CN105804725B - Petroleum underground non-contact ultrasonic liquid level monitoring system - Google Patents

Abstract

The invention discloses a non-contact ultrasonic liquid level monitoring system for oil wells, and relates to the technical field of oil well liquid level detection devices; it includes a plurality of ultrasonic liquid level detectors, and the upper end of the ultrasonic liquid level detectors is connected to an inner casing , the lower end is connected to the collar, and the lower end of the collar is connected to another inner casing; the ultrasonic liquid level detector includes an integrated support sleeve, an ultrasonic transmitting and receiving integrated circuit board, an ultrasonic transmitting sensor, and an ultrasonic receiving sensor , the integrated support sleeve has a special-shaped groove connected with the inner casing; the ultrasonic liquid level detector is connected with a steel pipe cable, the steel pipe cable is electrically connected to the ultrasonic transmitting and receiving integrated circuit board, and the other end is connected to the branch line Convergence joints, the branch line confluence joints are electrically connected with the ground power supply system, data acquisition processor and monitoring system; It is necessary to destroy the inner casing's own structure to sample the medium, so that the liquid level of the relevant monitoring points can be monitored in real time.

Description

A non-contact ultrasonic liquid level monitoring system for oil wells

technical field

The invention relates to liquid level monitoring equipment for oil and natural gas drilling, and more specifically, the invention relates to a non-contact ultrasonic liquid level monitoring system for oil wells.

Background technique

In oil and natural gas exploration and drilling, drilling mud is used to cool the drill bit, implement jet drilling, and bring the rock cut by the bottom hole drill bit from the bottom of the well to the surface. In addition, the density of the drilling mud can also be adjusted. , so that the mud liquid column in the wellbore annulus is balanced with the downhole pressure, and this balance can prevent possible blowout accidents. During the tripping process, when the drilling tool is lifted, the wellbore liquid level will drop, and the height of the drop is proportional to the number (length) of the tripping drill pipe, and the volume of drilling mud that should be replenished is also proportional to the length of the tripping drill pipe. The volume is equivalent, and it is injected into the wellbore through the mud injection device.

A conventional drilling mud injection device includes a main controller, a mud tank with an agitator and its liquid level monitor, an injection mechanism including a mud pump, an electric motor, an electric control box and a flow sensor, and an overflow return mechanism. The filling method is to manually calculate the number of drill pipes pulled out when pulling out the drill, and then input the main engine for processing, and then send the filling command and the volume of mud to be injected to the filling mechanism, which are executed and measured by the mud pump and the flow sensor installed at the pump port. , while feeding information back to the host to control its perfusion volume.

Under normal circumstances, the outflow of mud from the mud pool is in balance with the inflow of mud. If there is an imbalance, it will mean a blowout or leakage. When the mud level in the wellbore drops, it is necessary to inject mud in time and accurately, so it is necessary to monitor the depth change of the downhole drilling fluid level in real time.

In most cases, the liquid level monitoring of oil wells is based on manual experience to determine and identify the liquid level, and it cannot monitor the liquid level in real time, which is neither scientific nor accurate.

To measure the liquid level of the mud pool, the prior art generally uses a float type liquid level detector and a scale with scale on site, requiring drilling workers to manually observe, record and compare, and then judge whether there is overflow or lost circulation. Therefore, under normal circumstances, the amount of mud pumped from the mud tank to the downhole and the amount of mud returned from the downhole should be basically equal, but in the case of lost circulation, the mud returned from the downhole will be little or completely lost. At this time, the liquid level of the mud in the mud tank will drop rapidly; or when a well kick occurs due to a sudden high pressure downhole, the upward pressure from the downhole will push the mud in the downhole annulus to surge upwards and enter the mud tank. When the mud liquid level in the mud tank will rise rapidly; when these two situations occur, if can not be found in time and take the filling mud plugging or aggravating mud to implement killing, will cause serious accidents. In order to keep abreast of the liquid level in the mud tank, the current basic method is to arrange personnel to detect the liquid level in the mud tank at any time when drilling reaches the predetermined layer, and a liquid level indicator is equipped on the mud tank, and the other end of the display is controlled by a soft The rope is connected to a float. When the liquid level is at the set height, the float just floats, and the reading on the display is also at the set position. When the liquid level drops or exceeds the set height, the display will be pulled by the float. The dangerous liquid level is displayed downward or upward; some use sound waves or light to test the liquid level of the liquid level, and when the upper and lower limits of the liquid level are measured, it will alarm. The problem with these devices at present is: the former is connected by a soft rope, so the measured liquid level is inaccurate, and false alarms sometimes occur; although the latter adopts modern technology, all devices are electronic products, which are difficult to control in the harsh conditions of the drilling site. It is easy to be damaged when used in the environment, especially when cleaning the mud tank, it will inevitably cause damage to these electronic products, and the maintenance cost is also very expensive, and the maintenance must be completed by professional technicians.

In addition, the mud tank has a large volume, and after a well kick or a well leakage occurs, the liquid level of the mud tank changes slowly, so the well kick and well leakage accidents cannot be monitored sensitively. Therefore, there is a need for a system for rapid and sensitive monitoring of mud.

For the mud level in the wellbore, there is currently no mature and reliable technology in China for accurate and real-time monitoring, and it is impossible to directly use the ultrasonic principle to detect the downhole liquid level, especially non-contact application. There are also studies abroad on the use of ultrasonic waves for liquid media. However, due to the scattering and absorption characteristics of drilling fluid (mud), especially oil-based mud, to ultrasonic waves, it is very difficult to transmit ultrasonic signals even in a short distance.

Contents of the invention

The purpose of the present invention is to effectively overcome the deficiencies of the above-mentioned technologies, and provide a non-contact ultrasonic liquid level monitoring system for oil wells. Additional processing and changes can monitor the liquid level of relevant monitoring points in real time.

The technical solution of the present invention is realized in the following way: it includes a plurality of ultrasonic liquid level detectors, its principle and implementation plan are: the upper end of the ultrasonic liquid level detector is connected to the inner casing, the lower end is connected to the collar, and the The lower end of the hoop is connected with another section of inner casing; the ultrasonic liquid level detector goes downhole following the inner casing, and its drilling depth is the depth of the liquid level (or gas) at the monitoring and detection point, so it is an important tool for drilling Real-time monitoring of liquid level.

The ultrasonic liquid level detector includes an integrated supporting sleeve, an ultrasonic transmitting and receiving integrated circuit board, and an ultrasonic transmitting sensor and an ultrasonic receiving sensor electrically connected thereto. The ultrasonic transmitting sensor and the ultrasonic receiving sensor are arranged on the integrated supporting sleeve oppositely On both sides of the seat, the integrated support sleeve has a special-shaped groove connected with the inner sleeve;

The ultrasonic liquid level detector is connected with a steel pipe cable, and its connection part is provided with a sealed joint. The steel pipe cable is electrically connected to the ultrasonic transmitting and receiving integrated circuit board. The line confluence joints are respectively electrically connected with the ground power supply system, the data acquisition processor and the monitoring system.

In the above structure, a circuit board end cover is arranged above the ultrasonic transmitting and receiving integrated circuit board, a transmitting end cover is arranged above the ultrasonic transmitting sensor, and a receiving end cover is arranged above the ultrasonic receiving end sensor.

In the above structure, the transmitting end cover plate and the receiving end cover plate are respectively provided with a limit cover plate.

In the above structure, a cable clamp and a cable protector are installed on the outer surface of the inner sleeve, the cable clamp is used to fasten the above-mentioned steel pipe cable, and the cable protector protects the cable.

In the above structure, the steel pipe cable is connected to the ultrasonic liquid level detector through a pipe nut.

In the above structure, the ultrasonic liquid level detector is threadedly connected to the inner casing.

In the above structure, it includes two ultrasonic liquid level detectors, the upper end of the first ultrasonic liquid level detector is connected with the first inner casing, the lower end is connected with the first coupling, and the lower end of the first coupling is connected with the The second inner casing is connected, the upper end of the second ultrasonic liquid level detector is connected with the lower end of the second inner casing, and the lower end of the second ultrasonic liquid level detector is connected with the second collar.

The beneficial effect of the present invention is that: the present invention adopts such a special design that the ultrasonic sensor does not directly contact the medium to be monitored, which greatly shortens the distance of ultrasonic transmission, and can be completely free from water-based mud and oil in structure. The liquid level of the monitoring point can be monitored under the influence of the base mud and gas medium; the device solves the problem that the ultrasonic signal cannot be transmitted for a long distance due to the oil-based mud, and cleverly avoids the situation where there is a drill pipe in the casing. The problem of changing the direction of transmission and reception due to its interference; in addition, it solves the technical problem that the existing underground oil wells only rely on manual and empirical liquid level judgment and identification, and cannot achieve real-time monitoring of the liquid level; through the received different signals , from the different time parameters and the state of the voltage pulse signal to distinguish and identify, to determine whether the depth in the well is gas or mud medium, so as to guide the operators on the ground to perform corresponding operations; in the technical solution of the present invention, it meets the needs The determined medium is non-contact, that is, it does not need to destroy the inner casing’s own structure for medium sampling, nor does it require any additional processing and changes to the inner casing. It can be real-time through the ground computer data processing system and oscilloscope software. Monitor the liquid level of the relevant monitoring point (well depth); the present invention combines the principle of ultrasonic liquid level monitoring of petroleum drilling, and can also roughly determine the condition of the liquid medium at the monitoring depth, and can distinguish between water-based mud and oil-based mud, and a general understanding its specific gravity and viscosity.

【Description of drawings】

Fig. 1 is the sectional view of ultrasonic liquid level detector of the present invention;

Fig. 2 is the sectional view of A-A place in Fig. 1;

Fig. 3 is the front view of the ultrasonic liquid level detector of the present invention;

Fig. 4 is a side view of the ultrasonic liquid level detector of the present invention;

Fig. 5 is the sectional view of B-B place among Fig. 4;

Fig. 6 is a diagram of a specific embodiment of the present invention.

【Detailed ways】

The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

Fig. 1 is a cross-sectional view of the ultrasonic liquid level detector described in Embodiment 1 of the present invention.

Fig. 2 is the cross-sectional view of Fig. 1 (from top to bottom, the ultrasonic transmitting sensor slot 107, the short-distance ultrasonic transmission path special-shaped slot 108, and the ultrasonic receiving sensor slot 109).

Due to the sharp attenuation characteristics of high-frequency ultrasonic waves in gaseous media, if the interface of the special-shaped groove is gas, the ultrasonic receiving sensor cannot receive any acoustic signal. And if the special-shaped tank is filled with liquid medium, whether it is oil-based mud, water-based mud, high-density and high-viscosity mud, the ultrasonic signal can be transmitted in a short distance and received by the ultrasonic receiving sensor. The received signal is transmitted back to the ultrasonic transmitting and receiving integrated circuit through the wire, and after the gain amplification processing of the integrated circuit, the received signal is sent to the ground through the signal line of the steel pipe cable, and the ground can obtain the received signal through data processing or an oscilloscope. By comparing the difference of the acquired signals, the ground can judge whether the depth of the monitoring position is the mud level or the air interface. With such a special design, the ultrasonic sensor does not directly have any contact with the medium to be monitored, which greatly shortens the distance of ultrasonic transmission, and can be completely unaffected by water-based mud, oil-based mud, and gas media in structure. The liquid level at the monitoring point can be monitored. The device solves the problem that the oil-based mud cannot transmit the ultrasonic signal over a long distance, and cleverly avoids the problem that the ultrasonic wave is easily interfered by it to change the direction of propagation and reception when there is a drill collar in the casing.

Referring to Figure 6, the present invention discloses a non-contact ultrasonic liquid level monitoring system for oil wells, which utilizes the characteristics of ultrasonic waves having different propagation speeds in different media and the different penetration characteristics of gas, liquid, and solid media , to monitor the liquid level of oil well drilling fluid (commonly known as mud).

Specifically, as shown in FIG. 1 to FIG. 6, it is a disclosed specific embodiment of the present invention. In this embodiment, the non-contact ultrasonic liquid level monitoring system for oil wells includes a plurality of ultrasonic liquid level detectors 10, The number of ultrasonic liquid level detectors 10 can be set according to needs. The upper end of the ultrasonic liquid level detector 10 is connected to the inner casing 20, usually by threaded connection, and the lower end of the ultrasonic liquid level detector 10 is connected to the collar 30, in this embodiment, as shown in Figure 6, the present invention includes two ultrasonic liquid level detectors 10, the upper end of the first ultrasonic liquid level detector 10 is connected to the first inner sleeve 20, and the lower end is connected to the second A coupling 30 is connected, the lower end of the first coupling 30 is connected with the second inner sleeve 20, the upper end of the second ultrasonic liquid level detector 10 is connected with the lower end of the second inner sleeve 20, and the second The lower end of the ultrasonic liquid level detector 10 is connected with the second collar 30 .

In more detail, as shown in FIG. 3 to FIG. 5 , the ultrasonic liquid level detector 10 includes an integrated support sleeve 101, an ultrasonic transmitting and receiving integrated circuit board 102, and an ultrasonic transmitting sensor 103 and an ultrasonic receiving sensor 104 electrically connected thereto. , the ultrasonic emitting sensor 103 and the ultrasonic receiving sensor 104 are oppositely arranged on both sides of the integrated support sleeve 101, and the integrated support sleeve 101 has a special-shaped groove communicating with the inner casing 20; the ultrasonic liquid level detector 10 is connected to A steel pipe cable 105 is provided with a sealing joint 106 at the connecting part. The steel pipe cable 105 is electrically connected to the ultrasonic transmitting and receiving integrated circuit board 102, and the other end of the steel pipe cable 105 is connected to the branch line junction 106. 106 are respectively electrically connected with the ground power system, the data acquisition processor and the monitoring system. The steel pipe cable 105 is connected to the ultrasonic liquid level detector 10 through a pipe nut 1050

In order to maintain good sealing performance, a circuit board end cover 1020 is provided above the ultrasonic transmitting and receiving integrated circuit board 102, a transmitting end cover 1030 is provided above the ultrasonic transmitting sensor 103, and a receiving end cover 1040 is provided above the ultrasonic receiving end sensor 104; In addition, the transmitting end cover 1030 and the receiving end cover 1040 are respectively provided with a limiting cover 40 .

Continuing to refer to Fig. 6, a cable clamp 201 and a cable protector 202 are installed on the outer surface of the inner sleeve 20, the cable clamp 201 is used to fasten the above-mentioned steel pipe cable 105, and the cable protector 202 is connected to the steel pipe cable 105. protection, and the steel pipe cable 105 is connected to the ultrasonic liquid level detector 10 through the pipe nut 1050 .

Combined with the above structure, we describe the installation process and working process of the present invention in detail.

1. The upper end of the ultrasonic liquid level detector is connected to the inner casing, the lower end is connected to the collar, and then connected to the inner casing of the next section. In this way, multiple ultrasonic liquid level detectors are connected. In this embodiment, then Connect two ultrasonic liquid level detectors, and the measured positions are depth position A1 and depth A2 respectively.

2. Connect the custom-made steel pipe cable to the upper joint of the branch line confluence joint of the ultrasonic liquid level detector, use the pipe nut, front clamping core, and rear clamping core to thread it, make a good seal and tighten the conduit nut; respectively Connect the power signal cable, and connect the customized cable clamp and cable protector on each section of the inner sleeve.

3. Follow the inner casing to go downhole. At this time, the ultrasonic liquid level monitor 1 goes down to the required monitoring point 1 (depth position A1), and the ultrasonic liquid level monitor device 2 goes down to the required monitoring point 2 (depth position A2 ).

4. Connect the cable interface of the diversion and confluence joint with the ground power supply system, data acquisition machine processing, and monitoring system, and the whole system is connected in place.

5. Under normal circumstances, in normal mud circulation, the liquid level maintains a liquid level balance at the depth position A1, that is to say, positions A1 and A2 are in the liquid medium. At this time, the special-shaped grooves on the inner walls of the integrated support sleeves of the two ultrasonic liquid level detectors are filled with flowing liquid medium, and the ultrasonic liquid level detectors work normally, showing the generation and reception of ultrasonic pulse signals. At this time, it can be observed on the ground that every A detection point (depth position A1, depth position A2) will have approximately the same voltage pulse waveform.

6. When the mud level fluctuates, assuming that the liquid level drops from position A1 to a certain depth A', the output waveform at position A2 is not affected at all, and the medium interface at position A1 becomes air. At this time Do nothing. When the mud level drops below A2, the ultrasonic transmitting sensors in the ultrasonic level gauges at A1 and A2 pass through the 12mm thick steel wall, then through the air medium with the width of the special-shaped groove of 25mm, and then through the 12mm thick steel wall , due to the divergence effect of the air medium, the ultrasonic receiving sensor installed on the other side cannot receive its transmission signal. Therefore, the display waveforms in the A1 channel and A2 channel on the ground change, and basically no voltage pulse signal can be observed. At this time, start the alarm device, notify the ground to carry out corresponding operations, and inject mud, so that the mud liquid level rises to the depth position A1 and reaches the safe liquid level. Then pass through the mud medium with a width of 25mm special-shaped groove, and then pass through a steel wall with a thickness of 12mm. Due to the ultrasonic signal transmission effect of the mud liquid medium, the ultrasonic receiving sensor installed on the other side receives its transmission signal. At this time, observe the A1 channel on the ground The pulse signal returned to the original roughly similar level.

7. When there is a large imbalance in the mud liquid level, for example, due to the large liquid level change in the inner casing after tripping out, the liquid level drops rapidly at this time. When it is about to reach the depth position A2, the two The depth position of each monitoring point is filled with air medium. At this time, the pulse signal of channel A2 also disappears rapidly (the principle is the same as item 6). At this time, channels A1 and A2 have simultaneous alarms, which is a dangerous state, and the mud injection pump should be started. Perform irrigation. In the injection stage, if the injection time is too long and exceeds the theoretical time for filling sections A1 to A2, it means that the well is leaking and an alarm is required.

The invention continuously observes the ultrasonic transmission and reception signals in real time, can grasp the change of the liquid level in the casing in real time, understand whether the liquid level is in a safe state or an alarm state, and the ground staff can grasp the depth position of the downhole liquid level in time, so as to take different responses.

In the technical solution of the present invention, it is non-contact with the medium that needs to be judged, that is, it does not need to destroy the inner casing's own structure for medium sampling, and does not require any additional processing and changes to the inner casing. The data processing system and oscilloscope software can monitor the liquid level of the relevant monitoring point (well depth) in real time; in addition, the present invention can also roughly determine the condition of the liquid medium at the monitoring depth by combining the ultrasonic liquid level monitoring principle of oil drilling. Distinguish between water-based mud and oil-based mud, and get a general understanding of their specific gravity and viscosity.

The above descriptions are only preferred embodiments of the present invention, and the above specific embodiments do not limit the present invention. Within the scope of the technical idea of the present invention, various deformations and modifications may occur, and any retouching, modification or equivalent replacement made by those skilled in the art based on the above description shall fall within the protection scope of the present invention.

Claims (7)

1. A petroleum underground non-contact ultrasonic liquid level monitoring system is characterized in that: the ultrasonic liquid level detectors are connected with the inner sleeve, the lower ends of the ultrasonic liquid level detectors are connected with the coupling, and the lower ends of the coupling are connected with the other inner sleeve;

the ultrasonic liquid level detector comprises an integrated supporting sleeve seat, an ultrasonic transmitting and receiving integrated circuit board, an ultrasonic transmitting sensor and an ultrasonic receiving sensor which are electrically connected with the integrated supporting sleeve seat, wherein the ultrasonic transmitting sensor and the ultrasonic receiving sensor are oppositely arranged on two sides of the integrated supporting sleeve seat, the integrated supporting sleeve seat is provided with a special-shaped groove communicated with the inner sleeve, and the special-shaped groove is positioned between the ultrasonic transmitting sensor and the ultrasonic receiving sensor;

the ultrasonic liquid level detector is characterized in that a steel pipe cable is connected to the ultrasonic liquid level detector, a sealing joint is arranged at the connecting part of the steel pipe cable, the steel pipe cable is electrically connected to the ultrasonic transmitting and receiving integrated circuit board, the other end of the steel pipe cable is connected to a branching and converging joint, and the branching and converging joint is electrically connected with a ground power supply system, a data acquisition processor and a monitoring system respectively.

2. The downhole non-contact ultrasonic fluid level monitoring system for petroleum of claim 1, wherein: the ultrasonic transmitting and receiving integrated circuit board is characterized in that a circuit board end cover is arranged above the ultrasonic transmitting and receiving integrated circuit board, a transmitting end cover plate is arranged above the ultrasonic transmitting sensor, and a receiving end cover plate is arranged above the ultrasonic receiving end sensor.

3. The downhole non-contact ultrasonic fluid level monitoring system for petroleum of claim 2, wherein: and the transmitting end cover plate and the receiving end cover plate are respectively provided with a limiting cover plate.

4. The downhole non-contact ultrasonic fluid level monitoring system for petroleum of claim 1, wherein: the outer surface of the inner sleeve is provided with a cable clamp and a cable protector, the cable clamp is used for fastening the steel pipe cable, and the cable protector plays a role in protecting the cable.

5. A downhole non-contact ultrasonic fluid level monitoring system for petroleum according to claim 1 or 4, wherein: the steel pipe cable is connected to the ultrasonic liquid level detector through a pipe penetrating nut.

6. The downhole non-contact ultrasonic fluid level monitoring system for petroleum of claim 1, wherein: the ultrasonic liquid level detector is in threaded connection with the inner sleeve.

7. The downhole non-contact ultrasonic fluid level monitoring system for petroleum of claim 1, wherein: the ultrasonic liquid level detection device comprises two ultrasonic liquid level detection devices, wherein the upper end of the first ultrasonic liquid level detection device is connected with a first inner sleeve, the lower end of the first ultrasonic liquid level detection device is connected with a first coupling, the lower end of the first coupling is connected with a second inner sleeve, the upper end of the second ultrasonic liquid level detection device is connected with the lower end of the second inner sleeve, and the lower end of the second ultrasonic liquid level detection device is connected with a second coupling.