Method and apparatus for oilfield data repository

The invention relates to a method for performing operations of an oilfield having at least one wellsite, a surface network, and a process facility, each wellsite having a wellbore penetrating a subterranean formation for extracting fluid from an underground reservoir therein. The method includes storing oilfield data associated with a plurality of oilfield entities in a first data repository, obtaining a first target metamodel comprising structural description of a first plurality of data entities of the first data repository, obtaining a domain metamodel interleaved with a first mapping specification, the domain metamodel comprising structural description of a domain model for representing the plurality of oilfield entities in an application programming interface, obtaining a mapping specification associating the first target metamodel with the domain metamodel and forming the application programming interface based on the domain metamodel, the first target metamodel, and the first mapping specification using a computer implemented method.