FPSO availability effect on 3rd party liquid evacuation

MAR Consulting performed an availability study of a floating, production, storage and offloading (FPSO), which will be operating in the Eastern Mediterranean Sea. The development plan envisages the use of an FPSO with full offshore processing capabilities of the reservoir fluids. Conditioned gas will be exported to shore and tie-in to the country’s gas distribution grid. The associated light oil will be exported offshore by tandem offloading to a shuttle tank. The FPSO storage tanks were being considered to evacuate a third-party operator light oil from a nearby field, in addition to the light oil from the FPSO’s own operating field. […]

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 […]

Cyber-security assessment of SAS/ESD system

MAR Consulting performed a cyber-security assessment of a recent upgraded safety and automation system (SAS) on a platform in the North Sea. The main focus was on the emergency shutdown system (ESD) and supporting data network infrastructure. Cyber-security assessments are now required by functional safety standard IEC 61511:2016 Ed. 2. The main objective of the study was to identify cyber-security threats, breaches, and vulnerabilities in the system, with the potential to cause damage and downtime to the platform. Confidentiality consequences were not considered in this study. Each identified scenario was described in terms of consequences, existing barriers and risk ranked […]

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 […]

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.