JPH0428878B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION BACKGROUND OF THE INVENTION The present invention relates to a drilling gun used in well digging operations. More particularly, the present invention relates to a single wire selection drill hole gun system that can select and fire each gun in any order of a plurality of guns connected to an ignition chain.

A typical known drilling gun commonly used in well drilling operations consists of a plurality of guns connected vertically to form an assembly or ignition chain suitable for lowering into a wellbore. configured. Each gun contains one or more pine cone-shaped powder. Each gunpowder has a detonator or blasting cap that can be connected to an ignition signal wire that receives an electrical ignition pulse to detonate the gunpowder.

In well drilling operations, it is often desirable to be able to select the firing operation of each gun, rather than having all guns firing at the same time. If all guns are fired simultaneously, the spacing of the guns in the firing chain, which is usually a closely spaced array of guns, determines the bore spacing. On the other hand, when exploding gunpowder individually,
Drilling can be performed at different selected depths and in different selected areas (often widely spaced apart). As each powder is detonated, the ignition chain is repositioned to the next level where another drill hole is desired and another gun is activated. This process can be continued until the desired number of firings and proper drill hole spacing is achieved. Activating the guns one at a time provides an additional convenience, namely, being able to verify that each gun has been activated and that the appropriate number of holes have been obtained. .

However, when one gun is selected for ignition operation in the ignition chain device described above, a defect may occur that prevents proper ignition operation of the module. In other words, the gun to be selected may have a defect that prevents the gun from igniting, or
A defect may occur where the wrong gun is fired and this is detected only at the end, or a defect may occur where the wrong gun is fired and is not detected. All of these deficiencies, especially in many known devices, defeat the purpose of selectively firing the gun during drilling operations.

Many selective ignition systems and methods are used in the prior art to select a gun for ignition from among a plurality of guns in an ignition chain. U.S. Pat. No. 4,051,907 discloses one such system with a ground control unit that controls the selection and firing operation of guns in the ignition chain,
The control unit includes a subsurface master unit operatively connected to a plurality of identical slave subunits or ignition modules which are ignited in any order under the control of the master unit and the operator. prepared and lit.

Sequencing of the firing modules to select the modules to be fired is under the control of a control unit located on the ground. The selection process is
It starts with the topmost ignition module closest to the master unit. Each ignition module includes a pulse counter that receives pulses from the ground via the master-slave unit when the module is connected to power on the ignition signal line. A predetermined number of pulses (8 pulses) causes the counter to sequence over 9 counts. At the selected count, several operations are performed within the module. For example, at count 4, a current pulse is sent to the ignition signal line, at count 5, a switch is closed to charge the ignition capacitor with the voltage on the current ignition signal line, and at count 6, the current ignition signal line An ignition pulse with an amplitude equal to the voltage of ) and at count 9, a pass-through switch is closed to pass the ignition signal line power to the next lower module in the ignition chain.

The above process is repeated for the next module to be connected to power on the ignition signal line. Sequencing of the ignition modules continues, one at a time, as long as the eight pulses are generated without a change in power on the ignition signal line. When the ignition module to be selected and ignited is reached, it is activated by the master unit under the control of the operator.
only pulses are generated. These six pulses cause the pulse counter of the ignition module to be selected to count 5, which closes the switch and connects the ignition signal line to the ignition capacitor. At this point, the ground operator activates the ignition readiness switch, which increases the voltage on the ignition signal line and, in turn, the ignition capacitor.
This capacitor raises the gunpowder to a level sufficient to detonate it when discharged into the blasting cap. Six pulses prepare the ignition module for ignition and another pulse closes the ignition switch. This is because the voltage on the ignition signal line is now greater than the voltage on the blocking zener diode, allowing the ignition switch to close. When the ignition switch closes, the ignition capacitor is connected across the blasting cap circuit.

Known selective drilling systems, such as the one disclosed in U.S. Pat. No. 4,051,907, have a number of drawbacks. One drawback is that sophisticated above-ground and underground circuits are required, and continuous monitoring and interaction between above-ground and underground circuits is required during the selection process to select and prime the ignition module. is needed. Another drawback is that the sequencing of the ignition modules is only under the control of the ground equipment. Yet another drawback is the lack of a security mechanism to detect defects in the ignition chain that would prevent proper ignition of a selected module.

We therefore developed a single wire selection drill hole system that automatically sequences the ignition modules one at a time under the control of the module itself until the module to be selected receives power from the ignition signal line. It is requested that it be provided. When the module to be selected receives power from the ignition signal line, the module can be selected and ready to fire. It also determines whether one module is connected to the ignition signal line in the above sequence and is operating within the specified power limits, thereby selecting one module for ignition and causing only this module to ignite. It would be desirable to provide a single wire selection drilling system with a security mechanism to ensure pulse ignition.

SUMMARY OF THE INVENTION According to one aspect of the invention, the invention comprises a single ignition signal line electrically connecting the ignition control unit to each of a plurality of ignition modules, one at a time, in a predetermined sequence; Each of the above modules is connected to a control unit connected to it in a single line selection drilling system which connects each module to the next module under the control of module actuation time intervals formed within the module. One at a time, each module is connected to the ignition signal line in a predetermined sequence, each module forming its actuation time interval in response to being connected to the ignition signal line, and the next module in said sequence is the last to connect. a module for ignition, characterized in that at the end of the activation time for the module that has been activated, the module for ignition is automatically connected to the ignition signal line if this module has not been selected for ignition during that activation time interval; A method for selecting is provided.

According to another feature of the invention, in a single wire selective drilling system for selectively detonating the gunpowder in a plurality of ignition modules, one at a time, (a) a single ignition signal line; a control unit operatively connected to said module by;
The ignition signal lines carry both power and control signals between the control unit and the module, and (b) are vertically connected to each other to form an elongated assembly suitable for lowering into a wellbore. further comprising a plurality of selectable ignition modules, said assembly including said control unit, and each module including () at least one pyrotechnic powder, each module firing one at a time in a predetermined sequence.
(1) automatically connects to and receives power from the ignition signal line, and () internally forms a module actuation time interval in response to receiving power through the ignition signal line; during which a module and its powder are selected for ignition by said control unit, and each module not selected for ignition during the actuation time interval passes the ignition signal line to the next module in said sequence. A system is provided that features automatic connection.

For a thorough understanding of the invention, the invention will now be described in detail with reference to the accompanying drawings in which like parts are designated by like reference numerals.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to FIG. 1 of the accompanying drawings, an ignition chain device 10 according to the invention is installed in a wellbore 1 having a wellcase 2.
is shown suspended therein by cables 12. The ignition chain 10 has at its top end a control unit 14 connected to a cable 12. This control unit 14 serves to generate the control signals and power in the ignition line 3 necessary to select the ignition modules for ignition and detonate their powder. This control unit 14
Connected to each other below are a plurality of identical ignition modules 5, which form an elongated assembly suitable for lowering into the wellbore 1.

The control unit 14 includes a current detection means 6 for detecting the amount of current flowing through the ignition signal line 3, a control signal to the ignition module to select the module to be selected and prepare for ignition, and a control signal for the ignition module to select the module to be selected and prepare for ignition. It comprises a control signal generator 7 for generating ignition pulses to detonate selected and primed modules, and a controllable power supply 8 for generating the necessary voltages and currents to power the ignition modules.

Each ignition module 5 includes at least one pine cone-shaped gunpowder 26 (see FIG. 2) and a detonator 24 associated therewith, and is an igniter for drilling into underground strata through the well case 2. That is, it forms a gun. Each module also includes a module logic circuit 18 which cooperates with the control unit 14 and the signals on the ignition signal line 3, which in FIG. The signal leads 16 and 22 are shown generally as shown in FIG. As will be explained below, the ignition signal lines from the control unit 14 to the various modules 5 are connected to one ignition signal line 3 in particular, with the various modules being connected to the control unit 14 one at a time in a defined sequence. It consists of a series of segmented leads that are sequentially electrically connected to each other to form a wire. Each module 5, when physically connected to another module in the device 10, makes electrical contact with a portion of the ignition line of the module to which it is connected. That is, the section 16 of the ignition line of the module just connected makes electrical contact with the section 22 of the next superior module to which it is connected.

Still referring to FIG. 1, each ignition module 5 is provided with controllable switching means, shown as switches 20 and 21, which are responsive to module logic 18 to switch the input to the ignition module. Either the input 16 of the ignition line 3 is connected (switch 20) to the output 22 of the ignition line 3 (which sends the ignition line power to the next module of the device) or the input 16 of the ignition line 3
is connected to the detonator 24 of the pine cone-shaped gunpowder 26 (switch 21). If the switch 21 is closed on a module, this module becomes the module selected for firing and the module logic circuit 18 of this selected module
inhibits further sequencing of the submodules of device 10 by closing switch 20 and inhibiting ignition line power from being transmitted to the next submodule. Modules that are sequenced but not selected during each actuation time interval may include a switching position such that the pass-through switch 20 grounds their detonators to prevent accidental ignition. .

Sequencing of the selectable ignition modules begins with the topmost module connected to control unit 14. The top module is
It receives power from the control unit 14 when power is first applied to the ignition line 3. Thereafter, as each ignition module completes its selection process and is not selected for ignition, the next submodule in the device is connected to the ignition line. This process continues until the bottom module has executed its selection sequence.

The selection sequence for each ignition module 5 will be described with reference to FIG. 2, which is a functional block diagram of a typical ignition module. Referring now to FIG. 2, the input 16 of the ignition line 3 is connected to a constant current power supply 29 for regulating the voltage of the ignition line 3 to form the supply voltage for the circuitry of the module. The ignition line is also connected to an ignition line pulse detector 37. The output from ignition line pulse detector 37 is connected to flip-flop 41. Pulse detector 37 and flip-flop 41 constitute stop pulse detector 34, which generates a stop pulse that terminates the module activation time interval when that module is selected and to be armed. The ignition line pulse detector 37 detects when the control unit 14 generates a selection/prime pulse on the ignition line 3 in response to a voltage pulse on the ignition line.

Each module also includes counter circuit means 32 which, in response to internal oscillating clock 28, establishes a module operating time interval within the module during which:
Modules can be selected for ignition.
Oscillating clock 28, together with the number of bits of binary counter 35 included in counter means 32, determines the length of the module operating time interval. A power reset pulse generator 30 is also included in each module 5 for generating a reset pulse when power is first received via the ignition line 16. The power reset pulse is generated by the counter 35.
The actuation time interval is started by resetting .

The power reset pulse has the additional function of generating a current increase pulse through the firing line 3 to the control unit 14 to indicate that the next module is connected to the firing line 3.
This current pulse is an identification pulse for the module and must meet several conditions. First, the magnitude of the current increase in ignition line 3 must be within a predetermined range in order to indicate that the modules just connected will operate within acceptable limits and only one module will respond to ignition line power. Must be within. Second, the occurrence of the identification pulse must be within a predetermined window measured from the last identification pulse in the firing line.

The control means 14 includes means (not shown) for detecting the amount of current in the ignition line. There are many reasons for monitoring this current. First of all, by counting the number of identification pulses generated on the ignition line, the control means 14 can determine which module has just been connected to the ignition line. In this way, the module to be selected can be detected as the modules are automatically sequenced through their operating time. or,
The control means 14 also includes means for generating both a selection and preparation signal and an ignition pulse for detonating the selected and prepared module.

Also shown in FIG. 2 is a stop pulse detector 34 which includes an ignition line pulse detector 37 responsive to the signal at the input 16 of the ignition line 3; A flip-flop 41 generates two control signals in response to the output of the binary counter 35. First, the STOP CLOCK signal is output by flip-flop 41 on line 50 to one input of AND gate 33. Further, the output from the oscillation clock 28 is also sent to the AND gate 33. AND gate 33 outputs a clock signal to counter 35 when enabled. Signal STOP CLOCK acts as a disable signal to prevent counter 35 from receiving any more clock signals when receiving a selection pulse via firing line 3.

When signal STOP CLOCK becomes a logic 0, AND gate 33 is prevented from supplying any further clock signals to counter 35. STOP CLOCK
The signal ARM CONTROL output by flip-flop 41 as soon as the signal goes to logic 0.
becomes logic 1. This ARM CONTROL appears on signal lead 39 to ignition switch 21. The signal ARM CONTROL closes the ignition switch 21 and connects the cathode of the Zener diode 43 to the detonator 24 associated with the gunpowder 26 of the module. The anode part of the Zener diode 43 is connected to the input 16 of the ignition line 3. In this preferred embodiment of the invention, the selection pulse in the ignition line 3 also serves to prime the module.

In the above-described improved drilling system with single wire selection, the selection and ignition preparation functions are separated to improve the feedback security mechanism to avoid failure during ignition that would lead to defective operation. There is. In particular, one pulse is used to select a module and a series of three prime pulses are used to prime the module in a predetermined sequence. The first warm-up pulse primes the module and increases the current in the fire line 3. This current increase must be within a predetermined range. The second ignition preparation pulse eliminates this current increase. If the value of the current increase is acceptable and the current increase is cleared by the second warm-up pulse, a third pulse is generated to prime the module. An ignition pulse can then be generated that detonates the gunpowder, ensuring that one and only one module ignites.

Further referring to FIG. 2, flip-flop 41 of stop pulse detector 34 acts as a set-reset type flip-flop, with a set signal being sent from firing line pulse detector 37 and a reset signal being sent from counter 35. It will be done.
The reset signal to flip-flop 44 is
ENABLE, which is a logic one state when the Q11 output from 12-bit binary counter 35 is true. When the reset input to flip-flop 41 is a logic one, a pulse on the set input can "set" the flip-flop to a logic one. Therefore, a pulse detected by firing line pulse detector 37 changes the state of flip-flop 41 (from a logic 0 to a logic 1) only if the signal ENABLE sent from counter 35 via signal lead 46 is true. ).
During the first part of the module's activation time interval, the signal ENABLE is not a logic one. After a certain number of clock pulses have been counted, the signal ENABLE goes true, starting the second portion of the module's operating time interval. It is during this second part that the modules are selected and primed for firing.

Furthermore, the AND gate 33 includes a binary counter 35.
Another output is also sent from (Q12), which represents the most significant bit of the 12-bit counter. This Q12 output signal PASS-THROUGH also controls a pass-through switch 20 which serves to connect the input 16 of the ignition line 3 to the output 22. Additionally, signal PASS-THROUGH prevents the clock signal from oscillating clock 28 from reaching counter 35. As mentioned above, the flip
Flop 41 allows AND gate 33 to pass clock pulses from oscillator 28 to counter 35 regardless of what pulses are detected by firing line pulse detector 37 during the first portion of the run time interval. do.

The passage of the first portion of the time interval is indicated when the signal ENABLE on signal lead 46 becomes a logic one, thereby setting flip-flop 41 on subsequent pulses detected by firing line pulse detector 37. and the AND gate 33 can be rendered inoperable. If no firing line pulse is detected by detector 37 during the second part of the actuation time interval, the Q12 output of counter 35 will eventually become true and signal PASS
-THROUGH is generated to prevent further clock signals from being sent to the counter 35. At the same time, pass-through switch 20 closes and transfers the ignition line power to the next lower module. Closing pass-through switch 20 represents the end of the selection process for that module, after which the module is connected to ignition line power. Counter 25 is prevented from receiving any further clock signals until the module is reset by removing power from firing line 3.

The timing relationship between the signals of the plurality of ignition modules and control unit 14 during module sequencing is shown in FIG. Referring to FIG. 3, for a typical selection sequence including three ignition modules, the ignition line voltages and currents are shown when the third module is the module to be selected. Upon applying power in the form of voltage and current to the ignition line, module No. 1 begins to internally develop its module operating time interval. In FIG. 3, the operating time interval of each module is the first part T1.
and a second portion T2. The first portion T1 represents the time interval from when the module first receives power to when the output Q11 of binary counter 35 becomes true. The second part T2 of the time interval represents the other part of the actuation time interval and represents the time when the output Q11 from counter 35 is true. In other words, the end of the second portion T2 of each module time interval is indicated when the Q12 output of binary counter 35 becomes true and the Q11 output becomes false (a true state is represented by a logic 1). and a false condition is represented by a logic 0).

When module No. 1 receives power, an identification pulse is generated on the ignition line 3. This pulse is shown as a current increase in the firing line current. This increase indicates to control unit 14 that the module is connected to the ignition line. If the amplitude of the current increase in the firing line as a discrimination pulse does not fall within a predetermined range, the control unit 14 stops sequencing the modules. This is because it is indicated that more than one module 5 is malfunctioning in response to the application of power to the ignition line 3, or that the module just connected does not operate within a predetermined range. As indicated by the signal for the ignition line current shown in FIG. To increase. These increases in ignition line current occur because each module remains connected to the ignition line at the end of its module activation time interval and continues to draw current until reset by removal of power to the ignition line.

In the case of the example shown in Figure 3, module No.
At the end of the module activation time interval for No. 1, its pass-through switch 20 is closed connecting module No. 2 to ignition line power. As shown in Figure 3, module no.
2 and module No. 1 are connected to the ignition line,
Causes an effective increase in the amount of current in the ignition line. This is commonly referred to as a step function increase.
Superimposed on this step increase is module No. 2
This is the identification pulse for

In addition to the identification pulse amplitude falling within a predetermined range, the control unit 14 monitors the time interval measured from the reception of the last identification pulse to the reception of the next identification pulse. Unless each identification pulse falls within a predetermined time window measured from the last pulse of the ignition line 3, a fault condition is indicated and the control unit 14 terminates further sequencing of the ignition module.

A further function of the identification pulse sent to the control unit 14 is that it allows the control unit 1 to know to which module the power in the ignition line 3 has just been connected.
Its purpose is to act as a crop pulse that allows counting by 4. Therefore, when the identification pulse for module No. 3 is received and the identification pulse conditions are met, the control unit 14:
We know that the module to be selected, module 3, has just been connected to the ignition line 3.

As mentioned above, the pulses appearing on the firing line during the first part of the time interval have no effect on module selection and readiness. Only during the second portion _T2 of the activation time interval is flip-flop 41 enabled to receive the set pulse detected by firing line pulse detector 37 to select and prime the module. In the example shown in FIG. 3, since module No. 3 is the module to be selected, the control unit 14 activates the selection and ignition readiness indicated as a voltage pulse on the ignition line during time T2 for module No. 3. A pulse is generated in the ignition line. When ignition line pulse detector 37 detects a voltage pulse on the ignition line during the second portion of the module actuation time interval, flip-flop 41 is triggered to terminate further counting operation of counter 35 and to switch ignition switch 21. to ARM
Generate CONTROL signal. This ARM
When CONTROL is true, ignition switch 21 closes and connects module No. 3 detonator 24 to the ignition line via Zener diode 43.

Application of a further clock signal to counter 35 is dependent on reception of the selection pulse and flip-flop 4.
1 set operation, the module no longer performs the operation time interval forming operation and is in the selected state. Selection of further lower module is completed and control unit 1
Module No. 3 can be detonated when No. 4 attempts to provide an ignition pulse to the ignition line. If detonation of a selected and primed module is not desired, the selection sequence can be repeated by momentarily removing the voltage and current in the ignition line and resetting all modules to their initial state. When the power is removed, all pass-through switches 20 and ignition switches of the module 3 are switched to the open position, so that when power is restored again, only the first module connected to the control unit 14 is in the ignition line 3. Receive electricity.

To summarize the invention, the single wire selection drill gun system disclosed herein includes a plurality of identical ignition modules connected together to form an elongated assembly suitable for lowering into a wellbore. . The assembly includes a control unit that provides power and ignition line signals to each ignition module as each module is sequentially connected to the control unit, one at a time.

Each ignition module defines an activation time interval within it, during which the module is selected and primed by the control unit. The actuation time interval begins when power is applied to the module by connecting the module to the ignition line. Each firing interval has first and second portions. During the first portion, the ignition module generates an identification pulse to the control unit indicating that the next module is connected to the ignition line. In this way, the control unit counts the modules as they are connected to the ignition line and determines when the module to be selected forms the operating time interval. During the second portion of the module actuation time interval, the control unit selects the module for firing by generating a selection control pulse on the firing line. Pulses occurring on the ignition line during the first portion of the actuation time interval are ignored by the module. This is because the module is only selected and primed during the second part of the activation time interval.

As a security mechanism to prevent attempts to ignite the module when conditions on the module are not acceptable, each module generates an identification pulse on the ignition line, which the control unit monitors and
Determining whether the module is operating within an allowable power range and determining whether sequencing of the module has occurred within a specified time range. Only in suitable conditions will the control unit select the module to be selected and prepare it for firing.

The selection process for each ignition module 5 will be described with reference to FIG. 5, which shows a functional block diagram of a typical ignition module 5. In FIG. 5, the input 16 of the ignition line 3 is shown connected to a regulated power supply 29, which generates the supply voltage for the circuitry of the module. For the following discussion, it will be assumed that the ignition module shown in FIG. 5 has just been connected to ignition line power by the closure of switch 20 in the module immediately above it.

The ignition line is also shown connected to a control pulse detector 34. The control pulse detector 34 is
It consists of an RC network that shifts the DC level of a control pulse applied directly to the clock input of a 4-bit shift register 38. The clock input stage of the shift register acts as a comparator to detect control pulses.

Control pulse detector 34 applies a signal STOP CLOCK to the Q1 output of shift register 38 in response to the firing line selection control signal during the actuation time interval.
occurs. If the selection control signal is received at an appropriate time during the actuation time interval,
A module is selected for ignition by terminating the activation time interval for that module, inhibiting further closing of switch 20, and blocking power to modules subordinate to the selected module. In addition to detecting the ignition line selection control signal, the control pulse detector 34
detects the sequence of ignition preparation control signals from control unit 14. This sequence of ignition control signals is used as a security detection method to determine whether one and only one ignition module 5 responds to the ignition preparation sequence.

Further explaining FIG. 5, the 4-bit register 3
The last three stages of 8 constitute the ignition prime circuit, which generates feedback current pulses to the control unit 14 in response to the sequence of ignition prime control signals detected by the control pulse detector 34. This feedback current pulse in the ignition line 3 indicates to the current sensing means 6 in the control unit 14 that one and only one ignition module is responsive to the sequence of ignition ready control signals. As discussed below, this feedback current pulse serves as a security detection method for problems causing improper firing of the drilling gun.

As mentioned above, the ignition preparation sequence feedback current pulse sent through the ignition line 3 is a current pulse of a predetermined amplitude greater than the steady state current in the ignition line to indicate that only one ignition module will respond. have an increase. The four-bit shift register 38 operates to generate this predetermined current pulse on the firing line in the following manner. Line 4 to shift register 38 (data (D) input)
As long as the 6 signal is a logic 0, the control signal or pulse detected on the ignition line sequentially shifts the logic 0 into the various stages of the shift register 38.
A logic 0 in a stage of shift register 38 represents a reset condition. Therefore, a pulse detected by pulse detector 34 when the D input to shift register 38 is a logic 0 will not cause any change in the logic state of the shift register and therefore the ignition preparation circuit will have no effect. do not have.

When the data input to shift register 38 is a logic one, the first control signal on the firing line detected by stop pulse detector 34 shifts a logic one into the first stage of the shift register. As mentioned above, the signal STOP of the output Q1 of the first stage
CLOCK, which is applied to signal line 50. The function of this signal STOP CLOCK is to prevent the oscillating clock 28, which is the internal time reference of the logic circuit 18, from generating any further clock signals. The absence of further clock pulses terminates the formation of the module's active time interval and terminates further sequencing of the modules below it. This first received control signal represents a selection control signal for selecting the module for firing. In other words, when STOP CLOCK goes to logic 1, this module is selected for firing. The conditions under which the D input of shift register 38 becomes a logic 1 will be described in detail below.

Any further control signal detected by the stop pulse detector 34 when the D input is a logic one shifts its corresponding logic one to the shift register 38.
, so that a logic 1 is shifted each time each control signal is detected. 2nd stage output Q2 and 3rd stage output of shift register 38
A resistor R2 is connected between Q3 and Q3.

According to the invention, if a module is selected for ignition by receiving a selection control signal at an appropriate time, a series of ignition preparation pulses are activated by the control unit 14 to trigger the ignition of this selected module 5. A ready-to-fire feedback current pulse is generated to the ready circuit to indicate that one module is responding. This series of ignition preparation control signals are sent via the ignition line 3
Consists of two pulses. The first pulse causes the Q2 output of shift register 38 to go to logic one. At this time,
The Q3 output of shift register 38 is a logic 0;
Therefore, the 4-bit register 38 causes current to be supplied through the resistor R2 in the direction from Q2 to Q3. This increases the current draw for the power supplied by the ignition line by an amount determined by the magnitude of resistor R2. If one ignition module is responding, a predetermined current increase occurs.

Upon reception of the second ignition preparation pulse, a logic 1 is shifted into the third stage of shift register 38 and the resistor
Both sides of R2 become logic 1. This logic state removes the current increase in the ignition line current and returns it to the current level for the reset state of the ignition preparation circuit 38.
Therefore, if the amplitude of the current pulse increase in the ignition line current due to the first and second ignition preparation pulses falls within the permissible range, the control unit 14 prepares the module for ignition.

To prepare for ignition of the module, connect the ignition line 3 to the 3rd
This is accomplished by generating an ignition readiness control signal. As a result, the fourth shift register 38
Stage Q4 becomes logic 1. Q4 of shift register 38
The output is provided on signal line 39 as the signal ARM CONTROL. This signal ARM
CONTROL is a controllable ignition preparation switch 21
sent to. In the case of the present invention, each of the ignition preparation switch 21 and the pass-through switch 20
Model IRSC232 by International Rectifier
It is a solid state switch manufactured by When the switch 21 closes, the pine cone-shaped gunpowder 2
The detonator 24 for 6 is connected to the input 16 of the ignition line 3.
connected to prepare the module for ignition.

As mentioned above, module selection and ignition preparation is performed by the stop pulse detector 3 when the data input D to the 4-bit shift register 38 is a logic one.
This is performed when a control signal is detected by 4. The data input to shift register 38 is a logic one during one portion of the module actuation time interval.
and is formed as follows. Clock oscillator circuit 28 is provided as a module time base for generating clock pulses that are counted by a 14-bit binary counter 34 to form operating time intervals for the module. The operating time interval of each module is divided into two equal parts T1 and T2 (see FIG. 3). 1st
During part T1 of , the module performs an identification process, so that module 5 generates a plurality of feedback pulses to control unit 14. These pulses are processed by the control unit 14 to uniquely identify which module 5 currently forms the active time interval.

The D input to shift register 38 is a logic 0 during the first portion T1 of the actuation time interval, preventing selection of the module for firing. During the second part T2 of the operating time interval, the module is enabled by the control unit 14 to select, prime and fire. During this second portion T2, the D input to shift register 38 is a logic one. The logic level of the D input is controlled by a 14-bit binary counter 35, the operation of which will be described in detail below.

As mentioned above, during the first part of the module activation time interval, a unique identification pulse is generated to the control unit 14 to identify which module 5 is currently forming the activation time interval. The generation of this unique identification pulse is performed as follows. Power-on reset circuit 30
and a 4-bit shift register 33 is provided with each ignition module 5, which signal generator generates a plurality of feedback current pulses to the control unit 14 during the first part of the module operating time interval. do. Power on reset circuit 30 generates a power reset pulse to clear logic circuit 18 when power is received at ignition line input 16.

4-bit shift register 33 functions similarly to shift register 38. That is, if the date input D is a logic one, the clock pulse shifts the logic one through the various stages of the register.

As shown in FIG.
The clock signal source is the output of the oscillating clock 28. The data input to shift register 33 comes from a 14-bit binary counter 35, which is also responsive to clock 28. 6th of binary counter 35
Stage output Q6 is sent to shift register 33 as data D input. Therefore, the binary counter 35
A series of 1's and 0's are timed to shift register 33 in response to a change in the logic state of the Q6 output. Q1 output and Q3 of shift register 33
A resistor R3 is connected between the output and the resistor R3 operates in the same way as the resistor R2 to connect Q1 and Q3.
When there is a difference in the logic state of the ignition line power, a current increase is formed in the ignition line power. According to the invention, resistors R2 and R3 cooperate with shift registers 38 and 33, respectively.
represent first and second load connection means forming a current increase in the ignition line 3.

The Q13 output of binary counter 35 is also sent to signal line 48 as a control input to solid state bypass switch 20, which outputs input 16 of the ignition line in response to the output Q13 logic state. 22 to power the next lower module of the device. Thereafter, when the oscillating clock signal is stopped when a logic 1 appears on the Q13 output, pass-through switch 20 remains closed until power is removed from the firing line.

As previously mentioned, the module operating time interval is determined by the time required to count a predetermined number of clock cycles of clock 28. In the case of the present invention, the first portion of the module's operating time interval T1 is calculated from the time the ignition line power is applied to the module (when the power reset pulse appears) to the Q12 of the binary counter 35.
Measured until the output becomes a logic one. The second part T2 of the module actuation time interval is the output
Length of time Q12 is logic 1 (output Q12 is logic 1
(the length of time from when Q13 becomes logic 1 to when output Q13 becomes logic 1).

As shown in FIG. 5, output Q13 of binary counter 35 is provided as a second enable input to oscillator clock 28, inhibiting generation of the clock signal when output Q13 is a logic one. If clock 28 is disabled while output Q13 is true (logic 1), this indicates that the module is not selected for firing and the operating time interval for this module has completed, and this module is not selected for firing. It is placed in bypass until power is removed from the line.

Once each module forming the actuation time interval has been uniquely identified, the control unit 14 determines whether the module currently forming the actuation time interval is the module to be selected for firing and prepared for firing. You can know exactly whether it is there or not. A defective module that does not form an actuation time interval down the hole will have its unique identification pulse within the series of pulse envelopes for these modules when sequencing all modules and selecting no module for firing. It can be detected by the absence of an envelope.

For the preferred embodiment of the invention, each module generates 64 current pulses in the firing line during T1. Control unit 14 counts the pulses received during portion T1 of each module's actuation time interval and determines the time required for that module to generate 64 pulses. The time interval thus formed represents the envelope of the feedback identification signal from a particular module. Since the oscillator clock circuit can be varied slightly, each module easily creates a unique pulse envelope for that module.

To do this, the oscillating clock 28 of each ignition module can be modified slightly to create a unique envelope pulse for each module, which envelope uniquely identifies each module. Measured towards the top or bottom of the hole. In this way, there is no need to count how many modules are connected to the firing line in the selection sequence. The unique identification pulse determines when a given module is connected to the firing line to form an actuation time interval. Since 64 pulses must be received,
Isolated nozzle pulses on the firing line do not introduce error conditions.

Although 64 pulses is an ideal number, the total number of pulses received can be varied or reduced, and the module is still uniquely identified. Therefore, 64±n pulses can be used and in this way also a given module can be uniquely identified.

Connected to the reset input of shift register 33 is the Q12 output of binary counter 35. Therefore, shift register 33 operating in conjunction with the Q6 output of binary counter 35 and clock 28
generates a predetermined number of short current pulses in width in the ignition line 3 until such time as Q12 becomes a logic one. When Q12 becomes a logic 1, shift register 33 is reset to no longer generate current pulses on the firing line. In addition to resetting shift register 33, the Q12 output of binary counter 35 is also sent to the data D input of shift register 38 as a signal labeled ENABLE.

Referring now to FIG. 4, there is shown a timing diagram of various signals within a single wire drilling system according to the present invention. For the signal shown in Figure 4,
A third module below the control unit 14 is
This is the module that should be selected.

FIG. 4 shows the first and second portions T1 and T2 of each module actuation time interval. During the first part T1 of each module actuation time interval, the current signal in the ignition line 3 is 64
current pulses are formed. For purposes of illustration, the time intervals required for each module to generate the 64 pulses are different, and therefore the resulting envelope pulses _t1 to _t4 have different widths, and each pulse has a different width than its associated Uniquely identifies the module. The noise pulse that occurs between module No. 1 and module No. 2 has a narrow pulse envelope with respect to the identification pulse, and is ignored by the control unit 14 because it does not contain the correct number of current pulses. and reported on the ground as a possible effect.

Since module No. 3 is the module to be selected, control unit 14 generates a module selection control signal and a series of three fire ready selection control signals during the second portion T2 of the module actuation time interval. These control signals are applied as voltage pulses to the power voltage of the ignition line. The first received during the second part T2 of the operating time of module No. 3
The control signal selects the module for firing, thereby terminating further formation of the module activation time. This in turn prevents further sequencing of the submodules.

When module No. 3 receives a selection control pulse during the second portion T2 of the module actuation time, this module enters the selected state and during this state the module is activated by the security feedback detection sequence. Once it is determined that the engine is operating, it can be prepared for ignition.
In this security detection sequence, the ignition preparation circuit is
It starts when the ignition preparation control signal is received. As mentioned above, the ignition prime circuit creates a predetermined current pulse increase in the ignition line current shown in FIG. 4 as a ignition prime state pulse. If a suitable value for the current increase is detected, a second warm-up pulse is generated by the control unit 14 to remove the warm-up current pulse.

If an appropriate value is detected as the ignition preparation state pulse, the control unit 14 generates the third ignition preparation control signal and switches the ignition preparation switch 21 (the fifth
(see figure) and connect the electrical tube 24 to the ignition line 3. When the fire ready switch 21 is closed, the control unit 14 can generate a firing pulse on the firing line when it is desired to fire that module. However, rather than detonating the module, control unit 14 can reset the module to select another module by simply removing power from the firing line without generating a firing pulse. This security mechanism provides a unique identification envelope for each pulse as a function of the given operating conditions that the gun is currently experiencing, since temperature fluctuations encountered in the bore can cause wandering in the time base of each ignition module. line and can be used to sequence each ignition module to determine if all modules are operating properly. When the time base wanders, uniquely identifying the module64
The time required to generate each pulse varies.

As a redundancy check for security readiness pulses during the fire-ready sequence, control unit 14 determines whether the modules are operating as expected by measuring the current increase as each module is added to the fire line. can be determined. At the beginning of each module activation time interval, the increase in current in the firing line as each module is added to the firing line is shown in FIG. 4 as a step function.

One important feature of the present invention is that a redundant security detection method is provided to determine a defective condition or failure in the ignition system before attempting to fire the gun. These failures are classified as either failures that result in improper gun firing, which can be noticed, or failures that prevent improper gun firing from being detected.

As mentioned above, the response from each module that occurs during the first portion of the module's actuation time interval is a train of 64 feedback current pulses. Control unit 14 detects these feedback pulses and shapes the pulse train envelope to uniquely identify the module when it is connected to the firing line. To increase immunity to noise in the ignition line 3, the 64 pulses generated during the first part of the operating time interval of each module are such that the number of pulses detected during that sequence is a certain number of the correct number. If it is within, it is recognized as correct. Thus, spurious pulse trains such as the noise pulses shown in FIG. 4 are discarded and their occurrence can be signaled to equipment on the ground.

During the operating time intervals of the various modules, there are security features that determine that the modules are functioning properly. The envelope of the feedback pulse during the first portion of the actuation time interval is a long time interval, approximately half the module's actuation period. The control unit 14 is configured to accept a wide range of operating period values;
These can be measured with high precision. Each module 5 of gun device 10 can be distinguished by the frequency distribution of their clocks 28. The distribution of different frequencies, even if not made to different frequencies, represents a random process such that the differences between adjacent modules cannot always be measured, but the probability of this condition leaving a fault undetected is low enough. . Otherwise, the modules can be arranged sequentially in the device, adjusted to different values of the operating period.

Since the present invention allows each module to be sequenced without firing the modules, the time interval of each module can be measured before firing the gun. These values make it possible to form a reference table of operating time versus module position, which can later be used to confirm selections during drilling operations.

A further security detection system concerns the measurement of the line current of the ignition line 3. The control unit 14 is equipped with a highly accurate measurement of the current delivered to the ignition line. After a module is selected, the current in the firing line is proportional to the number of modules connected to this line and thus represents the selected module.

The total drawn current produced by all ignition modules connected to the ignition line is not accurate enough to indicate the number of modules, but it is , a predictable current change occurs. Before lowering the drilling device 10 into the hole and activating the gun, a preliminary value of the supply current can be measured by selection cycles of increasing length. In other words, how does this increase in firing line current occur for each module by performing a selection cycle selecting module No. 1, then performing a selection cycle selecting module No. 2, and so on? It is possible to judge whether These measurements can be performed in the same way as the identification pulse measurements.

Checking the operating time interval and line current is a security feature in situations where a fault reduces the operating period of a module to zero or a faulty module is powered together with the next subordinate module, and this is taken into account. bypassed without

In most drilling systems in which the present invention can be utilized, the firing actuation of the gun destroys the electrical wire passing through the gun. Although this condition is inconvenient as it limits the arbitrariness of selection, it is useful in locating the last fired gun. This can be accomplished by counting the modules that can still communicate with the control unit.

The number of interconnected modules is measured by a selection cycle of unlimited length. The control unit 14 counts the feedback pulse train and thus the number of modules. Measuring the supply current when the last module is bypassed indicates the condition of the line below the last fired gun. This measurement makes it possible to search for wiring defects between modules. The control unit 14 is capable of detecting open or shorted lines and determining up to which guns the system can still operate.

After a selection cycle in which a module is selected and primed to fire, the operative module must only be capable of applying ignition current to the blasting cap. However, one of the bypassed modules is defective and remains "active" after being bypassed. A module with a defective circuit will fire in parallel with the selected module and will ultimately go undetected. As a security feature against this defect, the selected module is not prepared to accept the ignition current immediately after the selection control signal is applied to the ignition line 3, requiring a ignition preparation sequence consisting of a number of ignition preparation control signals. .

As mentioned above, ignition preparation is carried out according to the invention by sending three further control pulses to the ignition line 3 similar to those used in the selection process. Only selected modules must be able to receive these pulses.

The first ignition preparation pulse increases the supply current drawn to the actuating module by a certain amount;
The second pulse holds this current at its previous value. If the increase in current is within an acceptable range, a third pulse finally closes the ignition preparation switch 21 between the detonator or blasting cap 24 and the ignition line 3. Simultaneously, or slightly after the third ignition warm-up control pulse, control unit 14 connects the ignition capacitor to the ignition line to generate ignition current.

If there is a defective module during the intermediate pre-ignition stage after selection, including a closed switch to the blasting cap, this defect condition can be detected by measuring the line current during or before the pre-ignition sequence. Detected.

In summary of the present invention, in the single wire selection drilling gun system disclosed herein, a plurality of identical ignition modules are connected together to form an elongated assembly suitable for lowering into a wellbore. Ru. The assembly includes a control unit which, when each module is sequentially connected to the control unit, one at a time,
Power and ignition line signals are generated to each ignition module.

Each ignition module forms an operating time interval within it, during which the module
The control unit selects and prepares for ignition. The actuation time interval begins when power is applied to the module by connecting the module to the ignition line. Each firing interval has first and second portions. During the first part, a unique identification pulse is generated to the control unit, which indicates that a particular module among the plurality of modules is connected to the ignition line and forming an actuation time interval. . In this way, the control unit can determine when a particular module is available for selection.

During the second portion of the module actuation time interval, the control unit selects the module for firing by generating a selection control pulse on the firing line. Pulses applied to the ignition line during the first portion of the actuation time interval are ignored by the module. This is because the module is only selected and primed for firing during the second part of the actuation time interval.

Once a module is selected, the control unit generates a series of three ready-to-fire signals to prime that module. The first and second ignition readiness control pulses form a current pulse increase of predetermined amplitude in the power of the ignition line, one and one
Indicates to the control unit whether the module is responding to the fire preparation sequence. If the current increase is within an acceptable range, the control unit generates a third ignition ready control signal to connect the module's powder detonator to the ignition line. Once a module is primed, control unit 14 can either generate an ignition pulse to detonate the powder, or remove power from the ignition line to reset all modules and start another module. The selection process can also be repeated as desired.

The preferred embodiments of the present invention have been described above. However, additions, deletions, substitutions, or other modifications will be apparent to those skilled in the art and to those familiar with the present disclosure without departing from the scope of the invention as defined in the claims. For example, the present invention has described a single ignition line 3 that carries both power and control signals between the control unit 14 and a plurality of ignition modules 5. It will be appreciated that more than one signal line may be used to transmit power and control signals from the control unit to the module and still achieve the benefits of the present invention. A single line may be used to carry the control signals for selection and ignition preparation separately from the ignition line power and feedback signals, in which case the signal line is segmented as described above. be done.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the ignition chain device of the present invention suspended in a well hole, FIG. 2 is a functional block diagram of the embodiment of the ignition module shown in FIG. 1, and FIG. FIG. 4 is a functional block diagram of an alternative embodiment of the ignition module shown in FIG. 1, and FIG. The figure selects the module of the format shown in Figure 4,
FIG. 3 is a timing diagram illustrating the operation of the present invention to prepare for and ignite the ignition. DESCRIPTION OF SYMBOLS 1... Well hole, 2... Well case, 3... Ignition line, 5... Ignition module, 6... Current detection means, 7... Control signal generator, 8... Power supply, 10
...Ignition chain device, 12...Cable, 14...
Control unit, 18...Modular logic circuit, 2
1, 22...Switch, 24...Detonator, 26...
Gunpowder, 28...clock, 29...constant current power supply,
32... Counter circuit means, 33... AND gate, 34... Stop pulse detector, 35...2
Advance counter, 37...Ignition line pulse detector,
41...Flip-flop, 43...Zener diode.

Claims (1)

Claims: 1. having a single ignition signal line electrically connecting the ignition control unit to each of the plurality of ignition modules one at a time in a predetermined sequence;
Each of the above-mentioned modules is connected to the control unit connected to it to the next module, each under the control of the module actuation time interval formed within the module, in a drilling system with selection by a single signal line. modules are connected to the ignition signal line one at a time in a predetermined sequence, each module forming its actuation time interval in response to being connected to the ignition signal line, and the next module in said sequence is: for ignition, characterized in that at the end of the activation time for the last connected module, this module is automatically connected to the ignition signal line if this module was not selected for ignition during that activation time interval. How to select modules for. 2. each module receives power and a ignition signal from the control unit via the ignition signal line, and the method further includes: forming within () a module actuation time interval during which the module is selected for firing by a selection control signal from said control unit; and ( ) an identification pulse transmitted to said control unit via said ignition signal line to indicate that the next module has been connected to the ignition signal line; and (b) the end of the module operating time of the last connected module. Claim 1, further comprising the step of automatically connecting said ignition signal line to the next module in said sequence if said module is not selected for ignition during its operating time. the method of. 3. The method of claim 2, wherein the step of forming an identification pulse includes generating an identification pulse that uniquely identifies the module during each module's actuation time interval. 4. The step of connecting each module to the ignition signal line comprises: (a) applying power to the ignition signal line in the form of voltage and current so as to energize the module connected to said ignition signal line; and (b) (c) forming a module actuation time interval at the module last connected to power on the ignition signal line; (c) at the end of each module actuation time interval transmitting the power on said ignition signal line to the next module in said sequence; and (d) repeating steps (b) and (c) until the module to be selected forms an active time interval. Method described. 5. Each module actuation time interval consists of (a) a first part in which the module generates an identification pulse and applies it to the ignition signal line, and (b) a selection pulse in which the control unit selects the module for ignition. and a second portion adapted to be received by the module via an ignition signal line.
The method described in section. 6. The method according to claim 2, wherein the step of forming the identification pulse includes the step of forming a current increase in the power of the ignition signal line where the amplitude of the current change in the ignition signal line is within a predetermined range. Method. 7. The identification pulse of each module must occur within a predetermined time window measured from the occurrence of the last identification pulse.
The method described in section. 8 (a) forming a ignition arming pulse in the energizing module when the energizing module is to be ready for ignition; and (b) generating the selected ignition pulse when the ignition arming pulse prepares the module for ignition. A method as claimed in claim 1, comprising the step of connecting a conduit section of an ignition module to the ignition signal line so that an ignition pulse of the ignition signal line can detonate the selected ignition module. . 9. The step of forming an identification pulse that uniquely identifies the module comprises the step of forming a predetermined number of current pulses in the firing line such that the time interval for generating the current pulses represents the identification pulse. The method according to scope 3 or 4. Claim 9 comprising the step of providing each module with a separate predetermined time base for generating identification pulses such that the time intervals of the identification pulses for the modules are each different.
The method described in section. 11. Connecting the selected ignition module to the ignition signal line when a module is selected for ignition so that an ignition pulse on the ignition signal line can detonate the selected ignition module. The method described in item 10. 12. Connecting the ignition module to the ignition signal line comprises: (a) forming a predetermined increase in current in the ignition signal line in response to the first ignition readiness control pulse, the predetermined current increase being one (b) removing a predetermined current increase in the current in said ignition signal line in response to a second ignition ready control pulse; 11. Connecting the ignition module to the ignition signal line in response to a third ignition readiness control pulse generated when the predetermined change in current in the ignition signal line is within an acceptable range. The method described in. 13. Claims 1 to 1 further comprising the step of grounding each ignition module that is connected but not selected by the control unit.
The method described in any of Section 2. 14. A method according to any one of claims 1 to 13, forming a power reset signal in each module when each module is connected to the ignition signal line to initiate each actuation time interval. . 15. The method of claim 5, wherein the first and second portions of each actuation time interval are equal in length. 16 Each module connected to the ignition signal line but not selected remains connected to the ignition signal line in an inactive state, and the module in the inactive state momentarily removes power from the ignition signal line. Claim 1 is reset to be sequenced again by
16. The method according to any one of paragraphs 1 to 15. 17 Gunpowder in multiple ignition modules one at a time
In a single signal line selection drilling system for selectively detonating one module at a time, the system comprises: (a) a control unit operatively connected to said module by a single ignition signal line;
The ignition signal lines carry both power and control signals between the control unit and the module, and are further (b) vertically connected to each other to form an elongated assembly suitable for lowering into a wellbore. a plurality of selectable ignition modules, said assembly including said control unit, and each module including () at least one pyrotechnic powder, each module igniting one at a time in a predetermined sequence; automatically connected to and receives electrical power from the signal line, and () internally forms a module actuation time interval in response to receiving electrical power via the ignition signal line, the time interval during which the module operates; The time at which a module and its powder are selected for ignition by said control unit, and each module not selected for ignition during the actuation time interval automatically passes the ignition signal line to the next module in said sequence. A system characterized by connecting. 18. The system of claim 17, wherein each module, in response to receiving power via the ignition signal line, forms an identification signal that uniquely identifies the module during its activation time interval. 19. The control unit comprises: (a) means for detecting the amount of power current appearing on the ignition signal line so as to detect when the module is connected to the ignition signal line; and (b) a control signal on the ignition signal line. means for generating, the control signal comprising: () a selection control signal for selecting a module to be selected for ignition; and () a series of ignition signals for connecting the selected module's powder to an ignition signal line. 19. The system of claim 17 or claim 18, comprising a readiness control signal and () an ignition control signal for detonating the explosive in the module selected for ignition. 20 The ignition signal line of each of the ignition modules has an input and an output, and each of the ignition modules is configured to: (a) in response to receiving electrical power via the input of the ignition signal line; an identification signal generator for generating an identification signal to the control unit indicating that one of the ignition signal lines is connected to the ignition signal line; a module actuation time interval former, said module actuation time interval being a time during which said module is selected for firing; a stop pulse detector responsive to the selection signal and the time interval former to terminate the formation of the module actuation time interval and to terminate further module selection; (d) further comprising a series of ignition preparation control signals; and (e) a ignition preparation circuit for connecting the pyrotechnic charge of the module to an ignition signal line in response to the ignition pulse detector and the ignition signal line, thereby arranging the module to ignite; a pass-through switch responsive to the interval former to connect the input of the ignition signal line to its output at the end of the module actuation time interval, thereby connecting power to the next ignition module in the assembly; 20. The system of claim 19, comprising: 21. The identification signal generator includes: (a) a power reset circuit responsive to receiving power via the ignition signal line input to form a power reset pulse for initiating an operating time interval of the module; and (b) a first load responsive to the power reset pulse for generating a predetermined number of pulses on the firing signal line such that the time required to generate the predetermined number of pulses represents an identification signal that uniquely identifies the module; A system according to claim 18 or 19 or 20, comprising connection means. 22. The ignition signal line of each of the ignition modules has an input and an output, and each of the ignition modules is configured to: (a) cause the module to ignite in response to receiving electrical power via the input of the ignition signal line; (b) a module actuation time interval shaper responsive to the identification pulse generator to form a module actuation time interval; (c) the module activation time interval is the time during which the module is selected for firing; and (c) the selection pulse sent via the input of the firing signal line and the time interval former; a stop pulse detector responsive to terminating the formation of the module actuation time interval and connecting the pyrotechnic charge of the module to the ignition signal line to select the module for ignition, and (d) further comprising: Responsive to the module actuation time interval generator to connect the input of the ignition signal line to its output at the end of the module actuation time interval, thereby connecting power to the next ignition module in the assembly. 18. The system of claim 17, comprising a pass-through switch. 23. The identification pulse generator includes: (a) a power reset circuit responsive to receiving power via the ignition signal line input to form a power reset pulse that initiates an operating time interval of the module; and (b) and load connection means for increasing the current in the ignition signal line in response to the power reset pulse such that the increase in current pulse represents an identification pulse of the module.
The system according to item 0 or item 21. 24. The activation time interval generator of the ignition module comprises: (a) a clock oscillator for generating a digital time base clock signal; (b) counting a predetermined number of clock pulses in response to the stop pulse detector and clock signal;
a binary counter for determining the length of the module actuation time interval, the counter () outputting a first signal when a first portion of said time interval occurs; and () outputting a first signal when a first portion of said time interval occurs; 24. The system of claim 23, wherein the system outputs a second signal when a portion occurs. 25. (a) said identification signal is generated during a first portion of said time interval; and (b) said module is adapted to receive a selection pulse during a second portion of said time interval. The system according to paragraph 24. 26. said stop pulse detector comprises: (a) means for detecting a voltage increase at an input of said ignition signal line, the voltage increase during a second portion of said actuation time interval being representative of a selection pulse; and (b) further , in response to said detection means and said module time interval former to disable a clock signal to said binary counter and select by said detection means during said second portion of said module operating time interval. disabling means for generating an ignition switch signal when a pulse is detected; and (c) further connecting an input of the ignition signal line to the pyrotechnic powder of the ignition module in response to the ignition switch signal. 27. A system according to claim 24 or claim 26, comprising a controllable switch. 27. said stop pulse detector: (a) comprising means for detecting a control signal at an input of said ignition signal line, the control signal received during a second portion of said actuation time interval selecting a module for ignition; (b) further responsive to said detection means and said module time interval former to disable a clock signal to said binary counter, such that said selection pulse is not transmitted during said second portion of said module actuation time interval; Claim 26 comprising disabling means for terminating further sequencing of the module if received.
The system described in Section. 28 The series of ignition preparation signals includes first, second, and third ignition preparation control signals, and the ignition preparation circuit includes: (a) the stop pulse detector and the first and second ignition preparation control signals;
second load connection means for generating a pulse of a predetermined magnitude to the control unit in response to a ready-to-ignite signal to indicate that only one module is responsive to the ready-to-ignite signal; and b) a pyrotechnic connection switch for connecting the input of the ignition signal line to the pyrotechnic powder and priming the module in response to the third ignition preparation signal and the stop pulse detector. The system described in Section. 29 The stop pulse detection means further comprises a zener diode connected between the ignition signal line and the controllable switch, the zener diode being below a predetermined voltage when the module is selected for ignition. 27. The system of claim 26, wherein the ignition pulse has a voltage amplitude greater than a predetermined voltage. 30 (a) applying power to the ignition signal line with a voltage and current of sufficient magnitude to energize the module but not sufficient to ignite the module; and (b) selecting the operative module. Claims 1 and 2 include generating a selection pulse during a module actuation time interval to select the module for firing by means of an ignition pulse comprising sufficient power on the ignition signal line to detonate the ignition module when the module is activated. The system according to any one of clauses 17 to 29.