Tubing annulus communication for vertical flow subsea well

A wellhead assembly, comprising:

• a tubular wellhead member;
• a tubing hanger for supporting a string of production tubing defining a tubing annulus around the outer circumference of the tubing;
• a tubing hanger support member which secures the tubing hanger relative to the tubular wellhead member;
• a valve block located above the tubular member, having at least one valve and a valve block passage extending axially therethrough for communicating with the string of production tubing;
• a production riser extending from a platform to the valve block with a production passage for conveying well fluid to a surface platform;
• a conduit extending from the platform alongside the riser;
• and
• a tubing annulus passage from the tubing annulus through the tubing hanger support member offset from the tubing hanger that communicates with the conduit.

A wellhead assembly, comprising:

• a tubular wellhead member;
• a tubing hanger for supporting a string of production tubing defining a tubing annulus around the outer circumference of the tubing;
• a tubing spool having a lower portion the that lands on and engages a grooved profile on the upper portion of the tubular wellhead member, which secures the tubing hanger relative to the tubular wellhead member;
• a valve block located above the tubular member, having at least one valve and a valve block passage extending axially therethrough for communicating with the string of production tubing, the valve block being adapted to connect to a production riser extending from a platform a production passage for conveying well fluid to a surface platform and being adapted to a connect to a conduit extending from the platform alongside the riser;
• and
• a tubing annulus passage from the tubing annulus through the tubing hanger support member offset from the tubing hanger that communicates with the conduit.

A method of producing a subsea well and communicating with a tubing annulus in the well, comprising the steps:

• (a) providing a subsea wellhead assembly;
• (b) lowering a tubing hanger into engagement with the wellhead assembly, the tubing hanger supporting a string of production tubing;
• (c) providing a tubing annulus passage through the wellhead assembly around the tubing hanger, the tubing annulus passage being in communication with a tubing annulus in the well around the string of production tubing;
• (d) connecting a riser assembly from a Christmas tree at the surface of the sea to the wellhead assembly;
• (e) extending a conduit alongside the riser assembly to the wellhead assembly so that the conduit is in fluid communication with the tubing annulus passage;
• (f) flowing well fluids up the tubing and the riser assembly to the platform;
• and
• (g) communicating between the surface platform and the tubing annulus through the conduit and the tubing annulus passage.