Abstract: Initialization data independent of logging curve data values (such as grid definitions and starting depths) are transmitted to a remote terminal where well log curve displays are desired. Data corresponding to magnitudes of successive adjacent points on the curves are then sequentially transmitted as delta values. Each delta value is the difference in magnitude between two adjacent sample points on a given curve. Transmission of redundant and unnecessary information such as integer values of curve samples is thereby eliminated. Large amounts of well log data may then be transferred quickly to remote locations at low data transmission rates associated with conventional telephonic communication links. Cumulative error resulting from reconstructing curve sample magnitudes from delta values is eliminated by a bi-directional transmission error checking scheme.