干热岩闭环地热系统井壁稳定及热能提取方法

打开文本图片集

中图分类号：P314 文献标志码：A

Abstract：To address the technical challenges associated with enhanced geothermal systems， including hydraulic fracturing stimulation， induced seismicity， and uncertainties in reservoir permeability，this study explores an alternative development pathway with improved environmental compatibility and operational stability， namely the closed-loop geothermal system （CLGS）. Through a comparative analysis，the technical advantages of CLGS are systematically clarified. First，the research progress on the mechanical stability and eficient heat extraction modes of CLGS under long-term operation is comprehensively reviewed.Particular emphasis is placed on analyzing the effects of diferent injection-production parameters on heat extraction performance，and the thermal energy extraction efficiency of various heat production modes is comparatively evaluated. Furthermore， the stability mechanisms of the wellbore under coupled thermo-fluid-solid processes are investigated.The results indicate that， for CLGS，a spiral welbore configuration can significantly enhance long-term heat exchange capacity，with the average heat exchange per unit wellbore length increased by 23.73% over a 50 a operation period. Intermittent heat extraction markedly improves heat transfer eficiency，resulting in an average thermal output increase of and a cumulative heat production enhancement of 34.6% . In addition，the injection rate is demonstrated to play a critical regulatory role in the evolution of the heat extraction cycle and the stress disturbance process of the wellbore.

Key words： hot dry rock；welbore stability； thermal energy extraction methods； enhanced geothermal system;closed-loop geothermal system

0 引言

我国高度重视地热能的开发利用。（剩余21431字）