Workover riser compensator system

A latch device for separating a workover riser from a sub sea isolation system in the event of over-tensioning of the workover riser, the latch device comprising:

• a first latch portion adapted to be connected to the sub sea isolation system;
• a second latch portion adapted to be connected to the workover riser, the second latch portion being moveable relative to the first portion from an operating configuration to a released configuration;
• a latch releasably connecting the first portion to the sub sea isolation system, the latch being movable between an engaged position in which the latch is engaged with the sub sea isolation system and a disengaged position in which the latch is disengaged from the subsea isolation system;
• wherein, in use, when the tension in the workover riser exceeds a pre-determined value, relative movement of the second latch portion with respect to the first latch portion from the operating configuration to a displaced configuration permits the latch to move from the engaged position to the disengaged position, releasing the latch device from the sub sea isolation system such that the workover riser is separated from the sub sea isolation system
• wherein the second portion moves relative to the first portion at a pre-determined tension which is selected, in use, to ensure that riser tensioning device will raise the workover riser clear of a plurality of subsea isolation system BOP rams, permitting unobstructed closure of the rams.