Quantitative Determination of Safety Integrity Level on Offshore Metering and Custody Transfer Facility

Abstract

A quantitative way for determining the Safety Integrity Level of Safety Instrumented System (SIS) on Offshore Metering and Custody Transfer Facility in Campeche Bay Mexico is presented in this work. The methodology that was employed in order to assess and determine the Reliability parameters of SIS; which was carried out in three steps: 1. Identify undesirable events that can damage to personnel using the API-14C and to, the facility and the environment (by oil spill in hoses when the oil tanker is filled), 2. Estimate the severity and consequences of risk, using safety layer matrix of ISA S84.01 and, 3. Quantify the severity of each risk identified with the fault tree analysis. This last step uses the minimal cut sets, an innovative concept in petroleum industry, this provides valuable information about possible combinations of fault events, that can result in a critical failure of the system. The period of maintenance of the main SIS components (sensors, logic solver and final element), was reduced applying redundancy in the primary element. Furthermore, the results obtained of this analysis can be used by insurance companies or institutions that certify under standards of process quality and safety.