RU2224095C1 - Accumulative perforator - Google Patents

Abstract

FIELD: explosive operations technology. SUBSTANCE: device has hollow charges, detonation means, U-shaped cartridge clips with opening in the middle portion for fixing the charge, terminal parallel racks placed at angle of 90 degrees to perforator axis. Cartridge clip is made of protective screening metal with opening in each terminal rack for interconnecting cartridge clips by means of bolts for forming a frame of needed length with capability of placing charges in each cartridge clip. Terminal racks are made in relationship of F=(0.5...0.8)D and L=(1.3...1.7)F, where L and F are accordingly length and width of terminal racks, D - charge diameter. EFFECT: possible perforation of passages at angle to well wall and lessened mutual effect of nearby hollow charges explosions. 2 cl, 4 dwg

Description

The proposed cumulative perforator relates to the technique of perforating blasting in wells and can be used for secondary opening of the borehole formation zone.

Cumulative rotary hammers are known, both case-mounted and open-frame, in which various types and designs of frames and holders are used for installing cumulative charges on them.

The device [2] uses flat metal strips to install charges in the openings of which cumulative charges are installed. Phasing is provided by turning each subsequent section of the tape relative to the previous one by a certain angle.

In devices [1, 3], cumulative charges are mounted on tapes of a zigzag and spiral shape, changing the geometric characteristics of which you can get one or another perforator size, phasing angle and perforation density. [1] and [3] also described perforators that use an individual molded holder for each charge, which can be rotated by a fixed angle relative to the adjacent holder, as well as an angle profile that provides a phasing angle of 90 and 270 degrees.

Tubular metal rolling for the installation of cumulative charges was used in [5], [6], [8], [9], [10] and [11], and in [12] it was rolled in the form of a gutter.

In the puncher [7], charges are installed in the holes of short metal plates connected by bolts in such a way as to preserve some backlash to ensure assembly flexibility.

All of the above-mentioned structures implement, to one degree or another, the task of opening the formation in the well with a given phasing and permissible perforation density. The disadvantage of existing designs is that they provide the ability to vary phasing only stepwise, for example 0, 30, 60, 90 degrees, the installation of any phase angle, for example 10, 25, 36 degrees, etc., is impossible without a major change in design. In addition, existing structures are designed to penetrate the channel in the reservoir only at an angle of 90 degrees to the wall of the well, which reduces the efficiency of penetration under certain geological conditions (for example, when perforating complex thinly intersecting formations).

In the design of the perforator [5], each charge is placed in a cast metal holder; the clips are connected into garlands of the required length using cotter pins. In this case, the phase orientation of neighboring charges can be carried out in a wide range using the corresponding end grooves and ridges. In addition, the punch frame of the connected separate cages allows you to collect a punch garland of any length that is a multiple of the distance between adjacent charges, and provides a uniform density of charges located in contrast to tape and tube frames.

At the same time, the phasing angle can be changed only stepwise, cumulative jets can penetrate channels in the formation only at an angle of 90 degrees to the borehole wall. In addition, this design does not provide for the reduction of the known effect of the mutual influence of explosions of neighboring cumulative charges on each other, which is especially noticeable at the maximum perforation density (and, accordingly, the minimum distance between charges) and leads to a sharp decrease in the penetration depth of cumulative charges.

The closest analogue of the invention is a design known from the source [13]. This design is a cumulative perforator containing cumulative charges, explosive devices, clips having a U-shaped profile with a hole in the middle part for securing the charge, end parallel flanges made at an angle of 90 degrees to the axis of the perforator.

The main disadvantage of such a punch is the penetration ability relative to the size of the punch, since the frame in the form of a steel rod does not allow full use of the cross section of the punch to accommodate charges of large dimensions.

The present invention is a cumulative perforator, the design of which allows the installation of any phasing angle, to provide the possibility of punching perforation channels at an angle to the well wall and significantly reduce the effect of the mutual influence of explosions of adjacent cumulative charges.

This goal is achieved by the fact that in a cumulative perforator containing cumulative charges, explosive devices, clips having a U-shaped profile with a hole in the middle part for securing the charge, end parallel flanges made at an angle of 90 degrees to the axis of the perforator, the clip is made of screening protective metal with a hole in each end shelf for connecting the clips to each other using bolts in the frame of the required length with the ability to set charges in each clip, making maximum use of the cross section of the perforation operators. The cage is made of metal, while the end shelves (shelf width F = (0.5 ... 0.8) D, where D is the diameter of the charge, shelf length L = (1.3 ... 1.7) F) provide screening and protection against mutual influence in the explosion of two adjacent charges, which makes them possible to be located at a minimum distance from each other.

The holes in the middle part of the cage can also be made at an angle within 45 ... 70 degrees to the axis of the frame with the possibility of installing the charge obliquely to the axis of the punch.

The device of the invention is shown in figures 1-4.

Figure 1 shows a cumulative perforator with a phasing angle of charges of 0 degrees;

In FIG. 2 shows a cumulative perforator with an angle of phasing charges 180 degrees;

In FIG. 3 is a view A of FIG. 2, showing the dimensions of the end flanges of the clip;

In FIG. 4 shows a cumulative perforator with a phasing angle of charges of 45 ... 75 degrees;

Cumulative charges 1 are fixed in the holes of the clips 2. The clips are interconnected by bolts 3 and nuts 4. Since the axis of rotation of the clip coincides with the longitudinal axis of the punch, you can smoothly set any phasing angle from 0 (Fig. 1) to 180 degrees (Fig. .2) without violating the dimensions of the device. The material and dimensions of the end shelves of the clips 2 are selected in such a way as to provide maximum shielding to reduce the mutual influence of the cumulative charges during their explosion. Charges 1 can be located perpendicular to the longitudinal axis of the punch (Fig. 1 and Fig. 2), and at an angle of 45 ... 75 degrees to it (Fig. 4). A garland of clips with charges equipped with a detonating cord 5 and initiating means 6 is lowered into the well on cable 7.

Cumulative punch works as follows. After installation in the well at a predetermined depth, the initiating means 6 is activated, which transmits detonation to the detonating cord, from which cumulative charges are triggered. Cumulative charges, triggering, pierce the casing, cement and formation, forming in the last perforation channel.

Sources of information

1. US patent No. 5662178 from 02.09.1997.

2. US patent No. 4694754 from 09/22/1987.

3. US patent No. 5638901 from 06/17/1997.

4. US patent No. 5241891 from 09/07/1993.

5. US patent No. 4951744 from 08/28/1990.

6. US patent No. 5323684 from 04/28/1994.

7. US patent No. 3865199 from 02/11/1975.

8. US patent No. 5775426 from 07/07/1998.

9. US patent No. 5785130 from 07.28.1998.

10. US patent No. 5797464 from 08.25.1998.

11. US patent No. 5829538 from 03.11.1998.

12. US patent No. 5542480 from 08/06/1996.

13. Shooting range, explosive apparatus and equipment, Ramenskoye branch of the All-Russian Research Institute of Geophysics, Moscow, Nedra, 1976, poster No. 12, Zak. 6408 / P-2327.

Claims (2)

1. Cumulative perforator containing cumulative charges, explosives, clips having a U-shaped profile with a hole in the middle part for mounting the charge, end parallel flanges made at an angle of 90 ° to the axis of the perforator, characterized in that the clip is made of screening protective metal with a hole in each end shelf for connecting the clips to each other using bolts in the frame of the required length with the ability to set charges in each clip, while the end shelves are made in the ratio F = (0.5 ... 0.8) D, L = (1.3 ... 1.7) F, where F is the width of the end shelves; D is the diameter of the charge; L is the length of the end shelves. 2. The cumulative perforator according to claim 1, characterized in that the holes in the middle part of the holder are made at an angle within 45-70 ° to the axis of the frame with the possibility of installing a charge obliquely to the axis of the perforator.

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