The 1D TDEM forward modeling for induced polarization media
ZHOU Lei1, YAN Liang-Jun1, XIE Xing-Bing1, WANG Zhi-Gang2, SUI Jun-Jie3
1. Key Laboratory of Exploration Technologies for Oil and Gas Resources, Ministry of Education, Yangtze University, Wuhan 430100, China;
2. BGP, China National Petroleum Corporation, Zhuozhou 072751, China;
3. Sinopec Geophysical Research Institute, Nanjing 210000, China
To study the IP effect ("induced polarization effect") generated by IP media according to the rule of TEM response, the authors firstly solve the electromagnetic responses which have the same K-factor, introduce the Dias model describing IP effect in the frequency domain, and then use the sinusoidal transform to get TEM response with the IP information. As the chargeability increases, the amplitude of the electric filed is changed in the homogeneous half-space. With the increase of the relaxation time, the IP anomaly appears in the late time. And the IP anomaly appears in the early time when the polarization resistance coefficient is increased. Among different resistivity models with the same chargeability in the middle layer, it can be summarized that the H-type model can easily show the polarization layer, while the K-type is the worst model to manifest the induced polarization effect, with the performance of the A and Q-type lying between H and K type.
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