Apparatus and Method for Separating a Tubular String from a Subsea Well Installation

An apparatus for separating a tubular string from a subsea well installation, the apparatus comprising:

• a heave compensator operable to place the tubular string in tension;
• a subsea actuator assembly positioned within the tubular string having a piston initially fixed relative to a cylinder that define a chamber therebetween;
• a subsea controller operably associated with the subsea actuator assembly;
• a subsea safety tree operably associated with the tubular string including a retainer valve, a shut-in valve assembly, a vent sleeve and a latch assembly;
• and
• a fluid delivery subsystem in fluid communication with the chamber and the retainer valve, the shut-in valve assembly, the vent sleeve and the latch assembly,
• wherein an output signal of the subsea controller generated responsive to receipt of a predetermined input signal releases the piston such that the tension in the tubular string shifts the piston relative to the cylinder causing operating fluid within the chamber to energize the fluid delivery subsystem, thereby actuating the retainer valve, the shut-in valve assembly, the vent sleeve and the latch assembly.

An apparatus for separating a floating facility from a subsea well installation, the apparatus comprising:

• a heave compensator operably associated with the floating facility;
• a tubular string supported in tension by the heave compensator, the tubular string including a subsea safety tree operably associated with the subsea well installation, the subsea safety tree including a retainer valve, a shut-in valve assembly, a vent sleeve and a latch assembly;
• a subsea actuator assembly positioned within the tubular string having a piston initially fixed relative to a cylinder that define a chamber therebetween;
• a subsea controller operably associated with the subsea actuator assembly;
• and
• a fluid delivery subsystem in fluid communication with the chamber and the retainer valve, the shut-in valve assembly, the vent sleeve and the latch assembly,
• wherein an output signal from the subsea controller releases the piston such that the tension in the tubular string shifts the piston relative to the cylinder causing operating fluid within the chamber to energize the fluid delivery subsystem to actuate the retainer valve, the shut-in valve assembly, the vent sleeve and the latch assembly.