Disclosed are compliant variable tension risers (106) to connect
deep-water subsea wellheads (102) to a single floating platform (104).
The variable tension risers (106) allow several subsea well-heads (102),
in water depths from 4,000 to 10,000 feet, at lateral offsets from
one-tenth to one-half of the depth, to tie back to a single floating dry
tree semi-submersible platform (104). Also disclosed are methods to
counter buoyancy and install variable tension risers using a weighted
chain ballast line (228, 230).