Abstract
The origins of offshore drilling work and the development of structures used at sea are traced. Comparison of the various types illustrates the advantages and disadvantages of each. Tables show the numbers in operation, being built, and the apparent liability of each type to damage.
Typical bore-hole structures are illustrated, the need for undersea well-heads explained and their development into a sea-bed completion is discussed. Much more research is necessary before this can be considered a practical proposition.
The design of drilling barge equipment is compared with typical land rigs and the development of drilling equipment, including the sophisticated electric drive and turbo-drill, discussed.
Rigs in various types of barge are compared. Fire precautions and other safety equipment are described. The problems associated with control by the driller lead to complications of motive power layout.
The lecture describes in some detail the design of the semi-submersible drilling barge Sea Quest, illustrates the weight problems and their effect on floating stability and indicates the need for management decisions on the degree of resistance to damage. This is measured by the variable deck load of drilling equipment that can be held on board and the degree of weather deterioration that can be tolerated before disengaging the drill from the hole.
The need for, and extent of, diving is discussed, with some comparison between diving vehicles. Weather too is an essential factor of work in the North Sea and both pre-surveys and day-to-day reporting are described.
Get full access to this article
View all access options for this article.