Expediting Model Creation in Symmetry Using GIS Data
Several new features have been developed in Symmetry’s Field Workspace to enhance integrated modeling. The goal being to model the entire hydrocarbon flow path from reservoir through facilities, forecast production, and allow the user to model facilities in steady state and dynamically. The new features expedite model creation, help evaluate and visualize results, and assist the user in creating geographically and topographically accurate network models. This article will highlight two of the many new GIS related features including:
- Network Connection Tool (NCT)
- Bore Utility
Network Connection Tool (NCT)
Imported pipeline shapefiles are generally not fully connected when imported. For large models, this can lead to hundreds or thousands of nodes and pipe segments requiring intervention to create a fully connected pipeline network. To do so manually would be prohibitively time consuming or even impossible as many nodes may lie on top of each other and their lack of connection may not be visible.
The Network Connection Tool (NCT) helps the user clean up imported shapefiles by identifying and listing unconnected nodes and wells/sources and impossible flow directions such as all pipe converging to a single node. It then provides automation to make the connections en-masse for user-selected nodes. The criteria is a user-specified radius around nodes to look for another one to connect to. If multiple connection options exist, the NCT will leave the nodes for the user to make the connection manually using their judgment. Nodes originally on the list that are automatically connected with the NCT then fall off the list leaving a running tally of unconnected nodes.
Where manual connections are required, the list provided by the NCT is interactive allowing the user to click on a listed node and zooming to that location on the map. The user can then add wells/sources, create or drag pipe segments, or flip segment directions to make the appropriate connections. When the connection is made, those nodes fall off the list. If the user inadvertently creates a non-connection or impossible flow path, the nodes in question will automatically be added to the list.
Use of the NCT can decrease the time it takes to connect imported shapefiles by hours if not days depending on the size of the model. In some situations, it permits completion of the model since the lack of connections may not be identified without it.
Detailed human-created elevation changes such as road or river crossings may become important due to their potential for liquid holdup, especially for dynamic flow modeling. Generally, these are not available in topographic maps and shapefiles that can be imported so they must be added manually. To do so requires the user to potentially split pipe, add nodes and modify the assigned elevations for each crossing. If there are a lot of crossings, this could be extremely time-consuming to not only modify the pipe segments but externally calculate the expected node elevations of the bores. There is also the chance of error when entering the new elevations.
Once the location of a crossing/bore is identified, the Bore Utility can be used to define the bore by specifying four points along the pipe leg and the depth of the bore from the existing elevations. Specifying the points is done simply by clicking the appropriate location on the pipe with the mouse.
The four points to be defined are as follows:
a) The start of the first build section at current pipe elevation
b) The end of the first build section at the bore bottom
c) The start of the second build section at bore bottom
d) The end of the second build section back at current pipe elevation
The user has a rapid method of updating the elevation profile of their pipe network to account for bores not included in topographic data and reduce the potential of entering erroneous elevations. This saves a lot of time in model updating and elevation reconciliation expediting the creation of the model and performing the desired evaluations.
As part of the integrated workflow, the features presented allow the user to quickly generate Symmetry models for large gathering systems honoring the geography and topography. This permits the user to evaluate and understand the flow conditions, either in steady state or dynamically, and make more informed decisions regarding design, troubleshooting or optimization of their pipe systems and facilities.
Please contact your local VMG office for more information.
Gordon Slemko, P.Eng., VMG Calgary