RU2320866C2 - Device for hydroimpulsive well bottom zone treatment - Google Patents

Abstract

FIELD: oil production, particularly to stimulate oil production by repeated hydroimpulsive reservoir treatment.

SUBSTANCE: device comprises flow string 1, implosion chamber 11 with piston arranged in it. Upper implosion chamber 11 is communicated with expanded pipe 9 provided with windows 10. Lower implosion chamber end has spring-loaded valve 13. Valve 13 is arranged in body 12 having windows 14 and pressure raisers 15. Device also has hydraulic cylinder 4 installed between flow string 1 and expansion pipe 9. Arranged in hydraulic cylinder 4 is piston 5 secured to piston 8 of implosion chamber 11 and spring-loaded with return spring 17 from top thereof. Blind side of hydraulic cylinder is communicated with hole annuity. Rod end of hydraulic cylinder is provided with pipeline 16 for working liquid delivery from flow string 1.

EFFECT: increased efficiency and reliability of repeated hydroimpulsive bottomhole reservoir zone treatment and possibility of device usage in horizontal and inclined wells.

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Description

The invention relates to the oil industry and can be used to increase oil recovery in producing wells with multiple hydro-pulse stimulation.

Currently, devices are known that provide multiple hydro-pulse effects on the bottomhole zone of the well [Patent for invention RU 2254456 from 06.20.2005, 1. The device includes a cylindrical pump casing with an inlet in the upper part that is plugged in the lower end part and connected in the upper part to the tubing. A plunger with a cylindrical lateral surface and with a diameter equal to the inner diameter of the pump casing with an inlet in the upper part and an outlet with a check valve in the bottom is installed with the possibility of reciprocating movement.

Closest to the claimed invention is a device described in the work of A. Popov. “Impact effects on the bottomhole zone of wells”. - M .: Nedra, 1990, pp. 106-109, where an implosion generator of reusable action is considered.

The device consists of an implosion chamber, a plunger, a valve with a spring, a housing with windows for fluid outlet, pressure concentrators and an expanded part with windows for fluid inlet.

The principle of operation of the device is that when the plunger is raised to the expanded part into the chamber in which the vacuum is created, the liquid column collapses, creating a pressure pulse in the area of the case windows and a depression pulse in the expanded part with windows for liquid inlet.

The plunger is lifted using standard mechanisms (lifting unit A-50M, LT-11 KM, A-50 U or similar). The plunger is attached to the winch either with a hose system Ф 16 mm or a cable Ф 16 mm, while the load on the rods or cable due to pressure on the plunger (under the plunger is a vacuum) is ~ 3-10 ⁴ I (3 tf) at well depth 2.5 km. The return stroke of the plunger is carried out due to the weight of the rod string.

The impact on the reservoir is repeated many times (10-100 times), after which, if necessary, the tubing (tubing) together with the hydrogenerator is raised to the next section of the reservoir and the impact is repeated.

In all the described devices for hydroimpulse stimulation of the formation, the plunger must be lifted from the surface using a rod and cable system, in addition, currently used implantation devices for repeated hydrodynamic stimulation of the formation have the following disadvantages, but

- low productivity due to the need to collect and lower the rod string to the depth of the reservoir;

- a significant probability of rod breakage at a large depth of the well due to the dead weight of the rod string and the additional load from the presence of vacuum under the plunger;

- the impossibility of using existing implosive hydrodynamic generators of reusable action in deviated and horizontal wells.

The objective of the invention is to increase the efficiency and reliability of the implosion device for reusable hydroimpulse effects on the bottomhole formation zone and the possibility of its use in horizontal and deviated wells.

This technical result is achieved by the fact that the device for influencing the bottomhole formation zone, including the tubing string, an implosion chamber with a plunger placed in it, the upper end of which is connected to an expanded pipe having windows, and its lower end is equipped with a spring-loaded valve installed in the housing, having windows and pressure concentrators, in addition, the device is equipped with a hydraulic cylinder installed between the tubing string and the extended pipe with an inside piston rigidly connected to the implosion plunger chamber and spring returning from above, while the rodless cavity of the hydraulic cylinder communicates with the annulus, and its rod cavity is equipped with a pipeline for supplying working fluid from the tubing string.

The drawing schematically shows a device for hydroimpulse effects on the bottomhole formation zone.

A hydraulic cylinder 4 is attached to the tubing string 1, located in the casing 2 with perforation 3, the piston of which 5 is connected to the plunger 8 through a piston 6 sealed by a gland 7. An expanded pipe 9 with windows 10 is fixed to the lower end of the hydraulic cylinder 4, which is connected to the upper the end of the implosion chamber 11, and the housing 12 of the spring-loaded valve 13 with the windows 14 is attached to its lower end. Pressure concentrators 15 are mounted on the housing 12. A pipeline 16 is used to supply the working fluid from the tubing 1 to the rod cavity of the hydraulic cylinder 4. The return spring 17 assigned to return the piston 5 with the piston 8 to its lowest position.

A device for hydroimpulse effects on the bottomhole formation zone works as follows: the device together with the tubing string 1 is lowered into the well so that the windows 14 of the housing 12 are located at the level of perforation 3 of the casing 2.

The plunger of the hydrodynamic generator is driven by a hydraulic cylinder 4 installed between the tubing string 1 and the expanded pipe 9 with windows 10, the piston 5 of which is connected to the plunger 8, and the pressure necessary for the piston 5 to move upward is supplied through the tubing string 1, on which the device is fixed, from the surface. The volume of the casing 2 of the well is filled with fluid (for example, water), while the plunger 8 and the piston of the hydraulic cylinder 4 are in the lower position, and the rodless cavity of the hydraulic cylinder 4, which communicates with the annular space of the tubing 1, is filled, like the implosion chamber 11, with the borehole fluid . Liquid is pumped into the tubing string 1 and a pressure P is created that is sufficient to overcome the force of the return spring 17 and lift the piston 5 connected to the plunger 8 at a speed of 0.7-1 m / s, until the plunger 8 exits into the expanded pipe 9 with windows 10 .

A liquid column from the annulus of the tubing 1 through the windows 10 and the implosion chamber 11 falls down at a speed of 120-150 m / s and, having pressed the spring-loaded valve 13, creates a pressure impulse that is transmitted through the windows 14 and perforations 3 in the casing 2 to the formation rock and reveals cracks, increasing the permeability of the formation in the bottomhole zone.

After depressurization in the tubing 1, under the action of, for example, a compressed return spring 17, the piston 5 together with the plunger 8 returns to its original position. The device is ready for the next exposure.

The supply of liquid under pressure through the tubing string 1 to the rod cavity of the hydraulic cylinder 4 is provided by a pump station and a switchgear (not shown).

The analysis shows that when applying pressure to the tubing 1 of 10 MPa by a pump with a flow rate of 100-120 l / min, it is possible to ensure reliable operation of the proposed device. The return spring 17 is calculated from the condition of overcoming friction in the sealing devices of the rod and plunger.

Thus, the proposed invention allows to increase the efficiency and reliability of the implosion device for reusable hydroimpulse effects on the bottomhole formation zone and to ensure the possibility of its use in horizontal and deviated wells.

Claims (1)

A device for influencing the bottom-hole zone of the formation, including a tubing string, an implosion chamber with a plunger located in it, the upper end of which is connected to an expanded nozzle having windows, and its lower end is equipped with a spring-loaded valve installed in a housing having windows and pressure concentrators, characterized the fact that it is equipped with a hydraulic cylinder installed between the tubing string and the extended nozzle with a piston located inside, rigidly connected to the plunger of the ipmlozion chamber and spring return on top rifle, while the rodless cavity of the hydraulic cylinder is in communication with the annulus, and its rod cavity is equipped with a pipeline for supplying working fluid from the tubing string.