Underground multi-stage ultrasonic anti-scaling device

Abstract

The invention discloses an underground multi-stage ultrasonic anti-scaling device which can be connected to an oil pipe, a fairing is arranged at the front end of the device to adjust the flowing rule of a circulating medium, a generator turbine is arranged at the rear end of the fairing, the generator turbine is installed on a bearing iron core of a generator rotor, and when the medium flows through the turbine, the turbine is driven to rotate; the generator rotor and the generator stator form a generator, the output end of the generator is connected with the ultrasonic generator through a wire, and electric energy of the generator is transmitted to the ultrasonic generator. An oscillating circuit, a voltage amplifier, a power amplifier and an output transformer component are arranged on the circuit board to form the ultrasonic generator, and the electric energy is converted into a high-frequency current signal. The ultrasonic transducer converts high-frequency current signals transmitted by the ultrasonic generator into mechanical waves. The device is simple in structure, the well opening rate of the gas well is increased, unnecessary oil pipe replacement and well washing operation are avoided, the gas reservoir of the gas well is protected, and the gas production rate of the gas well is increased.

Description

Technical Field

[0001] The present invention relates to the field of exploration and development operations, and particularly to a downhole multi-stage ultrasonic scale prevention device. Background Art

[0002] At present, a large number of solid blockages such as black flaky, sandy mud mass-like grayish-white particles have appeared in some production wells in Dongping and Jianbei gas fields during development, bringing great difficulties to normal data testing, sand face exploration, liquid level exploration and other conventional testing operations of gas wells. Due to the appearance of the blockages, the testing tools cannot be smoothly lowered to the expected position, or the testing tools are stuck and difficult to salvage. The blockages will also cause a sharp decrease in the gas well production and pressure, seriously affecting the single-well production and the development of the gas reservoir. The gas wells need to frequently replace the string operations, and the development cost increases sharply.

[0003] The existing scale removal methods mainly include chemical scale prevention and physical scale prevention. The chemical scale removal method adds chemical substances in the medium to achieve the purpose of inhibiting precipitation and dissolving precipitation.

[0004] For the scale samples of single wells in Dongping and Jianbei gas fields, indoor experiments were carried out to detect and study the scale sample components, and the scale formation mechanism was clarified. On this basis, the research on the plugging fluid formula for different types of blockages has a long cycle, slow effect and high cost. The scale sample components of 6 scale-forming wells in Jianbei and Dongping blocks have great differences, and have the following characteristics: the scale sample on the pipe wall: the shape is flaky, the crystal is dense, and the main components are barium sulfate, strontium sulfate, calcium sulfate, calcium carbonate, and clay minerals; the scale sample at the bottom of the well: the shape is massive, the structure is loose, and the main components are calcium carbonate and calcium sulfate.

[0005] During the production process of gas wells, substances in the formation enter the wellbore along with the gas flow and formation water. During the lifting process, the substances change and form precipitates attached to the pipe wall of the gas well tubing, causing changes in the tubing flow channel. The precipitates attached to the pipe wall are dispersed in flakes on the pipe wall, resulting in unstable gas well production, blocked flow channels, and the inability to lower downhole testing tools, and the inability to measure downhole data, affecting gas well data acquisition and data analysis, and affecting gas reservoir development and adjustment. Scale formation will also occur in the seepage channels. At present, practice has proved that after the formation is acidified, the gas production has a significant increase, indicating that scale formation will occur in the seepage channels, seriously affecting the gas well production.

[0006] During the production process of gas wells, substances in the formation flow through the seepage channels along with the gas flow and formation water and enter the wellbore. During the seepage process, the substances change and form precipitates attached to the seepage channels, causing changes in the flow channels, resulting in pressure and production fluctuations. It is necessary to solve the problem of reduced or blocked seepage channels. Summary of the Invention

[0007] To overcome the above-mentioned deficiencies of the prior art, the present invention provides a downhole multi-stage ultrasonic scale prevention device, which includes a downhole turbine generator, an ultrasonic generator, and an ultrasonic transducer. The device is connected to the oil pipe. A fairing is provided at the front end of the device, and a generator turbine is provided at the rear end of the fairing. The generator turbine is installed on the bearing core of the generator rotor. The output end of the generator is connected to the ultrasonic generator through a wire to transmit the electric energy of the generator to the ultrasonic generator. The ultrasonic transducer converts the high-frequency current signal transmitted by the ultrasonic generator into a mechanical wave.

[0008] The technical solution of the present invention is as follows:

[0009] A downhole multi-stage ultrasonic scale prevention device, which includes a downhole turbine generator, an ultrasonic generator, and an ultrasonic transducer. The device is connected to the oil pipe. A fairing is provided at the front end of the device, and a generator turbine is provided at the rear end of the fairing. The generator turbine is installed on the bearing core of the generator rotor. The output end of the generator is connected to the ultrasonic generator through a wire to transmit the electric energy of the generator to the ultrasonic generator. The ultrasonic transducer converts the high-frequency current signal transmitted by the ultrasonic generator into a mechanical wave.

[0010] The ultrasonic generator is an integrated circuit board that receives the electric energy transmitted by the generator.

[0011] The downhole turbine generator is composed of a fairing, a generator turbine, a generator rotor, and a generator stator.

[0012] The ultrasonic transducer is composed of a wire and an oscillator. The ultrasonic transducer converts the high-frequency current signal transmitted by the ultrasonic generator into a mechanical wave.

[0013] An oscillation circuit, a voltage amplifier, a power amplifier, and an output transformer component are provided on the circuit board of the ultrasonic generator. The above components are connected in series to form the ultrasonic generator, which converts electric energy into a high-frequency current signal.

[0014] A generator turbine is provided at the rear end of the fairing. The generator turbine is installed on the bearing core of the generator rotor. When the medium flows through the turbine, it drives the turbine to rotate. A generator stator is provided outside the generator rotor to form the power generation part.

[0015] The device is installed on the oil pipe of the gas well and is lowered into the gas wellbore along with the oil pipe.

[0016] One or more devices can be lowered to prevent scale formation on the inner wall of the formation seepage channel and the oil pipe.

[0017] The ultrasonic transducer converts the high-frequency current signal into a mechanical wave and conducts it to the medium.

[0018] In the present invention, an ultrasonic generator and an ultrasonic transducer convert electrical energy into ultrasonic waves to perform descaling and scale prevention on the surrounding radiation area, achieving wellbore cleaning, ensuring the smoothness of the bottom-hole seepage channel, and making substantial progress and having effects in improving the gas well production, reducing gas well operations, and preventing tubing blockage. The structure of the present invention is simple, durable, safe and reliable, and convenient for maintenance, which can improve the gas well opening rate, avoid unnecessary tubing replacement and well flushing operations, protect the gas reservoir of the gas well, and increase the gas production of the gas well. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a schematic diagram of a downhole multi-stage ultrasonic scale prevention device of the present invention;

[0020] Reference numerals: 1-device body, 2- fairing, 3-generator turbine, 4-support frame, 5-positive wire, 6-negative wire, 7-generator stator, 8-voltage amplifier, 9-ultrasonic transducer oscillator, 10-oscillator, 11-power amplifier, 12-output transformer, 13-generator rotor. DETAILED DESCRIPTION OF THE INVENTION

[0021] The following are specific embodiments of the present invention to further describe the technical solutions of the present invention, but the present invention is not limited to these embodiments.

[0022] Existing technical solutions to solve this problem currently

[0023] One is to re-perforate and adjust the layer.

[0024] The second is acid fracturing to remove precipitates.

[0025] The third is to inject a scale inhibitor for cleaning and scale prevention, which can only solve the structural problem in the tubing and cannot solve the problem of reduced or blocked seepage channels.

[0026] The present invention belongs to physical scale prevention, which fully combines the utilization of bottom layer energy, the functions of generators and ultrasonic waves, realizes combined innovative applications, and has prominent features and substantial progress compared with the existing technology.

[0027] In view of this, the present invention provides a downhole multi-stage ultrasonic scale prevention device and a using method. Ultrasonic descaling uses the combined effects of cavitation, activation, shearing and inhibition effects of ultrasonic waves on fluid media to disperse, crush and shed scales, so as to achieve the purpose of scale prevention. It also has the characteristics of simple operation, high automation degree, low operation cost, online continuous operation, reliable working performance, high efficiency, and no environmental pollution.

[0028] Research on the anti-scaling mechanism: the "inhibitory" effect can change the physical and chemical properties of the liquid body through the action of ultrasonic waves, and can inhibit the nucleation and growth of ions in water at the two-phase contact surface. Therefore, the number of scaling ions adhering to the heat transfer surface is reduced. Practical research has proved that the longer the ultrasonic wave acts, the better the anti-scaling effect of the anti-scaling substance. Research has confirmed that when water is under the action of ultrasonic waves and the ultrasonic energy is large enough, that is, "power ultrasound" can generate a short-term, local, extremely high-temperature, high-pressure, and high-intensity electric field extreme physical environment in the conduction medium under normal temperature and pressure conditions. The liquid will produce the so-called "acoustic cavitation effect", which will trigger many mechanical, physical, chemical, biological and other effects, achieving the purpose of anti-scaling and descaling in the liquid.

[0029] The present invention includes a downhole turbine generator, an ultrasonic generator, and an ultrasonic transducer;

[0030] The downhole turbine generator is composed of a fairing, a generator turbine, a generator rotor, and a generator stator.

[0031] The ultrasonic generator is composed of an oscillation circuit, a voltage amplifier, a power amplifier, and an output transformer.

[0032] The ultrasonic transducer is composed of a wire and a vibrator.

[0033] The device can be installed on the gas well tubing and lowered into the gas well borehole along with the tubing. According to needs, one or more devices can be lowered to achieve the purpose of preventing and controlling scale formation on the inner wall of the formation seepage channel and the tubing.

[0034] A downhole multi-stage ultrasonic anti-scaling device of the present invention can be applied to the gas well tubing. During the gas well operation, the inventive device is installed at a preset position and lowered into the gas well borehole along with the tubing. According to needs, one or more devices can be lowered. During the gas well production process, the high-pressure medium flows through the inventive device, driving the generator to rotate. The electric energy generated by the generator is transmitted to the ultrasonic generator through the wire. The ultrasonic generator converts the electric energy into a high-frequency current signal and transmits it to the ultrasonic transducer. The ultrasonic transducer converts the high-frequency current signal into a mechanical wave and conducts it to the medium, achieving the purpose of preventing and controlling scale formation on the inner wall of the formation seepage channel and the tubing.

[0035] The device can be applied to the gas well tubing. During the gas well operation, the inventive device is installed at a preset position and lowered into the gas well borehole along with the tubing. According to needs, one or more devices can be lowered. During the gas well production process, the high-pressure medium flows through the inventive device, driving the generator to rotate. The electric energy generated by the generator is transmitted to the ultrasonic generator through the wire. The ultrasonic generator converts the electric energy into a high-frequency current signal and transmits it to the ultrasonic transducer. The ultrasonic transducer converts the high-frequency current signal into a mechanical wave and conducts it to the medium, achieving the purpose of preventing and controlling scale formation on the inner wall of the formation seepage channel and the tubing.

Claims

1. A downhole multi-stage ultrasonic scale prevention device, characterized in that: It includes a downhole turbine generator, an ultrasonic generator, and an ultrasonic transducer. The device is connected to the oil pipe, and a fairing is provided at the front end of the device. A generator turbine is provided at the rear end of the fairing. The generator turbine is installed on the bearing core of the generator rotor. The output end of the generator is connected to the ultrasonic generator through a wire to transmit the electric energy of the generator to the ultrasonic generator. The ultrasonic transducer converts the high-frequency current signal transmitted by the ultrasonic generator into a mechanical wave.

2. The downhole multi-stage ultrasonic scale prevention device according to claim 1, characterized in that: The ultrasonic generator is an integrated circuit board that receives the electric energy transmitted by the generator.

3. The downhole multi-stage ultrasonic scale prevention device according to claim 1, characterized in that: The downhole turbine generator consists of a fairing, a generator turbine, a generator rotor, and a generator stator.

4. The downhole multi-stage ultrasonic scale prevention device according to claim 1, wherein: The ultrasonic transducer consists of a wire and an oscillator. The ultrasonic transducer converts the high-frequency current signal transmitted by the ultrasonic generator into a mechanical wave.

5. The downhole multi-stage ultrasonic scale prevention device according to claim 1, wherein: An oscillation circuit, a voltage amplifier, a power amplifier, and an output transformer component are provided on the circuit board of the ultrasonic generator. The above components are connected in series to form the ultrasonic generator, which converts electric energy into a high-frequency current signal.

6. The downhole multi-stage ultrasonic scale prevention device according to claim 1, wherein: A generator turbine is provided at the rear end of the fairing. The generator turbine is installed on the bearing core of the generator rotor. When the medium flows through the turbine, it drives the turbine to rotate. A generator stator is provided around the generator rotor to form the power generation part.

7. The downhole multi-stage ultrasonic scale prevention device according to claim 1, characterized in that: The device is installed on the oil pipe of the gas well and is lowered into the gas well borehole along with the oil pipe.

8. The downhole multi-stage ultrasonic scale prevention device according to claim 1, characterized in that: One or more devices can be lowered to prevent scale formation on the inner wall of the formation seepage channel and the oil pipe.

9. The downhole multi-stage ultrasonic scale prevention device according to claim 1, wherein: The ultrasonic transducer converts the high-frequency current signal into a mechanical wave and conducts it to the medium.

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