SRS (Structural Reanalyses Systems)

Publisert: 26. March, 2021

Offshore structures will during their lifetime undergo changes, due to degradation of materials, fatigue, etc., damage, soil strains, changes in environmental conditions or more visible changes such as new modules or other modifications. In order to document what such changes means to the integrity of the structures, new analyses must be performed, so-called reanalyses.

A better way to perform reanalyses is to build an analysis model that is maintained, which we have chosen to call an SRS model (Structural Reanalysis System), also referred to as a digital twin. This ensures that you always have an updated model available that is completely quality assured and maintained with associated documentation. Loads, weights and ground conditions can be quickly updated based on measured values. This ensures emergency preparedness in the event of incidents and ensures efficient implementation of reanalyses regardless of the cause. This increases safety and saves the client cost.

The Petroleum Safety Authority Norway, (PTIL) set requirements in their regulations (in the management regulations and the activity regulations) for the operators to be prepared for such reanalyses. A separate "Norsok standard" has also been established that meets the government requirements for this; N-006 Assessment of structural integrity for existing offshore load-bearing structures.

Many of the installations on the NCS are old, many have passed their original design life and have had their life extended for further production,  or new fields have been linked to the installation, so-called tie-ins. It is especially important to control theese installations to ensure further safe operation. In addition, design documentation is often inaccessible. In order to obtain the required information, projects often become dependent on people who were involved in the design and construction phase, people who are often close to retirement, or retired. Experience transfer for these installations is important in order to maintain sufficient knowledge of some of the largest structures of our time.

By establishing and maintaining SRS models, we can ensure emergency preparedness, meet government requirements and achieve transfer of experience. In addition, it is time and cost saving. Shelldesign, a OO developed software, is developed with applications that are particularly suitable for assessing long-term effects and residual capacity. We have also developed routines that streamline labor-intensive  modelling of prestressing forces in structures. We have also significantly strengthened our marine expertise, which means that we can also assess and establish new environmental loads for implementation in the SRS models.

Recently,  Dr.techn. Olav Olsen have established SRS models for several concrete installations on the Norwegian shelf, and we believe there may be more projects to come. With our long history and detailed knowledge of offshore concrete structures, are in unique position to offer these services with high quality and help ensure continued safe operation of these installations for many years to come.