RU2137914C1 - Device for making perforation passages in casing string of well - Google Patents

Abstract

FIELD: oil and gas production industry. SUBSTANCE: device is used in drilling and repair of oil and gas wells. Device has tubular body which carries hydraulic cylinder case adapted for reciprocating motion. Also provided are hydraulic cylinder piston which is connected with wedge-type pusher, cutter holders with perforation cutters, wedge-type pusher, and return spring. Wedge-type pusher is made in the form of two right-angled triangles. Triangles are joined by their side surfaces over smaller leg. Each cutter holder is made for possible sliding in radial direction relative to each other and is adapted for interaction with inclined surface of wedge-type pusher. Tubular body is connected with piston and is adapted for advanced movement so as to cut perforation holes in string and productive reservoir. Reverse movement of piston is used to return device to initial position. Application of aforesaid embodiment of device ensures perforation of casing strings of small diameter. Device having cutters with large outreach is of simplified design. EFFECT: higher efficiency. 3 dwg

Description

 The invention relates to the oil and gas industry, in particular to the field of drilling and repair of oil and gas wells, to create perforation channels in the casing.

 It is known "Device for creating perforation channels" (see av. St. N 1776772, MKI 5 E 21 B 43/114, BI N 43, 1992), containing a housing with longitudinal channels and inclined grooves, a cylinder with an annular piston and a cutting tool in the form of cutters with longitudinal channels to create a hydraulic connection with the channel of the body in the extreme upper position of the cutter.

 The disadvantage of this device is that for the formation of cracks in the wall of the casing string it requires a reciprocating motion of the cutter, which complicates the technology of perforation and operation of the device, in addition, the creation of perforation channels in the form of longitudinal slots mechanically weakens the string, which can lead to emergency situations.

 Closer in technical essence is the "Device for creating perforation channels in the casing" (see Pat. Of the Russian Federation N 2070279, MKI 6 E 21 B 43/114, from 08. 09. 94 g), including a tubular housing with on it, with the possibility of reciprocating movement, the body of the hydraulic cylinder, the piston of the hydraulic cylinder connected to the wedge pusher, a tool holder with perforating cutters, a wedge pusher and a return spring.

 The disadvantage of this device is that it: firstly, is difficult in design; secondly, it cannot be used in casing strings of small diameter, since, due to its design features, when manufacturing it in a reduced form, the length of the cutters exit is less than the thickness of the perforated pipe and cement stone behind the string, in addition, it does not develop efforts sufficient for cutting perforation channels.

 The objective of the invention is to provide a device for perforating casing strings of small diameter with a large overhang of the cutters and simplifying its design.

 The problem is solved by the described device for creating perforation channels in the casing of the well, including a tubular casing with a reciprocating movement, a casing of a hydraulic cylinder, a piston of a hydraulic cylinder connected to a wedge pusher, tool holders with perforating cutters, a wedge pusher and a return spring , new is that the wedge pusher is made in the form of two right-angled triangles, counter-folded by the side surfaces at a smaller a tete, and each tool holder is made with the possibility of sliding in the radial direction relative to each other and directly interacting with the inclined surface of the wedge pusher, while the tubular body is connected to the piston with the possibility of translational movement of the latter for cutting through the column and the productive collector of perforation holes and reciprocal movement of the piston for returning the device to its original state.

 The analysis of patent and scientific and technical literature did not reveal technical solutions with a similar set of essential features, which allows us to conclude that the criteria for "novelty" and "technical level" of the proposed solution are met.

In FIG. N 1 schematically shows the proposed device in its original position;
in FIG. N 2 section of the device according to AA;
in FIG. N 3 type B device.

 The device comprises a tubular body 1 with a reciprocating movement, a hydraulic cylinder housing 2 and a composite shank 3. A hydraulic cylinder piston 4 is placed inside the hydraulic cylinder housing 2. A saddle 5 and a corresponding ball valve 6 are placed inside the tubular housing 1, in the end part of the tubular body 1, a hole is made in which a finger 7 is placed, passing through the slotted slot 8 of the piston of the hydraulic cylinder 4. The finger 7 supports an annular stop 9, which serves as a stop for the return spring 10, pack which extends at the other end into the piston of the hydraulic cylinder 4. In the tubular body 1, a drain window 11 is made, which is placed in the initial state opposite the cavity of the hydraulic cylinder formed by the internal end of the hydraulic cylinder housing 2, the hydraulic cylinder 4 and the outer surface of the tubular housing 1. All movable joints necessary for operation are equipped with seals 12, 13 and 14. The tubular body 1 is screwed into the adapter 15 for connection with a tubing string (see Fig. not shown) with a supporting nut 16 placed on it, which serves as a stop for the cylinder body 2. Inside the composite shank 3 there is a wedge pusher 17 made in the form of two right-angled triangles, counter-folded by the side surfaces along a smaller leg, connected to the piston of the hydraulic cylinder 4, within of this connection, a transfer hole 18 is made in the wedge 18. Fixing guides of the “dovetail” type are made on the inclined surfaces of the wedge pusher 17, toolholders 19 with cutters are mounted on them, the tool holders 19 are made with the possibility of sliding in a radial (relative to the axis of the punch) direction relative to each other and with the possibility of reciprocating movement relative to the wedge pusher 17, from falling out the tool holders 19 supports the end of the composite shank 3. To create a hydraulic differential pressure during operation, the tubular body 1 is provided inlets 20. Auxiliary fasteners are not shown in the drawing.

 During operation, the device is connected to the tubing string and lowered into the well (not shown in the diagram).

 The device operates as follows.

 When the device is lowered into the well, the borehole fluid passes through the overflow hole 18 and valve 6, thereby reducing the buoyancy of all equipment. Upon reaching the calculated place, the valve 6 sits in its seat 5, thereby preparing the device for operation.

 The perforation process is started by pumping liquid into the tubing string. The latter through the hole 20 enters the cavity of the hydraulic cylinder formed by the inner end of the body of the hydraulic cylinder 2, the piston of the hydraulic cylinder 4 and the outer surface of the tubular housing 1, while the piston of the hydraulic cylinder 4 begins to move (in Fig. N 1) down. Together with it, the wedge pusher 17 attached to it moves, pushing the tool holders 19, held from axial movement by the end of the shank 3, while the tool holder cutters 19 are inserted into the perforated production casing and perforated holes are cut through it. When window 11 reaches the well cavity, pressure is released inside the device to the pressure of the hydrostatic column of liquid, the pressure jump at the wellhead. After that, the fluid injection is stopped.

 The tubing begins to lift, while the tubular casing 1 is lifted, and the hydraulic cylinder casing 2 with the shank 3 and the wedge pusher 17 remain in place, held by the tools of the tool holder 19 embedded in the perforated production casing. The finger 7, moving together with the tubular casing 1, compresses the return spring 10 and carries along the piston of the hydraulic cylinder 4 and the cutters of the tool holder 19 exit the perforated production string, freeing the wedge pusher 17 and the associated piston of the hydraulic cylinder 4, the return spring 10 when this returns the piston of the hydraulic cylinder 4, and with it the entire device to its original state, that is, the device is ready to perforate the next interval.

 If necessary, lifting the device to a predetermined height, the perforation process is repeated.

 Technical appraisal and economic advantages of the device are as follows. Possibilities have appeared to perforate production cores of small diameter and to ensure the maximum overhang of cutters for their penetration into productive reservoirs, which is especially important in wells with horizontal bottom hole. The use of the device provides a more perfect opening of formations, reduces material costs and time for perforation, maintains well support by creating a sparing mode of opening (creating holes), which, in turn, prevents premature flooding of the well.

References:
1. Analogue: "Device for creating perforation channels", av. St. N 1776772, MKI 5 E 21 B 43/114, BI N 43, 1992

 2. Prototype: "Device for creating perforation channels in the casing", US Pat. Russian Federation N 2070279, MKI 6 E 21 B 43/114, dated 08.09.94

Claims (1)

 A device for creating perforation channels in a well casing, including a tubular housing with a reciprocating housing of a hydraulic cylinder, a hydraulic piston connected to a wedge pusher, tool holders with perforating cutters, a wedge pusher and a return spring, characterized in that the wedge the pusher is made in the form of two right-angled triangles, counterclosed by the side surfaces along a smaller leg, and each tool holder is made with sliding in the radial direction relative to each other and direct interaction with the inclined surface of the wedge pusher, while the tubular body is connected to the piston with the possibility of translational movement of the latter for cutting through the column and the productive collector of perforation holes and return movement of the piston to return the device to its original state.

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