Published on: 06/12/2020
The oil and gas industry is constantly facing new challenges. With the increasing demand to reduce operational costs, having a tool which allows process optimization solutions is always top-of-mind. ALFAsim’s latest release tackles some of these issues through the implementation of new features and options to make user’s lives easier and to ultimately provide more accurate results and improved computational costs.
The just-released ALFAsim version (1.7.0) brings about improvements for annulus flow simulation by allowing service or injection lines to be connected at the annulus top boundary, broader restart options, and a new transient heat transfer model that takes into account materials heat capacity. This release also offers better plot usability and the expected text-based input, allowing ALFAsim to be integrated into more complex workflows.
It is now possible to connect service lines to a well through its annulus. A new annulus port is available for connecting an edge in the network and edge groups can be created to include the annulus and its connection flow.
Two previously available buttons to import edge/well profiles were merged into a single one in order to simplify its use.
Liquid hydrocarbon is now referred to as “oil” instead of “liquid”.
The user is now able to determine the frequency to save restart files (Autosave restart frequency), in a folder named <PROJECT>.restart_files located next to the project’s data folder. A new option in the GUI (keep former results) allows the project to keep previous results while simulating with a restart file.
When using keep former results mode, the simulation will continue from the selected restart file conditions and time, but will keep previous results from before the restart file’s time step.
Replaced previous “Swap profiles” button on Edge/Well profile editor by a new “Invert Trajectory” button in the Manual Profile Edit window, which will effectively invert the whole trajectory in the table.
A transient wall heat transfer model was added, which accounts for heat transfer and heat capacity along pipe walls.
Changed unit of GOR (gas-oil ratio) attributes to Standard volume per Standard volume, which contains the new unit “sm3/sm3”. GOR is available for Mass nodes, Mass Source equipment, Reservoir Inflow equipment.
New button at the top bar exports all results (trends and profiles) to Excel files.
Plot preview for input values in the editors can be zoomed in/out and panned and its axes can be configured (unit, range, etc.) in the same way as for results plots.
Time Options has two new input parameters available:
• Initial Time: Initial simulation time, will affect all transient inputs such as time-dependent tables and also used with the restart feature
• Initial Time Step: Time step size to be used at the beginning of the simulation, will be automatically adjusted throughout the simulation run
When multiple runs are visualized, it is possible to set up a time step merging strategy to define how curves from different runs are displayed.
The following limitations from ALFAsim’s previous version were addressed:
• Heavy Components: It is no longer required to have at least 3 heavy components in the fluid composition
• Multiple fluids: When using two or more fluids in the same network, it is possible to have fluids with only light components along with fluids using heavy components
• Viscosity model: option added
It is now possible to configure different PVT models for an annulus’ top boundary and initial conditions.
ALFAsim now supports running a simulation by using a command line informing an ALFAsim Case file (.alfacase) through the –from-yaml-file option. The user interface now supports importing ALFAsim Case files (.alfacase) into the application.
These options were renamed as Numerical Options. A button and context menu were added to restore its default configuration.
Support was added to select a custom friction factor model via plugins. It requires a Software Development Kit ALFAsim-SDK version 0.4.
In the previous version, an error was generated when deleting an edge equipment from a Genkey imported file. This error was fixed.
Fixed profile output for Edge Groups which contain a Well with an Annulus enabled. The Annulus output is discarded when visualizing the Edge Group results.
Tracers will not be considered in Gas Lift Valves.
When using Keep Former Results option with Restart as Initial Conditions Strategy:
• The statistics displayed in the Plot windows are not updated to the restarted simulation and should be disconsidered
• Trends that are generated from profiles after the simulation is run will be erased and will only show the results from the restart point ahead
If Annulus flow simulation is enabled, user needs to check “nonsplit equipment” in the Numerical Options advanced tab in order to use Valves and Pumps
Compositional PVT Model:
• Single-component simulations are not yet supported
• All fluids with heavy components must have the same minimum number of single carbons
• When adding heavy components to the fluid composition, the number of single carbons must be ordered sequentially
• The compositional model currently does not work with the Steady State Solver
Flow pattern output data was updated in 1.7.0 and flow pattern results from previous ALFAsim versions are displayed incorrectly, requiring a new simulation
For ALFAsim users:
1. Access the ESSS support center
2. Enter Username (your e-mail) and Password
3. If this is your first time accessing the portal, select Forgot my password
4. Download the installer for ALFAsim version 1.7.0
Should you experience any difficulties while downloading or using this version, please do not hesitate to contact us. As always, your feedback and suggestions are greatly encouraged and appreciated. Our technical support team may be reached at support.esss.co.