考虑强地下水渗流影响的地热开采综合评估  

Comprehensive assessment of geothermal exploitation considering impact of strong groundwater seepage

作　　者：金涛 杨乐 温凯 郭攀 杨金才 刘冠男[3] Jin Tao;Yang Le;Wen Kai;Guo Pan;Yang Jincai;Liu Guannan(CHN Energy Ningxia Heating Co.,Ltd.,Yinchuan 750004,China;Ningxia Lixing Architectural Research Institute Co.,Ltd.,Yinchuan 750021,China;State Key Laboratory for Geo Mechanics and Deep Underground Engineering,China University of Mining and Technology,Xuzhou 221116,China)

机构地区：[1]国能宁夏供热有限公司,宁夏银川750004 [2]宁夏力行建筑研究院有限公司,宁夏银川750021 [3]中国矿业大学深部岩土力学与地下工程国家重点实验室,江苏徐州221116

出　　处：《能源与环保》2025年第2期165-174,共10页CHINA ENERGY AND ENVIRONMENTAL PROTECTION

基　　金：国家自然科学基金重点项目(51934007);深地科学与工程教育部重点实验室开放基金课题(DUSE-202305);“构造与油气资源”教育部重点实验室开放研究基金(TPR-2022-07)。

摘　　要：在常规的U型管地热开采工程中,采热管跨越地下水渗流地层,其采热效率会受到不同程度的影响。宁夏平原青铜峡库区地热储层地下水充沛,因施工、采热、基建等因素导致地下水渗流现象普遍且复杂,地热储层孔隙率有着复杂的时空非线性演化特性。为此,提出了地应力、热传导效应及地下水压力耦合效应下的U型管地热开采模型,并采用有限元方法求解强地下水渗流特性下地热开采效率、地热储层温度及地下水压力的时空演化规律。结果表明,数值模型计算结果与实地地热开采数据吻合较好;不同地下水渗流方向对地热开采的影响显著,由下至上的地下水渗流方向对地热开采最有利;不同地热储层孔隙率对地热开采也有着较为明显的影响。对于地下水由地下向地表渗流的工况来说,更大的地热储层孔隙率有着较好的采热效率;而对于其他地下水渗流方向,更小的地热储层孔隙率更有益于地热开采。研究成果将为宁夏平原强地下水渗流背景下的地热开采提供重要的理论参考依据。In conventional U-shaped tube geothermal exploitation projects,if the heat-collecting pipes cross groundwater seepage strata,their heat collection efficiency will be affected to varying degrees.The groundwater in the geothermal reservoir of the Qingtongxia reservoir area in Ningxia Plain is abundant,and groundwater seepage phenomena are common and complex due to factors such as construction,heat-collecting,and infrastructure,in addition,the porosity of the geothermal reservoir has complex spatiotemporal nonlinear evolution characteristics,therefore,a U-shaped tube geothermal exploitation model under the coupling effects of ground stress,heat conduction effect,and groundwater pressure was proposed.The finite element method was used to solve the spatiotemporal evolution laws of geothermal extraction efficiency,geothermal reservoir temperature,and groundwater pressure under strong underground water seepage characteristics.The results show that the numerical model calculation results agree well with the actual geothermal exploitation data in the field.Different groundwater seepage directions have a significant impact on geothermal exploitation,and the direction of groundwater seepage from bottom to top is most favorable for geothermal exploitation.Different porosities of geothermal reservoirs also have a significant impact on geothermal exploitation.For the working condition where groundwater seeps from underground to the surface,a higher porosity of geothermal reservoirs has better heat-collecting efficiency,while for other groundwater seepage directions,a lower porosity of geothermal reservoirs is more beneficial for geothermal exploitation.It is expected that the results of this study will provide important theoretical reference for geothermal exploitation under the background of strong underground water seepage in Ningxia Plain.

关 键 词：地热储层 地下水渗流 孔隙率 多场耦合 数值模拟 

分 类 号：TK529[动力工程及工程热物理—热能工程] P314.2[天文地球—固体地球物理学]