A method and apparatus for drilling and completing multiple wellbores from
a single drilling rig and from within a single wellhead is provided. In
one embodiment, a template is disposed at a predetermined location
downhole within a casing. In one aspect, a first casing string is lowered
with the template to the predetermined location and disposed within a
first wellbore. A second wellbore may be drilled through a bore in the
template. A second casing string may then be lowered through the bore
into the second wellbore. In another embodiment, at least two wellbores
are drilled and completed from a surface casing having a crossover
portion.