摘要
煤炭地下气化过程中气化炉腔体的稳定性是保障气化炉安全稳定生产的重要条件。本文基于吐哈—三塘湖盆地沙尔湖凹陷煤层的地层物性、尺寸、热力学参数及岩石力学等参数,通过离散元方法建立地质—腔体模型,研究了不同形态腔体在不同压力情况下的蠕变稳定性,得到腔体塑性区分布规律,通过对腔体进行长期蠕变行为计算,得到了可能的地表沉降情况。结论表明,蠕变过程中塑性区趋向于分布于腔体内壁,整体来说以剪切破坏为主,在腔体壁面外1 m范围内并未出现大面积向外扩展的情况;在地下1000 m处形成特征半径5 m的腔体,由腔体蠕变本身对地表所带来的沉降比较有限,地表沉降的主要来源是地层自身性质。本研究对地下煤炭气化运行及废弃过程中的腔体稳定性评价具有指导意义。
The stability of the cavern in the process of underground coal gasification is an important issue for ensuring gasification production.Based on the formation physical properties,dimensions,thermodynamic parameters and rock mechanics parameters of the coal formation in the Shaerhu Sag of the Tuha-Santanghu Basin,the geological-cavity model is established by the discrete element method,and the different pressures of different cavities are studied.Under the conditions of creep,the distribution of the plastic zone of the cavity is obtained,and the subsidence of the ground surface is obtained by calculating the long-term creep behavior of the cavity.The conclusion shows that the plastic zone tends to be distributed on the inner wall of the cavity,and on the whole it is dominated by shear failure.There is no large-scale outward expansion within 1 m of the cavity wall.As for a cavity with a radius of 5 mat 1000 m underground,the subsidence to the surface caused by the cavity creep itself is relatively limited,and the main source of surface subsidence is the creep of the coal formation itself.This research provides guidance for the evaluation of the stability of the cavity during the operation and abandonment of underground coal gasification.
作者
董京楠
何爱国
刘奕衫
郭文彬
熊浩宇
乔磊
张应斌
DONG Jingnan;HE Aiguo;LIU Yishan;GUO Wenbin;XIONG Haoyu;QIAO Lei;ZHANG Yingbin(CNPC Engineering Technology R&D Company Limited,Beijing 102206,China;National Elite Institute of Engineering,CNPC,Beijing 100096,China;Engineering Research Center for the Safe Exploitation and Comprehensive Utilization of Mineral Resources at Universities of Inner Mongolia Autonomous Region,Hulunbeir 021008,China;HydroChina-ITASCA R&D Center,Hangzhou 311122,China)
出处
《石油科学通报》
CAS
2024年第4期690-698,共9页
Petroleum Science Bulletin
基金
中国石油集团有限公司课题(JT 2019E-25、2020D-5008-08、2021DJ5402)联合资助。
关键词
煤炭地下气化
腔体稳定性
地表沉降
underground coal gasification
cavern stability
surface subsidence
