Methods are provided in which reliance is placed on a first and second
barrier respectively positioned in a well 10 to provide well control
during well suspension, completion and/or workover operations. Each of
the barriers is below the depth of the lowermost end of a completion
string when that string is installed in the well. By not placing either
barrier higher up in the well-bore, both of the barriers can remain in
place during suspension and completion and workover operations, thus
obviating the need to use a BOP stack to supplement well control. This
results in a considerable saving in drill rig time and thus significantly
reduces the cost of constructing a well.