METHOD AND SYSTEM FOR INSTALLING SUBSEA WELL TREES

The disclosure provides a method and system of installing subsea well trees, comprising: creating a glory hole having a depth below a seabed at a well location of a hydrocarbon reservoir; moving a floating offshore platform coupled with a foundation, the platform having a topsides and a caisson with downwardly extending walls defining an inner volume between the walls, the foundation coupled to the caisson walls, and the caisson walls having adjustable buoyancy; lowering the offshore platform with the foundation into the glory hole; drilling from the topsides into the hydrocarbon reservoir below the foundation to create a well; installing a well tree on the well, the well tree being disposed in the glory hole below the height of the seabed; coupling the well tree to a flow line; releasing the offshore platform from the foundation; and reusing the offshore platform to install other foundations at other predetermined well locations.