RU8407U1 - PRODUCTIVE LAYER DEVICE - Google Patents

Abstract

1. A device for processing productive formations containing an acoustic resonator with an input part oriented towards the incoming flow of the working agent and a divider installed in front of the resonator, characterized in that it contains a flow cavity installed in the working agent flow and limiting its cross section, the outlet of the flow cavity is made in the form of at least one venturi, and the resonator and the divider are installed inside the flow cavity, and in the bottom of the resonator in the total waste otverstie.2. The device according to claim 1, characterized in that the flow cavity is made in the form of a pipe segment.

Description

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DEVICE FOR PROCESSING LAYERS PRODUCTIVITY OF PLASTES

The utility model relates to the oil and gas industry, and in particular to devices for creating high-intensity sound fields in a formation to increase its productivity.

A device for creating high-intensity sound fields (a, c.l2S2324 class B About B1 / 20) is known. The device consists of a housing, a central cylindrical rod located in the nozzle coaxially with the latter, and a hollow resonator mounted on the rod.

The disadvantage of this device is the need to supply compressed gas to a nozzle with a pressure higher than critical to ensure high efficiency (| efficiency of converting the kinetic energy of the jet into sound vibrations. When operating production wells with a large amount of back pressure of the medium, this leads to the need to have a pressure value at the inlet of the emitter at least three to four times the working. This, in turn, leads to the use of field energy technology equipment unreasonably high power and entails a significant increase in the cost of the production process.

A device is also known - a gas-jet sound emitter for exciting intense sound vibrations in a high-speed gas stream (a.s. 15562034 class B 06 V 1/20). The emitter comprises a cylindrical body made in the form of a cup with radial holes in its wall for supplying a working medium, an inlet diaphragm in the form of a di (M) pattern with an opening, and an outlet diaphragm fixed with a nut. Gas from the collector of the technological device flows through radial openings into the cavity of the emitter body and then into the diffuser. Barrels of a wall-mounted supersonic jet form in it, expire through the inlet diaphragm into the resonant region of the body and then through the hole in the outlet diaphragm in the form of a high-speed pulsating, slightly diverging gas jet. The pulsation frequency is determined by the ratio of the diameters of the apertures, the length and diameter of the resonating cavity.

For the effective operation of this device, a compressed gas supply with a pressure higher than critical is also provided, which requires the use of field power technology equipment of unjustifiably high power and leads to an increase in the cost of the production process.

A similar device is also known (US patent N 3376847 NII 116-137) - an acoustic generator, which is a whistle, in the design of which there is a resonant cavity placed on the path of the jet, and a rod. The latter protrudes from the specified cavity into the stream in order to control the frequency of oscillation generation. This device has the same disadvantages, namely: the need to supply compressed gas to the nozzle with a pressure higher than critical.

Thus, the devices of generation of acoustic oscillations considered above are characterized by low profitability.

Known technical solution (Brocher Eric and Duport. Resonance tubes in a subsonic flowfield. AJAA Journal. 1988, 26, N 5, 548-55S), which allows to excite intense pressure fluctuations. In the resonator placed in the subsonic flow of the working agent, the generation of oscillations is achieved using a divider installed in the stream in front of the inlet section of the resonator. Excitation of oscillations; due to the effect of the interaction of waves propagating in the shear layer formed in the wake behind the divider, and acoustic waves generated in the resonator.

This technical solution is the closest in essence to the proposed solution and therefore is selected as a PROTOTYPE. The device consists of a resonator, which is a pipe open at one end, and a divider coaxially mounted in front of it. The divider can be of various shapes (for example, rectangular, wedge-shaped, etc.).

The device is installed coaxially with the flow direction of the subsonic flow of the working agent. When the flow flows onto the divider, a shear layer develops in the wake after it, in which vortexes are present, which leads to the appearance of waves interacting with acoustic waves, the gene, s, -. I am ;, .,

resonator, resulting in the formation of acoustic pressure oscillations of high amplitude.

Such acoustic devices are structurally simple, since they lack moving structural elements. They work well at high temperatures, when exposed to vibrations and shock loads.

These devices do not require additional energy sources, since the kinetic and potential energy of a subsonic flow is used to excite acoustic vibrations. Using the device, oscillations of both low (tens of hertz) and high (kilohertz) frequencies can be excited by changing the length of the resonator.

It is known that the zone of influence of acoustic impact on the formation can reach hundreds of meters. A similar effect is observed when exposed to infrasonic (up to 20 Hz) and low-frequency (up to hundreds of Hz) oscillations.

A large impact radius is achieved due to the small absorption of wave energy and can be used to improve the filtration properties of the reservoir in the entire interwell space.

The acoustic impact at the structural level affects the zone with a radius of 1 meter to several tens of meters, effectively used for processing bottom-hole zones. The impact at the structural level is carried out at vibrational frequencies equal.

Thus, at low frequencies a high efficiency of the wave action in the interwell space is ensured.

To generate acoustic low-frequency vibrations, long resonators are needed. So, for example, to generate acoustic vibrations in an air stream with a frequency of 25 Hz, a cavity with a cavity length of up to 3.4 m is required.

However, during operation of the known device, condensate contained in the working agent will accumulate in the emitter cavity. This is due to the fact that getting into a semi-closed cavity with a ratio of length to diameter of more than 10 (and resonators for generating low-frequency oscillations are characterized by a ratio exceeding 100) of the condensed phase.

due to the large excess of its density over the density of the gava fav, it accumulates at the bottom of the cavity, gradually reducing the effective length of the resonator channel.

The process of pumping a working agent into the formation is quite long (from several hours to several months). Under these conditions, the characteristics of the acoustic emitter can change significantly, which will lead to a change in the frequency of the generated oscillations and, as a result, to a decrease in the efficiency of wave action on the formation. So. with a decrease in the cavity cavity length by 25% (from 3.4 m to 2.55 m), the oscillation frequency in the air stream will also increase by -25% (from 25 Hz to 37.5 Hz). In this case, the degree of filling of the free cavity of the resonator increases as its length increases, which makes it difficult to generate infrared and low-frequency oscillations.

Studies of Hartmann-Sprenger resonators, performed at sufficiently large values of their relative length (10 or more), established that during inflow even a supersonic flow penetrates into the cavity only 3/4 (and slightly more) of its depth (V.G.Dulov Nonlinear small perturbation theory for thermoacoustic phenomena in semi-enclosed volumes. Preprint N 11-89. SB ITPM AN SSSR. Novosibirsk, 1989). As a result of this, even a gavoobrazny medium in a significant part of the volume in the bottom zone of the resonator does not participate in mass transfer and is not updated. Moreover, the condensed part of the flow is not removed by the gaseous subsonic jet of the bottom zone of the resonator.

1) Thus, one of the significant disadvantages of the considered device is an uncontrolled change in the frequency of generated rubyanie. This will lead to a decrease in the effectiveness of the wave action on the formation — a decrease in the intensity of production and a decrease in oil recovery.

2) In the process of pumping the impact agent into the formation over time, the injectivity of the well changes. The latter, due to a change in the speed of sound in the stream with a change in pressure, also affects the frequency of oscillations and can lead to the cessation of oscillation generation. Consequently, another disadvantage of the known device is the limited conditions for its operation - only in wells with a fairly stable value of the Inutriplast pressure.

3) Further, the internal diameter of wells operated in the fields is significantly ambiguous (from 120 to 20 mm). At the same time, to ensure stable parameters of the oscillation generator, a well-defined flow rate is necessary. This entails a change in agent flow rate, depending on the diameter of the well being operated, which complicates the production process, the need to equip the field with a ground supply system for the agent, oriented to the ultimate power, determined by the presence of large diameter wells. So, when the emitter is installed in the well with a S20 mm dialet, to ensure the minimum critical velocity in the agent flow, its mass flow rate will be required, more than three times higher than the flow rate if the device is installed in the well with a 130 mm diameter. An increase in mass flow rate leads to an increase in the energy intensity of the equipment used and, at the same time, to a more intensive increase in back pressure in the formation, and, as a result, to a change in the oscillation frequency, and even to a reduction in their generation.

The problem to which the claimed utility model is directed is to create a device for processing productive formations, providing increased efficiency and economy of impact on the productive stratum by increasing the stability of the emitter parameters in the presence of condensate in the flow of the working agent, and when changing the diameter of the well , as well as by eliminating the danger of disruption of the process of oscillation generation.

The dryness of the utility model lies in the fact that the known device designed for processing productive formations, containing an acoustic resonator with an inlet oriented towards the incoming flow and a divider installed in front of the resonator, for solving the task - CONTAINS A FLOW CAVITY INSTALLED IN THE WORKING AGENT FLOW TARGETING ITS CROSS-SECTION, AT THIS, THE OUTPUT PART OF THE FLOW CAVITY IS PERFORMED AS A LESS THAN ONE VENTURI TUBE, AND THE RESONATOR PI IS INSTALLED WE ARE INSIDE THE FLOW CAVITY, AND A WASTE HOLE IS COMPLETED IN THE BOTTOM OF THE RESONATOR.

In addition, a specific embodiment of the device is possible, in which the FLOW CAVITY is PERFORMED in the form of a pipe cut.

To ensure the stability of the generated frequency and to exclude the possibility of disruption of the generation of the acoustic emitter, a constructive joint of the venturi and the resonator (with a drain hole providing efficient drainage of condensate from the resonator) is provided by means of a flow cavity, which together with the venturi also serves to reduce energy consumption during operation of the emitter in wells with different inner casing diameters.

Thus, only a complete combination of the proposed structural elements of the device provides a solution to the problem.

The device shown in the drawing. A device for processing productive formations contains an acoustic resonator 1 with a drain hole 2 and a divider 3 installed with a gap in front of the resonator 1. The resonator 1 and the divider 3 are aligned with it in the flow cavity 4. The flow cavity 4 can be made of a piece of metal pipe. A venturi 5 (or a combination of venturi) is connected to the flow cavity 4, to the outlet of which the input unit 6 of the working agent into the formation is connected through holes 7.

A device for processing productive formations is installed vertically at the bottom of the well, connecting previously, for example, with a tubing through which the working agent receives a compressible fluid (gas), for example, air, nitrogen, COo, superheated steam, etc.

The device operates as follows: a working agent, for example, air is supplied under pressure into the flow cavity 4, in which a subsonic flow is formed. When the flow flows onto the divider 3, a shear layer is formed after it, in which vortex structures propagate with a certain periodicity, which leads to the appearance of waves interacting with the flow in the resonator 1. As a result, resonant pressure oscillations in the cavity of a large amplitude are induced.

The acoustic vibrations generated by the revonator 1 propagate through the flow of the working agent in the flow cavity 4, the body of the flow cavity 4 and further into the reservoir. The flow of the working agent flowing around the resonator 1 enters the venturi 5 and then through the openings 7 of the input unit 6 into the reservoir .

Condensate entering the cavity of the resonator 1 with a stream is discharged through the opening 2 into the working agent behind the resonator 1 (in front of the venturi 5).

The presence of a flowing cavity 4 allows one to form the necessary pair of levers of the flow of the working agent (i.e., to set certain speeds) when flowing onto the divider 3, focusing on commercially available field equipment (for example, compressors). This ensures the necessary operating conditions for the emitter, regardless of the inner diameter of the casing of the wells. The difference in casing string diameters is currently up to 1.5.

As is known, in the process of injection of a working agent into the formation, the formation backpressure may change. As a result, during the subsonic flow of the working agent in the device, the flow parameters (speed) will change, which in some cases will lead to a stall or change in the frequency of oscillation generation in the resonator 1. The installation of a Venturi 5 will ensure independence of the flow parameters in the device up to an increase in back pressure in formation to a value of 0.8-0.85 of the pressure at the inlet to the device. Thus, the expansion of the area of maintaining unchanged energy parameters (frequency, power, etc.) of the emitter is provided when the amount of back pressure at the bottom of the well changes.

The adjustment of the frequency of acoustic vibrations by the device is provided both by changing the installation distance of the divider 3 from the resonator 1, and by replacing the resonator of one length with another.

several sizes of Venturi tubes, calculated for different flow rates and pressures of the exposure agent. Under the operating conditions of a particular field, one of the most suitable Venturi tubes is selected, which ensures the supply of a working agent in accordance with the technology of processing the formation available in the field equipment. The remaining venturi tubes are muffled.

The specific implementation of the proposed technical solution does not seem to be time-consuming. This, in particular, applies to the choice of the cross-sectional area of the drain hole in the bottom of the resonator. The procedure for determining it is as follows: the working agent used (for example, air), entering the compressor inlet, is characterized by absolute humidity depending on the pressure and ambient temperature (the mass content of water vapor in a unit volume of air is 1 m-). In the extreme case, it is characterized by maximum absolute humidity (mass content of saturated water vapor in 1 m of air). At a relative humidity of 100%, the absolute and maximum absolute humidity are equal to each other. As a rule, compressor units are designed for operation in conditions of 100% relative humidity of the working agent. When the agent is supplied to the bottom of the well, its temperature can significantly decrease (to values below ambient temperature). As a result, the transition of high-grade water vapor to condensate is possible, which will enter the resonator. The maximum amount of condensate per unit time is determined by the product of the volumetric flow rate of the compressor per unit time by the mass content of saturated water vapor in 1 m of air and the ratio of the square sections of the resonator and the flow cavity.

The cross-sectional area of the drain hole in the resonator is determined by the dependence including the mass flow rate per unit time, the coefficient of discharge through the hole (depending on the shape of the hole), the density of the liquid and the pressure drop across the drain hole. With sufficient accuracy for practice, the amplitude of pressure fluctuations in the cavity of the resonator can be taken as the pressure drop.

the resonator is given in (Brocher Eric and Duport Elisabeth. Resonance in a subsonic flowfield, AIM Journal. 1988, 26, N5, 548 - 552).

Calculation example:

1) The source data.

exposure agent is air;

relative humidity - 100%;

ambient temperature - + 33 ° C;

volumetric performance

compressor (q) - 1.8 (2.32 kg / s);

Mach number in flow

cavity (M) - 0.1;

flow pressure (Ra) - 15 kg / cm; .

adiabatic exponent (y) - 1.43 (1.4);

flow area

cavities (RP.P.) -

cavity cross-sectional area

resonator (Fp) - 5 cm.

2) Calculation.

2.1Absolute humidity at a temperature of 33 ° C rp 35g / m (see Pocket Guide of the Oil Refiner. Leningrad, Chemistry, 1989. p.454).

2.2 The maximum content of condensate entering the flow cavity of the device

, 8 63 g / s.

2.3 Limit content of condensate entering the cavity

rnp mnn-Fp / Fnn 63-5 / 38.5 8.2 g / s.

2.4. The primary amplitude of the pressure oscillations in the cavity

2.5 The cross-sectional area of the drain hole in the bottom of the resonator (taking into account the alternating value a1y of the plateau relative to the pressure in the flow - pa)

where 2 is the coe (M) patient, taking into account the alternating sign of the amplitude; ) 1 - flow rate through the hole

(e.g. 0.7); p - specific gravity of the condensate (water), p 0.001 kg / cmF 2ihp / MI / 2ip5p 2- 0.0082 / 0.7 | / 2- 981- 0.001 -4.2 0.0082 cm With a round hole, its diameter is

doTB l 4Fyir 1.02 mm.

For any other gas that is used as an exposure agent (nitrogen, COo superheated steam, etc.), the calculation of the diameter of the drain hole in the resonator can be carried out in a similar way.

The use of a device for processing productive formations makes it possible to ensure high reliability of the process of stimulating the formation, increasing its return and increasing profitability by using anergy of the flow of the working fluid to excite acoustic sound waves by the emitter when the latter acts on the formation.

- 10 F 2 np / j42gpAP

Claims (2)

1. A device for processing productive formations containing an acoustic resonator with an input part oriented towards the incoming flow of the working agent and a divider installed in front of the resonator, characterized in that it contains a flow cavity installed in the working agent flow and limiting its cross section, the outlet of the flow cavity is made in the form of at least one venturi, and the resonator and the divider are installed inside the flow cavity, and in the bottom of the resonator in the total waste hole. 2. The device according to claim 1, characterized in that the flow cavity is made in the form of a pipe segment.