废弃煤矿采空区CO2封存控制压力计算方法研究

崔晓松; 郭世豪; 胡李华; 原文涛; 程丽媛; 王姣霞; 杨美萍; 耿杰; 吴云

doi:10.13928/j.cnki.wrahe.2025.07.020

水利水电技术（中英文） ›› 2025, Vol. 56 ›› Issue (7) : 262 -273. DOI: 10.13928/j.cnki.wrahe.2025.07.020

新能源

废弃煤矿采空区CO₂封存控制压力计算方法研究

崔晓松 ¹^,²^,³^,⁴ ,
郭世豪 ²^,³ ,
胡李华 ²^,³ ,
原文涛 ¹^,⁴ ,
程丽媛 ¹^,⁴ ,
王姣霞 ¹^,⁴ ,
杨美萍 ¹^,⁴ ,
耿杰 ¹^,⁴ ,
吴云 ²^,³

作者信息 +

Research on calculation methods for CO2 storage control pressure in goafs of abandoned coal mines

Xiaosong CUI ¹^,²^,³^,⁴ ,
Shihao GUO ²^,³ ,
Lihua HU ²^,³ ,
Wentao YUAN ¹^,⁴ ,
Liyuan CHENG ¹^,⁴ ,
Jiaoxia WANG ¹^,⁴ ,
Meiping YANG ¹^,⁴ ,
Jie GENG ¹^,⁴ ,
Yun WU ²^,³

Author information +

文章历史 +

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摘要

【目的】将CO₂封存于采空区是解决我国废弃煤矿地下空间资源再利用问题并实现“双碳”目标的可行技术途径，具有广阔发展前景，但目前仍面临诸多挑战。为提高采空区封存CO₂的安全性和效益，需建立CO₂封存全过程的控制压力指标及其计算方法。【方法】以山西常村煤矿采空区CO₂封存控制压力优化为案例，研究首先分析了不同温度和压力条件下CO₂的物理性态，依据山西地区气候温度和废弃煤矿埋深条件，确定CO₂注入工艺，并分析其在采空区中的封存性态；其次，基于CO₂在盖层中的封存原理和防止地下水入渗的原则，提出CO₂采空区封存的上下限压力概念，给出计算方法并分析主要影响因素；最后，结合常村煤矿采空区的具体地质条件，得出该采空区CO₂封存控制压力的大致范围。【结果】山西地区年平均气温15℃,废弃煤矿埋深多为100~300 m,在此温压条件下，CO₂在采空区中将呈现液-气二相封存特征；常村煤矿可利用采空区空间容量达150.92万m³,CO₂封存最大压力建议为8~10 MPa,最小压力建议为4~6 MPa,这表明该地区具有较大的封存潜力。山西地区废弃煤矿采空区容量大、温压条件适中，地下水头压力较低，具备大规模封存CO₂的潜力。【结论】封存下限压力较小，控制压力上限主要取决于盖层突破压力和破裂压力。以盖层封闭能力为基础，若对采空区进行密封处理以利用密闭空间封存CO₂,则需综合考虑密封成本和实施方法，并重新建立力学模型。通过对山西地区采空区CO₂封存控制压力的计算方法的研究，可为废弃煤矿大规模CO₂封存技术发展提供有益参考。

Abstract

[Objective] Storing CO₂ in goafs is a feasible technical approach for addressing the issue of reusing underground spaces in abandoned coal mines in China and achieving the “dual carbon” goals, with promising application prospects. However, it currently faces numerous challenges. To enhance the safety and efficiency of CO₂ storage in goafs, it is necessary to establish control pressure indicators and their calculation method for the entire CO₂ storage process. [Methods] Taking the optimization of CO₂ storage control pressure in the goaf of Changcun Coal Mine in Shanxi Province as a case study, the physical properties of CO₂ were first analyzed under different temperature and pressure conditions. Based on the climatic temperatures in Shanxi and the burial depth conditions of abandoned coal mines, the CO₂ injection process was determined, and its storage characteristics in the goaf were analyzed. Subsequently, based on the storage principles of CO₂ in the caprock and the requirement for preventing groundwater infiltration, the concepts of upper and lower pressure limits for CO₂ storage in goafs were proposed, along with corresponding calculation method and analyses of major influencing factors. Finally, integrating the specific geological conditions of the goaf in Changcun Coal Mine, the approximate range of CO₂ storage control pressure in this goaf was derived. [Results] The annual average temperature in Shanxi was 15 ℃, and the burial depths of abandoned coal mines generally ranged from 100 to 300 m. Under these temperature and pressure conditions, CO₂ exhibited liquid-gas two-phase storage characteristics in the goaf. The available goaf space capacity in Changcun Coal Mine was 1.509 2 million m³, with maximum control pressure for CO₂ storage recommended to be 8~10 MPa and the minimum control pressure recommended to be 4~6 MPa, indicating significant storage potential in the region. The goafs of abandoned coal mines in Shanxi had large capacities, moderate temperature and pressure conditions, and low hydraulic head of groundwater, indicating their potential for large-scale CO₂ storage. [Conclusion] The lower limit of storage pressure is relatively small, while the upper limit of control pressure primarily depends on the breakthrough pressure and fracture pressure of the caprock. Based on the sealing capacity of the caprock, if sealing the goaf is required to utilize the enclosed space for CO₂ storage, it is necessary to comprehensively consider sealing costs, implementation method, and the re-establishment of mechanical models. The investigation of calculation method for CO₂ storage control pressure in goafs in Shanxi provides valuable references for the application and development of large-scale CO₂ storage technology in abandoned coal mines.