Glossary

Jack-up rig

mobile offshore drilling platform with retractable legs on which the platform rests on the sea bed when in use. Used for drilling in relatively shallow water.

Jacket

the structure used to support an offshore steel production platform.

Jacket platform

a platform constructed entirely of steel. Such platforms are generally kept in position by means of steel piles driven into the sea bed.

Jet bit

a modified drill bit utilising a hydraulic jet to increase the drilling rate.

Jets

the nozzles (usually three in number) in the drill bit through which the drilling mud emerges from the drill string during drilling operations.

Joint venture

an investment undertaken by a consortium, usually with one member acting as operator.

Jug hustler

a member of a seismic crew who operates the geophones

Junked

when equipment is lost down a well and cannot be retrieved economically (or fished), the well is junked, i.e. plugged and abandoned

Jurassic period

the period of geological time which began roughly 180 million years ago and ended roughly 130 million years ago.