8.3 Role of “Well” and “Wellbore” Concepts as Applied in Completion

Most WITSML data objects are children of the wellbore data object. This organization is logical given that drilling operations are happening in only one wellbore within a well, at any given time. However, in a completed well with multiple wellbores, installed equipment spans all wellbores. For this reason, in the completion data object, the parent data object is the well, although many of the child data objects of completion fit under the wellbore concept.

Figure 8.3-1 shows the main associations with well (blue boxes) and with wellbore (pink boxes).

• The wellhead is associated with well.
• The whole set of completion equipment, downhole components, is also associated with well.
• Individual strings and the equipment in them, and boreholes are associated with wellbore.
• Concerning flow, wellbore completions and contact intervals are associated with wellbore.
• However the well completion data object, representing flow out of the wellhead, is associated with well because it may be a commingled flow from multiple wellbores.
• The well CM ledger can associate with multiple wells. Each entry in the ledger is associated with a well and, if appropriate, also with a specific wellbore.

Figure 8.3-1 Completion data object in the context of well (blue boxes) and wellbore (pink boxes).