摘要
地温测量是地热田勘查中的常用方法,热田地表以下不同深度的温度特征对地热田勘查靶区的圈定具有重要意义。采用米测温、百米测温孔和勘查孔等方法,获取了谷露热田不同深度的温度场特征。结果显示:地表以下一米的温度异常区在桑曲河以西呈团块状分布,在桑曲河以东呈近SN向的带状展布。地表以下一百米范围内的温度场在浅部呈椭圆形NE向延伸,且热田北部的温度高于南部;随着深度的增加,高温异常区逐渐过渡为SN向延伸,与热田中F4-2断裂的走向一致,表明F4-2断裂对热田具有重要的控制作用。根据不同深度温度场形态,认为热田中心位于地表热异常中心的北侧。地热流体从深部到浅部运移过程中,在南北方向上,有从北向南的运移趋势;在东西方向上,有从西向东的运移趋势。F4-2断裂与F4-3断裂夹持区域是热田未来的主要勘查区域,钻孔应围绕F4-2断裂与F4-3断裂控制的基岩裂隙型热储进行部署,且应侧重于热田的北侧。在方法的适用性上,米测温受限于勘查深度,仅能反映热田近地表的温度异常;百米测温不但可以反映热田不同深度温度场的变化,对热田范围、地热流体来源等也有较好的指示。
Geotemperature measurement is a common method in geothermal exploration.The characteristics of temperature changes at different depths of the geothermal field are significant to delineate the exploration targets.In this paper,the characteristics of temperature field at different depths were obtained by means of meter temperature measurement,temperature measurement hole and exploration hole.The temperature anomaly area about 1 m below the surface is distributed in a block to the west of the Sangqu River,and in a nearly north-south belt to the east of the Sangqu River.The temperature anomaly area about 100 m below the surface extends in the shallow part in an elliptical northeast direction,and the temperature in the north of the geothermal field is higher than that in the south;with the increase of depth,the temperature anomaly area gradually transits to the south-north extension,which is consistent with the trend of the heat conduction fault F4-2in the thermal field,indicating that fault F4-2plays an important role in controlling the thermal field.According to the characteristics of temperature field at different depths,it was considered that the center of the thermal field was located in the north of the surface thermal anomaly.In the process of geothermal fluid migration from deep to shallow,there was a migration trend from north to south in the north-south direction;in the east-west direction,there was a migration trend from west to east.The clamping area of fault F4-2and fault F4-3is the main exploration direction of the thermal field in the future.The drilling should be arranged around the bedrock fissure type thermal reservoir controlled by fault F4-2and fault F4-3,and focuses on the north side of the thermal field.The 1 meter temperature measurement can only reflect the temperature anomaly near the surface due to its shallow exploration depth.The 100 meter temperature measurement result can not only reflect the change of temperature field at different depths of the geothermal field,but also have a good indication of the source of geothermal fluid.
作者
张松
谢迎春
郝伟林
高洪雷
孙国强
胡先才
ZHANG Song;XIE Yingchun;HAO Weilin;GAO Honglei;SUN Guoqiang;HU Xiancai(CNNC Geothermal Exploration Technology Center,Beijing Research Institute of Uranium Geology,Beijing 100029,China;CNNC Kunhua Energy Development Co.,Ltd.,Hangzhou,Zhejiang 31ll13,China)
出处
《世界核地质科学》
CAS
2022年第4期733-745,共13页
World Nuclear Geoscience
关键词
西藏
谷露地热田
温度场特征
地热勘查
Tibet
Gulu geothermal field
temperature field characteristics
geothermal exploration
