Automatic drilling process and apparatus

摘要

This invention relates to a process of automatic drilling with an in-hole motor particularly of the turbine type. The invention relates to apparatus and process by which the draw works responsive to a signal generated by an in-hole tachometer in the form of a train of pulses of period responsive to the rpm of the motor is sensed by a pressure transducer which generates a signal which is responsive to the rpm of the motor telemetrically in the form of the train of pulses. The signal is converted into a pressure applied to the brake of the draw works driven to hold the tension on the drilling lines and thus holds the rpm of the motor substantially consistant. In the best mode disclosed, this is accomplished by producing an electrical signal responsive to the train of pulses and storing said signal between pulses and generating a pneumatic pressure responsive to the stored signal and applying a force to said driver responsive to said last named pressure.