This paper is based on the transient electromagnetic theory of a thin sheet. The induced EMF formula (as a function of vertical conductance and depth in the central loop transient electromagnetic method) was derived b...This paper is based on the transient electromagnetic theory of a thin sheet. The induced EMF formula (as a function of vertical conductance and depth in the central loop transient electromagnetic method) was derived by using the reciprocation law and the formula from the electrical component of EMF induced by a magnetic dipole source over a thin sheet. At the same time, the inversion algorithm of all-time apparent vertical conductance and apparent depth was derived by using the induced EMF and its first derivative. In the transition area there is no distortion for the calculated apparent vertical conductance curve. The location where the curves slope was changing corresponds to an electric interface of the layer. This is because the curve of the slope is directly proportional to the conductivity. Comparing the shapes of the neighboring curves in the same section line, the interfaces of the same layer can be continuously traced, resulting in a high quality CLTEM get-electric section. Theoretical testing with two models shows that the curves of all-time apparent vertical conductance represents the electric property of each layer and its variation. Finally, the authors show application examples of apparent vertical conductance interpretation. The mapped apparent vertical conductance section has fine electric division from the inversion algorithm and is in good co-herence with the inverted resistivity section. This demonstrates that the interpretation method of all-time apparent vertical conductance is feasible and展开更多
文摘This paper is based on the transient electromagnetic theory of a thin sheet. The induced EMF formula (as a function of vertical conductance and depth in the central loop transient electromagnetic method) was derived by using the reciprocation law and the formula from the electrical component of EMF induced by a magnetic dipole source over a thin sheet. At the same time, the inversion algorithm of all-time apparent vertical conductance and apparent depth was derived by using the induced EMF and its first derivative. In the transition area there is no distortion for the calculated apparent vertical conductance curve. The location where the curves slope was changing corresponds to an electric interface of the layer. This is because the curve of the slope is directly proportional to the conductivity. Comparing the shapes of the neighboring curves in the same section line, the interfaces of the same layer can be continuously traced, resulting in a high quality CLTEM get-electric section. Theoretical testing with two models shows that the curves of all-time apparent vertical conductance represents the electric property of each layer and its variation. Finally, the authors show application examples of apparent vertical conductance interpretation. The mapped apparent vertical conductance section has fine electric division from the inversion algorithm and is in good co-herence with the inverted resistivity section. This demonstrates that the interpretation method of all-time apparent vertical conductance is feasible and
