It is widely recognized that gas lifted wells introduce more risk to an OPCO’s production facilities, than any other well type. This is because, unlike other wells, gas lifted wells always have a large volume of pressurised gas in the tubing - casing annulus (TCA), commonly referred to as the ‘A’ annulus. They also introduce a potential leak path from the tubing to the TCA or A Annulus.
Excerpts from the ‘de facto global standard’ well integrity guidelines, published by NORSOK [1] and Oil and Gas UK [2], are shown below. They respectively describe the volume of pressurised gas in a gas lifted well TCA as a “significant risk” and a “major accident hazard”.
This white paper discusses these risks and shares examples of where they have resulted in incidents in the past. The industry best practices, which are increasingly being employed by international OPCOs and NOCs, to reduce the risks to a level, which is currently considered As Low As Reasonably Practicable (ALARP), are described. Finally, the technologies being used to achieve an ALARP risk level in gas lifted wells are described in detail.
