Patent ID: 7946790

Claim:
A bottom-surface connection installation for at least two undersea pipes resting on the sea bed, the installation comprising: a first hybrid tower comprising: a first rigid pipe having a vertical riser with its bottom end fastened to a first base anchored to the sea bottom at a depth of at least about 1000 m and connected to a first said undersea pipe resting on the sea bottom, and having its top end tensioned in a substantially vertical manner by a first float immersed under the surface, at a depth of at least about 100 m, to which said top end is connected; and a first flexible connection pipe providing a connection between a floating support and the top end of said vertical riser; and at least one second rigid pipe rising from the sea bottom where it rests or from a second undersea pipe resting on the sea bottom and to which its bottom end is connected, to below the surface, where its top end is connected to at least one respective second flexible connection pipe connecting it with the same said floating support: wherein the bottom end of said at least one second rigid pipe is not anchored to said first base; wherein the top end of said at least one second rigid pipe is connected respectively to a second float situated substantially at the same depth as said first float and fastened rigidly to said first float, one against the other; and wherein said second rigid pipe is selected from the group consisting of a catenary pipe constituted by the end of a said second undersea pipe resting on the sea bottom rising to below the surface following a catenary curve with essentially continuously variable curvature up to said second float; and a second vertical riser, having its bottom end fastened to a second base anchored to the sea bottom independent from said first base and connected to a second undersea pipe resting on the sea bottom; and wherein both said first and second bases comprise anchors embedded in the sea bottom and spaced apart, so that the two vertical risers form between them an angle α of from about 1° to about 10°.