| 摘要 |
<p>The present invention relates to a method of installing one or more subsea templates at preselected sites on a seabed. The method is comprised of the steps of providing a column stabilized variable draft semisubmersible drilling rig having at least one submersible hull including a unit for supporting a template on the hull, a derrick, primary apparatus associated with the derrick for raising and lowering a riser through a moon pool on the rig spaced laterally from the hull, and secondary hoisting apparatus on the rig including a cable unit adapted to be connected to the template. At least one submersible template is adapted to have controllable positive and negative buoyancy. The steps further include loading the template on the support unit for the template using a crane and at least one of the hoisting apparatus to position the template over the support unit; lowering the template onto the support unit and ballasting the template to shift the weight of the template to the support unit; and transporting the template to a predetermined site on the seabed with the drilling rig. The method further includes the steps of connecting the template to the primary and secondary hoisting apparatus; venting ballast from the template to float the template free of the support unit while controlling the position of the template with the hoisting apparatus; taking up the primary hoisting apparatus and slacking off the secondary hoisting apparatus to position template under the moon pole; and lowering the template to the seabed with the hoisting apparatus.</p> |
