RU2589442C1 - Downhole source of plasma-pulse action - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: borehole pulse plasma source comprises a housing accommodating control unit, energy storage unit and plasma emitter, device for supply of metal conductor mounted on a separate base and including means of drawing metal conductor, motion transmission means and reel with metal conductor wound thereon. Device for supply of metal conductor is located in sealed housing and is configured for rigid connection with plasma emitter, means of drawing metal conductor is made in form of movable and fixed modules with U-shaped slots in which there are through recesses to accommodate guide plates, and at ends of protrusions there are lugs for attachment of axes therein, on which there are sharpened cams with torsion springs enabling swinging of cams on axis. Guide plates can move vertically and can be fixed in a preset position in through recesses of movable and fixed modules, and at ends of guide plates there are grooves for direction of metal conductor.

EFFECT: higher reliability of well source of plasma-pulse action.

19 cl, 6 dwg

Description

FIELD OF TECHNOLOGY

The invention relates to the oil and gas industry, mainly to downhole geophysical instruments.

BACKGROUND

From SU 247530 A1, publ. 11.28.1969, a borehole source of elastic vibrations is known, comprising a borehole projectile connected to a ground cable with a ground control unit, in which an energy storage device, a charger, a spark gap with an ignition circuit, an electrohydropulse spark gap with two electrodes, a device for supplying a metal wire to the working interelectrode space, including a wire storage drum, a wire pulling mechanism driven by a solenoid armature, a dog pusher, a solenoid connected to the armature a, ratchet wheels in contact with the dogs, spring-loaded broaching rollers mounted on the same axis as ratchet wheels and a return spring connected to the solenoid armature. To ensure stable generation of electrohydropulse discharges, an exploding wire is used in this source, which previously closes the gap between the electrodes. When a voltage pulse is applied to the discharge gap closed by a wire, the wire explodes, forming a plasma channel that initiates the discharge.

The main disadvantage of this borehole source of elastic vibrations is the complexity of the design of the wire drawing mechanism and its low reliability. In addition, the current in the discharge circuit of the storage capacitors is not controlled in the indicated source. The process of charging the storage capacitors is carried out through the conductive fluid of the well, located between the electrodes of the electrohydropulse spark gap, and practically does not depend on the closure of the electrode gap by a wire. If the gap is not closed by a wire, then when the ignition circuit and the spark gap are triggered, the storage capacitors are discharged through a conductive liquid in the gap between the electrohydroimpulse spark gap electrodes. In this case, the energy stored in the capacitors is spent on heating the conductive liquid and dissipated in the surrounding space. In this case, elastic vibrations do not occur and there is no effect on the bottomhole zone of the wells. In order to achieve the necessary efficiency of using a downhole source of elastic vibrations, it is necessary to increase the number of working pulses, which will require additional energy costs.

The closest analogue of the claimed invention is a borehole source of elastic vibrations disclosed in RU 2248591, publ. 03/20/2005. The well-known source of elastic vibrations known from the closest analogue is made in the form of a downhole projectile, in which an energy storage device, a charger, an electrohydropulse spark gap with two electrodes and a device for supplying a metal wire into the working interelectrode space of the spark gap are located. The wire pulling mechanism includes two metal plates fixed by the ends on the diametrically opposite sides of the rod and pressed by the opposite pointed ends by means of springs to the wire, which is located on the guide pad. The plates are oriented at an acute angle to the wire, which ensures their alternate engagement with the wire and movement towards the working space of the arrester due to the reciprocating antiphase movement of the pointed ends of the plates during the reciprocating movement of the rod connected by a rod and a swinging arm with a movable armature of the solenoid . A drum serves as a supply of wire. At the same time, the solenoid and the swinging lever connected through the rod with its anchor are located on one side of the dielectric plate, and the drum and pushing plates with pointed ends, the guide pad for the wire and the rod are located on the other side of the dielectric plate, and the shaft shank passes through the hole in the latter.

The disadvantages of this device include low reliability, high labor costs for adjusting the wire feed mechanism, relatively large dimensions of the structure in diameter and the inability to fit it into the limited dimensions of a downhole tool designed to work in deviated horizontal wells, which reduces the versatility and limits the scope of the device .

SUMMARY OF THE INVENTION

The objective of the claimed invention is to develop a borehole source of plasma-pulse exposure, which reduces the complexity of preparing for the operation of the device and its maintenance, as well as improving the reliability of the device.

The technical result of the invention is to increase the reliability of the downhole source of plasma-pulse exposure.

The specified technical result is achieved due to the fact that the downhole plasma-pulse source contains a housing in which a control unit, an energy storage device and a plasma emitter are located, a metal conductor feed device mounted on a separate base and containing a metal conductor pulling means, motion transmitting means and a reel with a metal conductor wound around it. The feed device of the metal conductor is located in a sealed casing and is made with the possibility of hard connection with a plasma emitter. Moreover, the means of pulling the metal conductor is made in the form of a movable and stationary modules with U-shaped grooves, in which there are through slots for accommodating guide plates, and at the ends of the protrusions there are eyes for fixing axes on them, on which pointed cams with torsion springs are located providing the ability to swing the cams on the axis. In this case, the guide plates are arranged to move vertically and be fixed in a predetermined position in the through slot of the movable and fixed modules, and grooves are made at the ends of the guide plates for guiding the metal conductor.

The axes of the pointed cams in the eyes are fixed using removable clamps.

The fixed and movable modules are arranged to accommodate guide inserts with U-shaped grooves in their grooves.

Through holes are made in the guide inserts for moving the metal conductor.

The guide inserts are arranged to move vertically and fix in a predetermined position in the U-shaped groove of the movable and fixed modules.

The guide inserts are designed to swing in their grooves of pointed cams.

The motion transmission means is made in the form of a solenoid with an armature connected to a pusher containing an insulator and a spring through an extension cord.

The solenoid with the anchor is fixed in the shell containing the front and rear walls.

The front wall of the sheath is rigidly connected to the base of the means for pulling the metal conductor.

A plug is rigidly fixed to the back wall of the shell, which is configured to fasten bobbins to it with a metal conductor wound on it.

A reinforcing ring is attached to the fork.

The movable module is rigidly fixed to the pusher.

The pusher is rigidly fixed to the base of the pulling means of the metal conductor.

The fixed module is rigidly connected to the base of the pulling means of the metal conductor.

The reel is equipped with a brake in the form of a curved plate with a torsion spring.

The sealed casing of the metal conductor feed device is filled with mineral oil.

The downhole source housing is configured to be rigidly connected to a cable head containing a geophysical cable and connected to a control unit.

The base of the pulling means of the metal conductor is configured to be rigidly connected to the centering device.

An anchor is provided with a through hole for moving a metal conductor containing a plastic tube.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be more clear from the description, which is not restrictive and given with reference to the accompanying drawings, which depict:

FIG. 1 is a general view of a borehole source of plasma-pulse exposure;

FIG. 2 is a general view of a metal conductor feed device;

FIG. 3 is a longitudinal section through a metal conductor feed device;

FIG. 4 is a cross section of a fixed module;

FIG. 5 is a general view of a movable module;

FIG. 6 is a general view of a fixed module.

1 - control unit; 2 - energy storage; 3 - plasma emitter; 4 - feed device of a metal conductor; 5 - centering device; 6 - cable head; 7 - geophysical cable; 8 - the base means of pulling a metal conductor; 9 - fixed module; 10 - movable module; 11 - pointed cams; 12 - a guide plate; 13 - torsion spring; 14 - removable clamps; 15 - guide insert of a fixed module; 16 - guide insert of the movable module; 17 - a pin; 18 - locking screw; 19 - a spring of a pusher; 20 - a pusher; 21 - an insulator; 22 - anchor extension; 23 - a plastic tube; 24 - solenoid; 25 - solenoid anchor; 26 - front wall of the shell of the solenoid; 27 - the shell of the solenoid; 28 - the back wall of the solenoid shell; 29 - fork; 30 - reinforcing ring; 31 - metal conductor; 32 - a reel with a metal conductor wound around it; 33 - reel brake; 34 - a lock-nut; 35 - screw; 36 - locking screw; 37 - sealed casing.

DETAILED DESCRIPTION OF THE INVENTION

The downhole plasma-pulse source contains a housing in which a control unit (1) is located, containing a modem for communication with a ground control panel, a high-voltage transformer and a voltage multiplier, an energy storage device (2) containing parallel-connected capacitors and a contactor-discharger, a plasma emitter ( 3) containing high-voltage and low-voltage electrodes, a device (4) for supplying a metal conductor mounted on a separate base (8) and containing means for pulling a metal conductor, motion transmission means and a reel (32) with a metal conductor (31) wound on it in the form of a calibrated wire. In this case, the device (4) for supplying a metal conductor is located in a sealed casing (37) and is made with the possibility of hard connection with a plasma emitter (3). Moreover, the means of pulling the metal conductor is made in the form of a movable (10) and fixed (9) modules with U-shaped grooves, in which there are through slots for placement of guide plates (12) in them, and at the ends of the protrusions there are eyes for fixing axes in them on which the pointed cams (11) with torsion springs (13) are located, providing the possibility of swinging the pointed cams (11) on the axis. In this case, the guide plates (12) are made with the possibility of vertical movement and fixing in a predetermined position in the through slot of the movable (10) and fixed (9) modules, and grooves are made at the ends of the guide plates (12) to guide the metal conductor (31).

The axis of the pointed cams (11) in the eyes is fixed using removable clamps (14).

The fixed (9) and movable (10) modules are made with the possibility of placing guide inserts (15, 16) in their grooves with a U-shaped groove for moving a metal conductor (31) in it.

In the guide inserts (15, 16), through holes are made for moving the metal conductor.

The guide inserts (15, 16) are made with the possibility of vertical movement and fixing in a predetermined position in the U-shaped groove of the movable (10) and stationary (9) modules.

Guide inserts (15, 16) are made with the possibility of swinging in their grooves of pointed cams (11).

The motion transmission means is made in the form of a solenoid (24) with an armature (25) connected to a pusher (20) containing an insulator (21) and a spring (19) through an extension cord (22).

A solenoid (24) with an anchor (25) is fixed in the shell (27) containing the front (26) and rear (28) walls.

The front (26) wall of the shell (27) is rigidly connected to the base (8) of the means for pulling the metal conductor (31).

A plug (29) is rigidly fixed to the rear wall wall (28) of the shell (27), which is configured to fasten bobbins (32) to it with a metal conductor wound on it (31).

A reinforcing ring (30) is fixed to the fork (29).

The movable (10) module is rigidly fixed to the pusher (20).

The pusher (20) is rigidly fixed to the base (8) of the pulling means of the metal conductor (31).

The fixed (9) module is rigidly connected to the base (8) of the pulling means of the metal conductor (31).

The bobbin (32) is equipped with a brake (33) in the form of a curved plate with a torsion spring (13).

The sealed casing (37) of the metal conductor feeder (31) is filled with mineral oil.

The downhole source housing is configured to be rigidly connected to a cable head (6) containing a geophysical cable (7) and connected to a control unit (1).

The base (8) of the pulling means of the metal conductor (31) is made with the possibility of hard connection with the centering device (5).

An anchor (25) has a through hole for moving a metal conductor (31), containing a plastic tube (23).

Downhole source of plasma-pulse exposure works as follows.

In accordance with FIG. 1-6 from the ground control panel via a geophysical cable using control units (1) and an energy storage device (2), voltage pulses are applied to the solenoid (24), which reciprocates the armature (25) and the associated pusher (20), which in turn reports reciprocating motion to the movable module (10). When moving the latter in the feed direction of the metal conductor (31), i.e. towards the plasma emitter (3), the cam located in it (11) stands upright and cuts the tip into the body of a metal conductor (31) lying in the groove of the guide plate (12). Thus, the metal conductor (31) advances by the amount of travel of the armature (25). At this time, the cam (11) located in the stationary module (9) slides along the surface of the advancing metal conductor (31), pressed against it by a torsion spring (13) and not preventing it from moving. When the movable module (10) is returned, the cam (11) belonging to it slides along the metal conductor (31) without dragging it along, and the cam (11) of the stationary module (9) becomes aback, crashing into the body of the metal conductor (31) and fixing it during idling of the movable module (10). Then the process is repeated.

The degree of adhesion of the cams (11) to the metal conductor (31) is regulated by moving the guide plates (12) in height, after which they are fixed with locking screws (18) with locknuts (34) on both sides. To maintain coaxiality, the groove of the guide plate (12) and the passage hole for the metal conductor (31), the guide inserts (15, 16) of the fixed (9) and movable (10) modules, respectively, are also height-adjustable and fixed with locking screws (36).

The brake (33) prevents the unwanted inertial rotation of the bobbin (32), constantly pressing with the torsion spring (13) to the turns of the metal conductor (31).

The number of operation pulses of the solenoid (24) required to close the electrodes of the plasma emitter with a metal conductor (31) is determined empirically in preparing the device for operation.

At the end of the operation of the device (4) for supplying a combustible metal conductor from the ground panel, a command is sent to increase the voltage and accumulate electric energy in the capacitor block of the energy storage device (2). Upon reaching the required level of charge of the capacitors, which is controlled by the ground control panel, a command is issued to operate the contactor-discharger, which supplies a high voltage pulse to the high-voltage electrode of the plasma emitter (3). Instantaneous heating of the metal conductor (31), its evaporation, explosion, and the formation of a plasma channel in the interelectrode space of the emitter (3) occurs, and a shock wave is formed that propagates in the borehole fluid and in the skeleton of the reservoir.

Compared with the closest analogue, the use of movable and fixed modules with pointed spring-loaded cams allows excluding kinematic links of the mechanism from the design, such as a swinging lever, pusher, carrier (rotating rod), articulated joints, and minimizing the probability of mismatch of the antiphase movement of the pushing pointed elements, which provides increased reliability of the device. In addition, the arrangement of the parts of the mechanism in the axial direction, allows to reduce the diametrical dimension of the device, which expands the scope of the device as a whole, for example, in deviated horizontal wells.

When blunt cams are blunt, the exact positioning of the guide plates and the pointed cams is not ensured, which leads to unreliable adhesion of the cams to the metal conductor and makes it difficult to feed the metal conductor to the plasma emitter. The use of guide plates in a fixed and movable module with the ability to move them vertically and with fixation in a predetermined position allows for accurate mutual positioning of the guide plates and pointed cams, leading to reliable coupling of the cams with a metal conductor, which increases the reliability of the device.

The use of a brake in a bobbin with a metal conductor wound around it ensures the inertia rotation of the bobbin is excluded during the reciprocating movement of the bobbin, as a result of which wire loops are formed, which causes tangling of the latter and jamming of the metal wire feed device, therefore, the use of a bobbin with a brake provides increased reliability device operation.

Thus, the present invention allows to obtain a borehole source of plasma-pulse exposure, which allows to increase the reliability of its operation.

The invention has been disclosed above with reference to a specific embodiment. Other specialists may be obvious to other embodiments of the invention, without changing its essence, as it is disclosed in the present description. Accordingly, the invention should be considered limited in scope only by the following claims.

Claims (19)

1. A downhole source of plasma-pulsed action, comprising a housing in which a control unit, an energy storage device and a plasma emitter are located, a metal conductor feed device mounted on a separate base and containing a metal conductor pulling means, a motion transmission means and a bobbin with a metal wound thereon a conductor, while the feed device of the metal conductor is located in a sealed casing and is made with the possibility of hard connection with plasma radiation atelier, moreover, the means for pulling the metal conductor is made in the form of movable and fixed modules with U-shaped grooves, in which there are through slots for placement of guide plates in them, and at the ends of the protrusions there are eyes for fixing axes on them, on which pointed cams with torsion springs, providing the ability to swing the cams on the axis, while the guide plates are arranged to move vertically and fix in a predetermined position in the through slot IG Petritskaya and fixed modules and at the ends of the guide plates are made grooves for guiding the metal wire. 2. The downhole source according to claim 1, characterized in that the axis of the pointed cams in the eyes are fixed using removable clamps. 3. The downhole source according to claim 1, characterized in that the fixed and movable modules are arranged to place guide inserts with a U-shaped groove in their grooves. 4. The downhole source according to claim 3, characterized in that through holes are made in the guide inserts for moving the metal conductor. 5. The downhole source according to claim 4, characterized in that the guide inserts are arranged to move vertically and fix in a predetermined position in the U-shaped groove of the movable and fixed modules. 6. The downhole source according to claim 5, characterized in that the guide inserts are made with the possibility of swinging in their grooves of pointed cams. 7. The downhole source according to claim 1, characterized in that the motion transmission means is made in the form of a solenoid with an armature connected to a pusher containing an insulator and a spring through an extension cord. 8. The borehole source according to claim 1, characterized in that the solenoid with the anchor is fixed in the shell containing the front and rear walls. 9. The downhole source according to claim 8, characterized in that the front wall of the shell is rigidly connected to the base of the means for pulling the metal conductor. 10. The borehole source according to claim 8, characterized in that a plug is rigidly fixed to the rear wall of the shell, configured to fasten bobbins to it with a metal conductor wound thereon. 11. The downhole source according to claim 10, characterized in that a reinforcing ring is fixed to the plug. 12. The downhole source according to claim 7, characterized in that the movable module is rigidly mounted on the pusher. 13. The downhole source according to claim 12, characterized in that the pusher is rigidly fixed on the basis of the means of pulling a metal conductor. 14. The downhole source according to claim 1, characterized in that the fixed module is rigidly connected to the base of the means for pulling the metal conductor. 15. The downhole source according to claim 10, characterized in that the reel is equipped with a brake in the form of a curved plate with a torsion spring. 16. The downhole source according to claim 1, characterized in that the sealed casing of the metal conductor feed device is filled with mineral oil. 17. The downhole source according to claim 1, characterized in that the downhole source housing is configured to be rigidly connected to a cable head containing a geophysical cable and connected to a control unit. 18. The downhole source according to claim 1, characterized in that the base of the means for pulling the metal conductor is made with the possibility of a rigid connection with a centering device. 19. The downhole source according to claim 7, characterized in that a through hole for moving a metal conductor containing a plastic tube is made in the anchor.

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