摘要：

在“双碳”目标下，地热能因其清洁高效、储量丰富和低碳环保的特点，成为能源转型的重要方向。针对群井采灌条件下地热田的渗流—传热演化特性及布井优化问题，本文以雄安高铁片区地热田为研究对象，基于COMSOL Multiphysics 构建三维渗流—传热耦合数值模型，并结合现场生产井水温和水位监测数据进行参数校正。在此基础上，设计新增20口地热井(10采10灌)，通过模拟线性布井、交错布井和三角形布井3种布井方案下的生产井水位、温度及动态可采地热资源量的变化，系统对比分析了不同方案对储层稳定性及换热效率的影响。结果表明：线性布井方案结构简单、便于实施，但热能动员范围有限，整体可采资源量最低，且边界生产井易形成局部水位降落漏斗；交错布井方案采灌分布更均匀，能够有效抑制局部超采，延缓冷水突破并维持较高的储层热稳定性，动态可采地热能演化最平稳；三角形布井方案在运行初期热能动员能力最强、可采资源量最高，但在高密度生产井区域冷水渗透风险增加，运行后期存在局部热衰减趋势。50年尺度上，交错布井与三角形布井的可采地热资源总量均较线性布井提高1%以上，其中交错布井在资源利用效率与系统稳定性之间取得最佳平衡，建议作为研究区地热田高效、可持续开发的优选布井模式。研究结果可为中深层水热型地热田群井采灌条件下的布井方案优化、开发效果评价及可持续运行提供理论参考。

关键词: 群井采灌, 渗流传热, 布井优化, 动态可采地热能, 数值模拟

Abstract:

Under the “dual-carbon” target, geothermal energy has become an important direction for energy transition due to its characteristics of being clean and efficient, having abundant reserves, and being low-carbon and environmentally friendly. Aiming at the seepage-heat transfer evolution characteristics and well-pattern optimization of geothermal fields under multi-well production and reinjection conditions, this study takes the geothermal field in the Xiong’an high-speed railway area as the research object. A three-dimensional coupled seepage-heat transfer numerical model was constructed based on COMSOL Multiphysics, and parameter calibration was carried out by combining field monitoring data of production-well water temperature and groundwater level to ensure consistency between numerical results and actual operation conditions. On this basis, twenty additional geothermal wells were designed, including ten production wells and ten reinjection wells. By simulating three well-pattern schemes—linear, staggered, and triangular—the variations in production-well water level, temperature, and dynamic recoverable geothermal resources under different schemes were analyzed, and the influences of different schemes on reservoir stability and heat-exchange efficiency were systematically compared. The results show that the linear well pattern has a simple structure and is easy to implement; however, its thermal mobilization range is limited, the overall recoverable geothermal resources are the lowest, and boundary production wells are prone to forming localized groundwater drawdown cones. The staggered well pattern exhibits a more uniform distribution of production and reinjection, which can effectively suppress localized overexploitation, delay cold-water breakthrough, and maintain relatively high reservoir thermal stability, resulting in the most stable evolution of dynamic recoverable geothermal energy. The triangular well pattern shows the strongest thermal mobilization capacity and the highest recoverable geothermal resources during the early stage of operation, but the risk of cold-water intrusion increases in areas with high production-well density, leading to a tendency of localized thermal attenuation in the later stage of operation. On a 50-year timescale, the total recoverable geothermal resources of both the staggered and triangular well patterns are more than 1% higher than those of the linear well pattern. Among them, the staggered well pattern achieves the best balance between resource utilization efficiency and system stability and is recommended as the preferred well-pattern scheme for the efficient and sustainable development of the geothermal field in the study area. The research results can provide theoretical references for well-pattern optimization, development performance evaluation, and sustainable operation of multi-well production and reinjection systems in mid- to deep-depth hydrothermal geothermal fields under similar geological settings and operating conditions.

Key words: multi-well production and reinjection, seepage and heat transfer, well pattern optimization, dynamic recoverable geothermal energy, numerical simulation

中图分类号: 

• P314

• TE3