Multimodal Interaction and Residual Fusion for Cross-Well Acoustic-Impedance Reconstruction

Cross-well acoustic-impedance reconstruction combines seismic observations with retained auxiliary logs whose relationships change between wells. We introduce Multimodal Interaction and Residual Fusion (MIRF), which expresses multimodal fusion as an additive correction to a source-supervised seismic estimate. Three residual heads propose updates, a conditional router determines their composition, and an admission coefficient controls the applied magnitude. Separate anchor supervision retains a seismic reference for examining the effect of auxiliary-log correction. Using the original processed-log protocol on Penobscot L-30 to B-41 transfer, ten matched seeds reduce mean root mean squared error (RMSE) from 1905.5 to 1489.6 kRayl and mean absolute error from 1659.5 to 1178.4 kRayl relative to the standalone seismic CNN. MIRF also has the lowest mean RMSE among four matched neural fusion alternatives in this direction. Bidirectional comparisons, ablations, and depth-resolved profiles locate the benefits in reduced broad reconstruction bias and show how component effects change with transfer direction.