RU2147336C1 - Device for hydraulic-pulse treatment of bed - Google Patents

Abstract

FIELD: oil and gas production industry. SUBSTANCE: device has string of pump-compressor pipes, implosive chamber with pressure concentrators and with windows. Plunger with actuator and spring-biased valve is installed in implosive chamber. Device is provided with upper adapter and lower adapter both having branching passages. Upper adapter is secured on string of pump-compressor pipes, lower adapter is fastened on implosive chamber. Plunger has through-holes, radial passage and distributing mechanism. Distributing mechanism is made up of spring-biased pusher with circular groove, seat, and spring-biased locking member with throttling hole. Lower part of plunger in combination with throttling hole both create intermediate space. Actuator of plunger is made in the form of at least one hydraulic cylinder with hollow rod and with piston rigidly secured on rod. Hydraulic cylinder is provided with reversing switch. Hydraulic cylinder is located between upper adapter and lower adapter. Rod is installed in adapters and can move vertically. Lower end of rod is secured in plunger, upper end of rod is located in pump-compressor pipe. When liquid is delivered into string of pump-compressor pipes, device produces hydraulic impacts in bottom-hole zone of well. Pressure of hydraulic impacts exceeds rock pressure. Instantaneous hydraulic impacts produced by embodiment of device increase positive action brought to bear on bottom-hole zone of well. EFFECT: higher efficiency. 1 cl, 2 dwg

Description

 The invention relates to devices used in the oil and gas industry, mainly for pulsed impact on the bottomhole zone to increase oil recovery.

 A device for hydraulic explosion (see A.S. N 956766, E 21 B 43/26, 1980), including a tubing string, a packer with a check valve installed in it, communicating the under-packer space with the over-packer, installed in a string of saddle tubes under the throttle valves, the diameter of the upstream saddle being larger than the previous one.

 However, the known device has a low efficiency of hydroshock impact on the reservoir, because the value of the instantaneous hydraulic shock created by the fall of the liquid column will be significantly lower than necessary due to shock absorption by compressed air in the under-packer space. The non-return valve installed in the packer does not provide instant air flow into the over-packer space due to a sufficiently small passage of the valve cross-section.

 The closest in technical essence and the achieved result to the claimed device is a multiple implosion device (see. "Impact effects on the bottom hole zone of the wells", by A. A. Popov-M .: Nedra, 1990, p. 106), lowered into a well to the formation on tubing and consisting of an implosion chamber with an upper expanded part and pressure concentrators, a plunger rigidly fixed to the rope, and a spring-loaded valve installed in the lower part of the device.

 However, the effectiveness of the known device is low, because hydraulic shock force is lower than the value necessary for impacting the bottom-hole formation zone for its hydraulic fracturing. This is due to the fact that the drive of the plunger (winch of the tractor-lift) does not provide instantaneous speed of rise of the plunger, because as it rises, from the moment the lower end of the plunger reaches the upper expanded part of the implosion chamber, only the passage opening of the chamber is slowly opened and, accordingly, the liquid flows slowly both from the pipe string and from the annulus into the lower part of the chamber.

 The inventive device solves the problem of increasing the effectiveness of the impact on the bottomhole formation zone by creating an instant hydraulic shock.

 To solve this problem, a device for hydro-pulse treatment of a formation containing a tubing string, an implosion chamber with pressure concentrators and windows, a plunger with an actuator and a spring-loaded valve is equipped with an upper and lower sub with outlet channels mounted respectively on the tubing string and an implosion chamber, wherein the plunger is provided with slotted holes, a radial channel and a distribution mechanism, and the plunger drive is made in the form of at least one about a hydraulic cylinder with a hollow rod and a piston rigidly fixed to the rod with a reversing switch, and the hydraulic cylinder is located between the upper and lower sub, and the rod is installed in the sub with the possibility of vertical movement, the lower end of the rod is fixed in the plunger, and the upper end is located in the tubing , the distribution mechanism is made in the form of a spring-loaded pusher with an annular groove, a saddle and a spring-loaded locking element with a throttling hole, forming with the lower part unzhera transition cavity.

 In FIG. 1 shows a General view of the device, a section; in FIG. 2 - reversible switch in an enlarged view.

 The device impulse stimulation on the reservoir contains an implosion chamber 1 with pressure concentrators 2 and windows 3, a spring-loaded valve 4 and a plunger 5 with slotted holes 6, a radial channel 7 and a distribution mechanism consisting of a spring-loaded pusher 8 with an annular groove 9 located in the chamber 1 10 and a spring element 11 with a throttling hole 12, forming with the lower part of the plunger 5 the transition cavity 13, the upper sub 14 with the outlet channel 15, connected with the column of tubing 16, and a lower sub 17 with an outlet channel 18 connected to the implosion chamber 1, a hydraulic cylinder 19 located between the sub 14 and 17.

 The hydraulic cylinder 19 is made with a hollow rod 20 and a piston 21 rigidly mounted on the rod 20. The piston 21 is equipped with a reversing switch, consisting of a spool 22 with annular grooves 23 and 24, mounted with axial movement, and channels 25, 26, 27. The hollow rod 20 is installed in the sub 14 and 17 with the possibility of vertical movement. One end of the rod 20 is located in the tubing 16, and the other in the implosion chamber 1 and is rigidly fixed to the plunger 5.

 The device operates as follows.

 The upper sub 14 is connected to the tubing string 16. In this case, the hollow rod 20 with the piston 21 is in its lowest position. The spool 22 of the reversing switch is in its highest position, interacting with the upper end of the lower sub 17, and closes channel 27. Channel 25 is connected through channel 23 to channel 26. Plunger 5 is in its lowest position. The spring-loaded plunger 8 is in its highest position, blocking the radial channel 7. The locking element 11 and the spring-loaded valve 4 are in the highest position.

 In this form, the device on the tubing string 16 is lowered into the well. Well pipe fluid is supplied into the pipe string 16 from the wellhead under pressure, which enters the rod cavity 20 and passes through the channel 25 through the groove 23 and the reversing switch channel 26 into the lower cavity of the hydraulic cylinder 19, and through the throttling hole 12 into the cavity 13 of the shut-off element 11 .

 In this case, the annular fluid through the drainage channels 15 and 18 fills the upper cavity of the hydraulic cylinder 19 and the upper cavity of the implosion chamber 1, respectively.

 When the fluid pressure in the lower cavity of the hydraulic cylinder 19 reaches the value necessary to overcome the annular fluid pressure, the piston 21 begins to move upward together with the stem 20 and the plunger 5 attached to it. In this case, a low pressure zone is formed between the plunger 5 and the spring-loaded valve 4. In the process of moving the piston 21 upward, the lower cavity of the hydraulic cylinder 19 is filled with well fluid, and the upper cavity of the hydraulic cylinder 19 and the upper cavity of the implosion chamber 1 are freed from the annular fluid through the outlet channels 15 and 18 of the sub 14 and 17.

 When the piston 21 reaches its extreme upper position, the pusher 8, interacting with the end face of the sub 17, moves downward relative to the plunger 5. In this case, the annular groove 9 of the pusher 8 is aligned with the radial channel 7. The fluid from the cavity 13 instantly flows into the lower cavity (plunger) of the implosion chamber 1 with low pressure. This leads to a pressure drop in the transition cavity 13 of the locking element 11, which drops sharply, opening the holes 6 of the plunger 5. The fluid from the tubing 16 rushes into the lower cavity of the implosion chamber 1, creating an instantaneous hydraulic shock with a pressure exceeding mountainous.

 At the time of water hammer under pressure of fluid flow, valve 4 is pushed down, windows 3 open and water hammer is transmitted to the formation. In this case, pressure compensators 2 prevent the propagation of a shock wave in the upper and lower annular spaces.

 At the same time, the spool 22, interacting with the lower end of the sub 14, moves downward relative to the piston 21, closes the channel 25 and opens the channel 27. The downhole fluid begins to flow through channels 26 and 27 into the upper cavity of the hydraulic cylinder 19. The piston 21 with the rod 20 and plunger 5 begin to move down (to the starting position). Further, the process is repeated many times.

 Thus, the claimed device allows you to get instant hydraulic shock, due to which the bottomhole pressure acting on the bottomhole formation zone for its hydraulic fracturing increases.

Claims (2)

 1. The device impulse action on the reservoir containing the string of tubing, an implosion chamber with pressure concentrators and windows, a plunger with an actuator and a spring-loaded valve, characterized in that it is equipped with upper and lower sub with outlet channels mounted respectively on the column of the pump compressor pipes and an implosion chamber, wherein the plunger is provided with slotted holes, a radial channel and a distribution mechanism, and the plunger drive is made in the form of at least one gy a cylinder with a hollow rod and a piston rigidly fixed to the rod with a reversing switch, the hydraulic cylinder located between the upper and lower sub, and the rod installed in the sub with the possibility of vertical movement, the lower end of the rod is fixed in the plunger, and the upper end is located in the tubing.  2. The device according to claim 1, characterized in that the distribution mechanism is made in the form of a spring-loaded pusher with an annular groove, a saddle and a spring-loaded locking element with a throttling hole, forming a transition cavity with the lower part of the plunger.

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