Sensitive deep-well-drilling hook load measuring system
AssigneeTexaco Inc.
InventorsHerbert A. Rundell, Russell W. Hall, Jr.
Life of this patent
Estimating the term…
Abstract
A hook load measuring system for improving the sensitivity of such measurements in deep-well-drilling operations. It employs a transducer actuated by the hook load and an output signal from the transducer that covers the full range of hook-load variation. There is an arrangement for nulling the signal at any given setting, and then for measuring change in a predetermined direction with greatly increased sensitivity.
Claims2
In a deep-well-drilling combination employing a derrick having a crown block for supporting a sheave, a traveling block with pulley for supporting a hook to support a drill string and a bit at the lower end thereof, and a cable passing over said sheave and pulley, said cable being anchored at one end with a weight transducer for measuring the hook load, the improvement comprising in combination
- a potentiometer having a sliding contactor actuated by said transducer in proportion to said hook load,
- means for applying an electromotive force to said potentiometer,
- a second potentiometer connected to said electromotive force and having a sliding contactor,
- circuit means for connecting said sliding contactors to measure the difference in electric potential,
- said circuit means comprising
- a variable resistor,
- a meter for measuring said difference in potential,
- a fixed resistor, and
- amplifier means connected across said fixed resistor for amplifying the input to said meter,
- a precision third potentiometer,
- a null meter, and
- additional circuit means including switch means for calibrating said first and said second potentiometers.
In a deep-well-drilling combination employing a derrick having a crown block for supporting a sheave, a traveling block with pulley for supporting a hook to support a drill string with a bit at the lower end thereof, and a cable passing over said sheave and pulley, said cable being anchored at one end with a weight transducer for measuring the hook load, the improvement comprising in combination
- a first potentiometer having a sliding contactor actuated by said transducer in proportion to said hook load,
- a source of DC potential,
- a second potentiometer having a resistor connected across said potential source and having a sliding contactor,
- a variable resistor connected in series with said second potentiometer sliding contactor,
- a galvanometer having an input circuit,
- a DC amplifier having an input and an output,
- a fixed resistor connected in series with said variable resistor,
- first circuit means for connecting said DC amplifier input across said fixed resistor,
- second circuit means for connecting said DC amplifier output to said galvanometer input circuit,
- a multipole multiposition switch,
- third circuit means for connecting said fixed resistor to one pole of said switch,
- fourth circuit means for connecting said first potentiometer sliding contactor to one position of said switch corresponding with said one pole,
- a precision third potentiometer,
- a null meter, and
- fifth circuit means including said switch poles and positions for alternatively measuring said hook load or calibrating said second potentiometer or calibrating said first transducer-actuated potentiometer.
Dependencies are inferred from the claim text.