Method and system for transient electromagnetic-induced polarization field separation and multi-parameter information extraction

A method for transient electromagnetic-induced polarization field separation and multi-parameter information extraction, comprising following steps:

• S1, obtaining electromagnetic data influenced by an induced polarization effect, wherein the electromagnetic data influenced by the induced polarization effect is induced polarization-electromagnetic field data;
• S2, performing a separating treatment of an induced polarization field and an electromagnetic field on the electromagnetic data influenced by the induced polarization effect, to obtain a pure electromagnetic response field and a pure induced polarization response field;
• and
• S3, based on the pure electromagnetic response field and the pure induced polarization response field, respectively performing a multi-parameter information inversion to complete an extraction of geoelectric parameters, wherein the geoelectric parameters comprise a predicted layer thickness, a predicted resistivity and a predicted polarizability;
• wherein the S2 specifically comprises:
• constructing a first convolutional neural network;
• obtaining the pure electromagnetic response field by a separation from the induced polarization-electromagnetic field data based on the first convolutional neural network;
• specifically:
• recording the induced polarization-electromagnetic field data as EMIP, and recording the pure electromagnetic response field and the pure induced polarization response field as EM and IP respectively;
• and according to an electromagnetic induction principle and the induced polarization effect, obtaining:
• EMIP=EM+IP 1
• wherein due to different geoelectric models, the EMIP, the EM and the IP are all different, so mappings between the EMIP and the EM, or between the EMIP and the IP are nonlinear, and two kinds of the mappings are recorded as F1 (x) and F2 (x) respectively, satisfying:
• EM=F1(EMIP) 2
• I=F2(EMIP) 3
• selecting the mapping F1 (x) as a mapping to be learned, obtaining the EM from the EMIP by formula 2, and then obtaining the IP by formula 1, realizing a field separation, that is, the pure electromagnetic response field, and recording as ,
• =Net1(w,EMIP) 4
• wherein w is a parameter matrix to be learned;
• subtracting the pure electromagnetic response field from the induced polarization-electromagnetic field data to obtain the pure induced polarization response field, and completing the separating treatment of the induced polarization field and the electromagnetic field, specifically:
• obtaining a predicted induced polarization field from the formula 1, that is, the pure induced polarization response field, and recording as ,
• =EMIP−=EMIP−Net1(w,EMIP) 5
• so as to separate the induced polarization field and the electromagnetic field from the induced polarization-electromagnetic field.