Drilling rig contracts are lengthening, in response to increasing demand, reduced rig availability, and long lead times for new construction.Additional newbuild contracts, and announcements of new rig construction yards may increase supply in a few years, but manufacturing bottlenecks remain. Capital expenditure announcements indicate that worldwide drilling activity will be steady in 2007.Rig contractsDrilling contractors are attracted by both high day rates and long contract duration. The worldwide increase in day rates for most drilling units is reported regularly in the media. But a study by Rigzone noted the increasing length of contract periods for different rig types, across 13 dif...