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.

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 […]

Reliability assessments of safety critical equipment

MAR Consulting AS is performing periodic reliability assessments of different types of safety critical equipment installed on the offshore platforms of a major Danish oil and gas operator. Among others, the assessment covers shutdown valves, blow down valves, different types of sensors and transmitters, etc….The work consists of extraction of offshore failure reports; failure analysis and classification; and calculation of failure rates and probability of failure on demand (PFD). The results are directly utilized to adjust (or support) the preventive maintenance intervals, resulting in major cost savings and/or increased safety and reliability.