The JAS (Java Agent-based Simulation) Library

Drilling by the rotary method is conducted from a floating vessel. The driving joint of the drill string, e.g. a kelly driven by a rotary table or a top joint rotated by a power swivel, includes a splined telescopic joint and hydraulic piston and cylinder means whose pressure is controlled in response to a function of the drill string tension, e.g., dead line tension or cylinder pressure, to maintain desired drill string tension, e. g., constant tension, corresponding to desired bit loading. Motion of exterior part of driving joint relative to vessel is same as that of corresponding joint relative to drill rig operating on land; motion of part of drill string in hole relative to hole is same as that of drill string relative to hole when drilling on land.