METHOD FOR QUANTITATIVELY SEPARATING THE EFFECTS OF ELECTROMAGNETIC INDUCTION AND INDUCED POLARIZATION

This invention is related to the methods of electro-geological survey. Essentially, it consists in measuring of the process of transient over a polarizable medium using a dipole-axial device as impulses of current are sent through this medium. Several functions are formed in such a way as to ensure different manner of their dependence on the electromagnetic induction field and induced polarization field. One of these functions is formed in such a way as to increase an electromagnetic induction and induced polarization ratio as compared to DU(t)= –¡U(t)/–¡U 0 , where –¡U 0 is the difference of potential ”U measured during the passage of current. The second of these functions is formed in such a way as to decrease the electromagnetic induction and induced polarization ratio as compared to DU(t). The third of these functions is formed as a combination of time and spatial derivatives of the transient field. Simultaneous inversion of all the input functions is executed, including DU(t) obtained in one point of recording. The geo-electrical model of the cross-section is obtained. The obtained model's polarizability is reset to zero for all layers, and, through forward modeling, the electromagnetic induction field (EM) is calculated. The wave numbers of the said model are reset to zero, and, through forward modeling, the field of the induced polarization (IP) galvanic component is calculated. The change of the induced polarization (IP) galvanic component for the area is calculated and its geological interpretation is carried out. The technical result: the possibility to carry out quantitative determination of the intensity of the fields for quantitative separation of electromagnetic induction and induced polarization effects with the error within 0.5%, and the possibility to ensure larger time interval of fields separation from 1 ms to several seconds, including that for the cross-sections having high conductivity. 3 claims of the formula, 13 illustrations.