The TCO Annulus Pressure Relief System was developed to tackle the problem of trapped B-annulus pressure build-up due to thermal expansion during well start-up and production. The product is run as an integral part of the production casing and is approved as an ISO 14998 V0 barrier featuring a relief valve and check valves in addition to an integrated filtration system.
Conventional approaches constantly relieve pressure as the B-annulus pressure “tracks” the A-annulus pressure. Such constant pressure relief reduces the life of the well, risks barrier integrity and alters the supporting pressure inside and outside of the casing.
TCO’s patented Annulus Pressure Relief System makes the B-annulus pressure independent of the downstream back pressure in A-annulus, given that the B-annulus is greater than in the A-annulus and the relief valve opening pressure. This unique feature means that the volume that is bled off from B to A-annulus and the resulting pressure in B-annulus can be pre-determined through the relief valve setting.
The result is a reliable bleed of volume and a desired and known resulting B-annulus pressure, allowing for maintaining the production casing barrier and the B-annulus pressure support.
Features and Benefits
Applications