On the Parameters tab, installation parameters may be specified for installation stages defined on the Installation Stages tab. You can vary a wide range of parameters; cable length and vessel offset, for example. Open the Parameters tab, which is shown in the figure below.
No parameters need to be specified for Stage 1 because it is to be simply a static analysis of the base model. For all subsequent stages, you are going to have the program progressively lengthen the cable while simultaneously moving the vessel to model the abandonment procedure. The final length of the cable is to be 700m and the final offset of the vessel is also going to be 700m from its initial position.
Select Stage 2 from the Stage drop-down list. To lengthen the cable, make sure that Parameter Type is set to Cable, which it is by default.
The Component Name drop-down list contains a list of all the cables currently included in the selected Model component. There is only one cable in your model, the cable in your pipeline. It will appear as PipeLine(1)_Winch Cable as shown in the figure below. This is a unique name made up of the name of the pipeline and the name of the cable within the pipeline.
The overall change in cable length (700m) is to be evenly distributed between the 15 stages. Press the Define button and enter the new cable length of 50m (700m divided by 14) as shown in the figure below and press OK to confirm.
Defining Cable Length
Now that you have completely defined a parameter to be modified in Stage 2 – an increase in cable length – add this parameter definition to the list of parameters by clicking on the Add button. The parameter appears in the list as shown in the figure below.
Stage 2 – Increasing Cable Length
Before progressing, note that parameters can be removed or modified in exactly the same way that stages themselves can; by selecting them in the list and using the Remove and Update buttons respectively.
It is possible to specify as many parameters as required per stage. Leave Stage as 2 and change Parameter Type to Vessel Offset. The Component Name drop-down list now contains a list of all the vessels currently included in the selected Model component. Select Lay Vessel(1) to proceed.
Note that the Component Name 2 drop-down list is now active. Specifying a vessel offset requires specifying two components, a Vessel component and a Vessel Offset component. Select 50m Surge Offset from Component Name 2. Press Define to open the dialog shown in the figure below. The default is to Add the offset. To remove an offset is to have it applied in reverse. Press OK to close the dialog and confirm that the offset is being added.
Adding Vessel Offset
Your parameter is now fully defined, press Add to include it in the list. The list of parameters should now appear as shown in the figure below.
Parameters for the third and subsequent installation stages can be quickly added using the Automate Stages dialog which is discussed later under the ‘Generate Subsequent Stages’ heading. However in the meantime it is necessary to define some installation criteria for the first two stages.