6.1 Wellbore Geology Data Object

The wellbore geology data object (WellboreGeology) (Figure 6.1-1):

• Provides the unambiguous modeling of data for different levels of geological description and interpretation; it covers the areas of geology and hydrocarbon show evaluation that are performed at the wellsite.
• References a parent wellbore.
• Is a growing data object because as measurements are taken (at increased depth) that data is added to the wellbore geology object.

• Includes several “part_ objects” to support streaming data with ETP. These part objects exist for geological intervals for cuttings, interpreted lithology, and show evaluation. The sections below provide more information.

Figure 6.1-1 UML diagram of the wellbore geology data object—high-level view. The main sub-objects include: cuttings geology interval, interpreted geology interval, and show evaluation interval.

The wellbore geology object addresses the following main tasks in wellbore geology, which is reflected in the object design:

• Cuttings descriptions (CuttingsGeologicInterval)
• Geological interpretation (InterpretedGeologyInterval)

• Show evaluation (ShowEvaluationInterval)

Figure 6.1-2 shows the use of separate geology intervals for cuttings, interpreted lithology, and show evaluation as they might be presented on a graphical mud log. The following sections describe the related data objects and their usage.

Figure 6.1-2 Mud log showing cuttings, interpreted lithology, and show evaluations.

The following pseudo-code example shows the hierarchy of the main wellbore geology objects, which are explained below.

WellboreGeology

ShowEvaluation[0..1]

ShowEvaluationInterval[0..*]

InterpretedGeology[0..1]

InterpretedGeologyInterval[0..*]

GeochronologicalUnit[0..*]

LithostratigraphicUnit[0..*]

InterpretedIntervalLithology[0..1]

CuttingsGeology[0..1]

CuttingsGeologyInterval[0..*]

CuttingsIntervalLithology[0..*]

CuttingsIntervalShow[0..*]

LithologyQualifier[0..*]