Subsea is important for Norway and new concepts emerge due to a need for cost reductions
Subsea technology is important for development of Norwegian petroleum resources and represents a large export industry for Norway. It is expected that 68 out of 88 discoveries on the Norwegian Continental Shelf will be developed with a subsea solution . Driven by the need for cost-reductions, novel subsea concepts and technologies emerge, such as all-electric, new subsea processing technologies, more integration between topside and subsea control systems or between process control and process safety systems, more use of sensors to monitor process condition and integrity of safety systems, etc.
Innovation is encouraged by regulations, but not fully supported by existing standards
The Norwegian HSE regulations cater for and encourage the evaluation of new innovations through its functional requirements. However, existing standards and guidelines, derived from best practices for traditional technologies and operational concepts, may not provide relevant support for demonstrating safety of such new concepts. Consequently, traditional or “hybrid” solutions are often chosen to ensure safety demonstration within the timeframe of the project. Furthermore, without a common approach (work-processes and methods), the means for sharing of experience and improving best practices within the industry is lacking.
Fail-safe principles and independent barriers are key components in the regulations, but are difficult to achieve in practice
Key principles in the Norwegian regulations are fail-safe principles, independence of process and safety systems, and independence of different safety barriers. Ensuring independence can be difficult – and knowing just how independent individual safety barriers are, may be an even greater challenge: While independence of different safety functions is often assumed on a high level, more subtle dependencies may still exist, arising from physical dependencies (e.g. stemming from communication and information exchange), logical dependencies (e.g. in software), location dependencies (e.g. common external events), etc. Thus, the actual level of independence of safety functions is not fully known today, and increased digitalization may lead to even more dependencies. It is therefore prudent to develop approaches and methods for concept evaluation with the potential to increase the overall level of safety, even when these concepts involve a higher level of integration of control and safety systems than what is current practice. Rather than formulating requirements as if the systems where independent, it is important to formulate requirements that ensure a safe implementation of systems with dependencies, or more specific criteria for when independency must be met and when it may be potentially relaxed.
A new framework is needed to support demonstration of safety for novel subsea technologies
The above has been recognized as common challenges by the project partners. They see a need for reducing the complexity of subsea facilities and a common approach that can properly demonstrate safety for new technologies that deviate from traditional practices. The project aims to develop a framework (process, method, tools) that provides the industry with a faster approach for safety demonstration. The project will bring together safety and subsea experts from the regulator (Petroleum Safety Authority – PSA), operators (Equinor Energy, VNG, Neptune Energy, Lundin), manufacturers (ABB, TechnipFMC and Aker Solutions), two of Norway’s leading academic research groups on safety (NTNU and University of Stavanger) and DNV GL. This will ensure alignment with the industry and regulator needs and a sound scientific basis. Together with the use-cases, more in-depth studies on selected topics will be carried out by a PhD and a Post-doc researcher. The selected use-cases are:
- All-electric safety systems: Demonstrate safety for solutions for which existing fail-safe philosophies do not apply, and new ones are needed. For example; condition monitoring of actuators and batteries may offer better status on technical integrity that may offset the fail-safe solution offered by the traditional mechanical spring activated valve.
- Simplified subsea process solution: Demonstrate safety for a subsea process/compression solution where sensors and control elements (hardware and software) are shared between process- and safety systems. A life-cycle perspective and a more dynamic approach to safety demonstration are needed.
- A third use-case will be selected by partners in the framing phase of the project.
The framework aims to be a supplement/alternative to current standards where this is suitable, and will also be applicable for fast-track subsea projects:
- It will build on the new uncertainty-based risk definition of PSA, where knowledge, uncertainty and the effect of assumptions are key principles in evaluating safety, and will cover the full risk picture (i.e., not only focus on barriers (such as probability of failure on demand), but also on demand characteristics and the detectability, severity and ability to mitigate consequences in a subsea environment).
- It will be based on a systems perspective, to identify and assess new and emerging failure modes stemming from increasingly complex, integrated, software-intensive and cyber-physical system.
- It will consider safety in a life-cycle perspective, taking into account the opportunities for improved monitoring, diagnostics, prognostics and dynamic online safety demonstration in operations, enabled by digitalization and new technologies.
The framework development is based on use-cases and more in-depth research
The framework development process is illustrated below. It identifies two main phases: (i) The analysis and early demonstration of novel safety concepts, in which potential elements of governing standards and new methods are developed and tested with the use cases, and (ii) the framework development, including clarifications and analysis of results of use cases. The main deliverables are the new framework and a set of proposals for new design philosophies.
The project idea was identified in SFI SUBPRO, and the research herein has been directed to understand and describe the above-mentioned gaps in knowledge and methods. The resources needed to close the identified gaps are beyond the scope of the SUBPRO centre, and should involve more subsea actors, in particular manufacturers. Safety 4.0 will focus additional research efforts into topics with large innovation potential and accelerate the innovations that are needed for new safety demonstration methods, which in turn will support innovative technological solutions. Further, the PSA called for such an industry initiative at the 2016 NFA conference in Kristiansand.
The research, concepts and the framework from this project may inform future updates of regulations and standards, and can be valuable and applicable to other industries beyond subsea.