Oil is the energy lifeblood related to China’s industrial development,but now China’s oil exploration is becoming more and more difficult,according to the current reserves can only be exploited for about 20 years,traditional surface exploration is more and more difficult to find new oil,need to go deep into the well to better explore the distribution of oil in the formation,increase the recovery rate of oil in the well.Based on the transient electromagnetic detection theory,a numerical model of inter-well exploration is established,the stratigraphic response characteristics of different stratigraphic conditions are discussed,and the damping least squares inversion method is studied.In this paper,the basic principles of inter-well transient electromagnetic detection are analyzed,a numerical model of well-to-well exploration is established by COMSOL Multiphysics software,and the response characteristics of uniform formation model and non-uniform formation model are studied.The forward response of D-type and G-type stratigraphic models was studied in the two-stratigraphic model of heterogeneous stratigraphy,and the orthomorphic response characteristics of A-type,K-type,H-type and Q-type strata were studied in the three-layer strata,and the response laws of the conductivity,burial depth and thickness of anomalous bodies to the formation were discussed in the anomalous formation.In this paper,based on the calculation results of forward numerical calculation,the research of damping least squares inversion is carried out.The basic principle of damping least squares method and the basic steps of inversion are discussed,and the selection method of damping factor in the inversion process,as well as the determination method of Jacobian matrix and objective function,are discussed.According to the above method,the inversion iterative calculation of different strata was carried out,and the inversion study of uniform strata and the inversion study of layered strata were mainly carried out,among which the inversion study of D-type and G-type stratigraphic models was carried out in two strata,and the inversion research of A-type,K-type,H-type and Q-type stratigraphic models was carried out in the three-layer strata,and the inversion results of these strata were discussed.Based on the forward calculation of inter-well transient electromagnetic detection,the research of damping least squares inversion is completed,and the research results show the effectiveness of the damping least squares inversion method in inter-well transient electromagnetic detection,and provide a theoretical basis for the subsequent research of well-to-well transient electromagnetic detection method. |