RU2274730C2 - Borehole assembly for bottomhole formation zone treatment and impulsive device for borehole assembly - Google Patents

Abstract

FIELD: oil production equipment, particularly for bottomhole formation zone treatment.

SUBSTANCE: borehole assembly comprises pipe string and impulsive device hydraulically connected with elastic vibration oscillator by overflow channel. Impulsive device and elastic vibration oscillator are arranged in hollow bodies connected one to another by sleeve provided with at least one window. Elastic vibration oscillator and impulsive device outputs are connected by pipe having at least one window communicated with sleeve window by channel. Lower hollow body end is closed with cap. Upper hollow body is connected with pipe string. Impulsive device and elastic vibration oscillator are hydraulically linked through inputs thereof. Impulsive device includes body with supply channels, piston and bush with grooves for stop, annular cavity arranged in body and provided with orifices for stop receiving and piston underside part communicated with space below the bush. The piston and the bush are spring loaded relative the body. Seat is installed in the body. Upper bush part has valve and is arranged in annular cavity of the body so that valve may be installed in seat and displaced along seat axis and annular cavity. The supply channel has pressure or flow regulator. Piston is installed in axial body cavity and spring-loaded relative it through rod. Piston head part is hydraulically connected with piston underside part and with space above seat and valve through the rod.

EFFECT: increased operational efficiency due to extended capabilities and widened range of application in wells of different types having different depths and reduced power inputs.

16 cl, 2 dwg

Description

The invention relates to the oil and gas industry, as well as to the technique of generating elastic vibrations and can be used as oilfield equipment for cleaning the bottom-hole formation zone (PZP) from clogging materials during development, resuscitation and increasing productivity of wells, in particular wells operating in difficult development conditions , as well as inclined horizontal wells and second shafts of existing oil wells and water wells. In addition, the invention can be used in the mining industry to initiate and intensify downhole hydraulic mining.

A device for the development and processing of productive horizons by creating high-frequency waves of tension and compression in the reservoir fluid with depression on the reservoir (AS No. 1740640, class E 21 V 43/25, publ. In BI No. 22, 92 d), consisting of a jet pump suspended with a packer on a pipe string, where a high-frequency hydrodynamic emitter is placed in the pump mixing chamber, in front of the nozzle.

A disadvantage of the known device is the low efficiency of cleaning the bottom-hole zone from colmatant due to the small energy level of the vibrational effect on the contaminated area of the bottom-hole zone. This is due both to the features of the implemented mechanism of creating oscillations, and to the significant absorption of high-frequency vibrational energy in the well fluid and the saturated porous medium of the reservoir.

Closest to the proposed invention is downhole equipment for processing the bottom-hole formation zone (RF patent No. 2175718, class E 21 B 43/25, publ. In B.I. No. 31, 2001), containing a jet pump with a housing, including mixing chamber, nozzle chamber with a passage through the packer and filter clutch. Inside the filter clutch, a relay valve and a flow or pressure regulator are installed. A hydrodynamic emitter is installed under the packer on the pipe string at the level of the perforation interval. The relay valve is equipped with a time relay and is installed between the pressure regulator and the emitter. In parallel with the relay valve, a transfer channel is made. As a hydrodynamic emitter, a self-oscillating, low-frequency generator is used, which is consistent with the intrinsic resonance properties of the equipment and the downhole system.

The disadvantages of the device are due to the fact that during the implementation of the pressure increase cycle it is difficult to generate sufficiently high-amplitude pressure fluctuations at the bottom, and this is a prerequisite for processing efficiency, especially at zero productivity. In addition, the known device does not allow to fully implement, together with the action of elastic vibrations, any reagent effect on the formation, without which for certain categories of wells obtaining a sufficiently favorable result is difficult.

Also known is a downhole pulser (US Pat. RF No. 2136849, class E 21 B 43/00, published in B.I. No. 25, 99), including an adapter with a central channel for supplying fluid and a side gas supply channel with installed in They are non-return valves, a tubular body and an inner pipe acting as a gas storage chamber, in the lower part of which an exhaust valve is installed. Check valves are connected to the adapter and are concentrically placed relative to each other. A shut-off valve is installed at the bottom of the tubular body. The cavity of the gas storage chamber is connected to the side channel of the adapter, and the annulus is connected to its central channel.

The disadvantage of this device is that in the presence of free contact of the gas of the gas storage chamber with the liquid, it dissolves in it, and its solubility increases with the depth of installation of the device in the well. When creating oscillations, the gas is carried out together with the liquid from the well, reducing the energy intensity of the gas storage chamber. In addition, the inability to control the elastic element in the shutoff valve limits the amount of energy stored.

There is also known a device for the pulsed supply of liquid or gas (AS No. 427204, class F 16 k 21/12, published in B.I. No. 17, 74), in which a shut-off element is installed in the housing, made in the form of a valve with a shank, on which a plunger spring-loaded relative to the housing is mounted, interacting with the shank by means of an additional spring.

The disadvantage of this device is the small pulse power due to the small and unregulated volume of the ejected liquid due to the short period of time and the small passage area when the valve is opened. In this case, the valve opens against the flow of the outgoing fluid, which further reduces the time of its open state.

Closest to the proposed pulse device is a device for conducting water hammering on the bottomhole zone of the Impuls formation (AS No. 1716108, class E 21 B 43/25, publ. In B.I. No. 8, 92), which contains a housing with radial channels associated with the pipe string, a spring-loaded sleeve with grooves under the stopper and radial channels placed with the possibility of combining with the radial channels of the housing and stopper. The housing has an annular cavity for accommodating a spring-loaded annular piston with grooves for the stopper. The under-piston part of the annular cavity is in communication with the in-tube space above the spring-loaded sleeve, and the under-piston part is in communication with the in-pipe space below the spring-loaded sleeve.

The disadvantage of this design is its low efficiency due to the following technical limitations: the maximum pulse size due to the need for a piston spring, with a diameter exceeding the dimensions of the borehole space; the magnitude of the periods between pulses due to unregulated time of pressure growth in the space above the sleeve; the minimum flow rate due to leaks in the contacting surfaces of the sleeve and the housing.

The objective of the invention is to increase the efficiency of downhole equipment and a pulse device by expanding their functionality when processing the bottom-hole formation zone, as well as the range of applicability for depths and categories of wells while reducing energy costs.

The problem is solved in that in the well-known downhole equipment, including a pipe string, a pulse device hydraulically connected by a transfer channel with an elastic oscillation generator, according to the invention, the pulse device and an elastic oscillation generator are placed in hollow bodies interconnected by a coupling having at least one window, the outputs of the generator of elastic vibrations and a pulse device are connected by a pipe having at least one window communicated by the channel with the coupling window, the end face of the lower hollow the housing is equipped with a plug, and the upper hollow housing is connected to the pipe string, while the hydraulic connection of the pulse device and the generator of elastic vibrations is carried out through their inputs.

In this case, the pulse device can be configured to open when the pressure drop exceeds the nominal differential pressure of the generator of elastic vibrations, for combining the work of a single generator, or in conjunction with a pulse device or only one pulse device.

As a generator of elastic vibrations, a hydrodynamic generator of flow fluctuations based on vortex nozzles can be used to control, using the flow rate, the combined operation of downhole equipment.

In some cases, the generator of elastic vibrations can be equipped with a quarter-wave resonator-transformer made in the form of a pipe or with an elastic body with adjustable elasticity and matched with them in terms of the oscillation frequency to increase the amplitude of the pressure oscillations.

When placing the generator of elastic vibrations in the lower hollow body with a plug, the transfer channel should be equipped with a flow regulator.

When placing the generator of elastic vibrations in the upper hollow housing at its entrance, it is advisable to install a flow regulator.

A double-sided flow reflector can be installed in the nozzle from the output side of the pulse device and the generator of elastic vibrations towards the nozzle window.

It is possible to use a pulsed device as a body pipe, and the surface of its valve as a reflector, while output windows are made in the side surface of the body, which are communicated by a channel with the coupling window.

In the pipe string above the pulse device and the generator of elastic vibrations, an injector and / or a packer device can be installed to control the level of static pressure in the treated borehole space.

The problem is also solved by the fact that in the known pulsed device comprising a housing with power channels, a piston and a sleeve with grooves for the stopper spring-loaded relative to the housing, an annular cavity in the housing with stopper holes and a sub-piston part in communication with the space below the sleeve, according to the invention, a saddle is installed in the housing, the sleeve in its upper part is equipped with a valve and placed in the annular cavity of the housing with the possibility of installing the valve in the saddle and moving along the axis of the saddle and the annular cavity, can L supply includes a pressure regulator or flow, the piston is mounted in the axial cavity of the housing and spring biased thereto via a rod and above the piston portion fluidly communicates with subpiston and through the rod - with the space above the seat and the valve. It is advisable to provide the housing on the side of the space above the seat and valve with a hydraulic accumulator made in the form of a cavity with adjustable elasticity, and install a flow or pressure regulator and / or non-return valve in its supply line to expand the range of regulation of the time interval between pulses. In this case, the power channels of the pulse device and the accumulator can be combined. To control the power of pulsed radiation, the device may be further provided with an injector and / or packer. To ensure that the valve opens at a given pressure drop, the piston rod must be equipped with a seal and a spring travel regulator. The output of the pulse device can be made in the housing in the form of axial and / or radial channels below the seat and valve, centralizers can be made on the valve to fit it into the saddle, and additional seals on the external and internal surfaces of the valve to ensure a minimum flow rate. In this case, the saddle can be made movable relative to the housing.

Improving the efficiency of the proposed downhole equipment is achieved by ensuring coordinated operation in the optimal mode of both an elastic oscillator and a pulse device, the ability to control the exposure depth, combine exposure with injection of reagents, as well as increase the power of elastic exposure at the same energy consumption when processing deeper wells, including horizontal ones.

Figure 1 schematically shows the downhole equipment for processing bottom-hole formation zone;

figure 2 - presents a pulse device for processing bottom-hole formation zone.

Downhole equipment consists of two hollow bodies 3 and 4, lowered into a well 1 on a pipe string 2, connected by means of a coupling 5, in which a pulse device 6 and an elastic oscillation generator 7 are located, interconnected by a pipe 8 installed and fixed in the sleeve 5. The generator of elastic vibrations is equipped with a quarter-wave resonator at the output — a transducer made in the form of a pipe or an elastic body with adjustable elasticity, for example, an elastic body with a cavity filled with gas or a spring-loaded device, etc. a plug 9 is installed at the end of the hollow body 4, and a reflector 10 is installed in the inner cavity of the nozzle 10. In the coupling 5, a transfer channel 11 with limited bandwidth for supplying the elastic oscillation generator 7 and channel 12 is provided, which provides hydraulic communication between the window 13 of the pipe 8 and the window 14 of the coupling 5 .

It is possible to use an ejector installation 15 with a packer 16 located on a pipe string above the downhole equipment.

The pulse device comprises a housing 17 with a saddle 18. In the housing there is an annular 19 and axial 20 cavity and a bottom 21, which is made movable relative to the housing. A piston 22 with an external annular groove 23 and a rod 24 spring-loaded relative to the end surface of the cavity body with a spring 25 is installed in the axial cavity, and a nut 26 is installed at the end of the rod to control the stroke. Valve 27 and a sleeve 28 with an internal annular ring are located in the annular cavity 19 a groove 29 and with centralizers 30, which is spring-loaded relative to the bottom of the housing by a spring 31. The annular 19 and axial 20 cavities are connected by holes 32 for locating the clamps 33. To equalize the pressures above and below the piston 22 channels 34 are made in it, and the under-piston part of the axial cavity 20 is communicated with the space below the sleeve 28 via the channel 35. The housing 17 can be additionally equipped with a hydraulic accumulator 36 mounted on the side of its inlet 37, the flow regulator 38 is placed in the supply line of it. The volume of the hydraulic accumulator divided by an elastic membrane 39 into a cavity 40 filled with gas, and a cavity 41 filled with liquid.

Downhole equipment operates as follows.

Two hollow bodies 3 and 4 connected by a sleeve 5 are lowered into a well 1 on a pipe string 2, in which a pulse device 6 and an elastic oscillation generator 7 are installed, installed in a pipe 8 fixed in the sleeve 5, the sleeve having a window 14 connected to the window 13 the pipe using the channel 12, are installed at the level of the treated formation.

The working pressure drop across the generator of elastic vibrations and the pressure drop opening the valve of the pulse device, as well as the conductivity of the transfer channel, are preliminarily calculated based on the geological and field data of the processing object. When using the ejector installation, its flow-pressure characteristic is additionally calculated to achieve the required level of static pressure in the treated borehole space.

The output of the pumping unit is connected to the pipe string 2, and the annular space of the well is connected by a flow line with the reservoir to the working fluid, into which the receiving hose of the pumping unit is lowered. The working fluid from the pump unit under the calculated pressure is fed into the pipe string 2, then through the hollow body 3 and the transfer channel 11 into the hollow body 4 with a plug 9. In this case, the generator of elastic vibrations 7 starts to work in the optimal mode for it, initiating fluctuations in the fluid pressure deflected from the reflector 10 through the window 13 of the pipe 8, the channel 12 and the window 14 of the coupling 5 in the annulus. To start the pulse device 6, the pressure of the working fluid is raised, increasing the flow rate from the pump unit, and when the calculated opening pressure is reached, the device begins to emit pressure pulses into the annulus with the generation of elastic oscillations by the generator 7.

To operate with a single pulse device, the flow line is closed, stopping the circulation of fluid through the generator 7 and thereby its operation, and the pressure in the pipe string 2 is raised and maintained until the estimated valve opening pressure of the pulse device 6.

When using the ejector installation 15 with the installation of the packer 16, the working fluid, passing through their transfer channels, enters the downhole equipment, from the outlet of which - into the annulus above the packer.

The pulse device operates as follows.

Before installation, with the selected operating pressure drop across the pulse device, the working stroke of the springs ensuring the opening and closing of the valve is controlled, the flow area of the flow regulator, as well as the elasticity of the gas cavity, are determined.

In the first phase of operation, the valve 27 installed in the seat 18 is fixedly fixed with the help of latches 33. The fluid through the flow regulator 38 enters the cavity 41, compressing the gas cavity 40 through the elastic membrane 39. The rate of pressure growth is ensured by the passage section of the flow regulator 38, as well as adjustable elasticity in the gas cavity 40. With increasing pressure, the piston 22 through the rod 24 and nut 26 compresses the spring 25. Upon reaching the pressure value at which the calculated spring travel leads to the coincidence of the outer annular groove ki 23 of the piston 22 with holes 32, there is a change in the positions of the clamps 33, which under pressure on the valve 27 release its inner annular groove 29 and are fixed in the piston 22. In the second phase of the device, the increased pressure sharply squeezes the released valve 27 from the seat 18 while the fluid that has come into motion under the action of the elastic energy of the compressed gas and lower pressure in the space below the sleeve 28 through the seat 18 and the radial channels 42 is ejected, venting the pressure in the gas cavity 40. In the third the phase of operation of the fluid pressure device, filling the space above the valve 27 through the flow regulator 38, is not enough to open the valve, and it returns to the seat 18 under the action of the spring 31, while the inner annular groove 29 of the valve 27 is aligned with the holes 32. Under the action of the elastic force the spring 25 presses the piston 22, freeing from the latches 33, which in turn are installed between the holes 32 and the inner annular groove 29 of the valve 27 with the fixation of the latter. While maintaining the calculated value of the pressure in the supply line, at which the stroke of the spring 25 leads to the coincidence of the outer annular groove 23 of the piston 22 with the holes 32, the phases of the pulse device are repeated.

Thus, the constructive implementation of the borehole equipment and impulse device that we offer allows us to carry out a depth-controlled effect on the bottom-hole zone of the formation, alternating between pulsed, vibro-microwave and vibro-microwave with pulsed radiation of elastic energy, more efficiently carry out the injection of reagents into the formation, process deeper ones, including and horizontal wells.

Claims (16)

1. Downhole equipment, including a pipe string, a pulse device, hydraulically connected by a transfer channel with an elastic oscillation generator, characterized in that the pulse device and the elastic oscillation generator are placed in hollow housings interconnected by a coupling having at least one window and generator outputs elastic vibrations and a pulse device are connected by a pipe having at least one window communicated by the channel with the coupling window, the end face of the lower hollow body is provided with a plug, and the upper hollow body with connected to the pipe string, while the hydraulic connection of the pulse device and the generator of elastic vibrations is carried out through their inputs. 2. Downhole equipment according to claim 1, characterized in that the pulse device is configured to open when the pressure drop exceeds the nominal pressure drop of the generator of elastic vibrations. 3. Downhole equipment according to claim 2, characterized in that a hydrodynamic generator of flow fluctuations based on vortex nozzles is used as a generator of elastic vibrations. 4. Downhole equipment according to claim 3, characterized in that the generator of elastic vibrations is equipped with a quarter-wave resonator-transformer made in the form of a pipe or an elastic body with adjustable elasticity and matched with them according to the frequency of oscillations. 5. Downhole equipment according to claim 4, characterized in that the generator of elastic vibrations is placed in the lower hollow body with a plug, and the transfer channel is equipped with a flow regulator. 6. Downhole equipment according to claim 4, characterized in that the generator of elastic vibrations is located in the upper hollow body, at the input of which a flow regulator is installed. 7. Downhole equipment according to claim 1, characterized in that a two-way flow reflector is installed in the pipe from the output side of the pulse device and the generator of elastic vibrations towards the pipe window. 8. Downhole equipment according to any one of paragraphs. 1-8, characterized in that the pipe string above the pulsed device and the generator of elastic oscillations is equipped with an injector and / or packer device. 9. A pulsed device for processing the bottom-hole zone of the formation, comprising a housing with a feed channel, a piston and a sleeve with grooves for the stopper spring-loaded relative to the housing, an annular cavity in the housing with stopper holes and a sub-piston part in communication with the space below the sleeve, characterized in that a saddle is installed in the housing, the sleeve in its upper part is equipped with a valve and placed in the annular cavity of the housing with the possibility of installing the valve in the saddle and moving along the axis of the saddle and the annular cavity, the power channel a pressure regulator or flow, the piston is mounted in the axial cavity of the housing and spring biased thereto via a rod and above the piston portion fluidly communicates with subpiston and through the rod - with the space above the seat and the valve. 10. The pulse device according to claim 9, characterized in that the housing on the side of the space above the seat and valve is equipped with a hydraulic accumulator with a cavity filled with gas, in the supply line of which there is a flow or pressure regulator and / or non-return valve. 11. The pulse device according to p. 10, characterized in that the power channels of the pulse device and the accumulator are combined. 12. The pulse device according to claim 9, characterized in that the stem is equipped with a seal and a spring travel regulator, which opens the valve at a given pressure drop. 13. The pulse device according to claim 9, characterized in that the output of the pulse device is made in the housing in the form of axial channels and / or radial channels below the seat and valve. 14. The pulse device according to claim 9, characterized in that the valve has centralizers for seating the valve in the seat, and on the external and internal surfaces of the valve additional seals. 15. The pulse device according to claim 9, characterized in that the saddle is movable relative to the housing. 16. The pulse device according to any one of paragraphs. 9-15, characterized in that it is further provided with an injector and / or packer.

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