RU2270330C1 - Hydromechanical slotted perforator - Google Patents

Abstract

FIELD: well drilling and operation, particularly to create perforation slots in casing pipes, cement stone and rock.

SUBSTANCE: perforator comprises base, pushing piston arranged inside the body and cutting disc advancing unit formed as rocking arm supported by central axis. The cutting disc is pinned to the first rocking arm lever. The perforator also has sliding support member connected to the second rocking arm lever so that the support member may be displaced out of the body in direction from the cutting disc simultaneously with cutting disc movement to press the cutting disc to production string surface to be cut.

EFFECT: increased manufacturability and productivity.

4 cl, 6 dwg

Description

The proposal relates to the field of drilling and well operation, and in particular to a device for opening reservoirs by creating perforation slits in production cores.

The prior art devices for slotted perforation of casing strings based on the use of a cutting tool in the form of a retractable rolling roller. Such a device is disclosed, for example, in RU 2151858 C 1, IPC 7 E 21 V 42/114, 06/27/2000, or in RU 2180038 C1, IPC 7 E 21 V 43/114, 02/27/2002. The described devices differ mainly in the design of the mechanism of attachment and extension of the cutting tool. The disadvantages of the above devices are the rapid wear of working parts, including the elements on which the rolling roller is mounted, as well as the difficulty of replacing the cutting tool, which requires complete disassembly of the device.

The closest analogue of the proposed perforator can be considered a hydromechanical slotted perforator according to the patent RU 32823 U1, IPC 7 E 21 B 43/114, 09/27/2003. The perforator contains a housing, a piston-pusher placed therein, a retractable cutting tool in the form of cutting disks mounted on the axes with a mechanism for their extension in the form of a beam mounted on the central axis with the possibility of rotation when the piston-pusher is moved. Its components are easy to manufacture and easy to replace.

However, a puncher of this design has an insufficient exit of the cutting unit beyond the production string. In addition, when operating columns of different diameters, it is necessary to produce additional perforators.

The objective of the proposed solution is to increase the manufacturability of the punch, ensuring increased productivity of the process.

The technical result that provides the proposed solution is the possibility of maximum output of the cutting disc beyond the production casing, which allows deeper destruction of the cement stone behind it. In addition, the proposed design of the punch allows you to use one device to work in production casing of various diameters.

The specified technical result is achieved by equipping a perforator containing a housing, a pusher-piston located therein, a cutting disk extension unit connected thereto, made in the form of a beam mounted on a central axis, on one arm of which a cutting disk is placed by an axis, with a sliding support element, located on the opposite arm of the rocker arm and made, for example, in the form of a rounded end of the arm of the rocker arm or mounted on the additional axis of the roller, while the supporting element in with the possibility of full extension of the punch body in the opposite direction relative to the cutting disk and to ensure clamping puncher to cut through the surface of the production tubing. At the same time, the perforator is equipped with interchangeable couplings, ensuring its use for work in production cores of different diameters.

The proposed design of the punch allows you to closely press the device to the perforated inner surface of the operated columns by providing emphasis retractable support element in the surface of the column from the opposite side. When the blade is worn, its inner diameter increases and its outer diameter decreases. If there is a gap between the perforator and the inner surface of the column, which is mandatory when the perforators work in accordance with known technical solutions, the output of the disk for forming a slit in the production string decreases, which ultimately leads to the impossibility of cutting through the gap with sufficient wear of the disk. The proposed device allows you to select this gap due to its clamping with a support element to the perforated wall of the column, which ensures the deepest exit of the cutting disc behind the column and deeper destruction of the cement stone behind it.

The universality of the punch is achieved due to the fact that couplings of various diameters can be wound on the ends of the device. For example, production casing with a diameter of 146 mm and 168 mm uses the same device with a diameter of 115 mm. To re-equip the device, it is enough to unscrew the upper and lower couplings of one diameter and replace them with others, while changing the cutting disc to a disk of the same diameter as the couplings.

In Fig.1 schematically shows the proposed device in the working position, Fig.2 is a transverse section along aa. Figure 3 (a, b) schematically shows two embodiments of a perforator with couplings of different diameters and supporting elements in the form of rollers. In Fig. 4 (a, b), there are two embodiments of the support element, the puncher in the working position is shown in thinner lines.

The hammer drill 1 includes a housing 2 and two couplings 3 and 4. In the upper coupling 3 there is a circulation valve (not shown), it is connected to the tubing (not shown). The lower clutch 4 fixes a spring (not shown), which serves to return the cutting unit and support element from the working position to the transport one. The above figures do not show all the elements of the perforator, however, it should be indicated that a piston, a hollow rod and a filter associated with the pusher piston are located in the housing 2. The piston-pusher, which has the form of a wedge plug, in which there are two channels: flushing and hydraulic monitor, is equipped with a seat for a ball valve that overlaps the central flushing channel.

The cutting disk 5 is fixed with an axis 6 on one arm of the rocker arm 7 mounted in the housing 1 on the central axis 8. On the other arm of the rocker arm 7 there is a retractable support element 9 in the form of a roller mounted on the additional axis 10 (Fig. 4a). In another embodiment, the arm of the rocker arm 7 is rounded and forms a retractable support element (figb).

The punch works as follows.

On the tubing string, the perforator 1 is lowered into the well to the perforation site. Having installed the device in the well, a direct washing of the pipe cavity and the device cavity is carried out from scale and mechanical impurities that enter the pipe cavity during geophysical work to bind the device to the interval. Then, a small diameter ball is thrown into the pipe cavity, which, passing through the tubing suspension, a hollow rod, is lowered into the seat of the piston-pusher and closes the central flushing channel. After that, the working pressure is created in the tubing. They begin to act on the piston-pusher, which, moving progressively along the axis of the device, abuts against the beam 7 and rotate it around the central axis until the contact of the cutting disk 5 and the sliding support element 9 with the wall of the production casing 11.

Creating stepwise pressure from 1.0 to 8.0 MPa in the tubing cavity, move the device up and down. Produce a gradual indentation of the cutting disk 5 into the wall of the production casing and cement stone behind it. In this case, the retractable support element 9, abutting against the wall of the production casing 11, selects the maximum gap between the device and the cut through the wall of the column.

After the formation of a perforation gap in the production string, the pressure in the pipe cavity is raised to 15.0 MPa, the jet monitor effect is realized. A liquid stream at high speed destroys the cement stone and the rock behind the production casing with its pressure and lavishes a cavity along the entire length of the gap. After washing the cavity, the pressure in the pipes is reset to atmospheric. Under the action of the return spring, the cutting unit with the supporting element 9 is assembled into the housing 2 of the perforator.

The technical and economic advantages of the proposed perforator are as follows.

1. A retractable support element in the form of a roller or ski significantly increases the resistance of the cutting disc and the service life of the punch, which allows the puncher to operate for a longer time without replacing the cutting unit, eliminating additional tripping operations. Deeper penetration of the cutting disc behind the production casing allows deeper destruction of the cement stone behind it, facilitating subsequent hydromonitor processing and development of the bottomhole zone.

2. The possibility of using couplings of the required diameter on the same hammer drill eliminates the cost of manufacturing additional instruments of different diameters for working in production cores of appropriate sizes, which makes the hammer universal.

Claims (4)

1. A hydromechanical slotted puncher, comprising a housing, a pusher-piston located therein, a cutting disk extension unit connected thereto, made in the form of a beam mounted on a central axis, on one shoulder of which a cutting disk is placed using the axis, characterized in that it equipped with a retractable support element located on the arm of the rocker arm opposite to the cutting disc, with the possibility of its extension from the housing in the opposite direction relative to the cutting disc at the same time and providing clamping drive to the cut surface of the production string. 2. The hammer drill according to claim 1, characterized in that the retractable support element is formed by a rounded end of the rocker arm. 3. The hammer drill according to claim 1, characterized in that the retractable support element is made in the form of a roller mounted on the rocker arm on an additional axis. 4. The hammer drill according to claim 1, characterized in that it is equipped with interchangeable couplings mounted on the housing, ensuring the use of a hammer for operation in production cores of different diameters.

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