Disclosed are compliant variable tension risers (106) to connect
deep-water subsea wellheads (102) to a single floating platform (104) in
wet tree or dry try systems. The variable tension risers (106) allow
several subsea wellheads (102), in water depths from 1220 to 3050 meters,
at lateral offsets from one-tenth to twice the depth or more, to tie back
to a single floating platform (104). Also disclosed are methods to
counter buoyancy and install variable tension risers using a weighted
chain ballast line (228, 230).