Measuring and testing – Borehole or drilling – Downhole test
Patent
1991-03-18
1994-09-20
Williams, Hezron E.
Measuring and testing
Borehole or drilling
Downhole test
3408543, 3408557, 439 27, E21B 4700
Patent
active
053478592
DESCRIPTION:
BRIEF SUMMARY
The present invention concerns a dynamometric measuring device for a drill pipe.
To produce a dynamometric device to measure forces and stresses exerted on the drill pipe, the major problem is not to take the measurement but to transmit it under optimal conditions to the data-acquisition unit responsible for processing it. Thus, taking into account the length of the cables linking the measuring unit to the data-acquisition unit, it is essential to guard against all conceivable causes of deterioration of the signals to be transmitted.
Furthermore, it is necessary to transmit the electrical signals from the rotating assembly constituted by the drill string to a fixed reference point constituted by the mast.
Finally, it is necessary to take steps to prevent the transmitted signals from being distorted by the passage from the moving parts to the fixed parts.
A first object of the invention is therefore to alleviate at least one of these disadvantages.
This object is achieved by the fact that the dynamometric measuring device for a drill pipe comprises, firmly attached to the rotating pipe, sensors and electronics for conditioning the signals supplied by these sensors, these electronics being firmly attached to the rotating parts, the sensors being disposed in a groove and the measurement signals being transmitted to a fixed part by a rotating commutator-fixed brush assembly, the crossing of the commutator-brush assembly being carried out at zero current.
According to another feature of the invention, the measurement signals from each sensor are transmitted by a channel constituted by an independent track and an earth track, each of the two tracks being in contact with a double pair of brushes, each brush having a characteristic resonant frequency.
According to another feature, the device comprises sensors for measuring the traction, the torsion, the longitudinal and transverse accelerations, the temperature and the speed of rotation of the drill pipe.
Another object of the invention is to ensure a compromise between the maneuverability and the location of the electronics.
This object is achieved by the fact that the electronics, firmly attached to the rotating parts and connected between the sensors and the rotating commutator, are constituted by amplifier stages of low output impedance for each measurement channel.
According to another feature, the power supply to the rotationally driven electronics is ensured by two supplementary channels.
Another object of the invention is to improve significantly the information, from the sensors, that one can exploit.
This object is achieved by the fact that a second electronic circuit is mounted on the fixed part connected to the brushes, this electronic circuit comprising, on the output side of each brush, a stage of follower-amplifiers of very high input impedance.
Another object of the invention is to limit to a minimum the number of compatible channels while maintaining the highest quality of signal analysis.
This object is achieved by the fact that the second electronic circuit comprises, on the output side of each follower-amplifier, a separation circuit for the DC component and a separation circuit for the AC component of the signal.
According to another feature of the invention, the separation channel of the DC component comprises a low-pass filter of cut-off frequency equal to 10 kHz in series with a line amplifier.
According to another feature of the invention, the separation channel of the AC component comprises a capacitor for cutting off the DC component, in series with a variable band-pass filter having a lower cut-off frequency of 0.1 Hertz and an upper cut-off frequency of 1 kHz and in series with the line amplifier.
Another object of the invention is to constitute a device that is reliable, sealed and flameproof.
This object is achieved by the fact that the assembly is mounted in a volume limited at its ends by upper and lower collars which are mounted so as to rotate with respect to the drill pipe and to form a seal, and a cylindrical sheath of length c
REFERENCES:
patent: 1665822 (1928-04-01), Shimizu
patent: 3047827 (1962-07-01), Stoddard
patent: 3614726 (1971-10-01), Richter, Jr. et al.
patent: 3626482 (1971-12-01), Quichaud et al.
patent: 3714822 (1973-02-01), Lutz
patent: 3855857 (1974-12-01), Claycomb
patent: 4190804 (1980-02-01), Pyne et al.
patent: 4545261 (1985-10-01), Gebben
patent: 4715451 (1987-12-01), Bseisu et al.
patent: 4821563 (1989-04-01), Maron
Thomas and Rosa, "Circuits and Signals: An Introduction to Linear and Interface Circuits", NY, John Wiley & Sons, 1984, pp. 164-166.
Horowitz and Hill, "The Art of Electronics", Cambridge, Cambridge University Press, 1980, pp. 53-55, 95 & 96.
Clayer Frederic
Henneuse Henri
Lutz Jean
Tanguy Jean-Luc
Brock Michael
Societe Nationale Elf Aquitaine (Production)
Williams Hezron E.
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