深井电场测量不极化电极特性研究

A study of the characteristics of non-polarized electrode in deep well electric field measurement

深井自然电场观测是监测地球深部地质活动的有效手段,对预防地震灾害、深部资源探测有着重要意义。地电场信号一般为mV级甚至μV级的微弱电信号,作为电场传感器的不极化电极,其性能会对测量结果产生重要影响。现有不极化电极主要依靠电化学原理进行工作,按照电化学相关理论,深井中的高温、酸性腐蚀等因素会对不极化电极性能产生严重影响。为检验深井高温及酸性环境对不极化电极的影响情况和电化学原理的不极化电极是否适用于深井测量,进行了相关实验,选取3种电极——Cu-CuSO4固体不极化电极、铅电极、石墨电极,在模拟深井环境下进行了实验测试。结果表明:常规不极化电极并不适合于深井环境下的电场测量,而石墨电极表现稳定,石墨材料适合作为深井电极制作材料。

Deep well natural electric field observation is an effective means to monitor the geological activities in the deep earth,and is of great significance to the prevention of earthquake disasters and the exploration of deep resources.In general,the ground electric field signal is a weak electrical signal of the mV level or even the light V level.As a non-polarized electrode of the electric field sensor,its performance will have an important impact on the measurement results.The existing non-polarized electrode works mainly on the principle of electrochemistry,but in the deep well,the high temperature,the acid corrosion and other harsh conditions exist.According to electrochemical theory,factors such as high temperature and acid corrosion will severely impact the performance of non-polarizable electrode.In order to make high temperature and acidic environment inspection of wells of non-polarizable electrode and the suitability of the principle of electrochemical non-polarizable electrode to deep well measurement and the related experiment,the authors selected three kinds of electrodes and tested them under simulated conditions of deep well testing.The results show that the principle of electrochemical non-polarizable electrode electric field measurement is not suitable for deep well environment,graphite electrode performance is stable,and graphite substances are suitable electrode materials for deep wells.