CN210690669U - System for real-time monitoring electric submersible pump unit leakage current - Google Patents

Abstract

The embodiment of the utility model discloses a system for monitoring the leakage current of a submersible electric pump unit in real time. the inner hole of the closed-loop Hall current sensor, so that the closed-loop Hall current sensor measures the magnitude of the leakage current in the form of alternating current from the current flowing through the cable sheath and converts the magnitude of the leakage current into a direct current analog value, wherein the current flowing through the cable sheath includes the leakage current in alternating current form and the parameter current in direct current form generated by a downhole measurement unit for measuring a plurality of downhole parameters of the submersible electric pump signal; a micro-control unit configured to receive the DC analog value and compare the DC analog value with a leakage current threshold; an alarm module configured to alarm when the DC analog value is greater than the leakage current threshold and make all The submersible pump unit stops working.

Description

A system for real-time monitoring of leakage current of submersible electric pump units

technical field

The utility model relates to the technical field of monitoring electric submersible pumps for oil exploitation equipment, in particular to a system for monitoring the leakage current of electric submersible pump units in real time.

Background technique

Insulators are often thought to be non-conductive, but in reality, almost no insulating material is absolutely non-conductive. For any insulating material, when a voltage is applied across it, a certain current will always flow through. The active component of this current is called leakage current, and this phenomenon is also called leakage of the insulator. In fact, leakage current is the current that flows through an insulating part of an electrical line or device when voltage is applied without a fault. Therefore, the size of the leakage current is one of the important indicators to measure the insulation performance of electrical appliances, and it is the main indicator of product safety performance. Limiting leakage current to a small value plays an important role in improving product safety performance.

In the field of oil exploration, under the action of applying voltage without fault, the electric submersible pump unit forms a loop between the three-phase wire and the cable sheath at the place where the insulation performance of the insulation layer of the three-phase cable is aging, resulting in a leakage current. . The underground environment of oil production wells is very complex. For example, the high temperature and high pressure environment and some oil well chemicals such as hydrogen sulfide and carbon dioxide will cause damage to the insulation of the transmission cable of the submersible pump unit, resulting in destructive failure of the system. Therefore, the measurement of the leakage current of the electric submersible pump unit is very important.

In the prior art, in order to ensure the safe use of the electric submersible pump, an insulation test is performed on the electric submersible pump unit before going down the well, that is, the leakage current of the electric submersible pump unit is measured. A 2.5KV-10KV megohmmeter was used in the measurement process. When measuring, connect the negative electrode of the test lead to the phase line, and the positive electrode of the test lead to ground. Although the output current of the megohmmeter is very small, if no protection measures are taken, the instantaneous high voltage generated by the megohmmeter will break down and damage the downhole equipment. Therefore, a high-voltage diode is also connected at the star point position of the motor in the passage to protect the downhole equipment during the insulation test. Unless the high-voltage diode breaks down, the downhole equipment will not have instantaneous high-voltage current flowing. The disadvantage of this method is that it can only ensure the reliability of the insulation performance of the electric submersible pump unit before going downhole, and cannot measure the insulation performance of the electric submersible pump unit in real time. Once the insulation fails, without the corresponding data support, the staff cannot There is no way to take corresponding measures to estimate the working conditions of the submersible pump unit. In order to know the insulation performance of the submersible electric pump unit under long-term operation, the submersible electric pump must stop working and remove all the oil pipes, which is a waste of time and money.

Another method for detecting the leakage current of the submersible electric pump unit is to connect a diode in anti-parallel between the power supply poles of the downhole parameter unit. When the uphole secondary instrument provides a positive voltage, the diode does not conduct, and the downhole circuit part can work normally. , can detect parameters other than the leakage current value of the unit. When the uphole secondary instrument provides back pressure downward, the anti-parallel secondary tube is turned on, and the downhole circuit part is bypassed, and other components cannot work at this time. The system current at this time is the leakage current of the submersible electric pump unit. The measurement of the neutral point leakage current is completed by detecting the current value in the loop. The disadvantage of this method is that the leakage current can be measured only when the reverse voltage is provided to the downhole, which cannot be monitored in real time.

At this stage, there is a set of very mature measurement specifications for the measurement of leakage current of household appliances in China, but this measurement method must be measured by a qualified testing organization. Users cannot measure leakage current without professional technical support.

Utility model content

In order to solve the above-mentioned technical problems, the embodiments of the present utility model are expected to provide a system for monitoring the leakage current of the electric submersible pump unit in real time; the monitoring of the leakage current can also be realized under the condition that the electric submersible pump is downhole and in working state; There is no need to provide back pressure to the downhole, and real-time monitoring can be realized; the monitoring technology is simple, and there is no need to provide users with professional technical support.

The technical scheme of the present utility model is realized in this way:

The embodiment of the present utility model provides a system for monitoring the leakage current of a submersible electric pump unit in real time, and the system includes:

A closed-loop Hall current sensor, the cable sheath of the three-phase cable for powering the submersible electric pump passes through the inner hole of the closed-loop Hall current sensor, so that the closed-loop Hall current sensor flows from the cable sheath The magnitude of the leakage current in AC form is measured from the current of a parameter current signal in the form of direct current generated by a downhole measurement unit that measures a plurality of downhole parameters of the electric submersible pump;

a micro-control unit configured to receive the DC analog value and compare the DC analog value to a leakage current threshold;

An alarm module is configured to alarm and stop the submersible electric pump unit from working when the DC analog value is greater than the leakage current threshold.

The embodiment of the utility model provides a system for monitoring the leakage current of the electric submersible pump unit in real time; by using the closed-loop Hall current sensor on the ground to measure the leakage current, it is not necessary to lift all the electric submersible pump unit out of the wellhead; the closed-loop Hall The current sensor can only measure the AC current value, and will not be affected by the DC parameter current signal that also flows through the cable sheath. It can monitor the current leakage of the submersible pump unit in real time; the closed-loop Hall current sensor and the measured current flow There is no direct electrical connection between the loops passing through, and it will not consume the energy of the loop through which the current to be measured flows. It has little impact on the loop and the measured value is relatively accurate; the measurement method is simple and does not require the user to have professional skills.

Description of drawings

1 is a schematic diagram of a system for real-time monitoring of the leakage current of an electric submersible pump unit provided by an embodiment of the present utility model;

2 is a schematic structural diagram of a submersible electric pump unit provided by an embodiment of the present invention and a system for monitoring the leakage current of the submersible electric pump unit in real time;

3 is a schematic structural diagram of a closed-loop Hall current sensor provided by an embodiment of the present invention;

4 is a schematic diagram of a method for real-time monitoring of leakage current of an electric submersible pump unit provided by an embodiment of the present invention.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

Referring to FIG. 1 , it shows a system 100 for monitoring the leakage current LC of the electric submersible pump unit 200 in real time according to an embodiment of the present invention. The electric submersible pump unit 200 includes an electric submersible pump 230 (see FIG. 2 ) powered by a three-phase AC power source 210 , wherein the three-phase AC power source 210 is the electric submersible pump via the frequency conversion controller 220 and the three-phase cable 240 . 230 to supply power, and the three-phase cable 240 includes three-phase conductors 241 , a cable armor 242 , and an insulating layer 243 between the three-phase conductors 241 and the cable armor 242 . The leakage current LC (shown by solid arrows in FIG. 2 ) is when the electric submersible pump 230 is powered by the three-phase cable 240 , where the insulation performance of the insulation layer 243 is degraded (for example, as shown in FIG. 2 ). The insulation aging point 244) is the alternating current flowing through the cable sheath 242 generated by the three-phase wire 241 and the cable sheath 242 forming a loop. The electric submersible pump unit 200 further includes a downhole measurement unit 250 (see FIG. 2 ) for measuring a plurality of downhole parameters (such as temperature, vibration, and pressure) of the electric submersible pump 230. The downhole measurement unit The parametric current signal PC in the form of DC generated by 250 (shown by the dashed arrow in FIG. 2 ) is transmitted to the surface through the cable armor 242, and the downhole measurement unit 250 is based on the star point between the uphole star point O1 and the downhole star point O2. The point equipotential principle is powered. The system 100 includes:

In the closed-loop Hall current sensor 110, the cable sheath 242 of the three-phase cable 240 for supplying power to the submersible electric pump 230 passes through the inner hole H of the closed-loop Hall current sensor 110 (see FIG. 2), so that the closed-loop Hall current sensor 110 The current sensor 110 measures the magnitude of the leakage current LC in AC form from the current flowing through the cable sheath 242 and converts the magnitude of the leakage current LC into a DC analog value, wherein the flow through the cable The current of the armor 242 includes the leakage current LC in the AC form and the parameter current signal PC in the DC form generated by the downhole measurement unit 250 for measuring a plurality of downhole parameters of the electric submersible pump 230;

a micro-control unit 120, configured to receive the DC analog value and compare the DC analog value with a leakage current threshold;

The alarm module 130 is configured to alarm when the DC analog value is greater than the leakage current threshold and to stop the submersible pump unit 200 from working.

The working principle of the closed-loop Hall current sensor 110 is as follows: the magnetic field generated by the measured current is induced by the Hall element 111 (see FIG. 4 ) of the closed-loop Hall current sensor 110, and the generated output signal drives the corresponding power tube to conduct it. It is turned on to generate a compensation current, and the compensation current flows through the wound secondary coil to generate a magnetic field. The magnetic field is just opposite to the magnetic field generated by the measured current, which compensates the original magnetic field and reduces the induction output of the Hall element 111 . When the magnetic field generated by the measured current is equal to the magnetic field generated by the compensation current, the compensation current will no longer increase, the magnetic field induced by the Hall element is zero, and the closed-loop Hall current sensor measures the current measured by the compensation current. It can be seen from the above working principle that the closed-loop Hall current sensor 110 can only measure the AC current value, so it will not be affected by the DC parameter current signal PC transmitted from the downhole through the cable sheath 242, so that the submersible electric pump can be monitored in real time. Current leakage of unit 200. Moreover, there is no direct electrical connection between the closed-loop Hall current sensor 110 and the loop through which the current to be measured flows, and will not consume the energy of the loop through which the current to be measured flows.

In a preferred embodiment of the present invention, as shown in FIG. 2 , the system 100 may further include a display screen 140 configured to display the DC analog value received by the micro-control unit 120 in real time.

In a preferred embodiment of the present invention, as shown in FIG. 2 , the system 100 may further include a host computer 150 , and the host computer 150 is configured to draw in real time corresponding to the DC analog value received by the micro-control unit 120 insulation performance curve. The insulation performance of the electric submersible pump unit 200 is a slowly decaying variable, so the leakage current LC representing the insulation performance of the electric submersible pump unit 200 is also a quantity that needs to be monitored in real time for a long time. The leakage current value is drawn into a curve graph that changes with time, the user can observe the change of the insulation performance of the electric submersible pump unit 200 with time, can judge the aging degree of the insulation performance in time, and predict the electric submersible pump unit 200 The insulation aging trend can be observed in order to take corresponding protective measures in time to ensure the safe operation of the submersible electric pump unit.

In a preferred embodiment of the present invention, as shown in FIG. 2 , the system 100 further includes a multi-channel analog quantity acquisition module 160, and the multi-channel analog quantity acquisition module 160 is configured to collect the closed-loop horoscope through the first channel. The DC analog value output by the current sensor 110 is sent to the micro-control unit 120 .

In a preferred embodiment of the present invention, as shown in FIG. 2 , the multi-channel analog quantity acquisition module 160 is further configured to collect the parameter current signal transmitted through the cable sheath 242 through the second channel and to collect the The parameter current signal is sent to the micro-control unit 120 .

FIG. 2 also shows the power supply for the closed-loop Hall current sensor 110 , the micro-control unit 120 , the analog acquisition module 160 , and the downhole measurement unit 250 . Referring to FIG. 2 , power supply modules S1 - S3 are installed on the uphole power supply board SP, and these power supply modules are supplied with power from, for example, the 85-265VAC power supply S shown in FIG. 2 . The power supply module S1 is, for example, a switching power supply, which provides a ±12V dual power supply voltage for the closed-loop Hall current sensor 110 and a 12V power supply voltage for the multi-channel analog acquisition module 160; the power supply module S2 is, for example, an AC model MTW3-S5H /DC module, which provides 5V power supply voltage for the micro-control unit 120; the power supply module S4 provides power for the downhole measurement unit 250 through the filter circuit 251 and the three-phase reactance winding 252, and the power supply module S4 is, for example, the AC/ DC module to generate 60V downhole power supply voltage.

For the above closed-loop Hall current sensor 110, FIG. 3 shows a schematic structural diagram of a closed-loop Hall current sensor 110 provided by an embodiment of the present invention. As shown in FIG. 3 , the closed-loop Hall current sensor 110 includes a closed-loop Hall element 111 and a transmitter 112 , and the closed-loop Hall element 111 measures the electrical For the magnitude of the leakage current LC, in order to facilitate the micro-control unit 120 to receive the leakage current signal, the transmitter 112 converts the magnitude of the leakage current LC into the DC analog value. The transmitter 112 includes four interfaces, the first interface I1 and the second interface I2 are dual power supply interfaces, the third interface I3 is grounded, and the fourth interface I4 is a transmission output interface, which can be produced by Shandong Yuanxing Electronics, for example. The leakage current transmitter converts the input 0-50mA AC current into 4-20mA standard DC current signal transmission output.

For the above system, see FIG. 4 , which shows a method for real-time monitoring of the leakage current LC of the electric submersible pump unit 200 provided by the embodiment of the present invention, and the method is applied to the real-time monitoring described in the above-mentioned embodiment. The system of the leakage current LC of the electric submersible pump unit 200, the method includes:

S401: The closed-loop Hall current sensor 110 measures the magnitude of the leakage current LC in AC form from the current flowing through the cable sheath 242 and converts the magnitude of the leakage current LC into a DC analog value;

S402: the micro-control unit 120 receives the DC analog value and compares the DC analog value with a leakage current threshold;

S403: The alarm module 130 alarms and stops the submersible pump unit 200 from working when the DC analog value is greater than the leakage current threshold.

For the technical solution shown in FIG. 4 , in a preferred embodiment, the method further includes displaying the DC analog value received by the micro-control unit 120 on the display screen 140 in real time.

For the technical solution shown in FIG. 4 , in a preferred embodiment, the method further includes that the host computer 150 draws an insulation performance curve corresponding to the DC analog value received by the micro-control unit 120 in real time.

For the technical solution shown in FIG. 4 , in a preferred embodiment, the method further includes that the multi-channel analog quantity acquisition module 160 collects the DC analog value output by the closed-loop Hall current sensor 110 through the first channel, and The collected DC analog value is sent to the micro-control unit 120 .

It should be noted that the technical solutions described in the embodiments of the present utility model can be combined arbitrarily if there is no conflict.

The above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited to this. Replacement should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims (10)

1. The utility model provides a system for real time monitoring latent oily charge pump unit's leakage current which characterized in that includes:

the closed-loop Hall current sensor is used for enabling a cable armor of a three-phase cable for supplying power to the electric submersible pump to penetrate through an inner hole of the closed-loop Hall current sensor, so that the closed-loop Hall current sensor measures the magnitude of leakage current in an alternating current form from current flowing through the cable armor and converts the magnitude of the leakage current into a direct current analog value, wherein the current flowing through the cable armor comprises the leakage current in the alternating current form and a parameter current signal in the direct current form generated by a downhole measuring unit for measuring a plurality of downhole parameters of the electric submersible pump;

a micro control unit configured to receive the DC analog value and compare the DC analog value with a leakage current threshold;

and the alarm module is configured to alarm and stop the electric submersible pump unit when the direct current analog value is larger than the leakage current threshold value.

2. The system of claim 1, further comprising a display screen configured to display in real time the dc analog values received by the micro-control unit.

3. The system of claim 1, further comprising an upper computer configured to draw an insulation performance curve in real time corresponding to the dc analog values received by the micro-control unit.

4. The system of claim 1, further comprising a multi-channel analog acquisition module configured to acquire the dc analog value output by the closed-loop hall current sensor through a first channel and send the dc analog value to the micro control unit.

5. The system of claim 4, wherein the multi-channel analog acquisition module is further configured to acquire the parametric current signal transmitted via the cable sheath over a second channel and send the parametric current signal to the micro-control unit.

6. The system of claim 1, wherein the closed-loop hall current sensor comprises a closed-loop hall element that measures a magnitude of the leakage current without a direct electrical connection to the cable sheath, and a transmitter that converts the magnitude of the leakage current to the direct current analog value.

7. The system of claim 1, wherein the closed loop hall current sensor is provided with a dual power supply voltage of ± 12V.

8. The system according to claim 1, characterized in that the micro control unit is supplied with a supply voltage of 5V.

9. The system of claim 4, wherein the multi-channel analog acquisition module is supplied with a supply voltage of 12V.

10. The system of claim 6, wherein the closed loop hall element is capable of measuring leakage currents between 0-50mA, and wherein the transmitter converts the alternating current between 0-50mA to a direct current analog signal of 4-20 mA.

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