2.2 WITSML Data Model Overview

The WITSML UML model is implemented and organized in an Enterprise Architect Project (EAP) file, grouped into packages as shown in Figure 2.2-1 . Each of the schema packages contains classes that represent the key data objects. The UML model is also the source for the XSD files (schemas), which are generated by an automated process. The zip file structure of the WITSML download (see Figure 1.3-1 Figure 1.3-1 ) reflects the UML file structure.

The UML model is available as part of the WITSML download. It is saved as an XMI file, which can be imported into any data modeling software tool.

Figure 2.2-1 The WITSML data model includes the Energistics common, WITSML common, and a package/high-level schema for each of the main data objects.

Main packages of the WITSML UML model are listed and described here.

common contains the classes that are used by all Energistics standards, which includes classes to consistently define base data objects and references, coordinate reference systems, and units of measure. For more information, see the CTA Overview Guide and CTA Technical Reference Guide.

witsml contains a version package (for example, v2.0) which contains these main packages:

• The doc class (folder), which contains a package for instance diagrams.
• The xsd_schemas class (folder) contains the packages within the EA project that are used to generate the XSD schemas (which are used to implement WITSML). It contains these packages:

• WitsmlCommon. Shared data objects and related objects that are shared across all packages in a RESQML project. Many objects are extensions of data objects that appear in the shared Energistics-wide common package.
• Package for each WITSML data object (Figure 2.2-1), which are each described in other chapters in this manual. See the table of contents.