|For Standard||CTA v2.1|
Each Energistics data object is defined by an XML schema definition (XSD) file, each of which is generated from the UML data model. For example, objects such as wells, grids, equipment, reports, etc. are defined by XSDs. Each instance of a data object is stored as an XML file.
Where possible, Energistics has established common design patterns, common types, and reference data which are implemented in the CTA or the individual domain standards (as appropriate).
These common patterns provide a rich set of integrated data objects for cross-domain workflows and make it possible for domain standards to share objects (instead of duplicating them). For example, WITSML defines wells and welllbores, which may be used by RESQML and PRODML.