Casing hanger annulus monitoring system

A method for communicating with a casing annulus in a wellhead assembly comprising the following steps:

• (a) providing a casing hanger in a bore of a tubular wellhead member, a casing annulus formed around a string of casing hanging from the casing hanger, and a passage that is in fluid communication with the casing annulus and the bore of the wellhead member;
• then
• (b) locating a valve in the wellhead member and closing the passage with the valve;
• then
• (c) cooperatively landing a lower component of a tubing hanger assembly in the bore of the wellhead member, engaging the valve with the lower component, and moving the valve from the closed position to an open position.

A subsea wellhead assembly comprising:

• a tubular wellhead housing having a bore, the wellhead housing being adapted to register with a tree assembly;
• a casing hanger adapted to be secured to a string of casing defining a casing annulus, the casing hanger landing in the bore of the wellhead housing;
• a casing annulus passage extending through a sidewall of the casing hanger from the casing annulus into the wellhead housing above the casing hanger;
• a barrier within the casing annulus passage that has an initial configuration blocking flow through the casing annulus passage;
• and
• the barrier being movable without being retrieved to open the casing annulus passage to allow monitoring of pressure within the casing annulus.

A method for communicating with a casing annulus in a wellhead assembly comprising the following steps:

• (a) providing a casing hanger in a bore of a tubular wellhead member, a casing annulus formed around a string of casing hanging from the casing hanger, and a casing annulus passage in a sidewall of the casing hanger that is in fluid communication with the casing annulus and the bore of the wellhead member;
• (b) locating a barrier in the casing annulus passage, the barrier having an initial configuration that blocks flow through the casing annulus passage;
• then
• (c) without retrieving the barrier, moving the barrier from the initial configuration to open the casing annulus passage.