JPS62242092A - Excavation overload preventive control method - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for drilling a well, and in particular, a method for preventing overload of drilling, which can protect the drilling site from overload when the drilling load becomes overload. This relates to a control method.

[Conventional technology] When drilling a well with an offshore oil drilling rig, an offshore mineral resources drilling rig, or an onshore oil drilling rig, the drilling bit is rotated and its own weight is used to make the drilling bit descend. Drilling a well.

In this well drilling, the layers in the ground are not aligned in the direction of drilling, and therefore the rotation f1 load of the drilling bit varies depending on the strata.

Conventionally, rotary machine electric motors, internal combustion engines, etc. have been used to rotate this drilling bit, and the electric
The load on the J aircraft and internal combustion engine was adjusted manually while checking the torque word.

[Problems to be Solved by the Invention] However, because the load is manually adjusted, it is not possible to accurately adjust the load, and if an instantaneous overload occurs during excavation, the motor for the rotary machine may be stopped due to the overload, or the excavation bit may be turned off. There is a problem that excessive wear or bending of the drill pipe cannot be prevented.

The present invention has been made in consideration of the above-mentioned circumstances, and when the rotational load becomes overload when rotating an excavation bit, the rotation drive means and the excavation bit are protected from overload. The purpose of the present invention is to provide a control method for preventing excavation overload that can protect the user from overloading.

Means and operation for solving problem F] In order to achieve the above-mentioned object, the present invention rotates an excavation bit with a rotary drive means and makes the excavation bit descend into a mine using an excavation drive means. J3 is a method for drilling a well, in which the load on the rotary drive means is detected, and when the load reaches a set maximum load, the excavation drive means stops the descent of the drilling pit, The load on the rotary drive means is detected, and when the load reaches the set maximum load, the excavation drive means is stopped as an overload, and the downward excavation of the excavation pit i~ is stopped, and in this state, the rotary drive means is When the load becomes small, the excavation drive means is driven again to cause the excavation drive to descend, thereby protecting the rotation drive means and the excavation bit from overload.

[Embodiments] Hereinafter, preferred embodiments of the excavation overload prevention control method according to the present invention will be described based on the accompanying drawings.

FIG. 1 shows an apparatus for carrying out the method of the present invention. In the figure, reference numeral 1 indicates a tower, which is installed on the ground 2 at an excavation M. .

A drill vibrator 3 is provided on the tower 1 so as to be movable up and down, and a drill vibrator 4 is attached to the tip of the vibrator 1 to the drilling pit 1. The wire 5 is connected to the upper end of the drill vibrator 3, and the wire 5 is connected to the pulley 6 provided at the top of the tower 1, and the excavation part is completed! It is wound around the drum 8 of the AC motor 7 for draw works, which is a ll device.

Inside the tower 1 is an electric motor 1 for a rotary machine which is a rotary drive means for rotating the drilling pits 1-4 via a drill vibrator 3.
A9 is provided, and a driving gear 10 of the electric motor 9 rotates the drill vibe 3 via a broken wave tooth medium 1 provided in the drill vibrator 3, thereby rotationally driving the drilling bit 4.

The load on the electric l1s9 for the rotary machine is detected by the overload control circuit 12, and when the load reaches the set maximum load, a stop signal 13 is output to stop the rotation of the AC motor 7 for the draw works. ing.

This overload control circuit 12 is an electric motor 1 for a rotary machine.
A current detector 15 detects the input Ti current value passing through the power cable 14 of f19, and the current value from the current detector 15 is compared with the set maximum load current value, and if the load current value exceeds the set value. and an overload detection circuit 16 that outputs a stop signal 13 when

Next, this overload control circuit 12 will be explained in detail with reference to FIG.

The current value detected by the current detector 15 is detected as a value proportional to the load current of the rotary machine electric motor 9,
This current value is input by the resistor 17 to the subtracter 18 as a voltage value input signal a.

A current reference device 19 consisting of a variable resistor connected to a positive power supply is connected to the subtracter 18, and a current reference t! corresponding to the load current value at the rated load state of the rotary machine electric motor 9 is preliminarily connected. The c voltage signal is input to the subtracter 18. The subtracter 18 subtracts the signal a detected by the Ti current detector 15 and the current reference signal set by the current base unit 19 to obtain a signal C corresponding to the overload current of the rotary machine motor 9. is output to the integrator 20.

The integrator 20 integrates the voltage signal corresponding to the overload current if the rotary machine electric motor 9 continues to be overloaded, and decreases the voltage signal by that amount if the load falls below the rated load. Therefore, the output signal Qd is set to an upper limit. The signal is input to the comparator 21.

An upper limit reference device 22 such as a variable resistor connected to a positive power supply is connected to the upper limit comparator 21, and the upper limit reference device 22 determines the upper limit corresponding to the preset overload capacity of the electric motor 1fi9 for the rotary machine. The reference voltage signal @ (setting maximum negative signal) e is input to the upper limit comparator 21. When the signal d from the integrator 20 is larger than the upper limit reference voltage signal C, the upper limit comparator 21 sends a signal f to excite the third relay coil 23, so as to touch the third relay contact 24. It has become.

On the other hand, a first relay contact (b contact) 26 for overload prevention and a second relay contact (a contact) 27 for starting are connected in series to the power line 25 of the AC ffi e R7 for de[1-works]. , the first relay coil 28 that operates the first relay contact 26 for over-negative direction prevention is connected to the control power source 29 in series with the third relay contact 24 that is opened and closed by the upper limit comparator 21, and 2 relay contact 27 actuating the second
A relay coil 30 is connected to a control power source 29 in series with a push button switch 31. Also push button switch 3
1 is connected in parallel with an auxiliary second relay contact 32 for self-holding the second relay contact 27 of A.

In the above, as shown in FIG. 1, the drilling bit 4 is
A type for rotary machines, which is a rotational drive means! It is rotated by the JJ machine 9, and at the same time, the wire 5 is paid out from the drawworks AC motor 7 and the respective drums 8, which are excavation driving means, and the excavation is carried out downward.

In this pile excavation, the rotary machine electric motor 9
is detected by the current detector 15 of the overload control circuit 12, and when the detected value reaches the set maximum load indicating overload, the overload detection circuit 16 sends a stop signal 13 to the draw works AC motor 7. output and stop the rotation of the electric 1FIJ machine 7.

As a result, the feeding of the wire puller 75 is stopped, and the drilling bit 4 rotates while substantially stopping at the digging position. Note that when this AC motor 7 for draw works is stopped, the motor 7 is free to rotate, but it is controlled by a speed reduction device from the motor to the drum 8, or by a reverse rotation prevention VtI! built in the drum 8! 7 stops the wire 5 from being fed out.

When the load on the rotary machine electric motor 9 is reduced, the overload prevention control circuit 12 cancels the stop signal 13, and the drawworks AC electric motor 7 is started again to allow the excavation bit 4 to move downward. be exposed.

This will be explained in detail by J in the signal waveform diagrams of FIGS. 2 and 3.

FIG. 3 shows each signal a of the overload control circuit 12 shown in FIG.
-f shows each voltage waveform change.

First, the rotary machine electric motor 9 is started, and when the push button switch 31 is pressed, the second starting relay coil 30 is energized, its second relay contact 27 is closed, and the draw works AC motor 7 is started. Ru. In this case, since the auxiliary second relay contact 32 is also closed at the same time, even if the pushbutton switch 31 is opened, the second relay coil 30 remains energized, and the second relay contact 27 is]! It is held in the same position. In addition, to manually stop the AC electric motor 8317 for draw works, press the push button switch (not shown) and the second relay contact 2
It is designed to open 7.

When the rotary machine electric motor 9 and the drawworks AC electric motor 7 are driven in this manner, the drilling pit 1-4 descends and excavates a well.

During this excavation, a signal a proportional to the load of the rotary machine electric l19 is detected by the Ti flux detector 15, and the subtractor 1
8, the signal of the current reference device 19 is already subtracted.

For example, if the input signal a changes as shown in the graph (A> in Figure 3), and the signal a@reference signal has already been subtracted, the output signal C of the subtractor IJ&18 will be as shown in the graph (B). become.

This output signal? The signal dG integrated by the tC/fi integrator 20 has the voltage waveform shown in graph (C), and it is input to the upper limit comparator 21, so 1. [The limit comparator 21 indicates no overload and compares it with the upper limit reference voltage signal 0, and when the signal d exceeds the signal e, the signal d exceeds the signal e as shown in the graph ([]). The signal f is output for the time t1 during which the signal f is present.

As a result, the third relay coil 23 is energized as shown in FIG. 2, and when the third relay contact 24 is closed, the first relay coil 28 for over-negative direction prevention is energized, and the second relay contact 27 is thereby opened. , power supply to the draw works AC power IJII1m7 from the power supply line 25 is stopped, and the electric motor 7
rotation is stopped.

After this, as shown in graph (C), when the signal d from the integral solid 20 becomes lower than the upper limit reference signal e, 1, limit comparison?
! The output signal f of i21 becomes zero potential, the third relay coil 23 is de-energized, the third relay contact 24 is opened, and the control power supply 2 is connected to the first relay coil 28 for over-negative direction prevention.
9 stops flowing, the first relay contact 26 is closed, and the draw works AC motor 7 is started again.

As described above, by detecting the load on the rotary machine electric motor 9 and stopping the rotation of the drawworks AC motor 7 when the load reaches the set maximum load, the rotation of the rotary machine electric motor 9 and the excavation pit 1- 4 can be protected from overload.

FIG. 4 shows another embodiment of the invention.

In the embodiment shown in FIG. 1, if the rotary machine electric motor 9 is overloaded, the drawworks message if the electric motor 7
Although the explanation has been given using an example in which energization is stopped, this example does not show an example in which a clutch 33 and a brake 34 are provided between the draw works AC motor 7 and the drum 8.

The overload prevention control circuit 12a includes a current detector 15 that detects the load of the rotary machine electric motor 9, and an overload detector that receives the detected value from the current detector 15 and detects when the detected value becomes the maximum set load. The overload detection circuit 16a controls the clutch 33 and brake 34 using air signals 35 and 36, respectively.

In the embodiment shown in FIG. 4, while digging is underway at the excavation pits 1 to 4, the clutch 33 is engaged by the air signal 5'33b+36 from the overload prevention 11' control circuit 12a, By loosely fitting the brake 34, the draw works telegram 1afJjJI 17 and the drum 8 are integrally connected, and the drum 8 is rotated by the rotation of the electric motor 7, and the drum 8 is paid out and excavation is performed at a predetermined descending speed. Bit 4 excavates.

If the rotary machine electric motor 9 is overloaded in this state, the overload prevention & IJ a11 circuit 12a disengages the clutch 33 and disconnects the electric motor 617 at the air signal @35.36, and operates the brake 34. The rotation of the drum 8 is stopped.

This overload prevention 1lI11 control circuit 12a will be explained with reference to FIG.

5 is basically the same as the circuit explained in FIG. 2, 9 is a rotary machine electric motor, 14 is its power cable, 15 is a current detector, 17 is a resistor, 18 is a subtracter,
19 is a current reference device, 2o is an integrator, 21 is an upper limit comparator,
22 is an upper limit reference device.

In this circuit 12a, a clutch control solenoid valve 38 is connected to an air line 37 that sends an air signal to the clutch 33, and an air line 3 that sends an air signal to the brake 34.
A control power line 41 to which a solenoid valve 40 for controlling the brake a11 is connected to 9 and which controls the opening of each solenoid valve 38,40.
．． 42 and 1st relay contact (b contact) for clutch 43 respectively
．． A first brake relay contact (a contact) 44 is connected.

On the other hand, a second relay coil 45 is installed in the upper limit comparator 21, and a second relay contact 46, which is opened and closed by the second relay coil 45, is connected to the control power source 29, and the second relay contact 46 is connected to the control power source 29. A first relay coil 47 for overload prevention is connected in series with the coil 47, and the first relay contact 43 for the clutch and the first relay contact 44 for the brake are opened and closed by the first relay coil 47.

The operation of this circuit 12a will be explained with reference to the voltage waveform diagram of each signal a to f in FIG. 6 and the flowchart of the clutch brake solenoid valves 38 and 40.

First, the voltage waveforms of graphs (A) to (D) in FIG. 6 are as explained in FIG. In this state, the second relay contact 4'6LL is open and the first relay coil 47 for overload prevention is not energized, so the first clutch relay contact 43 is open and the brake 1st
When the relay contact 44 is open and the clutch solenoid valve 38 is open as shown in graph (E), the brake ffi! The i-valve 40 is opened as shown in the graph ((:).

As shown in graph (C), when the signal d from the integrator 20 exceeds the upper limit reference @e, the output signal f is output from the limit comparator 21, and the second relay coil 45 is excited and its Close the second relay contact 4G, and close the first relay contact for overload prevention.
The relay coil 47 is excited 1a ff. When this first relay coil 47 is excited, the first clutch relay contact 43 is closed.

The first brake relay contact 44 is opened, and the graph (E
), the clutch solenoid valve 38 is overloaded.
It is closed for one hour, and as shown in graph (F), the brake solenoid valve 40 makes a loud noise at time t1.

In the embodiment shown in FIGS. 4 to 6, a clutch 33 and a brake 3 are connected between the draw works AC motor 7 and the drum 8.
4, in the event of an overload, the clutch 33 is disconnected and the AC electric motor 8317 for draw works is kept in a rotating state, and the drum 8 is stopped by the brake 34. For example, the brake 34 can be used to control the wire payout speed by rotating the rotary machine. It is also possible to set the digging speed to be slower than normal digging as long as the electric motor 9 is not overloaded.

In the above-described embodiment, a rotary machine type wJ machine 9 is used as the rotational drive means, but an internal combustion engine may also be used. In this case, load detection can be performed in the same way as the current detector 15 by using an axis 1-Luke current converter.

In addition, an AC motor 7 for draw works is used as an excavation drive means.
and the clutch 33 and the brake 34 at or between the drum 8
1 noise 1' E) from the drum 8
Although the explanation has been given using an example in which the descending speed of the excavation pits 1 to 4 is controlled through the draw works AC motor 7, it is of course not possible to use an internal combustion engine instead of the AC motor 7 for the draw works.

[Advantageous Effects of Explanation 1] As is clear from the above detailed description, the present invention exhibits the following excellent effects.

(1) The load on the rotary drive means that rotates the excavation bit is detected, and when the load reaches the maximum set load, the excavation drive means stops lowering the excavation bit. Means overload can be automatically prevented.

(2) Since it is possible to prevent overload of the rotation drive means, it is possible to prevent excessive wear of the detail bit and also to prevent the drill vibe from bending.

(3) Efficient excavation can be achieved and safety can be improved through automation.

[Brief explanation of drawings]

FIG. 1 is a diagram showing an example of an apparatus for carrying out the method of the present invention;
Figure 2 is a detailed diagram of the overload control circuit in Figure 1, Figure 3 is a diagram showing the voltage waveform of each signal in the circuit in Figure 2, and Figure 4 is a diagram showing the voltage waveform of each signal in the circuit in Figure 1.
Figure 5 shows a detailed diagram of the overload control circuit in Figure 4, and Figure 6 shows the voltage waveform of each signal in the circuit in Figure 5 and the opening/opening state of the solenoid valve. FIG. In the figure, 4 is an excavation bit, 7 is an AC motor for draw works which is an excavation drive means, 9 is an electric motor for a rotary machine which is a rotation drive means, and 12 is an overload control circuit. Patent applicant: Ishikawajima-Harima Heavy Industries Co., Ltd. Representative Patent Attorney Nobuo Kinutani 4...for excavation, 9...for rotary machining Figure 1, Figure 2, Figure 3, Figure 5

Claims (1)

[Claims] In a method of excavating a well by rotating a drilling bit by a rotational drive means and lowering the drilling bit by an excavation drive means, the load of the rotational drive means is detected, and the load is determined to be a set maximum load. An excavation overload prevention control method characterized in that the excavation drive means stops the descent of the excavation bit when the excavation drive means stops the descent of the excavation bit.