RU2346206C1 - Viscous fluid pumping method - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: invention refers to delivery of viscous fluids, and namely of oil and oil products, via piping. Viscous fluid pumping method includes pretreatment of viscous fluids with ultrasonic vibrations. Ultrasonic treatment is carried out by immersing and moving the oscillator made in the form of a pin and consisting of tandem cylindric-shaped sections of various diameter in the fluid being treated; at that, length of each section of larger diameter corresponds to one fifteenth part of wave length; total length of tandem sections of smaller and larger diameters corresponds to half of ultrasonic vibration wave length in the pin material at operating frequency of 22 kHz; ultrasonic vibrations are generated from the oscillator surface in the areas of transitions between cylindrical sections of various diameter with vibration range which is enough for the cavitation to appear in the fluid being treated; treated fluid is uninterruptedly supplied to oscillator central channel through an end hole provided in the submerged part of oscillator, and to radial channels located perpendicular to central channel and provided in oscillator sections of smaller diameter in a symmetric way relative to larger diameter sections; total section of all inlet channels corresponds to section of central channel outlet hole; treated fluid is removed through an outlet hole, and fluid pumping velocity is defined taking into account initial viscosity, size of oscillator and ultrasonic radiation power.

EFFECT: improving fluid pumping process efficiency due to decreasing fluid viscosity under the influence of combined ultrasonic vibrations of high intensity and thermal effect.

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Description

The invention relates to energy-saving and environmentally friendly technologies to increase the efficiency of the process of pumping viscous liquids, mainly oil and oil products.

It is known that the throughput and economic efficiency of the pipeline network depend on the properties of the liquids pumped through it. The main obstacle to providing the necessary pumping speed is viscosity. Reducing the viscosity of the pumped product reduces the hydraulic resistance of the pipeline network, which reduces the energy consumption for pumping. In areas of oil production with a low ambient temperature, the viscosity of the pumped liquid reaches such values that the energy consumption for pumping significantly increases the cost of the produced oil, and in some cases makes it practically impossible to pump it.

To increase the efficiency of the transportation process, viscous liquids are pre-treated. There are many known methods of processing liquids, mainly oil and petroleum products, in order to reduce its viscosity. All known methods can be divided into several groups:

1. The use of various liquids as thinners [1]. The disadvantages include the high cost of the process due to the need to add an additional product to a viscous liquid (for example, oil) and in most cases the inability to reuse the thinner.

2. The creation of an oil emulsion in water [2] using emulsifiers [3, 4]. The disadvantages include the use of expensive emulsifiers, the need to use large volumes of water, and the need for the process of recovering oil from the emulsion. Impact on the environment.

3. The impact on the liquid of various types of electromagnetic radiation and their combinations [5, 6]. The disadvantages include the low productivity of the method and high energy consumption.

4. Oil processing using ultrasonic vibrations of high intensity [7, prototype].

The essence of the method adopted for the prototype according to [7] is as follows. Oil processing is carried out using an ultrasonic piezoelectric transducer of the continuous type, which is a metal pipe with vibrators located on it. The pumped liquid passes through a cylinder made in the form of a thick-walled pipe made of a material with low acoustic impedance, the inner surface of which is cylindrical, and the outer surface is made in the form of a polyhedron, the sides of which are separated by longitudinal along the faces and ring grooves into radiating sections forming with piezoelectric elements and quarter-wave steel plates composite half-wave vibrators. Processing of the liquid during pumping through the pipe is carried out in the area of the emitters.

This pumping method ensured a decrease in the viscosity of the fluid entering the pipe and reaching the emitter location.

At the same time, the method adopted for the prototype has the following disadvantages:

1. The method does not provide for pre-treatment of viscous liquid before entering the pipe for pumping, which is not always practically feasible.

2. The converter consists of individual vibrators, the resonant frequencies of which can lie in a wide range of frequencies. At the same time, all vibrators are powered by a single generator that produces a voltage of a certain frequency, as a result of which part of the vibrators works with low efficiency or does not work at all. As a result, the processing is uneven from all sides. As a consequence of the above, the method is implemented with low energy use of ultrasound (efficiency less than 15-20%).

3. The area of intense exposure is enclosed in a small volume inside the pipeline section on which the emitters are fixed, beyond which the ultrasonic field decays quickly.

4. The impossibility of pumping and pumping viscous liquids from reservoirs, storages.

5. Processing must be done only when the internal cavity of the pipe is completely filled. Otherwise, the processing efficiency is sharply reduced.

Thus, the method adopted for the prototype is characterized by limited functionality, high complexity of manufacture, configuration and repair, as well as low efficiency.

The essence of the proposed technical solution is that the pumped viscous liquid is subjected to ultrasonic treatment as follows. Ultrasonic treatment is carried out by immersion and movement of the emitter in the processed liquid, made in the form of a rod, consisting of successively arranged sections of a cylindrical shape of various diameters, the length of each of the sections of a larger diameter corresponding to one fifteenth of the wavelength, the total length of the successively arranged sections of smaller and larger diameters corresponding to half the wavelength of ultrasonic vibrations in the rod material at an operating frequency of 22 kHz. Ultrasonic vibrations are emitted from the surface of the emitter in the transition zones between cylindrical sections of various diameters with an amplitude of vibration sufficient for cavitation to occur in the fluid being treated, the treated fluid is continuously introduced into the central channel of the emitter through an end hole in the immersed part of the emitter and radial channels located perpendicular to the central channel and made on the sections of the emitter of smaller diameter symmetrically with respect to the sections of larger diameter, mmar section of all input channels corresponds to the section of the outlet of the Central channel. The treated liquid is discharged through the outlet, and the pumping speed of the liquid is set taking into account the initial viscosity of the liquid, the dimensions of the emitter and the power of ultrasonic radiation.

The essence of the method is illustrated in the drawing, which presents a sketch of the installation that implements the proposed method.

The installation consists of an electronic generator 1 and an ultrasonic oscillating system 3 connected to it by an electric cable 2. An electronic generator is an electronic device that converts the energy of an industrial frequency electric network into the energy of electric oscillations of an ultrasonic frequency. One of the main requirements for an electronic generator is the need to ensure stable operation at the resonant frequency of an ultrasonic oscillatory system under any loads and radiation powers. During the operation of the oscillatory system, the working tool creates a high-intensity ultrasonic field around itself. The intensity of ultrasonic vibrations is selected sufficient for the formation of cavitation on the surface of the working tool 4. As a result of exposure to cavitation and ultrasonic vibrations, the viscosity of oil and other fluids included in it decreases. Paraffin, which is contained in oil and oil products as an impurity, is emulsified into oil under the action of ultrasonic vibrations, this reduces its precipitation on the walls of the pipeline and tanks and increases the efficiency of pumping. Also in the process, the working tool and the processed fluid are heated (due to viscous friction in the fluid and heat transfer from the emitter), which also helps to reduce viscosity. As a result, a region of liquid with a reduced viscosity 7 is created around the working tool, which is easily pumped out using traditional pumping units. The pumped liquid is pumped out through the end 5 and radial channels 6.

The advantages of the proposed method are:

1. The processing zone can be changed by simply moving the emitter;

2. The oscillation system with a radiating element fixed to it has one resonant frequency. The generator provides power to the oscillatory system precisely at the frequency corresponding to the resonant one, as a result, the efficiency of the apparatus as a whole is not lower than 50%;

3. High processing efficiency due to the high intensity of the generated ultrasonic field.

The technical result is to reduce the energy intensity and cost of the process of transporting viscous fluids by reducing their viscosity, to ensure the fundamental possibility of pumping and transporting oil at low temperatures.

The proposed method was implemented in an existing installation in the laboratory of acoustic processes and apparatuses of the Biysk Technological Institute of Altai State Technical University. To test the effectiveness, experiments were conducted on the processing of oil, vegetable and industrial oils in order to reduce their viscosity. The operation of the pilot plant made it possible to confirm the effectiveness of the proposed method and obtain a capacity of 1000 liters per hour with a power consumption of 3000 VA. Small-scale production of devices that implement the proposed method is planned to begin in 2008.

Literature

1. Application for invention No. 92010884 "Method for the production of high-viscosity oil."

2. United States Patent 5,013,462. Method for improving production of viscous crude oil.

3. United States Patent 4,249,554. Method of transporting viscous hydrocarbons.

4. United States Patent 4,239,052. Method of transporting viscous hydrocarbons.

5. RF patent No. 2232124 "Method for melting and lowering the viscosity of chemical products, mainly oil and petroleum products, and a device for its implementation."

6. RF patent No. 2103211 "Method for heating thickened products in a container and a device for its implementation."

7. RF patent No. 2222387 "Ultrasonic piezoelectric transducer type through passage".

Claims (1)

A method for pumping viscous liquids, including their preliminary processing by ultrasonic vibrations, characterized in that the ultrasonic treatment is carried out by immersion and movement of the emitter in the processed liquid, made in the form of a rod, consisting of successively arranged sections of a cylindrical shape of various diameters, the length of each of the sections of a larger diameter corresponding to one fifteenth of the wavelength, the total length of successively arranged sections of smaller and larger di the meter corresponds to half the wavelength of ultrasonic vibrations in the rod material at an operating frequency of 22 kHz, the ultrasonic vibrations are emitted from the surface of the emitter in the transition zones between cylindrical sections of various diameters with an oscillation amplitude sufficient to cause cavitation in the treated fluid, the treated fluid is continuously introduced into the central channel the radiator through the end hole in the submerged part of the radiator and radial channels located perpendicular to the cent the main channel and made in the sections of the emitter of smaller diameter symmetrically with respect to the sections of the larger diameter, the total cross section of all the input channels corresponds to the cross section of the outlet of the central channel, the treated liquid is discharged through the outlet, and the pumping speed of the liquid is set taking into account the initial viscosity, dimensions of the emitter and the power of ultrasonic radiation .