FR2483006A1 - APPARATUS AND METHOD FOR SIGNALING THE INTERIOR OF A MINE HOLE DURING DRILLING - Google Patents

Abstract

INVENTION RELATING TO DRILLING. ELECTROMAGNETIC SIGNALING DEVICE FROM INSIDE A MINE HOLE DURING DRILLING, TO A SURFACE STATION. IN A CONNECTION OF THE DRILL RODS, A TRANSFORMER 12 INCLUDES A WINDING CONNECTED BETWEEN TWO PARTS 6 AND 7 OF THE ELECTRICALLY ISOLATED TRAIN AND MEANS OF EMISSION AND OR RECEPTION OF SIGNALS 11 ARE CONNECTED TO THE OTHER WINDING OF THE TRANSFORMER. THE FIRST PART 6 PROVIDES A CURRENT PATH TO THE SAID STATION AND THE RETURN PATH THROUGH THE SECOND PART 7 AND THE FIELD. APPLICATION TO ROTARY TYPE DRILLING.

Description

The present invention, concerning the

  rage, relates to an apparatus and a method of signaling from the inside of a borehole being drilled. The invention also relates to a connector for telemetry in a train

of drill rods.

  Various measurement systems have been proposed to accompany drilling to perform measurements

  from the inside of a borehole, while the

  rage is in progress and transmit the measurement values to the surface. As with such systems there is no time wasted to remove the drilling rig and to insert a measuring probe into the borehole, these measuring systems during drilling save a lot of time. drilling and as a result significantly reduce the overall cost of the drilling operation. The systems that have been proposed so far can be classified into four basic types, namely the

  mud pressure pulse systems, the systems

  electromagnetic systems, metal wire systems

  acoustic systems. A range of electromagnetic systems have been proposed

  all rely on the transmission of

  electromagnetic training by the earth and / or the drill string. Nevertheless, none of the electromagnetic systems proposed so far has

  a reasonable signal-to-noise ratio for

  detected on the surface and consequently the speed

  transmission of information is highly

  moth-eaten. U.S. Patent No. 2,354,887 discloses an electromagnetic system in which measurement information signals are pulsed into a toroidal coil surrounding the drill string near the bit. . A variable magnetic field is associated with the pulsating current flowing in the coil and this field induces signals in the form of currents

  pulsed in the drill string. The circuits of

  The tower, offering itself to the currents which circulate in the train of stems as a result of this phenomenon, passes through the earth itself. The transmitted signals are detected at the surface in a receiving station connected between the drill string and an electrode grounded at a distance

  of the drill string. Nevertheless, because of the attenuation

  signals in the earth and losses in the coil core, the signal-to-noise ratio of the detected signals is poor and the system is

satisfactory in practice.

  The object of the invention is to provide a signaling apparatus which constitutes a system

  electromagnetic system that is inexpensive and capable of

  to put signals at high speed, with a report

acceptable signal-to-noise port.

  According to the invention, the apparatus

  signaling system incorporates a transfor-

  meter whose winding is connected

  between a first part of the drill string

  used to drill the borehole and a second

  part of the drill string which is electrically isolated from the first part and means for transmitting and / or receiving signals are electrically connected to the other winding of the transformer; the first part providing a current path to the signals flowing between the transformer and a receiving and / or transmitting station located at a location

  distant in line with the drill string

  rage and a return path is provided between the transformer and the receiving station and / or

  transmission of signals through the

  part one and field formations through

which one drills the hole of mine.

  Preferably said winding is the

  secondary bearing of the transformer and said

  other winding, the primary winding of the

  trainer and means of transmission-or issuance-

  Sion are electrically connected to the primary winding

  mayor to transmit signals to a station

remote reception.

  With this system the size of the transformation

  the number of revolutions of primary and secondary

  the transformer can be selected from

  to reduce losses in the core. In addition, the transformer, which is advantageously of the toroldal type, can be very small, so that it is of little storytelling and can be housed inside a small chamber formed in the drill string wall. Like the losses

  in the core are weak, the needs of

  of the means for transmitting and / or receiving signals are reduced, for example of the order of

  1 W, and can be provided by a battery.

  In a preferred embodiment of

  the invention, the first part and the second part

  are formed respectively by the upper and lower parts of a special telemetry connector, said parts being separated by an electrical insulator, and the transformer is disposed within a chamber in the wall of the connector, together with means for transmitting signals which comprise a battery and signal processing means such as the degree of attenuation of the signals

  transmitted depends on the distance over which the

  are transmitted and the electrical conductivity of the land through which the borehole is

  drilled, it may be advantageous to provide one or more

  repeater connectors between the fitting containing the measuring instrument and the surface. Each repeater connection can contain an identical set of means

  transmission, reception and amplification of

  signals, the signal transmission means being the

  same as those in the coupling which

  holds the measuring instrument. Since the fittings are relatively inexpensive to manufacture,

  a large number of people can be

  number of repeater connectors along the drill string.

  The invention also provides a method of signaling the interior of a borehole during drilling, using a drill string

  drill with one part and one part

  part which are electrically isolated from each other, this method comprising the transmission

  signals between transmission means and / or

  ception of signals and a receiving station

  and / or signal transmission, remote in the

  of the drill string, through a

  transformer whose winding is electric-

  connected between the first part and the second part and the other winding electrically connected to the signal transmission and / or reception means, the first part providing a current path

  for signals circulating between the transformation

  the signal receiving and / or transmitting station, a return path being provided between the transformer and the receiving and / or transmitting station via the

  part two and field training in the field of

  towards which the hole is being

  rage. The invention still provides a connection of

  telemetry for a drill string, which includes

  a first part and a second part which are electrically insulated from one another, a

  transformer whose winding is electrically connected

  between the first part and the second part and transmission and / or reception means

  signals, electrically connected to the other winding

  transformer, the first part provided

  a current path for signals that circulate

  between the transformer and a

  ception and / or signal transmission, located at a remote location in alignment with the drill string when the telemetry connector is disposed in a drill string, a return path

  being provided during drilling between the transformation

  and the receiving and / or transmitting station

  signals through the second part of

  and field formations through which

  a borehole is being drilled.

  In order for the invention to be more

  ciliently understood, reference will now be made to

  non-limiting manner, in the drawing appended hereto, in which:

  Figure 1 schematically shows a

  of a drill string incorporating a telemetry connector according to the invention and FIG. 2 is a longitudinal section

  of a telemetry connector according to the invention.

  Referring to Figure 1 which is pre-

  view only to illustrate the principle of the invention

  tion and not to show the detail-

  1 of the telemetry connector, it is seen that the telemetry connector 1 is disposed between two parts 2 and 3 of a drill string located in a drilling borehole 10. The coupling 1 is coupled to the part 2 by means of a screwed coupling

  4 of connection 1 and part 3 by means of a coupling

  bolted female 5 of the lo connector Part 2 -st coupled to a turntable (not shown)

  located on the surface through other

  parts and part 5 is coupled to a trephine or

  drilling (not shown), possibly by

through other parties.

  The connector 1 comprises an upper part 6 electrically connected to the part 2 and a part

  lower 7 electrically connected to part 3.

  The upper 6 and lower 7 parts are insulated

  electrically separated from each other by an isola-

  8. Inside the side wall of the connection is a chamber 9 which contains a

  He and a toroidal output transformer

  12 where the secondary school is connected between the

  In operation, a pulse signal of measurement information is applied to the primary of the transformer 12 by the electronic circuit 11.

  measure being, for example, those obtained by

  of an instrument used to measure the orientation

  of a drill hole, such as that described in the

  British patent No. 1509.2953 As a result a pulsed current signal is induced in the secondary of

  transformer 12 and this signal is transmitted to the sur-

  face by part 2 and the other parts of the train

  of stems between Part 2 and the surface.

  A return path for the signal is provided at

  through field formations through which

the drill hole 10 is drilled.

  The telemetry connector shown in FIG. 1 may be an emission connector only, for transmitting the measurement values supplied to it by a neighboring measuring instrument, or a repeater connector which receives a signal applied to it by the transmitter. train of stems; it processes this signal and transmits the processed signal. In the first case the electronic circuit 11 will comprise a battery and a

  signal processing circuit for modulating the

  supplied by the battery according to the measured values. In Figure 2 we see a repeater connection in longitudinal section. In this figure the similar parts are designated by the same reference numerals as in FIG. 1. It will be noted that the ring insulator

  8 is placed between the chamber 9 and the wall

  the insulator is in the general shape of S in section, so as to increase the resistance of the joint the upper and lower parts 6 * 7 The chamber 9 is separated from the outside by a lid

  13 which is hermetically sealed at its edges at

  yen of a seal 14 and is electrically insulated such that it does not provide a current path between the upper and lower parts 6

  7. In addition to the output transformer 12, the

  bre contains an input transformer 15, an am-

  input multiplier 16, a processing circuit

  18 and an output amplifier 17.

  The input and output transformers 12 could be replaced by a single transformer which would function both to receive and to

to transmit signals.

  The repeater is arranged so as to

  to receive and transmit signals in the multi-mode

  tiplex. For example, in a first

  period of one second, an input signal, transmitted

  by the transmitting connector alone or by another connection

  repeater cord located lower in the drill string, is detected by the input transformer 15 whose primary is coupled between the lower parts

  of the drill string and the return of earth and is am-

  folded by the input amplifier 16. In a second period for example 100 millisecon - =

  the signal is processed numerically by the

  cooked in order to eliminate errors and, in a

  third period of one second, for example, the

  The processed signal is amplified by the output amplifier.

  17 and transmitted by the output transformer 12, either to a receiver located on the surface or to another repeater located higher in the drill string, As the telemetry connections are of

  relatively inexpensive production and that the

  band and hence the possibility of trans-

  fast data mission a signal drops in

  the distance to which it is transmitted,

  Repeater connectors can be provided, if necessary

  sary, along the drill string with spacing

  going down to 300 m. This then allows for

  put signals with a data rate of about

  100 bits per second and with a power of

  about 1W per fitting and a width of

band about 100 Hz.

  If in the system proposed in U.S. Patent No. 2,354,887, it is considered

  that the drill string and the return path conduct-

  through the earth constitute a winding

  of a toroldal transformer whose toroidal coil surrounds the drill string serving as a primary,

  losses in the core, in the case of the ex-system

  in that patent and in that of the system

- glossed by the appended drawing.

  If the cross sectional area of the core

  toroldal is A and if the flux density of satura-

  If the secondary impedance is ZS, the power injected into the secondary can be written in the form P = 2)

  The maximum value of the electromotive force

  trice induced in the secondary is written in the form VS Ns max.cX (3) with NS = number of secondary turns

24830È06

  max = maximum value of the magnetic fluid pas-

  by the cross section of the toroldal core

  andW = 2.r.f =, where f is the frequency of the excitatory

  primary education. It follows from equations (1), (2) and (3) that if u2.PS. ZS 3 (4) NS o2.1. f.BSAT We can take as typical values

  for the core material of the toroid transformer

  Silicon iron dal: Bmax 1.2 Tesla Core losses at 200 Hz 3 5.5 watts.kg1

Density of the nucleus = 7 g ocm3.

  As a result of previous calculations with Hz, one can take, as impedance ZS of the drill pipe and the earth, 0,17 ohm Thus, for a torus of average diameter 14 cm

  surrounding the drill string with a winding

  a single turn, these typical values

  indicate a minimum size of area of

  5.9 cm2 core cross-section and a resulting minimum nucleus volume of 156 cm3 and the calculated minimum core mass of 1.1 kg

  consider the case where PS = 1 watt. Thus, in order to

  1 watt at the 200 Hz secondary circuit,

  the resultants in the core are about 6 watts.

  Moreover such a nucleus will be of codteuseo manufacture

  On the contrary, if the toroidal transformer

  dal of the system represented by the appended drawing tom--

  100 turns at its secondary, the minimum value for the cross sectional area of the core is about 4 mm2 and therefore the core can be extremely small, so that the losses in the

core are negligible.

Claims (13)

  1. Signaling apparatus since the   the interior of a borehole during drilling, in which, during use, signals are electromagnetically transmitted along the train of warp between transmitting and / or receiving means   signals at the bottom of the hole and a   reception and / or transmission of signals,   killed at a remote location in alignment with the drill string, a return path for the signals being provided through the terrain formations through which the drill hole is   during drilling, characterized in that a trans-   trainer (12) has an electrically connected winding   between a first part (6) of the train   rods and a second part (7) of the train of   which is electrically isolated from the first   first part (6), and that the means of   and / or receiving signals (11, 15 to 18) are electrically connected to the other winding of the   transformer (12), the first part (6) provides   - a current path for the signals   between the transformer (12) and the signal receiving and / or transmitting station and / or the   return journey being provided between the transformation   (12) and the receiving and / or broadcasting station   signals, the second part (7) and field formations0   2. Apparatus according to claim 1,   characterized in that one winding is the secondary winding of the transformer (12) and the other   winding is the primary winding of the   setting (12) and that transmission means   signals (11) are electrically connected to the   primary bearing to transmit signals to   a remote receiving station.   3. Apparatus according to claim 2, he   characterized in that the means for transmitting   (11) include means for processing   to modulate a carrier signal according to the in-   measuring formations received from a measuring instrument   safe. 4. Apparatus according to claim 1, 2   or 3, characterized in that it incorporates a multi-   of signaling devices distributed along the drill string, each of the devices   comprising a transformer (12) including a winding   electrically connected between first and second respective parts (6 and 7) of the train   stems and that means of emission and / or   ception of signals (11, 15 to 18) are connected electrically   the other winding, one of the said   positive being a transmitting device only for transmitting measurement values supplied to it by one measuring instrument and the other or   each other device being a repeater for   receive a signal that is provided along the   stem train, to process the signal and transmit be the processed signal.   5. Apparatus according to any one of   preceding claims, characterized in that   the transformer (12) is a toroidal transformer dal.   Apparatus according to one of the claims   preceding, characterized in that the transformation   the transmitter (12) and the transmitting and / or receiving means   (11, 15 to 18) are housed in a chamber (9)   formed in the drill string wall.   7. Apparatus according to one of the claims   precedents, characterized in that the means for transmitting   signal reception and / or reception (11, 15 to 18) are   adapted to be powered by a battery.   Apparatus according to one of the claims   characterized in that the first part and the second part (6 and 7) are respectively the upper and lower parts of a special telemetry connector (1), the parts in question   (6,7) being separated by an electrical insulator (8).   9. Telemetry connector for a drill string incorporating transmission means and / or   reception of the signals usable in the transmission   electromagnetic signaling along the train   stems between the coupling and a receiving station.   transmission and / or transmission of signals, located   far right in the alignment of the drill string, a return path for the signals being provided through the terrain formations through which the drill hole is being made.   drilling, characterized in that the coupling (1) com-   takes a first portion and a second portion (6 and 7), electrically isolated from each other, and a transformer (12) having a winding electrically connected between the first portion and the second portion (6 and 7) and in that the means for transmitting and / or receiving signals (11, 15 to   18) are electrically connected to another winding   transformer (12), the first portion (6) providing a current path for the signals flowing between the transformer (12) and the receiving and / or signaling station when the connector (1) is arranged in a drill string, the return path being provided during drilling,   between the transformer (12) and the receiving station   tion and / or transmission of signals, by the second   part (7) and field formations.   10. Telemetry connection according to the claim   9, characterized in that it consists of a transmission connection only for transmitting   measurement values provided to it by an instru- measuring instrument.   11. Telemetry connection according to the claim   9, characterized in that it is a repeater connector for receiving a signal supplied thereto along the drill string, for processing the signal   and to transmit the processed signal.   Telemetry connector according to Claim 9, 10 or 11, characterized in that the transformer (12) and the transmitting and / or receiving means (11; 15 to 18) are housed in a housing.   chamber (9) in the wall of the fitting (1).   13. Telemetry connection according to the claim   12, characterized in that the chamber (9)   is isolated from the outside by a cover (13).   14. Telemetry connector according to one of   Claims 9 to 13, characterized in that the   first portion and the second portion (6 and 7) are insulated from each other by an annular insulator (8) of generally S-shaped radial section   Signaling method since the   inside a borehole while drilling, in   which signals are transmitted electronically   magnetic device along the drill string between means for receiving and / or transmitting signals located towards the bottom of the hole and a reception and / or signal transmission station located at a remote location in alignment with the train of stems, a trip from   return for the signal being provided through the   field formations through which   the borehole is drilled, characterized in that a drill string having a first portion and a second portion (6 and 7) electrically isolated from each other is used and said method comprises the transmission of signals between the signal transmission and / or reception means (11; 15 to 18) and the signal receiving and / or transmission station via a transformer (12), one of which winding is plugged   electrically between the first part and the second   part (6 and 7) and the other winding is electrically connected to the signal transmission and / or reception means (11; 15 to 18), the first part (6) providing a current path for signals which circulate between the transformer (12) and the signal receiving and / or transmitting station and the return path being provided   between the transformer (12) and the regeneration station   ception and / or emission, by the second part (7) and field formations.   16. The method according to claim 15, characterized in that it comprises the successive transmission of signals between a multiplicity of   signaling devices, each of which includes   a transformer with a winding connected electrically and respectively between a first and a second part (6 and 7) of the train   stems and means of emission and / or reception   signals (11; 15 to 18) electrically connected to the other winding, the first of said devices   being a transmitting device only that transmits   puts the measurement values supplied to it by one measuring instrument and the other or each other device being a repeater device receiving a   signal provided to it-by an earlier   the signal and transmitting the processed signal.