APRS - Annulus Pressure Relief System

Annulus pressure build‑up (APB) is a critical well integrity risk, particularly in subsea, HPHT, and long cemented wells where trapped annular fluids expand during start‑up and production. If unmanaged, APB can lead to casing collapse, casing burst, or loss of well barriers—jeopardizing safety, production, and well life.

TCO’s Annulus Pressure Relief System (APRS) is a field‑proven solution designed to safely and predictably manage B‑annulus pressure throughout the life of the well. Integrated directly into the production casing, APRS provides controlled, one‑way pressure relief from the B‑annulus to the A‑annulus when a predefined absolute pressure threshold is reached. Once excess pressure is relieved, the system automatically closes, maintaining a known and stable annulus pressure.

Unlike conventional approaches such as burst disks or continuous bleed systems, APRS preserves casing support pressure and well barrier integrity. The system is fully ISO 14998 V0 gas‑tight qualified, incorporates check valves to prevent backflow, and includes integrated filtration to ensure reliable operation in debris‑sensitive environments.

APRS requires no surface access or intervention, making it ideally suited for subsea and hard‑to‑access wells. By preventing casing failure, maintaining production tubing barriers, and eliminating sacrificial components, APRS delivers a robust, long‑term safeguard for well integrity.