Changes

===Platforms===

===Platforms===

[[file:offshore-rigs_fig2.png|thumb|{{figure number|2}}Jackup rigs.<ref name=pt03r50 />.)]]

[[file:offshore-rigs_fig2.png|thumb|{{figure number|2}}Jackup rigs.<ref name=pt03r50 />]]

''Platforms'' use a ''jacket'' (a steel tubular framework anchored to the ocean bottom) to support the [[surface production equipment]], living quarters, and drilling rig ([[:file:offshore-rigs_fig1.png|Figure 1]]). Multiple [[Wellbore trajectory|directional wells]] are drilled from the platform by using a rig with a movable substructure. The rig is positioned over preset wellheads by jacking across on skid beams. After all the wells are drilled, the rig and quarters are removed from the platform. Smaller platforms use a jackup rig to drill the wells.

''Platforms'' use a ''jacket'' (a steel tubular framework anchored to the ocean bottom) to support the [[surface production equipment]], living quarters, and drilling rig ([[:file:offshore-rigs_fig1.png|Figure 1]]). Multiple [[Wellbore trajectory|directional wells]] are drilled from the platform by using a rig with a movable substructure. The rig is positioned over preset wellheads by jacking across on skid beams. After all the wells are drilled, the rig and quarters are removed from the platform. Smaller platforms use a jackup rig to drill the wells.