DOWNHOLE PRESSURE RELIEF APPARATUS

摘要

A downhole pressure relief apparatus (10) comprises a tubular member (18) configured to be located within a wellbore (12) to at least partially define a wellbore annulus (26), wherein the annulus (26) is subject to varying fluid pressure, and a chamber (36) associated with the tubular member (18). A valve arrangement (38) associated with the chamber (36) is provided and is configurable from a closed state to an open state in response to a pressure event, wherein, in use, in the closed state the chamber (36) is isolated from the wellbore annulus (26), and in the open state fluid (28) is permitted to flow into the chamber (36) from the wellbore annulus (26) to relieve pressure within said annulus.