RU2464412C1 - Device for casing string slit perforation - Google Patents

Abstract

FIELD: oil and gas production.

SUBSTANCE: proposed device comprises tubular case with top and bottom retainers arranged on its ends, each being provided with extending slips, perforating cutter, return spring and fixed locking element. Locking assembly is made up of a set of anchors with fixed slips arranged opposite extending slips. Said anchors are communicated via guide accommodating cutting assembly with cutter and spring fitted therein. Check valves are arranged in top anchor and cutting assembly.

EFFECT: larger depth of perforated channels, higher reliability, longer life, better reparability.

2 dwg

Description

The invention relates to the field of drilling and operation of oil, gas and injection wells, and in particular to a device for creating longitudinal perforation slots in a casing (production) string.

A device for slotted perforation of casing, based on the use of cutting tools in the form of cutters. Such a device is disclosed in patent RU 2070279, IPC 7 ЕВВ 43/114, 08.09.94, including a tubular housing with a reciprocating hydraulic cylinder, a piston of a hydraulic cylinder connected to a wedge pusher, a tool holder with perforating cutters, a wedge pusher and return spring.

The disadvantages of this device are as follows:

firstly, the device is complex in design; secondly, it cannot be used in casing strings of small diameter, since, due to their design features, when manufacturing it in a reduced form, the cutter exit length is less than the thickness of the perforated pipe and cement stone behind the string; thirdly, it does not develop efforts sufficient for cutting perforation channels.

Closest to the proposed invention is a device for creating perforation slotted channels in the wall of the well, comprising a tubular body, a hydrochambers body with the possibility of reciprocating motion, a hydraulic chamber piston rigidly connected to the cutter, high pressure hoses, springs (RF patent No. 2189436, ЕВВ 43 / 114, 09/20/2002).

The disadvantages of this device are the complexity of manufacturing, jamming of high pressure hoses, which significantly reduces the reliability of the equipment.

The technical result that the proposed invention provides is to perform slotted perforation, increasing the reliability and durability of the work while ensuring high maintainability.

The task to which the invention is directed is to increase the depth of the perforation channels, increase the reliability and durability of the device, while ensuring high maintainability.

This technical problem is achieved due to the fact that the device for slotted perforation of the casing strings includes a tubular body, at the ends of which upper and lower fixing units are installed, each of which contains retractable dies, a perforating cutter, a return spring, a stationary fixing element, according to the invention, a fixing unit made in the form of an anchor, in which stationary dies are installed opposite to the sliding dies, the hydraulic connection between the anchors is provided by a guide on which the cutting assembly with a cutter mounted therein and a spring in the upper anchor and the knife assembly formed check valves.

The invention is illustrated by drawings, which depict:

figure 1 is a frontal section of a perforator;

figure 2 is a section along aa.

A device for slotted perforation of casing strings includes a tubular body 1, at the ends of which an upper anchor 2 and a lower anchor 3 are installed. The upper anchor 2 contains retractable dies 4, stationary dies 5 and a check valve 6. The lower anchor 3 contains a retractable dice 7 and a stationary dice 5 A hydraulic connection between the anchors is provided by the guide 8. In the housing 1 between the anchors on the guide 8 there is a movable cutting unit 9 connected to the hollow rod 10. The cutting unit 9 contains a cutter 11, springs 12, a check valve 6 and a sweat switch ok 13.

The device operates as follows. The hammer drill is lowered into the well on tubing pipes. Then, overpressure is created in the cavity of the hollow rod 10, and due to hydraulic pressure through the channels, the working fluid passes through the valve 6 into the upper armature 2 and enters the lower armature through the channel of the guide 8, while the dies 4 and 7 are pulled out, fixing the perforator body. Using a drive at the mouth (rocking machine), the cutting unit 9 is moved downward, while after tearing off the ends of the upper armature 2 and the cutting unit 9, the check valve 6 is triggered, thereby ensuring a fixed placement of the perforator body 1 in the casing barrel. Having moved the cutting unit 9 to its lowest position, the flow switch 13 is activated and the channel for the working fluid opens, at which the cutter 11 extends and abuts against the casing wall. Maintaining the pressure of the working fluid, the cutting unit 9 is lifted by the working stroke to the upper extreme point where the flow switch 13 is activated, while the working fluid is discharged from the cavity of the cutting unit 9, and the cutter 11 returns to its original position using the spring 12. Producing reciprocating movement of the cutting unit 9 in the range of the stroke, a slotted perforation is formed on the barrel of the casing.

Claims (1)

A device for slotted perforation of casing strings, including a tubular body, at the ends of which are installed upper and lower fixing units, each of which contains retractable dies, a perforating cutter, a return spring, a stationary fixing element, characterized in that the fixing unit is made in the form of an anchor, in which opposite the retractable dies, stationary dies are installed, the hydraulic connection between the anchors is provided by a guide on which the cutting unit with the cutter and spring installed in it is placed, in the upper At the anchor and the cutting unit, check valves are made.

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