Residue graph content

Measured values for crude properties can be seen on the graph. An interactive, and a non-interactive mode are available when displaying measurements on the graph:

• In the Database module, or the Blend modules, measured values for crude properties can be viewed on the graph.

• In the other generation modules, measured values for crude properties can be viewed and edited on the graph.

The following types of data may be seen on the residue profile graph:

• Profile curve

• Cut values. See Cut Values below.

• Error lines

• Guide points. See Guide Points below.`

• Property constraints. See Property Constraints below.

When only one crude is shown on the graph, the measurement data associated with that property of the graphed crude is shown.

The residue profile curves shown that appear on the graph are themselves denoted in the Graph Legend. See Graph Legend below.

Cut Values

If the property profile selected on the LY or RY graph axis has been constructed using measured data, the measurements will be represented on the graph by h-bars. An h-bar essentially comprises a horizontal line, which spans the boiling point range of the cut measurement. In more detail,

• Distillate cuts are represented by horizontal lines, with small vertical ticks at their ends to indicate the extent of the cut. A vertical line may also be shown centred through the horizontal line the size of which indicates the uncertainty associated with the cut measurement.

• Residue and condensate cuts are represented by horizontal lines with an arrow at the right or left hand side to indicate that they are not bounded above or below in boiling point. Both residue and condensate cuts may also show a vertical line centred through the horizontal line. The size of the vertical line, if present, indicates the uncertainty associated with the cut measurement.

• Limit measurement values for cuts (for example, < 0.25 Sulphur % wt) are represented by horizontal lines, with a vertical line extending from the middle of the h-bar in the direction of the limit (downwards for < and upwards for >).

• Whole crude values, even when used to generate the profile, are not shown on the graph.

H-bars can appear on the graph as both unbroken and broken lines:

• Measurements which are present in the set of measurement data, and which are used to generate the profile, are shown as unbroken lines.

• Measurements which are present in the set of measurement data, but which were not used to generate the profile, are shown as broken lines.

You can toggle the display of H-bars on the graph by pressing the button on the Residue Profile Graph Toolbar. See Residue graph toolbar.

Where applicable, you can also manipulate H-bars on the graphs using the button on the Toolbar. See Edit guide points.

Guide Points

It is possible to add guide points to profiles, to carefully control their behaviour. These guide points are seen as small open circles on the graph.

Property Constraints

It is possible to add constraints to properties, to carefully control the behaviour of profiles on the graph. These constraints are indicated by a red line splitting two arrows pointing towards each other.

Graph Legend

The Graph Legend lists those crudes whose profiles are displayed on the Graph. Crudes are displayed in the legend in order of selection and are allocated different colours so as to be more easily distinguishable on the Graph.

Each entry in the legend comprises three pieces of information: the curve type of the property profile; the crude reference; and the Y-axis property, as described below:

• Property profile curve type. Property curves displayed on the graph can either be modelled, profile-based, or correlated. Correlated properties are indicated by a ƒ in the Graph Legend.

• Crude Reference. The reference identifying the crude.

• Y-axis property. The property shown in the property control for the corresponding Y-axis. In the case where the property control shows a group of properties, each constituent property of the group has its own separate entry in the graph legend.

  Tip: The Graph Legend can be resized by dragging the divider to the left hand side.