7.8.3 Data Model
|For Standard||WITSML v2.0|
Figure 7.8.3-1 is the UML model of the depth reg image data objects. This set of objects defines the raster log image as a series of rectangles, the contents of each rectangle (DepthRegTrack (Figure 7.8.3-2)), and how the rectangles are related. These objects bring together information about the image boundary, the header/alternate sections, metadata on log sections, calibration points, and depth curves. The schemas describe the dimensions of the raster image, rather than a dump of the data points of the raster curves, in a format that all other providers can use. Specific objects on the diagram include:
- DepthRegImage. The top-level object that contains all the information about the composition, layout, and depth registration of the raster well log file.
- DepthRegLogRect. Defines a region of an image containing a header or alternate sections as defined on Figure 7.8.2-1 .
- DepthRegRectangular. Uses four corner points (ul, ur, ll, lr) to define the position (pixel) of a rectangular area of an image, using x-y coordinates. Most objects point to this object because most are rectangles, and use this schema to define each rectangle.
- DepthRegLogSection. Defines the description and coordinates of a well log section, the curves on the log. An important element to note is log:refNameString; it is a reference to the actual log/data (in a WITSML server) that this raster image represents; this object does not contain the log data.
The three arrows at the lower left of this object—upperCurveScaleRect, lowerCurveScaleRect, and whitespace—are used to identify the corner points of rectangles bounding those elements of the raster log.
- DepthRegCalibrationPoint. Defines a mapping of pixel positions on the log image to significant locations on the log. Specifically, pixels along the depth track are tagged with the matching measured depth for that position.
- DepthRegParameter Defines parameters associated with the log section and includes top and bottom indexes, a description string, and mnemonic.
Figure 7.8.3-2 is a UML diagram of the DepthRegTrack, which identifies the rectangle for a single log track. The DepthRegTrackCurve provides a description of the actual curve, including elements such as line weight, color, and style, within a log track.