RU2572262C1 - Device for vibro-wave bottom-hole treatment of oil formation - Google Patents

Abstract

FIELD: oil and gas industry.SUBSTANCE: device comprises rigidly fixed cup (1) with slanting slotted cuts (2) and mounting thread (3) in the upper part for connection with tubing string (not specified). Inner diameter of cup (1) is designated as d. In the bottom part (4) of cup (1) there is straight hole (5) with diameter d1. From outside of the cup (1) there is spool valve (6) with slanting slotted cuts (7). At the valve (6) cuts are made in opposite direction relative to slots (2) of cup (1), thus forming turbine device with slots (2) of cup (1) serving as guide vanes and cuts (7) of the spool valve (6) serving as the impeller. The spool valve (6) is mounted at ball bushings (8). In order to reduce loss of working fluid fluoroplastic ring (9) is used. Ball (10) with diameter d2 has end-to-end channels (11) in three mutually perpendicular planes. Ball (10) ensures opening of feedthrough bottom hole (5) and fluid direction into working ports of the device.EFFECT: device ensures high efficiency of vibro-wave treatment of the formation bottom-hole by periodic impact of wave pulses of working fluid hydraulic shocks with the preset frequency as well as exclusion of round-trip operations and downtime of the well.2 dwg

Description

The invention relates to the field of oil and gas industry and can be used in the production of liquid and gaseous hydrocarbons to maintain reservoir pressure by pumping a working agent into the reservoir through it.

A device is known that provides a cyclic effect on the bottomhole formation zone (Allakhverdiev R.A. Intensification of inflow by the method of cyclic pulsed impact on the bottomhole formation zone // RNTS. Ser. Oilfield business and oil transportation, 1985, issue 3, p. 10-12) using cyclic injection and pressure relief from the well. As the working fluid use a fluid with the addition of surfactants.

A disadvantage of the known device is that it is ineffective with a large filter length and requires significant labor costs, since it affects only the most permeable part of the formation. Low-permeable or stratified parts of the formation remain unaffected by treatment.

Also known is a device for processing a bottomhole formation zone, including a body with channels. A spring-loaded differential piston and a check valve concentrically mounted in the housing are provided with a seat for seating the differential piston and connected to the differential piston with the possibility of telescopic connection (RU 2102577, published on 01.20.1998).

The disadvantage of this device is that it cannot be installed and removed without lowering and lifting the tubing, as well as changing the frequency of the generated pulses without changing their impact characteristics. A significant drawback is that the impact on the bottomhole formation zone by this device is carried out for a short time only during the repair work.

Closest to the claimed is a device of the microwave action on the bottomhole zone of the oil reservoir, including a hydraulic spool type vibrator, which creates pressure fluctuations due to periodic shutoff of the fluid flow by the spool, which consists of a housing in which the barrel is rigidly fixed in the form of a glass with slit-like slots on it generatrix. There is a hole at the bottom of the cylinder. On the barrel, a spool rotates with slit-like slots along the generatrix. The slots in the trunk and spool are made at a certain angle to their generators. The directions of the slots in the barrel and spool are opposite (Mineev B.P., Sidorov N.A. Practical Guide to Testing Wells, Moscow, Nedra, 1981, pp. 145-146).

The optimal (resonant) mode of operation of the prototype device is achieved when the flow rate of the working fluid is 24-26 l / s, which is established in the process of field tests. To create such a flow rate, it is necessary to have 3-4 pump units.

If there is one pumping unit of the type CA-320 with a working fluid capacity that it can develop (8-10 l / s), the prototype will not be able to reach the optimal operating mode. At this flow rate, the magnitude of the generated hydraulic pulses (pressure amplitude, pulse repetition rate) is insufficient for high-quality cleaning of the bottom-hole formation zone.

With an increase in fluid flow from 5 to 25 l / s for a known device, the pressure amplitude increases from 0.8 to 15 MPa. With a further increase in flow rate, the magnitude of the pressure amplitude of the hydrodynamic pulses decreases. Accordingly, depending on the flow rate, the frequency of hydraulic pulses varies from 35-40 to 200-500 Hz. Ensuring a given flow rate of the working fluid is necessary when generating a shock pulse and, therefore, to increase the effectiveness of the impact on the bottom-hole formation zone. That is, at a flow rate of 8-10 l / s, the required efficiency from processing is not achieved. In addition, difficulties arise when starting the device into operation, when creating the initial torque for rotation of the spool.

Thus, the disadvantage of the known device is the low efficiency, since it does not provide the formation of pulsed hydraulic shocks at optimal flow rates of the working fluid for high-quality treatment of the bottom-hole formation zone. In addition, installation and removal of the device requires the operation of lowering and lifting the tubing, which entails a simple well.

The technical result consists in creating a device design that provides high efficiency of the microwave processing of the bottom-hole formation zone by periodically applying hydraulic impulses to it of hydraulic shocks of the working fluid of a given frequency, as well as eliminating tripping and downtime of the well.

The essence of the invention lies in the fact that in the device of the microwave exposure to the bottom-hole zone of the oil reservoir, including a glass with oblique slit-like slots, on which a cylindrical spool with oblique slit-like slots made in the opposite direction relative to the cuts of the glass, and in the lower part of the glass a bottom passage hole is made, the diameter of the bottom hole of the glass is 0.79-0.81 of the inner diameter of the glass, and a ball is placed in the glass with the possibility of its displacement inside the cup and covering its bottom opening, and the ball is formed with through channels in three mutually perpendicular planes.

Placing a ball with through channels in three mutually perpendicular planes inside the glass allows you to block the bottom hole of the glass and provide periodic impact of wave pulses on the bottom of the well when flowing through the channels of the working fluid, that is, to increase the number and strength of periodic wave disturbances in the bottom caused by pressure drop during overlap bottom hole ball.

Hydraulic impulse shock will be accompanied by a rise in pressure and contribute to a sharp impulse outflow of the working fluid from the ball channels. The formation of a pulsed hydraulic shock with a frequency from 100 to 400 Hz, which is necessary for effective cleaning of the bottom-hole zone of the formation from colmatant, at optimal flow rates of the working fluid, is possible if a ball is used in the structure that covers the bottom hole and provides an additional impact effect.

Due to the free movement of the ball inside the glass after the cessation of the indicated operation, the ball is “washed” to the surface during the backwash of the well, which eliminates the descent-lifting operations of the tubing with the claimed device and thereby avoids the downtime of the well. The efforts made to “wash” the ball are minimal if the diameter of the bottom hole of the glass is 0.79-0.81 of the inner diameter of the glass. If this ratio is less than 0.79, then the efforts will increase and the efficiency will drop, if it is more than 0.81, then the ball will not be able to move freely along the glass.

The implementation of the through channels of the ball in three mutually perpendicular planes is necessary in order to ensure the overlapping of the passage bottom hole and the periodic impact of wave pulses on the bottom of the well when flowing through the channels of the working fluid to increase processing efficiency.

In FIG. 1 schematically shows the inventive device in the operating position (side view), FIG. 2 is a section A-A in FIG. one.

The inventive device contains a rigidly fixed glass 1 with oblique slit-shaped slots 2 and a fastening thread 3 in the upper part for connection with tubing (not shown). The inner diameter of the cup 1 is indicated by d. In the bottom part 4 of the glass 1 there is a cylindrical hole 5 with a diameter of d1. A cylindrical spool 6 with oblique slit-shaped slots 7 is installed on the outside of the glass 1.

On the spool 6, the slots are made in the opposite direction relative to the slots 2 of the cup 1, which forms a turbine device, in which the guiding device is the slots 2 of the cup 1, and the impeller is the slots 7 of the spool 6. The spool 6 is mounted on ball bearings 8. To reduce leakage of the working Fluoropolymer ring 9 is used.

A ball 10 of diameter d2 has through channels 11 in three mutually perpendicular planes. Ball 10 provides for the closure of the passage bottom hole 5 and the direction of the fluid in the working holes of the device.

The device operates as follows.

The device is rigidly fixed to the string of tubing at the beginning of operation and lowered to the bottom of the well to conduct a microwave exposure. Ball 10, sinking in the working fluid (the composition is established for each field and for each well by the team of the current well repair), moves freely in the cup 1 and closes the bottom cylindrical hole 5. When pumping the working fluid, the spool 6 due to its outflow from the slit-shaped openings 7 starts rotate and shut off the flow of the working fluid, as a result of which hydraulic shocks are formed, the frequency of which depends on the number of slots and the rotation frequency of the spool 6.

Water hammer is accompanied by an increase in pressure, which contributes to a sharp pulse outflow of fluid from the through channels 11 of the ball 10. In addition, the periodic outflow of fluid from the slots 7 during rotation of the spool 6 creates cyclic fluctuations in the environment.

With an increase in the flow rate of the working fluid from 5 to 15 l / s, the frequency of hydraulic pulses varies from 100 to 400 Hz. Resonant water hammer occurs at the optimum flow rate of the working fluid, above which the pressure amplitude decreases at a frequency of 200-220 Hz. The optimal mode of operation of the vibrator with a frequency of 200-220 Hz is achieved with a flow rate of 7-9 l / s, which can provide one pump unit type CA-320.

At the end of the vibrating microwave action, the ball 10 is “washed” to the surface by the backwash method. The well returns to normal operation.

Such a microwave action provides an effective cleaning of the bottomhole formation zone from the mud.

Claims (1)

The device of the microwave action on the bottomhole zone of the oil reservoir, including a glass with oblique slit-like slots, on which a cylindrical spool with oblique slit-like slots made in the opposite direction relative to the cuts of the glass is rotatably placed, and a bottom passage hole is made in the lower part of the glass, characterized in that the diameter of the bottom hole of the glass is 0.79-0.81 of the inner diameter of the glass, and in the glass there is a ball with the possibility of its movement inside glass and overlapping its bottom holes, and the ball is made with through channels in three mutually perpendicular planes.

Images