二氧化碳驱替煤层气技术发展现状分析

Research status analysis of CO_(2)-enhanced coalbed methane technology

在“双碳”背景下,CO_(2)驱煤层气(CO_(2)-ECBM)工业化应用是促进煤炭清洁高效利用和CO_(2)利用的重要途径之一,CO_(2)驱煤层气技术既可实现CO_(2)的地下封存利用又能提高煤层气采收率。与发达国家相比,我国的CO_(2)驱煤层气技术研发工作发展较慢,因而需从机制机理、现场实验方面阐述CO_(2)驱煤层气技术研究进展。首先从实验室模拟试验介绍煤吸附CO_(2)之后的体积膨胀、渗透率和力学性质的影响研究,然后从世界各地的现场试验介绍CO_(2)驱煤层气技术的发展历程和研究进展。低渗透煤层的注入性是制约该技术可行性的关键因素,因而低渗透煤层增渗技术的突破是中国驱替煤层气技术推广应用的前提。由于现有监测技术还不能完全满足驱替过程优化调控及安全性监测的需要,在CO_(2)驱煤层气技术的发展实施过程中需考虑气源、工艺、腐蚀、安全及投资等问题。针对驱替煤层气技术在工业应用中存在成本较高、市场激励机制不足等问题,需从国家和地方层面进一步完善煤层气开发利用政策,推进驱替煤层气技术健康发展。

In the context of“dual carbon”goals,the industrial application of CO_(2)-enhanced coalbed methane(CO_(2)-ECBM)is one of the important ways to promote the clean and efficient utilization of coal and the utilization of CO_(2).The CO_(2)-ECBM technology can achieve both underground CO_(2)storage and increased coalbed methane recovery rates.Compared with developed countries,the research and development of CO_(2)-ECBM technology in China has been relatively slow.Therefore,it is necessary to elaborate on the research progress of CO_(2)-ECBM technology from the perspectives of mechanism and site experiments.First,laboratory simulation experiments will be introduced to study the effects of CO_(2)adsorption by coal on volume expansion,permeability and mechanical properties.Then,the development history and research progress of CO_(2)-ECBM technology will be discussed based on field experiments from around the world.The injectivity of low-permeability coal seams is a key factor limiting the feasibility of this technology,making breakthroughs in enhancing injectivity in low-permeability coal seams a prerequisite for the promotion and application of coalbed methane displacement technology in China.Since existing monitoring technologies cannot fully meet the needs for optimizing control of the displacement process and safety monitoring,issues such as gas sources,processes,corrosion,safety,and investment must be considered during the development and implementation of CO_(2)-ECBM technology.To address the high costs and insufficient market incentive mechanisms associated with the industrial application of coalbed methane displacement technology,it is essential to further improve policies for the development and utilization of coalbed methane at both national and local levels,thereby promoting the healthy development of CO_(2)-ECBM technology.