Reliability modelling of over-pressure protection systems for oil and gas flowlines

Strategies such as providing a SIF on the common outlet from a wellhead tower, providing additional relief capacity and reducing sources of common cause failures were found to be effective in increasing the risk reduction factor achieved by the over-pressure protection system. Where such measures are insufficient, an alternative solution is to design all lines to the well shut-in pressure. This approach transfers the risk of over-pressure to the downstream separator, which must then be provided with adequate protection measures.