LOCAS

LOCAS is a user-friendly 2D axisymmetric finite-element software program specially dedicated to salt caverns. Many physical phenomena can be taken into account, allowing users to simulate and understand the complex behavior of a brine-filled or gas-filled cavern. Numerous calculation and post-processing features allow analysis of various cavern aspects, from short-term mechanical stability to long-term subsidence. Today, LOCAS is probably the most advanced tool for designing and optimizing salt caverns. Simulation of the non-linear elasto-visco-plastic mechanical behavior of salt caverns requires advanced constitutive models and accurate numerical implementations. Furthermore, because most involved phenomena are coupled, special procedures are required for thermal, mechanical, chemical, and hydraulical analysis. Although modeling a cavern is important in itself, many geotechnical engineering projects also involve modeling the wellbore. This is why one part of LOCAS includes the full wellbore modeling and allows finite-element computation of the mechanical behavior of the cementation.

LOCAS tab called "Cavern Main Characteristics"

LOCAS tab called "Stratigraphy"

Modeling

A 2D mesher is embedded in LOCAS. Several constitutive laws for rock salt are available (Norton-Hoff, Munson-Dawson, Lubby2, Lemaitre), and published sets of parameters are offered. Databases allow selection of existing datasets or creation of new ones. Cavern shape and loading can be defined easily within a few minutes.

LOCAS tab that shows the mesh

Loading

LOCAS tab showing the mesh

Design/Stability

Several damage and failure criteria can be considered. The onset of salt dilatancy can be precisely assessed through a wide set of criteria. Energy balance and storage capacity of a gas-filled cavern can be computed and optimized. Computations are performed using the most recent and effective algorithms; they are optimized and parallelized for Intel® multi-core processors.

Example of post-processing. Contour plot of deviatoric stress.

Optimizing

LOCAS allows determining and optimizing Working Gas Capacity.

Example of computed evolution of Working Gas Capacity

Post-processing features

The LOCAS post-processor has enhanced graphical features for displaying computational results. Many plots are available, including: evolution of cavern pressure, temperature, volume, gas inventory, involved powers, brine properties etc. Contour plots can be created for all stresses, temperature, dilation, etc. Movies can be created from contour plots (.avi format). Radial and vertical distribution of stresses can be plotted. Animation of the stress state in the invariants plane also can be created. All plots can be saved as text files, printed or sent as high-definition images to the Windows® clipboard to export them to other programs, such as Microsoft Word©.

LOCAS post-processing - "Flight of the bumblebee" in the invariants plane.

LOCAS post-processing - Water Phase Diagram

Demo / Video

Download video: 

HTTP FTP

MPEG-4 (.mp4)

MPEG-4 (.mp4)

AVI
AVI

Trial version

A trial version of LOCAS is available for 64-bit Windows®. It works on any Windows® platform from Windows® XP to Windows® 8. To download, please contact Brouard Consulting.