The use of 41) seismic to image fluid flow and locate bypassed oil between wells, especially in carbonate, is a great challenge. The seismic observables that change as hydrocarbons are extracted may not always be mappable because Gassman's equation normally does not predict the nature of velocity sensitivity to fluid change in most carbonates. However, reservoir-parameter changes caused by production directly affect seismic signals, and the seismic signature is preserved in the data volume if the effects are conditioned and equalized.