1. A method of performing an oilfield operation, comprising: obtaining a plurality of oilfield data sets each corresponding to one of a plurality of oilfield entities and comprising a plurality of data fields; generating a stochastic database from the plurality of oilfield data sets based on an artificial neural network of the plurality of oilfield data sets, wherein the artificial neural network comprises a self organizing map (SOM) having a plurality of SOM locations and comprising a plurality of maps screening the plurality of oilfield data sets to identify a plurality of candidates from the plurality of oilfield entities, wherein the screening is based on the stochastic database; performing a detail evaluation of each of the plurality of candidates; selecting an oilfield entity from the plurality of candidates based on the detail evaluation; and performing the oilfield operation for the oilfield entity.