粤港澳大湾区地热资源潜力评估

Assessment of Geothermal Resource Potential in the Guangdong-Hong Kong-Macao Greater Bay Area

粤港澳大湾区是中国参与全球竞争的重要空间载体,为平衡其区域经济发展对能源的需求与生态环境保护问题,大力开发地热资源是一种重要的途径。作者从大地构造、地层岩性和地温场特征分析入手,论证了大湾区赋存地热资源的可能性,综合考虑深部地温、岩石热物理性质和大地热流值等要素,通过建立网格单元对水热型和干热岩型地热资源量进行定量评价,并识别圈定地热资源高值区。初步研究结果表明:1)大湾区深、大断裂交汇发育,花岗岩广布,形成了有利于地热赋存和输送的地质环境,大地热流值也印证了该区域存在地热异常和良好热源。2)通过地温估算发现,当地层深度在1.3 km以下时,地温能达到70℃以上;当地层深度在5 km时,地温在168.81～233.61℃,干热岩具有较高的开采价值。3)大湾区5 km深度范围内,地热资源总量为5.83×1017 kJ,采收率取30%,预计可获取的地热能折合标准煤5.94×10~9 t,同时减少排放4.04×10~9 t的CO_2。4)地热资源赋存相对高值区主要沿东北向深大断裂带分布,集中在佛山、中山、江门、深圳和香港局部地区,单位面积上的资源赋存量为5.19×10~5 t/km2标准煤,建议为地热勘察与开采的重点区域。

As an important space carrier to participate in global competition,the Guangdong-Hong Kong-Macao Greater Bay area is facing the pressure from the energy demand and environment protection.Developing geothermal resources is an effective way to solve the problem.In this paper,the possibility of geothermal development in Greater Bay area was reasoned,based on the analysis of regional geotectonic,stratigraphic lithology and geothermal field.Considering deep ground temperature,rock thermal physical parameters and terrestrial heat flow,geothermal water resource and hot dry rock resource were quantitatively assessed through raster units.Further,high potential geothermal zones were distinguished.Results show that:1)the intersected fault structures and widely distributed granite in the Greater Bay area provide a favorable geological environment for the storage and formation of geothermal resource,which is verified by the measured terrestrial heat flow;2)the computing results indicates that temperature would be over 70℃at depth of over 1.3 km and 168.81~233.61℃at depth of 5 km,showing a high potential of geothermal resource;3)The estimate geothermal resources in the Greater Bay area amount to 5.83×10^17 kJ within the depth of 5 km.It is equivalent to the thermal value of standard coal of 5.94×10^9 t and can reduce the emission of CO2 by 4.04×10^9 t,when recovery rate is set at 30%.4)The area of high potential geothermal resources is mainly distributed along the northeast deep fault,i.e.in Foshan,Zhongshan,Jiangmen,Shenzhen and Hong Kong,where the unit geothermal resource potential is equivalent to standard coal of 5.19×10^5 t per square kilometer,and should be taken as key area for geothermal prospecting and exploitation.