Detonation assembly for explosive wellhead severing system

An apparatus for detonating an explosive charge positioned in a well bore using a firing assembly, said apparatus comprising:

• a fixed connector positionally captured within a well string extending into the well bore, said fixed connector having a first electrical contact and first conducting means electrically connecting said first contact to the firing assembly and the explosive charge;
• a lowerable connector movable through said well string into mating engagement with said fixed connector, said lowerable connector having an electrical energy source, a second electrical contact and second conducting means electrically connecting said energy source to said second contact;
• and
• retractable shutter means for sealingly electrically isolating said second electrical contact of said lowerable connector from the surrounding fluid environment to prevent discharge of said electrical energy source, said retractable shutter means longitudinally movable between a first position sealingly isolating said second electrical contact and a second position exposing said second electrical contact, said retractable shutter means biased towards said first position;
• said lowerable connector movable into mating engagement with said fixed connector moving said retractable shutter means longitudinally from said first position to said second position to engage said first and second electrical contracts thereby electrically connecting said energy source to the firing assembly detonating the explosive charge.

An apparatus for detonating an explosive charge positioned in a well bore using a firing assembly, said apparatus comprising:

• a fixed connector positionally captured within a well string extending into the well bore, said fixed connector having a first electrical contact formed on a male projection and first conducting means electrically connecting said first contact to said firing assembly, said firing assembly mounted within a shock absorbing cavity of said well string below said fixed connector;
• a lowerable connector movable through said well string into mating engagement with said fixed connector, said lowerable connector having a female receptacle with a second electrical contact disposed therein, an electrical energy source, and second conducting means electrically connecting said energy source to said second contact;
• and
• retractable means for sealingly electrically isolating said second electrical contact from the surrounding fluid environment to prevent discharge of said electrical energy source, said retractable means comprising a spring-biased piston movably disposed within said female receptacle between a first position sealingly isolating said second electrical contact and a second position exposing said second electrical contact, said retractable means biased towards said first position;
• said lowerable connector movable into mating engagement with said fixed connector, said male projection extending into said female receptacle moving said retractable means from said first position to engage said first and second contacts thereby electrically connecting said energy source to the firing assembly thereby detonating the explosive charge.

A connector assembly for completing a conductive path between a first apparatus and a second apparatus, said connector assembly comprising:

• a fixed connector positionally captured within a wall string, said fixed connector having a first electrical contact and first conducting means electrically connecting said contact to the first apparatus;
• a lowerable connector movable through said well string into mating engagement with said fixed connector, said lowerable connector having a second electrical contact and second conducting means electrically connecting said contact to the second apparatus;
• retractable means for electrically isolating said electrical contact of said lowerable connector from the surrounding fluid environment, said retractable means comprising a retractable sleeve movable between a first position sealingly isolating said second electrical contact and a second position exposing said second electrical contact, said retractable means biased towards said first position;
• said lowerable connector movable into mating engagement with said fixed connector to engage said electrical contacts thereby establishing an electrical path between the first and second apparatus, said isolating means retracting to expose said electrical contact of said lowerable connector as said lowerable connector engages said fixed connector.

A method for detonating an explosive charge within a well bore to sever a subsea wellhead comprising:

• positioning a first connector within the well bore, said first connector having a first electrical contact and first conducting means electrically connecting said first contact to a firing assembly for detonating the explosive charge;
• lowering a second connector into the well bore for mating engagement with said first connector, said second connector including an electrical energy source, a second electrical contact and second conducting means electrically connecting said energy source to said second contract, said second connector having longitudinally retractable shutter means movable between a first and second position and biased toward said first position for electrically isolating said second electrical contact to prevent discharge of said electrical energy source;
• retracting said shutter means as said first and second connector matingly engage to expose said second electrical contact;
• engaging said first and second contacts as said shutter means retracts thereby electrically connecting said energy source to the firing assembly;
• detonating the explosive charge to sever the wellhead;
• and
• removing the wellhead from the sea floor.