全直径碳酸盐岩样品时域激发极化响应特征OA

To investigate the time-domain induced polarization characteristics of carbonate rocks,the induced polarization and nuclear magnetic resonance experiments of 10 full-diameter cores of the Dengying Formation carbonate rocks were conducted,which contain no conductive minerals,under saturated water conditions and after centrifugation.The 2V constant voltage excitation was used in the experi-ments,and the attenuation of polarization voltage within 80 seconds was recorded after power failure.The time-domain responses of multi-stage Debye models were derived based on equivalent circuits,and the fourth-order Debye model can accurately characterize the polarization voltage attenuation characteristics of the samples.Combined with nuclear magnetic resonance T2 spectrum analysis,it was found that the total polarizability and secondary voltage of the sample both reflect the energy storage capacity of the sample,which is positively correlated with the water content of the sample.The smaller the size of the water containing pores in the sample,the faster the polarization voltage decay.Although centrifugation does not change the pore structure of rocks,it can lead to an increase in small-scale isolated water bodies in the pores,causing the accelerated attenuation of polarization voltage.