resources,and reducing the pressure of gas escape on the environment.In view of this purpose,the idea of“one surface borehole with multi-usage”gas drainage technology for abandoned wells was proposed based on the characteristics of the surface borehole and the abandoned wells in the mining area.By analyzing the conditions of the mining technology,overburden structure and abandoned wells in the test working face,the optimization and identification of abandoned wells,the surface borehole reconstruction technology,the installation of protective devices,the layout of gas drainage system and the gas drainage control technology were studied and put forward,with innovation in the determination method of the length of perforation and fracturing interval for the reconstruction of abandoned wells.Besides,a safety protection method based on the dynamic adjustment of oil casing annulus,double protection of combined casing and grading optimization of screen pipe was invented,thereby forming the"one borehole multi-usage"surface borehole gas drainage technology for abandoned wells.Specifically,the test on reconstruction and reuse of three abandoned wells(YC-50,YC-52 and YC-54)was completed in Yuecheng Coal Mine of Jincheng Mining Area.The cumulative gas drainage volume of surface wells was 2.5788 million m^(3),1.7250 million m^(3),and 1.2960 million m^(3) respectively.After Well YC-50 was put into production upon reconstruction,the maximum gas volume fraction at the upper corner of the working face within the gas drainage range of the surface well decreased from 0.77%to 0.4%,with a decrease of 48.05%.Besides,the gas volume fraction at the upper corner of the coal working face decreased by 52.38%after Well YC-52 was put into production upon reconstruction.Thus,the safe production of the mining face was ensured effectively,and the goal on“one surface borehole with multi-uasge”of abandoned wells was realized,with good economic and social benefits.The research results provide a reference for the reconstruction and utilization of abandoned wells in other regions.It is suggested that the“one surface borehole with multi-usage”scheme should be considered in the design stage of borehole gas drainage borehole predding wells in the future.Moreover,relevant technology research and development should be carried out to improve the quality of design wells and the problem of continuous reuse,so as to reduce the costs and enhance the efficiency.
作者
付军辉
FU Junhui(CCTEG Chongqing Research Institute,Chongqing 400037,China;State Key Laboratory of Gas Detecting,Preventing and Emergency Controlling,Chongqing 400037,China)
出处
《煤田地质与勘探》
CAS
CSCD
北大核心
2023年第3期1-9,共9页
Coal Geology & Exploration
基金
重庆英才计划项目(cstc2022ycjh-bgzxm0021)
山西省科技重大专项项目(20201102001)
山西省揭榜招标项目(20201101001)。
关键词
废弃井改造
一井多用
变形破坏
瓦斯抽采
采动区
renovation of abandoned wells
one surface borehole with multi-usage
deformation failure
gas drainage
mining area