天津地热对井回灌系统中的同位素示踪技术

为深入分析地热回灌开采中回灌水运移规律、求证热储参数，笔者选取二组中元古界雾迷山组地热对井，分别注入放射性同位素^35S（T1/2=87天）、^125I（T1/2=60天）进行示踪试验，并分别于第130天、51天检出峰值，以此数据计算出的热储层的渗透系数、导水系数等有关参数，与传统的抽水试验算出的结果吻合良好；注入示踪剂在地层中的运移方向也与抽水试验观测到的结果完全一致，且直观形象、检出精度更高。同位素示踪技术能为进一步深入研究热储层在回灌前后压力场、温度场、水化学场的变化特征提供大量基本数据，也为天津乃至华北地区地热资源实施循环开发提技术保障。

Isotopic Trace Technique in Geothermal Pair Recharging Well System in Tianjin

In order to obtain the recharged water moving law in the geothermal pair recharge-exploitation well system and the geothermal storage parameters,the authors selected two sets of the wells in the Middle-Proterozoic Wumishan formation to inject radiometric isotopic elements ~(35)S(T_(1/2)=87 days) and ~(125)I(T_(1/2)=60 days) to do the trace experiment.And the peak values are inspected after 130 days and 51 days separately.The infiltration parameters calculated based on the data in the geothermal aquifer,as well as the thermal conductivity.The parameters are well coincided with the result traditional pumping test calculations.The migration orientation of injected trace elements in the aquifer is also identified with the observed result of pumping test,and it is more direct,imaginal and precise.Thus the isotope trace technique for further profound investigation may provide with great amount of information such as geothermal aquifers of pressure field,temperature field and hydro-chemical field of geothermal aquifers and its change characters before and after the recharge.And the isotopic trace dement measurement may provide with technique service for geothermal circulate development and exploitation both for Tianjin and for North China.