基于Dias模型的天然场激发极化法有效参数

Effective Parameters of Natural Field Induced Polarization Method Based on Dias Model

为了从天然场源较强的电磁效应中提取有效的激电异常参数,找到能与目标介质物性和电化学过程相关的物理量进行异常评价,通过提出相位峰值偏移距和相对视频散率参数作为一对充要条件用以评价激电异常,同时选用表征频率域激电精度较高且参数丰富的Dias模型进行一维层状模型正演计算,通过分析复电阻率的相位特征验证相位峰值偏移距的有效性和适用性。结果表明,该参数与介质极化率有较好的正相关规律,在一些断面类型目标层极化率较高时该参数表现出较好的异常特征,在特定的电条件下该参数具备实际应用价值。

In order to find parameters related to the physical properties of the target medium and the electrochemical process to extract effective induced polarization anomaly parameters from strong electromagnetic effects of natural field sources,the peak phase offset and the relative apparent frequency dispersivity was put forward as the evaluation parameters of IP anomalies.The Dias model was used for the characterization of the frequency domain,while the one-dimensional layered model was applied for the forward calculation.The analysis of the phase characteristics of complex resistivity demonstrated the effectiveness of the peak phase offset parameter.The results show that the peak phase offset has a good positive correlation with dielectric polarizability.When dielectric polarizability of the target layer of some types of cross-sections is high,the peak phase offset shows good abnormal characteristics,suggesting that these parameters have an application value under specific geoelectric conditions.