Tried and tested, Part 2

Tony Davies, qedi, UK, outlines how proven industry techniques are supporting the successful management of major decommissioning projects.

Tools for commissioning extended to decommissioning

Systems used for commissioning

For the build mode as described in the introduction, good systems already exist throughout the Industry to ensure technical integrity, quality, safety and efficiency throughout each phase from concept through to operation.

The GoTechnology^® suite of tools was specifically designed for technical integrity, construction, completions, commissioning and operations solutions.

The suite currently offers three main tools:

• GoCompletions^®: a management system with a single database working at equipment tag and system levels for greenfield, brownfield and de-commissioning projects.
• GoPlan^®: for the low level planning of completions, commissioning and de-commissioning, this tool interfaces between Primavera and the CMS (Completions management system).
• GoProcedures^®: for the development and storage of commissioning and de-commissioning procedures and to capture and report on the progress of site activities.

A key aspect of the tools is the performance, ease of use and functionality they provide, which is achieved via an information hub arrangement. The hub uses the principles of common data and standardisation of information in order to select the appropriate data for use on the individual tool and by using this functionality allows the various component parts to share common data thus avoiding duplication and mistakes.

With this methodology, data can be cascaded throughout the various tools in a consistent and accurate manner and in this regard, the data flow has already been set to operate between engineering data warehouses for direct transfer of information.

Commissioning management systems for use in decommissioning

It is a relatively early period in the history of de-commissioning of major oil and gas assets, particularly offshore and in this regard there are few systems available that have been designed specifically for this purpose.

Since the company already had extensive experience in the area of commissioning, it made sense to use the existing and proven tools and techniques in order to design and build similar tools for de-commissioning. Subsequently, there is now a tool available that allows operators to use the approach that has been successfully used for the commissioning process and to be able to apply this same rigour to the de-commissioning process.

Using the GoCompletions process for de-commissioning

Figure 1 shows all the project phases of an asset, the activities covered by the GoCompletions commissioning process and how de-commissioning have been integrated within this process. In terms of delivery, the commissioning model has been similarly extended (Figure 2).

Figure 1. The project completion phases of an asset.

Figure 2. Deliveries within each phase.

Decommissioning handover points

Within each stage of the decommissioning process, as there are specific activities to be performed and as there are various parties involved in these activities - not necessarily from the same source - then in order to keep track as to what needs to be done, when it has been done and who has done it, a regime of certification and handover needs to be introduced.

Since the GoCompletions technique has been in existence for some time in the build phase and the tools are already available to help manage this process, again it makes sense to use these existing tools and extend them for use in the de-commissioning arena.

The tool is based on a minimum certification approach, as used in the company’s ‘GOC’ (Guidance on Certification) process, which has been in use for some 30 years on major brownfield projects around the oil and gas arena. It is still the preferred option for over 25 operating assets in the North Sea both in the UK and Norwegian sectors and both with operators and EPC contractors. By using this same minimum Certification approach for decommissioning, the regular GOC handover model is then extended from its current form (Figure 3) to include decommissioning (Figure 4).

Figure 3. The brownfield handover process.

Figure 4. The decommissioning handover process. 

As mentioned earlier, there are a number of individual groups and contractors involved in the overall decommissioning process, and each of these groups are responsible for executing a specific scope of work. Introducing an overall management system to govern all of these areas helps work to flow seamlessly from one group to the next.

This ensures that all parties use the same data to be able to manage and report on progress on each stage of the project, from shutdown, through de-commissioning, disconnect and removal using the same management tool.

Benefits for decommissioning projects

Having a single, web-enabled management tool for de-commissioning that is based on an already successful commissioning management tool allows the user to enjoy all of the same features that have been incorporated through experience and feedback from the people that have used it on the ground.

The GoCompletions decommissioning tool centralises all data with reference to certification, handover and technical integrity for each stage of de-commissioning, giving a one-stop project reporting facility.

The tool generates pre-populated decommissioning certificates from data directly downloaded from Engineering deliverables and avoids the use of having to run separate management systems within each stage of the project.

In the reporting functionality, at the management level the tool can graphically illustrate progress of the whole project on a single Chart and at the detailed level can show the status of progress of a single piece of equipment in the most minute level of detail, a welcome feature in helping to control and manage all de-commissioning activities.

To conclude, the use of established techniques, built upon decades of experience in the completions and commissioning process is now being used to help to ensure the safe and successful decommissioning of major assets offshore. The application may be new, but the tools, skills and processes behind the services are already proven.

Part 1 of this article can be reached here.

Adapted by David Bizley

Read the article online at: https://www.oilfieldtechnology.com/exploration/29112013/tried_and_tested_part_2/