Temperature activated zonal isolation packer device

A packer device for sealing against an inner surface of a surrounding pipe or casing string, for isolating zones or sections in an oil well, said packer device comprising:

• a tubing body,
• two expandable sealing elements,
• a cylinder/piston arrangement comprising a the cylinder and a movable element,
• wherein:
• the cylinder is closed at a first end thereof,
• the movable element is disposed at a second end of the cylinder, and
• said cylinder has a closed volume containing a fluid, arranged to expand when exposed to heat, thereby expanding said closed volume to exert a mechanical pressure on the movable element, initially locked in a fixed position by at least one shear member,
• the movable element is adapted to be released into an operative state at a predetermined axial force from said mechanical pressure exerted by the expanding closed volume in the cylinder, resulting in that the two expandable sealing elements are pressed radially outwardly so as to seal the packer device against the surrounding pipe-/casing string,
• the movable element comprises:
• an internal piston that is arranged inside the cylinder and which is axially movable along the tubing body, and
• an external piston that is connected to the internal piston and axially movable along the tubing body,
• the cylinder is axially movable along the tubing body,
• the two expandable sealing elements are attached to the tubing body and positioned one on each side of the cylinder/piston arrangement and against respective stop elements,
• the cylinder and the external piston are configured to move apart when the movable element is released into the operative state and the closed volume is expanded, and thereby expanding the two expandable sealing elements by means of the external piston being conically shaped and the first end of the cylinder being conically shaped, and
• the packer device comprises a locking system that is integrated in the cylinder and the external piston and which locking system keeps the two expandable sealing elements expanded,
• wherein the closed volume is defined by the cylinder and the internal piston.