PFD overpressure protection SIF on production header

MAR Consulting supported performing and documenting a Probability of Failure on Demand (PFD) calculation. Due to the addition of new wells to the offshore producing platform in the Norwegian Continental Shelf (NCS), an hazard analysis identified a potential overpressure scenario. The production header has mechanical protection (relief valves) and a Safety Instrumented Function as a redundant barrier. Hence, MAR Consulting calculated the average PFD for this low demand Safety Instrumented Function (SIF). The PFD, when compared to the required risk reduction for this scenario, is acceptable for a number of new wells.

Mini-FSA stage 3 equipment for an SPS

MAR Consulting performed a functional safety assessment (FSA) stage 3 for an engineering contractor and equipment supplier to a subsea production system (SPS). The SPS will be installed and operated in the Norwegian Continental Shelf (NCS). The equipment designed by the engineering company constituted the boundary for the FSA. The equipment is similar to the SPS currently in production in the tie-in field. Hence, the FSA focused mainly on installation, commissioning, and validation activities. MAR Consulting acted as an independent assessor to the project. The objectives were to ensure the equipment is fit for the safety instrumented functions; and is […]

FSA stage 2 of SPS (subsea production system)

MAR Consulting performed a functional safety assessment (FSA) stage 2 for the operator of a subsea production system (SPS). The SPS will be installed and operated in the Norwegian Continental Shelf (NCS). The FSA also included the SIS lifecycle phases typically assessed in an FSA stage 1. The scope was the subsea development design and boundaries towards the topside on the host platform. The scope of the assessment excluded topside tie-in modifications. MAR Consulting acted as an independent assessor to ensure the design of the SIS meets the required risk reduction and is in compliance with the standards, Norwegian rules, […]

FSA stage 3 – artificial lift modification project

The main objective of a functional safety assessment (FSA) is to demonstrate compliance with related IEC functional safety standards through an independent assessment of the development process. Hence, the FSA process is a fundamental tool to ensure that the Safety Instrumented System (SIS) fulfills its requirements as an active barrier to reduce the risk to acceptable levels. At least one FSA is typically required during a project phase. Nevertheless, it is highly recommended to perform at least 2 FSAs in order to anticipate potential non-conformances in due time. The FSA team shall have some degree of independence to the project […]

FSA stage 2 of subsea production system

MAR Consulting will perfom a functional safety assessment (FSA) stage 2 of a subsea production system (SPS) bound to be installed and operate in the Norwegian Continental Shelf (NCS). The end client is the  company engineering the SPS. The contract is in effect immediately. FSA stage 2 focus on the design and engineering of the safety instrumented systems (SIS). In this case, there are two autonomous independent SIS aiming at reducing risks to acceptable levels. Furthermore, MAR Consulting will ensure that the assumptions and actions identified on the previous FSA (stage 1) were verified and acted upon. In addition, the client requested […]

FSA stage 4 on long operating oil and gas asset

MAR Consulting partly produced a functional safety assessment, FSA stage 4 of a long operating oil and gas asset in the Norwegian Continental Shelf (NCS). The main responsibilities were to assess the safety requirements specifications (SRS) for the different safety instrumented functions (SIF) required to operate the asset; and how they have been maintained and applied during the operating lifetime of the facility. Of special importance to an FSA stage 4 is to understand how functional safety has been maintained during the many years of operations. In general, nowadays, there is special focus and emphasis on functional safety during the […]

SIL study of over-speed modules for gas turbine generators and compressors

MAR Consulting performed a functional safety/SIL study of over-speed safety instrumented functions (SIF) protecting gas turbine generators (GTG) and gas compressors installed in a floating, production, storage and offloading (FPSO) vessel. The SIFs included 2oo3 voting speed sensors and 1oo3 voting valves controlled by over-speed modules. The work covered the following phases of the safety instrumented system (SIS) lifecycle, as per IEC61511 Ed.1 and the client’s internal guidelines: Allocation of functions to protection layers (phase 2) using layers of protection analysis (LOPA); Safety requirements specification (SRS) (phase 3) with general and specific one-pagers SRS datasheets; Safety integrity level (SIL) compliance (phase […]

Functional safety assessment of automated safety system

MAR Consulting AS performed a functional safety assessment (FSA) stage 1 of a new emergency shutdown system (ESD). The reason for the upgrade is to substitute an obsolete automated safety system in an operating offshore oil and gas facility in the North Sea. The safety instrumented system (SIS) lifecycles phases assessed in this FSA were: hazard analysis; allocation of safety functions to protection layers; the initial version of safety requirement specifications (SRS); management of functional safety plan and verification activities. MAR Consulting followed the methodology developed based on hands-on functional safety experience (e.g. http://www.marconsulting.no/2017/06/10/sil-compliance-for-fg-systems and http://www.marconsulting.no/2017/05/25/fsa-stage-1-of-subsea-production-system/). In essence, a detailed evaluation of the […]