沂源县南麻-悦庄盆地地热资源成因及开发利用前景分析

Analysis on the Origin of Formation and Exploitation of Geothermal Resources in Nanma-Yuezhuang Basin in Yiyuan County

地热资源作为一种绿色、可持续利用的矿产资源备受关注。沂源县位于鲁中低山丘陵区,基岩大面积出露,大部分地区缺少地热形成的保温盖层,南麻-悦庄盆地为中、新生代沉降盆地,是沂源县地热形成最为有利的区域。在分析南麻-悦庄盆地地热地质钻探、岩屑编录、产能测试、水质化验,以及浅层地温孔测温等成果及数据资料的基础上,对盆地构造及地层发育特征、水文地质、地热地质、地温场特征等进行深入综合研究;发现寒武-奥陶纪碳酸盐岩裂隙岩溶热储是盆地内主要热储层,推测在盆地东北部热储层温度最高可达60℃,盖层为其上的石炭纪、侏罗纪、白垩纪、古近纪和第四纪地层,盆地沉降中心发育厚度超过900m,保温效果好,地热水来自盆地南部大气降水入渗后径流补给,热源以深部热流为主,断裂构造沟通深部热流也是盆地内热储层的增温热源之一,地热水中偏硅酸、碘化物含量达到医疗热矿水浓度。构造附近或交会处浅层地温明显升高的区域为进一步地热勘查的靶区,开发利用建议以地热为主题打造康养、旅游特色文化村(镇)。

Geothermal resources have received much attention as a green and sustainable mineral resources.Yiyuan county is located in the hilly area in the middle of Shandong province.Large areas of bedrock are exposed.Most of the areas are lack of thermal insulation cover for geothermal formation.NanmaYuezhuang basin is a Mesozoic and Cenozoic subsidence basin,which is favorable for the formation of geothermal resources in Yiyuan county.Based on the analysis of geothermal drilling,cuttings recording,productivity testing,water quality testing,and shallow geothermal hole temperature measurement in NanmaYuechuang basin and other results and data,basin structures and stratigraphic development characteristics,hydrogeology,geothermal geology,geothermal field characteristics have been studied comprehensively.It is found that the carbonate fissure karst reservoir in CambrianOrdovician is main thermal reservoir in the basin.It is speculated that the temperature of the thermal reservoir in the northeast of the basin can reach up to 60℃.The cap rocks are Carboniferous,Jurassic,Cretaceous,Paleogene and Quaternary strata.The subsidence center of the basin is developed with a thickness of more than 900m,and It has good thermal insulation effect.The geothermal water is supplied by runoff after the precipitation infiltration in the south of the basin,the heat source is mainly deep heat flow,the fault structure connects the deep heat flow and is also one of the heat sources for the thermal reservoir in the basin.The contents of metasilicic acid and iodide in geothermal water reach the concentration of medical hot mineral water.It is pointed out that the vicinity of the structure or the intersection is shallow.The area where the ground temperature of the layer significantly increased is the target area for further geothermal exploration.It is suggested to build a characteristic cultural village(town)with geothermal as the theme and tourism as the main body.It will provide a good reference for the exploration and development of geothermal resources in similar basins and regions.