2.4 Energistics Identifiers

To identify specific instances of a data object, Energistics standards use identifiers as defined in the Energistics Identifier Specification, which may be:

• A universally unique identifier (UUID), which identifies a single instance of a data object.

• NOTE: By definition, each Energistics top-level object (TLO) inherits from AbstractObject (in Energistics common), which means it must have a UUID and required metadata. For more information about TLOs, see the CTA Overview Guide.

• An Energistics Uniform Resource Identifier (URI), which identifies one or more instances of a data object.

NOTE: Identification in previous (pre-v2.0) versions of WITSML was unique only within a server and depended on defined hierarchies required to begin with well/wellbore. Now, with the use of UUIDs, top-level data objects must be universally unique.