RU2492315C1 - Cumulative sectional perforator for well - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: perforator comprises a row of sections connected to each other. Each section comprises a frame, where shaped charges are placed, being joined with detonating cords, a unit of explosion initiation, units of detonation reception-transmission, placed in joints of adjacent sections, every of which is formed by elastic bushings coupled at the ends and placed on each end of the section, each having two adjacent parallel through channels. One of these channels is axial, and the other one is peripheral. Explosive cartridges are tightly placed in these channels - accordingly, axial and peripheral boosters, which interact with each other by the side surface. Interaction between axial boosters of adjacent sections is provided at their ends. At the same time each of free ends of axial and peripheral boosters at the side of shaped charges of each section interact with ends of detonating cords placed with a part into the axial and peripheral channels of the tightened elastic bushing.

EFFECT: increased reliability of actuation of a cumulative sectional perforator in the specified mode, increased safety of works.

13 cl, 3 dwg

Description

The invention relates to the oil and gas industry and can be used for shooting and blasting in wells for the secondary opening of reservoirs.

Cumulative single-use rotary hammers are widely used in perforating and blasting operations, including due to the ability to lower long assemblies from several sections into the well.

Known cumulative sectional perforator for a single-use well, in which the connection of the individual sections is carried out using an adapter with a large internal hole, inside which are located the free ends of the detonating cords of the connected sections. At the same time, the ends of the cords are lapped tightly - the loops are interconnected by a soft wire through the threaded holes in the adapter (see, for example, Fridlyander L.Ya., Handbook for shooting and blasting equipment, Moscow, Nedra, 1983, p.19, Fig. 1.7 .).

A disadvantage of the known device is that the described connection provides reliable transmission of detonation only for high sensitivity cords. A number of modern detonating cords made of heat-resistant explosives or containing a large number of plasticizers do not transmit detonation when they overlap. In addition, there is also a low reliability and complexity of connecting detonating cords using a wire loop.

At present, cumulative sectional perforators for wells are widely used, in which the detonation circuit in the section connections - adapters and / or couplings involves the use of detonation amplifiers - boosters.

Known cumulative sectional perforator for the well, including the frame, cumulative charges placed in the frame, adapters with booster placed in them, detonating cords attached to the boosters, and the initiation unit (see, for example, RU 49894 U1, 10.12.2005).

This design provides for the transfer of detonation from detonating cords to boosters in the direction of its propagation.

A disadvantage of the known device is the need to connect boosters and detonating cords with a special device such as pincers, compressing the walls of the booster on a detonating cord. This option of connecting with the deformation of the walls of the booster near a sensitive explosive is dangerous and permissible only with the use of devices approved for use by Rostekhnadzor of the Russian Federation. In addition, such a connection, which is essentially difficult to detachable or inseparable, complicates or eliminates the possibility, if necessary, of disassembling sections of a cumulative perforator.

Detonating cords used in perforated explosive equipment, especially in heat-resistant design, do not have sufficiently high reliability. Therefore, periodically, especially on long sectional assemblies of cumulative perforators, a cessation of detonation occurs. At the same time, part of the cumulative charges burns out or explodes in a high explosive mode, which often leads to the destruction and jamming of cumulative perforators in the well.

In horizontal wells, cumulative perforators, assembled from many sections and reaching a length of several hundred meters, are lowered by pipes. For this option, the reliability of the full operation of the cumulative punch becomes especially relevant.

However, in the well-known cumulative sectional punchers, the reliability of their operation in the optimal mode — the operation of all cumulative charges in a given explosion mode — remains not high enough.

The technical result of the invention is to increase the reliability of the operation of the cumulative sectional perforator - all its charges in a given explosion mode, regardless of length, as well as to increase the safety of work.

The required technical result is achieved by the fact that the cumulative sectional perforator for the well includes a number of sections interconnected, each of which has a frame on which cumulative charges are connected, connected by detonating cords, detonation transmission and reception nodes located in the connections of adjacent sections, each of which is formed by elastic bushings mated at the ends, placed at each end of the section, each of which has two adjacent parallel through channels, one of which is axial and the other - peripheral, with explosive checkers placed in these channels with an interference fit - axial and peripheral boosters, respectively, interacting with each other on the side surface, and between axial boosters of adjacent sections - their ends, with each of the free ends of the axial and peripheral boosters on the side of cumulative charges each of the sections interact with the ends of the detonating cords, placed partly in the axial and peripheral channels of the elastic sleeve under interference.

Besides:

the cumulative sectional perforator is made case-shaped (to increase the reliability of its delivery without damage to a given depth of the well and increase the reliability of operation of all charges);

the elastic sleeve is made with a protrusion on the outer surface from the side of the end of the section, and the connection of the section has a corresponding bore under the protrusion, while the elastic sleeve is placed in the connection of the section and its bore with interference (to increase the reliability of fastening the sleeve itself, the links interacting with it and increase the reliability of the cumulative sectional perforator as a whole);

the axial and peripheral channels of the elastic sleeve are made stepwise in diameter to the dimensions of the axial and peripheral boosters and detonating cords (to increase the degree of interaction of detonating cords with boosters, to increase the reliability of detonation transmission and to increase the reliability of the cumulative sectional drill as a whole);

the sections of the cumulative sectional perforator are made in the form of adapters or couplings, or according to the “pipe to pipe” type;

when connecting sections in the form of couplings or according to the “pipe to pipe” type, the cumulative sectional perforator contains crosses for placement of elastic bushings in them;

the elastic bushings are made of rubber or polyurethane or polyurethane foam, and the diameters of their axial and peripheral channels for accommodating the corresponding boosters and detonating cords are 1-3% smaller than the diameters of the mentioned boosters and detonating cords (to optimize the interaction of detonating cords with boosters) ;

the coupling or adapter connecting the sections has a through step channel, in one of which there is an elastic sleeve with axial and peripheral boosters and detonating cords, and the second has a diameter of at least five diameters of the detonating cord (for free placement of detonating cords in a kind of pocket, excluding them excessive tension and violation of the necessary degree of interaction with boosters, providing the specified reliability of the transmission of detonation and operation of the device as a whole);

each of the elastic bushings has a detonating cord retainer relative to the boosters (an additional means of fixing the detonating cord relative to the boosters);

hexogen or octogen, or hexonitrostilbene with a density of 0.75-0.85 of the density of a single crystal of these explosives (selected as optimal means of enhancing detonation and increasing the reliability of the device) was chosen as a booster explosive charge;

the coupling or adapter is made detachable in two parts, which, when assembling the sections, can be connected with a tapered thread and sealed with rubber rings (to increase the reliability of the knock transmission unit);

on the outside of the elastic sleeve there are evenly spaced longitudinal shoulders of a triangular section (to increase the reliability of its fastening and the fastening of knock transmission units interacting in it);

the explosion initiation unit is made in the form of an explosive cartridge with an electric fuse placed in the lower or upper section so that the main sample of its explosive is located opposite the side surface of the explosive sample of one of the boosters, while the electric fuse is provided with an electric circuit (to increase the reliability of the device) .

Figure 1 shows a longitudinal section of the connection sections of the cumulative sectional perforator.

Figure 2 shows a diagram of an electrical circuit in a punch of several sections.

Figure 3 shows the installation diagram of the explosive cartridge type PVPD in the elastic sleeve.

Cumulative sectional drill includes a number of sections interconnected. Each of the sections has a frame 1, on which cumulative charges are placed (conventionally not shown). Cumulative charges are connected by detonating cords 2. The device has detonation receiving-transmitting nodes located in compounds of adjacent sections. Each of the knock-receiving knots is formed by elastic bushings 3 conjugated at the ends and placed at each end of the section. Each of the elastic sleeves 3 has two adjacent parallel through channels. One of these channels is axial, and the other is peripheral. Explosive pieces (detonation amplifiers) - boosters and, accordingly, axial booster 4 - in the axial channel and peripheral booster 5 - in the peripheral channel are placed in these interference fit channels. As a charge of explosive boosters can be used RDX or HMX, or hexonitrostilbene. Axial 4 and peripheral 5 boosters interact with each other on the side surface. Between the axial booster 4 and the axial booster 6 of adjacent sections, the interaction is provided at the ends of the mentioned boosters. Each of the free ends of the axial 4 and peripheral booster 5 from the side of the cumulative charges of each section interacts with the ends 7, 8 of the detonating cords 2, placed partly, respectively, in the axial and peripheral channels of the elastic sleeve under interference.

Additionally, the device may include a housing 9. Each of the elastic sleeves 3 may have a latch 10 detonating cords 2 relative to the axial 4 and peripheral 5 boosters. This lock can be made, for example, in the form of a clamp. To fix the elastic sleeve 3, for example, in the adapter 11 on its outer side, longitudinal beams 12 of triangular section evenly spaced along the lateral generatrix can be made, which are deformed by about half when installed in the adapter 11.

The elastic sleeve 3 in addition to the axial and peripheral channels for, respectively, the axial 4 and peripheral 5 boosters has two additional holes 13, into which two whiskers of the ring electrical contact 14 are inserted, bent 90 ° to the contact plane having an axial hole for the booster, the third mustache contact with the connected electric wire 15 passes through the peripheral hole, which provides an electrical circuit to the contact on the elastic sleeve of the next section or to the electric explosive cartridge 16 mounted in the lower or erhney section cumulative sectional punch. For the variant of descent of the device on the cable with electric explosion in one of the main channels, axial or peripheral, for example, an axial booster 4 can be installed, and in the second peripheral channel 5 adjacent to it, for example, an electric explosive cartridge 16 can be placed in such a way that its main explosive sample is located opposite the booster explosive sample. This can be achieved, for example, by varying the length of explosives intended for interaction in this particular (lower or upper) section of the cumulative sectional perforator. This solution provides reliable transmission of detonation. Using an electric explosive cartridge, for example, a safety action of the type “PVPD-N”, a circuit with its placement in the lower section is recommended. The electric wire from the electric explosive cartridge to the mass 17 is attached to a metal stud 18, for example, in the form of a nail mounted with an interference fit in the annular gap formed due to the longitudinal collars between the elastic sleeve 3 and the adapter 11. The elastic sleeve 3 can be made, for example, with the protrusion 19 on the outer surface, under which the connection sections has a corresponding bore. One of the channels 20 connecting the sections, for example, in the adapter 11 can be made with a diameter of at least five diameters of the detonating cord.

The device operates as follows. The knock transmit-receive nodes assembled in elastic bushings 3 are mounted on one side of the section in the frame 1 of the perforator on the other side of the section, for example, in the adapter 11. When screwing up individual sections, the detonation chain is joined. In this case, direct contact occurs only in part of the axial boosters 4 and 6 at their ends. The peripheral boosters 5 are arranged randomly when screwing up the sections.

In the known designs of cumulative sectional perforators, it is provided that the detonating cord is connected to the electric explosive cartridge at the end and the said cartridge is rolled up in the dule by a special device, which is a dangerous operation and the connection becomes integral. In this invention (see figure 3) provides for the installation of an electric explosive cartridge 11 in an elastic sleeve. A booster with a detonating cord, for example an axial booster 4, is fitted with an interference fit in the axial channel of the elastic sleeve. In another channel - peripheral - with an interference fit, for example, in addition to the peripheral booster 5, an electric explosive cartridge 11. The electric wire from the electric explosive cartridge 11 through one of the additional holes 13 is passed through the device to the electric input, and the other wire 17 is connected to the contact pin 18 in the form of a nail on the mass. This solution allows you to safely and quickly connect, and if necessary, disconnect the electric explosive cartridge 16 cartridge from the detonation circuit of the punch.

The cumulative sectional perforator assembly, after installing an electric explosive cartridge 16 to the detonating cords, during descent on a cable, or a firing head, during descent on pipes (not shown conditionally), is lowered into the well.

In the perforation interval, an electric explosive cartridge 16 or a firing head simultaneously initiates two detonating cords. In the explosion of an electric explosive cartridge 16, detonation is reliably transmitted to one of the boosters. If the detonation passed only along the peripheral booster 5, then through its lateral surface it will ensure the initiation of the adjacent axial booster 4, for example, which, in turn, will use, for example, the axial booster 6 in the next adjacent section. From it, detonation of the adjacent peripheral booster will be ensured and, thus, both threads of the duplicated chain of the entire cumulative sectional perforator will be used again.

The duplicated detonation chain can also be effectively used for sectional cumulative perforators, lowered on pipes and allowing the use of mechanical fuses, which can be installed in the upper section of the perforator. This case involves the use of the above-mentioned perforators with a larger number of sections.

The descent on the cable involves the use of perforators with fewer sections and the use of electric fuses installed both in the lower section and in the upper section. In any case, in accordance with the invention, a specially designed duplicated detonation circuit can be provided that provides the necessary reliability and safety of both maintenance and the actuation of the cumulative sectional perforator with a complete detonation of all cumulative charges in a given explosion mode.

Claims (13)

1. Cumulative sectional perforator, including a number of sections interconnected, each of which has a frame on which cumulative charges are placed, connected by detonating cords, an explosion initiation unit, detonation transmission and reception units located in the connections of adjacent sections, each of which is formed elastic bushings mated at the ends, placed at each end of the section, each of which has two adjacent parallel through channels, one of which is axial and the other peripheral, with these in interference with explosive blocks - respectively, axial and peripheral boosters interacting with each other on the side surface, and between axial boosters of adjacent sections with their ends, each of the free ends of the axial and peripheral boosters from the side of the cumulative charges of each section interacting with the ends of the detonating cords placed partly in the axial and peripheral channels of the elastic sleeve under interference. 2. The cumulative sectional perforator according to claim 1, characterized in that it is made body. 3. The cumulative sectional puncher according to claim 1, characterized in that the elastic sleeve is made with a protrusion on the outer surface from the side of the end of the section, and the connection of the section has a corresponding bore under said protrusion, while the elastic sleeve is placed in the connection of the section and its bore with interference . 4. The cumulative sectional drill according to claim 1 or 2, characterized in that the axial and peripheral channels of the elastic sleeve are made stepwise in diameter to the dimensions of the axial and peripheral boosters and detonating cords. 5. The cumulative sectional perforator according to claim 1, characterized in that the connections of its sections are made in the form of adapters or couplings, or according to the “pipe to pipe” type. 6. The cumulative sectional drill according to claim 1, characterized in that when connecting the sections in the form of couplings or in the form of "pipe to pipe" it contains crosses for placement of elastic bushings in them. 7. The cumulative sectional punch according to claim 1, characterized in that the elastic bushings are made of rubber, or polyurethane, or polyurethane foam, and the diameters of their axial and peripheral channels for accommodating the corresponding boosters and detonating cords are 1-3% smaller than diameters of said boosters and detonating cords. 8. The cumulative sectional drill according to claim 5, characterized in that the sleeve or adapter connecting the sections has a through step channel, one of which has an elastic sleeve with axial and peripheral boosters and detonating cords, and the second has a diameter of at least five diameters detonating cord. 9. The cumulative sectional punch according to claim 1, characterized in that each of the elastic bushings has a detonating cord lock relative to the boosters. 10. The cumulative sectional perforator according to claim 1, characterized in that the hexogen or octogen or hexonitrostilbene with a density of 0.75-0.85 of the single crystal density of these explosives is selected as the explosive charge of the boosters. 11. Case cumulative perforator according to claim 5, characterized in that the coupling or adapter is made detachable in two parts, which, when assembling the sections, can be connected with a tapered thread and sealed with rubber rings. 12. Case cumulative perforator according to claim 1, characterized in that on the outer side of the elastic sleeve there are evenly spaced longitudinal beads of triangular section. 13. The cumulative sectional drill according to claim 1, characterized in that the explosion initiation unit is made in the form of an explosive cartridge with an electric fuse placed in the lower or upper section so that the main sample of its explosive is located opposite the side surface of the explosive sample of one of the boosters while the electric fuse is provided with an electrical circuit.

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