A method of processing data generated from an energy industry or oilfield operation includes: receiving a data set representing parameter values generated during at least a portion of the operation, the parameter values including values of a plurality of parameters relating to the operation; dividing the data set into a plurality of data subsets, each data subset including values for multiple parameters; determining a measure of similarity between data in each subset relative to data in one or more other subsets; displaying a map of the data set in at least two dimensions, the map including a visual representation of each subset positioned relative to a visual representation of the one or more other subsets based on the measure of similarity; and analyzing the map to estimate a condition associated with the operation.