Patent ID: 8393415
Filing Date: 2013-03-12
Classification: E21B

Abstract:
1. A programmable logic controlled (PLC) subsoil automatic rotary drilling system for drilling oil, mineral and water wells and forming a pipe casing in a drilled well, wherein said system comprises, on a single supporting fixed or skidding substructure, a vertically extending drilling derrick associated with a plurality of pulling and pushing hydraulic cylinders acting in parallel to raise and lower an attachment, said attachment being connected to a fixed reference with cables and pulleys to provide a lifting cable end with a mechanical advantage greater than 2, for lowering and raising a plurality of well casing forming pipe elements to be introduced into and removed from a wellbore being drilled by said drilling derrick, each said cable having a dead end fixed to a cylinder carriage also supporting a plurality of transmission pulleys to handle together, while providing a standard hydraulic double acting cylinder system, two or three drilling pipe elements threaded together, having each a length of about 9.20 m, thereby said well casing forming pipe elements on said single supporting substructure are handled in a fully automatic manner to form said well casing, said drilling derrick reciprocally supporting a bidirectionally vertically movable rotary driving head, said driving head being supplied with and handling drilling bits, casing pipe elements, fittings and stabilizer elements and being driven by pulling hydraulic cylinders to overcome combined bending and compressive stress forces, wherein said drilling system further comprises, on said single supporting substructure, automatic swinging pipe element loader means for automatically gripping and loading said well casing forming pipe elements, wherein said pulling and pushing hydraulic cylinders vertically lift and lower said driving head by a vertical stroke corresponding to three times a stroke of said hydraulic cylinders, and wherein said driving head is a brakable driving head being braked as an operating load on said driving head exceeds a threshold operating load.