摘要
为开发广西合山煤田地下热水资源,以水文地球化学方法为主,通过石英温标法估算地热储层温度,并推测地下热水循环深度,研究地下热水赋存规律。结果显示,合山煤田地下热水补给、径流和排泄受岩溶构造控制,以顺地层为主,穿层次之;接受大气降水入渗补给,水质为HCO_(3)-Ca·Mg型;采用无蒸汽损失的石英温标法,估算热储层温度约80℃,识别出浅层地下水、浅层地下水与深部地下循环混合水和深部地下循环水3种类型;以井田内No.6钻孔数据为例,800 m孔深以下为深层地下循环水,其热储层温度为63.44~79.41℃,循环深度在2541~2704 m,与实际地层埋深相差较小,估算结果可信度较高;在1400 m以浅,有望探寻到水温约50℃热水;合山煤田地下热水的偏硅酸、温度均达到医疗要求;三、四煤层热导率低,孔隙率小,为热储层良好盖层;四煤层底板合山组下段和茅口组溶隙发育,为良好热水储层。研究成果对煤田地热资源的开发利用前景预测有一定的探索意义。
In order to develop geothermal water resources in Heshan Coalfield,Guangxi Provence,the temperature of geothermal reservoir was estimated by quartz temperature scale method based on hydrogeochemistry,and the circulation depth of geothermal water was speculated to study the occurrence law of geothermal water.The results show that the recharge,runoff and discharge of underground hot water in Heshan Coalfield are controlled by karst structure,which is mainly along and across the stratum.It receives infiltration recharge from atmospheric precipitation and the water quality is HCO_(3)-Ca·Mg type.By quartz geothermometers without steam loss,the thermal reservoir temperature is estimated to be about 80℃ and three types of water,namely,shallow groundwater,mixed water of shallow groundwater and deep groundwater circulating water and deep groundwater circulating water.Taking No.6 borehole data in the mine field as an example,the temperature of the thermal reservoir is 63.44℃ to 79.41℃,and the circulation depth is 2541-2704 m.The difference between the thermal reservoir temperature and the actual buried depth is small and the estimation result is highly reliable.The difference from the actual burial depth is small,indicating the high reliability of the estimation results.At the depth of 1400 m and around,it is expected to explore geothermal water about 50℃.The metasilicic acid and temperature of underground hot water in Heshan coal field meet the medical requirements.No.3 and No.4 coal seams have low thermal conductivity and small porosity,which are good caprock for thermal reservoir.The lower member of Heshan Formation and Maokou Formation in the floor of No.4 coal seam are developed with solution fissures,which are good hot water reservoirs.The research results have certain exploration significance for the development and utilization prospect prediction of geothermal resources in coalfields.
作者
赵冠华
ZHAO Guanhua(Guangxi Administration of Coal Geology,China National Administration of Coal Geology,Nanning 530299,China;No.150 Exploration Team of Guangxi Coal Geology,Nanning 530299,China)
出处
《煤田地质与勘探》
CSCD
北大核心
2021年第4期250-259,共10页
Coal Geology & Exploration
基金
中国煤炭地质总局广西煤炭地质局2019年重点科研项目(201902)。
关键词
合山煤田
水文地球化学
地下热水
温泉水质
温度预测
Heshan Coalfield
hydrogeochemical method
geothermal water
hot spring water quality
temperature prediction
