Abstract: A method for geological formation analysis may include collecting time-lapsed well-based measurement data from a first borehole in a geological formation over a measurement time period, and collecting time-lapsed electromagnetic (EM) cross-well measurement data via a plurality of spaced-apart second boreholes in the geological formation over the measurement time period. The method may further include determining simulated changes to a hydrocarbon resource in the geological formation over the measurement time period based upon a geological model using a processor, and using the processor to determine if the simulated changes are within an error threshold of the time-lapsed well-based measurement data and the time-lapsed cross-well EM measurement data. If the simulated changes are not within the error threshold, then the geological model may be updated.