Arrangement for controlling the progress of deep-well drilling

摘要

861,606. Boring earth. LICENTIA PATENTVERWALTUNGS-G.m.b.H. Nov. 8, 1957 [Nov. 12, 1956], No. 34872/57. Class 85. Deep well drilling rig, in which the drill bit 4 is driven by an electric motor 3 mounted at the lower end of a drill pipe 2 suspended from a winch 7, is controlled by circuits so interlinked that the rate of drilling is automatically adjusted to an optimum value. Liquid to wash out the cuttings is supplied to the pipe 2 by a hose and pump 8. Preferably the winch 7 is electrically driven. The difference between the desired torque and the actual torque at any given moment is fed through a circuit a to a regulator 15 which automatically controls the drive of the winch 7 to change the pressure of the pipe 2 on the drill and so restore the torque to the optimum value. A circuit b includes a regulator 17 responsive to the rate of drilling to vary the output of the pump 8 supplying water to the pipe 2. When the pump reaches its maximum output, the circuit b is put into reverse and used to regulate the rate of drilling. The optimum torque of the motor, which depends on the characteristics of the motor, is fed to an adjusting device 10 while the actual torque at any given time is fed to a converter 11, the difference between the two torques being determined by a device 14 in circuit with the regulator 15, which, if the working torque is too great, increases the torque on the winch to relieve the load on the drill bit and vice versa. The devices 10, 11, 14 and 15 maybe operated by D.C. The speed v at which the drill descends is recorded by a converter 12 and compared in a device 171 with the quantity of liquid fed by the pump 8, this quantity being measured and conveyed by a device 13, which feeds the device 17SP1/SP. The difference recorded by the device 171 is fed to the regulator 17 to change the output of the pump. When the output reaches its maximum a contact 8 closes and the rate of drilling is then controlled by the pump output. Variation in the output takes effect at the drilling bit with a time lag dependent on the length of pipe. This is compensated through a connection e from the regulator 17 to the servo-motor of the winch 7. A circuit d feeds the torque adjustment from the regulator 17 to the adjusting device 10. The liquid output is connected through a regulator 16 and a circuit f to the drive for the winch. The system may be operated using D.C. voltages as measuring means and to control values. The rate of drilling is determined by coupling a tachometer to the pulleys carrying the cable 5. Electromagnetic, hydraulic, electro-hydraulic or electro-pneumatic regulating systems may also be used.