RU2119581C1 - Device for hydraulic-impact treatment of bed - Google Patents

Abstract

FIELD: oil production industry. SUBSTANCE: device has pipes connected together into string, packer, adapter with dividing piston which divides axial passage into upper chamber and lower chamber, pulsing valve located above adapter and relieving valve located below adapter. Lower chamber is filled with liquid which is pressure-forced into bed. Poured into upper chamber is detonating liquid. Flow of liquid from well is directed into lower chamber. Detonating liquid is compressed by means of dividing piston. Vapor of detonating liquid is ignited. Due to action of pressure pulse, liquid from lower chamber is pressure-forced into bed. Multiple repeating of aforesaid bed treating process yields efficient results. EFFECT: higher efficiency. 4 cl, 3 dwg

Description

 The invention relates to devices for hydraulic fracturing and may find application in the oil industry.

 During the operation of oil, production and injection wells, microchannels become clogged in the porous reservoir medium. Accordingly, the permeability of the formation is deteriorating.

 The decrease in permeability of the bottomhole formation zone can occur for many reasons due to drilling, operation or repair work.

 The degree and depth of pollution of the reservoir is the main criterion for choosing the means of stimulation of wells. For this purpose, gyro shocks are widely used. They make it possible to instantly inject a chemical reagent into a reservoir at a pressure of 35.0 - 40.0 MPa, and the use of a hydrogenerator in combination with hydroshock installations allows cyclically washing the bottom-hole zone of the formation with variable loads on the formation. As a result of the actuation of the hydrogenerator, 6 to 8 alternating cycles (strokes) occur in the formation.

 The effectiveness of using hydraulic shock installations is due to the fact that they allow delivering the chemical reagent of the desired concentration to the zone of the perforation interval and driving it into the reservoir under high pressure.

 Water hammer installations are simultaneously a tool that allows you to pump a chemical reagent into the reservoir under pressure, a container that delivers the chemical reagent of the desired concentration to the perforation interval, and a hydraulic shock generator that cyclically flushes the reservoir.

 The use of technology using a water hammer installation allows you to increase the depth of processing of the reservoir to restore or improve permeability in comparison with other known methods of chemical treatment of the reservoir. Water hammer installations make it possible to free up special equipment used for chemical processing, reduce the time of the operation, increase the processing efficiency and significantly save the chemical reagent.

 A device for influencing the formation is known, containing concentrically located external and internal nozzles rigidly interconnected, nozzles communicating the cavity of the internal nozzle with the well, a packer located in the upper part on the outer surface of the external nozzle, valves located in the inner nozzle (1) .

 However, this known device is intended only for the formation of point perforations and is not suitable for hydraulic fracturing, which significantly reduces its technological efficiency.

 A device is known for hydraulic fracturing, including a housing with sliding cutters, with which holes are drilled in the cased hole in the casing and cement ring, and fracturing fluid is pumped through the holes thus formed, which fractures the reservoir in a predetermined interval (2).

 The disadvantage of this known device is its structural complexity. In addition, its operation requires the use of energy-intensive equipment.

 A device for hydraulic fracturing, including a casing with weakened sections in the interval of fracturing (3).

 However, when using this device, it is necessary to create high pressures for pumping hydraulic fracturing fluid, which is associated with the high strength of metal and cement stone, which fills the drillings and grooves during cementing and leads to an increase in thickness at the proposed fracture location.

 A known installation for hydropercussion treatment of a formation containing pipes connected to a column forming an axial channel of the installation, equipped with valves and a packer 4 - prototype.

 However, the strength of the water hammer on the formation during operation of this known installation is determined by the installation height of the lower bursting valve from the fractured formation and the depth of the well, which reduces the efficiency of this known device.

 The technical result achieved by the implementation of the invention is to increase the efficiency of the installation due to the multiple repetition of the process of stimulation.

 This is achieved by the fact that in the installation for hydraulic shock treatment of a formation containing pipes connected to a column forming an axial channel of the installation, equipped with valves and a packer, the column contains a sub with a dividing piston separating the axial channel into an upper chamber filled with air and detonating liquid under atmospheric pressure and a lower chamber with fluid pushed into the reservoir under atmospheric pressure, configured to communicate with the space of the well, one of the valves being made in the form of higher positioned relative to the sub of the pulse valve, and the other in the form of an unloading valve located below the sub.

 A distinctive feature of the installation for hydraulic shock treatment of the formation is also that the discharge valve consists of upper and lower bodies made movable relative to each other and fixed with shear screws, the packer is fixed to the lower body, in which an annular groove and an axial channel are made. A piston with an annular groove for fixing it with crackers is placed in the axial channel of the upper case, the crackers are equipped with a spring pressing them to the inner wall of the upper case. The axial channel in the upper case consists of two parts, the diameter of the lower part is equal to the diameter of the piston, and the upper is larger, at the base of the upper part there are dogs.

 A distinctive feature of the installation for hydraulic shock treatment of the formation is also that the piston in the sub is mounted with the possibility of fixation by an elastic element and hermetically separates the axial channel into the upper and lower chambers.

 In addition, the pulse valve consists of a fixedly connected sleeve and a housing in which an axial channel is made with a stepped spool installed in it with o-rings, fixed in the initial position by an elastic damper located above it with an adjustable pressing force, between the inner wall of the axial channel and the spool a cavity communicating with radial channels with an annular cavity made between the sleeve and the housing, a shut-off valve is mounted on the sleeve, in the housing of which an axis howling and radial channels and installed ball valve.

 An installation filter is additionally installed at the installation for hydraulic shock treatment of the formation.

 In FIG. 1 shows a diagram of an installation for hydraulic shock treatment of a formation; in FIG. 2 shows a discharge valve; in FIG. 3 - pulse valve.

 The installation for hydraulic shock treatment of the formation consists of a column 1 of tubing, pipe 2, a receiving filter 3, an unloading valve 4, a sub 5, a pulse valve 6, has a common axial channel 7. The pipe 2a is a shank, a filter 3 is connected to it. Pipe 3 2b connects the filter 3 to the unloading valve 4. The sub 5 is connected by a pipe 2c to the unloading valve 4 and a pipe 2g to the impulse valve 6, which is connected to the column 1 from above. The unloading valve 4 is made of lower 4a and upper 4b cases (Fig. 1), movable one rel relative to another and fixed by shear screws 8. In the axial channel 7a, made in the upper casing 4b of the discharge valve 4, there is a piston 9 with sealing rings 10 and an annular groove, as well as crackers 11. The diameter of the upper part of the axial channel 7a is larger than the diameter of the piston 9 and the diameter of the lower part of the axial channel 7a is equal to the diameter of the piston 9. At the base of the section of the axial channel 7a, made large diameter, dogs 12 are installed. Crackers 11 are equipped with a spring 13, which presses them against the inner wall of the housing 4b. A groove 14 is made in the lower case 4a and a packer 15 is installed. In the sub 5 there is a dividing piston 16 which is fixed by elastic elements and forms a sealed lower chamber 7b and a sealed upper chamber 7b, located respectively under and above the dividing piston, from fragments of the axial channel 7a 16. The pulse valve 6 consists of a sleeve 6a and a housing 6b (Fig. 2), connected motionlessly among themselves. An annular cavity 17 is made between them, communicating with the axial channel 7g by radial channels 18. In the axial channel 7g of the housing 6b, a stepped spool 19 with o-rings 20, 21 is installed. The spool 19 is fixed in the initial position by an elastic damper 22 with adjustable pressing force. An annular cavity 23 is formed between the inner wall of the axial channel 7g and the spool 19, which communicates with the radial channels 18 with the annular cavity 17. A shut-off valve 24 is fixed on the sleeve 6a, in the body of which the axial channel 7d and the radial channel 25 are made and a ball valve 26 is installed. The shut-off and drain valve 24 is attached to the base of the column 1. Packer 15 seals the annulus. Crackers 11 fix the piston 9 from moving. Dogs 12, prevent the piston 9 from falling to the bottom during installation operation. The larger diameter of the upper part of the channel 7a allows fluid to pass past the piston 9 when it hangs on the dogs 12. The spring 13 presses crackers 11 against the inner wall of the housing 4b, which, when cutting the screws 8, fixes the housings 4a, 4b with crackers 11 and a groove 14. Sealed the lower and upper chambers 7b, 7c, formed in the sub 5 by the piston 16, serve, respectively, for filling with fluid squeezed into the reservoir, and for filling with detonating fluid (a mixture of diesel fuel and ether). Completed in the valve body 24 of the axial 7d and radial 25 channels communicates and divides the ball valve 26.

 Installation for hydraulic treatment of the reservoir works as follows.

 The lower chamber 7b of the installation is filled with fluid squeezed into the reservoir. A detonating liquid is poured into the upper chamber 7c, while the air volume of the chamber must ensure complete combustion of the liquid during operation.

 The installation is lowered into the well by a liner 2a down with an emphasis on the face. The length of the shank should ensure the placement of the filter 3 in the area of the well treatment. The packer 13 is triggered. The annulus is sealed. Then, screws 8 in the discharge valve 4 are cut off under the weight of the installation. Crackers 11 enter the bore 12, release the piston 9 from the grip and fix the discharge valve bodies 4a, 4b to each other.

 Under the influence of the pressure drop (atmospheric in chambers 7b, 7c and annular), the fluid flow from the well through the filter 3 enters the lower chamber 7b and compresses the detonating fluid in the upper chamber 7c using the separation piston 16 using the separation piston 16. Ignition of its vapors occurs, the gases formed during combustion create a pressure pulse in the upper chamber 7c above the annulus, and the column of liquid under the separation piston 16 is pressed into the reservoir.

 With a drop in pressure below the annulus in the installation, re-compression and ignition of the detonating liquid occurs until it is completely burned. This ensures multiple repetition of the process of stimulation.

 After the detonating liquid burns out, a small volume of solution may remain inside the unit. To push it into the reservoir, ground equipment is used.

 Flushing liquid is supplied to the column 1 under pressure, which through the channel of the shut-off valve 24 through the annular cavity 17 and channels 18 enters the cavity 23 of the pulse valve 6. In this case, in the shut-off and drain valve 24, the channel 25 is closed by a ball valve 26 and the message with the annular space ceases.

 Under pressure, the spool 19 rises, opening the channel 7g. The flushing liquid enters the chamber 7b, 7c, displacing the liquid located there. When the pressure is equalized, the spool 19 is returned by the elastic damper 22 to its original position and the operation cycle is terminated.

 As a solution, any chemical reagent can be used (hydrochloric acid, surfactant, unstable gasoline, solvent, etc.) depending on the formation.

 The new installation can be effectively used in wells where there has been a decrease in the permeability of the bottomhole formation zone, in wells where salts, heavy hydrocarbons, mud filtrate, etc. are precipitated. in wells, after flushing or cleaning the bottom, as well as for pumping stuck equipment (ESP, tread), in this case, special nozzles are installed on the bottom of the installation. The installation can be used in combination with other means of well development.

 Sources of information.

 SU, copyright certificate N 570699, cl. E 21 B 43/144, 1977.

 US patent N 4119151, CL 43/112, 1978.

 SU, copyright certificate N 135445, cl. E 21 B 43/26, 1961.

 SU, copyright certificate N 956766, cl. E 21 B 43/26, 1982.

Claims (5)

 1. Installation for hydropercussion treatment of a formation containing pipes connected to a column forming an axial channel of the installation, equipped with valves and a packer, characterized in that the column contains a sub with a dividing piston that separates the axial channel into an upper chamber filled with air and detonating liquid under atmospheric pressure and a lower chamber with atmospheric pressure fluid squeezed into the formation, configured to communicate with the space of the well, one of the valves being in the form of laid down relative to the sub of the pulse valve, and the other in the form of an unloading valve located lower relative to the sub.  2. Installation according to claim 1, characterized in that the discharge valve comprises upper and lower housings made movable relative to one another and fixed with shear screws, the packer is mounted on the lower housing, in which an annular groove and an axial channel are made, in the axial channel the upper case there is a piston with an annular groove for fixing and crackers equipped with a spring pressing them to the inner wall of the upper case, the axial channel in the upper case is made of two parts, the diameter of the upper and lower parts respectively greater and equal to the diameter of the piston, and in the base of the upper portion mounted pawl.  3. Installation according to claim 1, characterized in that the dividing piston in the sub is installed with the possibility of fixation by an elastic element.  4. The installation according to claim 1, characterized in that the pulse valve contains a fixedly connected sleeve and a housing in which an axial channel is made with a stepped spool installed in it, fixed in the initial position, located above it with a damper with adjustable pressing force, between the inner wall an axial channel and a spool a cavity is formed, communicating by means of radial channels with an annular cavity made between the sleeve and the housing, a shut-off valve is fixed on the sleeve, in the housing of which an axle and second radial ball channels and set the water seal.  5. Installation according to claim 1, characterized in that it additionally has a filter.

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