Cap assembly for use with a tubing spool of a wellhead

A method of closing a subsea well in which the well having a wellhead with production tubing extending downwardly therefrom into an underground formation, the method comprising:

• affixing a tubing spool to the wellhead, said tubing spool having a tubing hanger therein, said tubing hanger supporting the production tubing;
• connecting a capping body to an upper end of said tubing spool, said capping body having an interior passageway extending therethrough so as to open at an upper end and at a lower end thereof, said interior passageway being aligned with said production tubing, said capping body having a valve cooperative with said interior passageway;
• inserting a plug into said tubing spool so as to plug said production tubing;
• closing said valve within said interior passageway of said capping body so as to prevent fluid from the subsea well from flowing outwardly of said interior passageway;
• opening said valve of said capping body so as to open said interior passageway;
• engaging said plug by a wireline extending through said interior passageway;
• and
• removing said plug by drawing said plug through said interior passageway.

A system for capping and closing a well, the system comprising:

• a wellhead;
• a production tubing extending through said wellhead;
• a tubing spool mounted on said wellhead, said tubing spool having a tubing hanger therein, said production tubing supported by said tubing hanger, said tubing spool having a mandrel extending upwardly therefrom;
• a capping body having a single interior passageway, said capping body having a connector at a bottom thereof, said connector affixed to said mandrel of said tubing spool so as to align said interior passageway of said capping body with said production tubing, said capping body having a mandrel extending upwardly therefrom, said interior passageway of said capping body extending through said connector and through said mandrel of said capping body so as to open at an upper end and at a lower end of said capping body, said capping body extending in end-to-end relationship with said tubing spool;
• at least one valve affixed to said capping body and located within and cooperative with said interior passageway thereof, said valve movable between a first position closing said interior passageway and a second position opening said interior passageway;
• and
• a plug positioned in said tubing spool so as to seal said production tubing, said plug positioned below said capping body so as to seal said production tubing, said interior passageway of said capping body having a diameter greater than a diameter of said plug so as to allow said plug to be removed by being pulled upwardly through said interior passageway when said valve is in the second position.