8.2 Data Model

Topic Version1Published11/11/2016
For StandardWITSML v2.0

The table here lists and describes the top-level data objects that define the set of completion data objects. Details of each are explained further in this section. Each of these objects has been converted into its own package in the UML model. For more information, see the XMI file downloaded with WITSML.

Data object

Parent Object


Downhole Component


Contains all the wellbore equipment in a well. Components are identified as to which wellbore they are in. This data object covers the openhole boreholes, the strings of equipment, the components in each string and the details of these components, and the connections from these elements to the reservoir.

Well CM Ledger

Well and Wellbore

This name is short for “Well Construction and Maintenance Ledger”.

Contains details of events (which were defined in Section Job vs. Event , Job vs. Event ). Each event also has a pointer to elements of downhole components that the event changed.

NOTE: Energistics common now provides an Activity Model data object, which may be implemented as an alternative to the Well CM Ledger.

Well Completion


Represents a “flow” or “stream” from the well (e.g., from a wellhead port) that is associated with a set of wellbore completions. When there is more than one such wellbore completion, the flows from them commingle in the well (the wellbore completions may be located in multiple wellbores). The well completion represents this commingled flow. It can be associated with business concept such as field, rights, etc.

Wellbore Completion

Well, Wellbore and Well Completion

Each wellbore completion represents a flowing connection between wellbore and reservoir. It contains contact intervals, which reference the physical aspects of these connections detailed in downhole components.