Updated as of: 29 May 2024 UTC+8

Skills required

Conducted a flow assurance and economic analysis using OLGA software to evaluate the cost-effective isolation method for a riser shutdown (SDV) valve replacement. Used the up-to-date compositional analysis, and incorporated pressure, temperature and flow trends into the simulation model. Developed specific procedure steps required for the depressurization to be done safely to avoid potential asset damage. Saved the company USD1mil by recommending the more cost-effective method.

Why depressurize pipeline?

In 1988 Piper-A (Piper Alpha) was engulfed in flames, killing 165 people (61 survived). Among the contributing factors were the continuous fuel feeding the fire from satellite platform Tartan.

graph TD
  Tartan -- oil --> Claymore -- oil --> Tee[ ]:::empty
  Tartan -- gas --> Piper-A --- Tee --> Flotta[Flotta oil terminal]
  Piper-A -- gas --> Claymore
  Piper-A -- gas --> MCP-01 -- gas --> Fergus[St Fergus gas terminal]
  Frigg -- gas --> MCP-01
  classDef empty width:0px,height:0px;

A riser SDV (shutdown valve) could prevent such occurrence, and therefore is a critical safety equipment. In my case, the riser SDV was passing and could not

Subsea to CPP pipeline depressurization