System Safety Integrity Level Analysis and Simulation for Subsea Valves

摘要

Safety Integrity Level (SIL) is becoming an important criteria(s) for acceptance for safety within the industry and this paper address system life cycle framework and the numerical simulation that relate to a High Integrity Pressure Protection System (HIPPS) Subsea Valve. The framework was based on the international standard IEC 61508 and IEC 61511 that provide the structure requirements relating to specification, design, integration, operation, maintenance, modification and decommissioning of a Safety Instrumented System (SIS). Simulation analysis of the SIS includes detailed Failure Mode and Effect Analysis (FMEA) leading to Fault Tree Analysis with logic table for each of the four cases: Safe Detected, Safe Undetected, Dangerous Detected and Dangerous Undetected. These safety analyses were based on the methodology within the IEC 61508, providing a structured verification process and the results were used to validate the HIPPS in compliance with Safety Integrity Level (SIL) 3 requirements. HIPPS is systems which are currently installed on the Subsea production system as a secondary barrier to prevent high pressure in the flowlines and risers.