RU2646927C1 - Device for successive initiation of perforating system - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: invention relates to the oil and gas industry, specifically to the structural part of perforating systems that are lowered into oil or gas wells on a geophysical cable and initiated by electric detonators, and can be used for perforating disparate intervals during a single trip. Device comprises a device body, an electric detonator, a detonating cord, an electric wire, a detonation transfer device, and a piston. Piston is located in a casing made in the form of a cylinder with a stepped through hole, has a sealing and initiating part and is fixed in the body from movement by a lock washer. Piston is insulated from the body by a sleeve-insulator and an insulating washer. In the mechanical chain of switching contacts the electronic contact switching unit made in the form of an electronic key, triggered by a change in the state of the sensor, is additionally included.

EFFECT: enabling triggering of only one of several perforating electric detonators from feeding one pulse from the explosive device in a strict sequence from the bottom up.

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Description

A device for sequentially initiating a perforating system relates to the oil and gas industry, namely, to the structural part of perforating systems that are lowered into oil or gas wells on a geophysical cable and initiated by electric detonators, and can be used to perforate disparate intervals in one round trip for generally accepted safe and widely common on the Russian market means of initiation, triggered by a high-frequency pulse of alternating current.

A device for a selective switch for a downhole perforator US20100208408 A1 is known, which is a device for sequentially activating sections of a cumulative perforator in a well, including a diode adapted to transmit electric current in response to a positive or negative current, a device that can change the polarity of the current from exposure to light, a relay connected in such a way that switching from the first to the second position in response to a change in current polarity occurs due to compound of the diode, the first relay coil and a device which performs polarity reversal of the effects of the light wave. The device also includes a switch, a housing; the switch has a mount for a diode, a device for changing the direction of a direct current and a relay, and also has a window for the passage of light outside the switch into a device that changes the polarity of the current.

 An analogue of US 8387533 B2 is also known, which is a downhole switch for operating a cumulative perforator, including a casing, a casing having first and second sides with an expanding through hole between them, the casing is located in the casing so that the second end is exposed to detonation shock waves the first electrical contact adjacent to the first side of the housing, a conductor located in the hole; a second electrical contact located in the hole adjacent to the housing of the second end; an intermediate electrical contact located in the hole between the first and second contacts, a thermoplastic polymer insulator located in the sleeve between the intermediate and second contacts, the device has two positions: in the first position, the intermediate contact, the conductive sleeve and the lower contact are closed, and the intermediate and upper the contacts are open, in the second position, the upper and intermediate contacts are closed, and the intermediate and lower contacts are open.

The disadvantage of both analogues is the impossibility of using this device design with electric detonators and explosive cartridges produced by the Russian Federation, triggered by a high-frequency AC pulse.

The closest technical solution is the "device for sequential initiation of a perforation system" according to patent RU 2561828 C2 dated 11.21.2013, published: 09/10/2015, IPC E21B 43/1185, F42C 15/40, comprising a housing, an electric wire, a piston, a cartridge, inside which has a detonating cord, a detonation transmission device, an electric detonator, an upper contact, characterized in that it is equipped with a movable electrical contact located on the first end part of the piston facing the upper contact, the upper part of the piston is made conical shape, on the second end part of the piston there is a blind hole with a diameter equal to the diameter of the upper end of the electrical contact of the lower section of the perforator.

The main disadvantage of this prototype is the high probability of the simultaneous operation of several electric detonators and, accordingly, the initiation of sections of a perforator, and the number of simultaneously triggered sections may also vary. The reason for this drawback is the duration of the pulse emitted from explosive devices designed to initiate domestic electric detonators ED-PN-M and explosive ammunition PVPD-N - the passport value of "at least 10 ms" can often develop into 400 ms, which leads, taking into account the speed fast processes of detonation of the cord and charges in sections, to switch several nodes of sequential initiation, triggered by the pressure of the detonation products, simultaneously connect several electric detonators perforator central chain and, accordingly, their simultaneous operation at the location of one of several disparate intervals. This fact was established by field and pilot tests, which generally makes the design described above inoperative.

The objective of the proposed technical solution is to create a reliable, efficient, technologically advanced system of sequential actuation of the sections of the perforator using domestic means of initiation.

The problem is solved by means of a device for sequentially initiating a perforation system comprising a device body, an electric detonator, a detonating cord, an electric wire, a detonation transmission device, a piston, the piston being located in a housing made in the form of a cylinder with a stepped through hole; the piston has a sealing and initiating parts and is fixed in the housing from movement by a locking washer; the piston is isolated from the housing by an insulating sleeve and an insulating washer; An electronic contact switching unit, made in the form of an electronic key triggered by a change in the state of the sensor, is additionally included in the mechanical contact switching chain.

The execution of the casing of the device in the form of a cylinder with a stepped through hole allows you to provide a given piston stroke and, accordingly, accurately transmit the alarm signal to the sensor and connect the next electric detonator to the central wire of the punch.

Providing the piston with sealing and initiating parts and fixing it in the housing from being moved by the fixing washer allows increasing the switching time, protecting the device from abnormal switching on the surface and sealing the connected electric detonator from the well fluid in the triggered perforator, which eliminates the probability of the operation of several electric detonators in one pulse from an explosive instrument.

Isolation of the piston from the housing by a bushing-insulator and an insulating washer allows for the transit of an electrical signal from the upper section to the intermediate, from the intermediate section to the lower through the piston.

The inclusion in the mechanical contact switching chain of an additional electronic contact switching unit, made in the form of an electronic key triggered by a change in the state of the sensor, allows you to adjust the response time, which also eliminates the likelihood of several electric detonators tripping in a single pulse from an explosive device.

Providing the device with either an inductive or pressure sensor or a photosensitive sensor allows the device to be used in wells with different environments.

Thus, all the features included in the independent claim, the proposed relative position of the device elements and their interaction ensure, when a single pulse is sent from the explosive device, the operation of only one of several electric detonators of the perforation system, in strict sequence from bottom to top, from section to section, from 5 to 4, then to 3, then to 2, and to 1 section, placed by the operator, at the time of the impulse to the location of one of several separate intervals,

A device for sequentially initiating a perforation system is shown in the drawings, in which Fig. 1 shows a longitudinal section of the device before actuation, Fig. 2 shows a longitudinal section of the device after actuation, Fig. 3 shows a functional diagram of an electronic contact switching unit, Fig. 4 shows the sequence of operations during the assembly of three sections of a cumulative perforator with two devices for sequential initiation of the perforation system.

In FIG. 1-2 depict: device housing 1, piston 2, piston sealing part 3, piston initiating part 4, piston housing 5, nut 6, contact rod 7, sealing rings 8, 9, fixing washer 10, insulator sleeve 11, insulating washer 12, an electronic contact switching unit 13, an electric detonator 14, a detonating cord 15, a transfer charge 16, a detonator latch 17, a terminal 18, a punch center wire 19, an electric detonator wire 20, an electric detonator coil 21.

In FIG. 3 shows a working diagram of an electronic contact switching unit 13, which shows: a piston 2, an initiating part 4 of a piston, an electronic contact switching unit 13, an electric detonator 14, a central punch wire 19, an electric detonator wire 20, an electric detonator coil 21, a sliding contact 22, a sensor 23, electronic key 24.

In FIG. 4 depicts the sequence of operations A to G when working with an assembly of three sections of a cumulative punch with the first and second sequential actuation devices, which show the casing 25, casing cement 26, rock 27, geophysical cable 28, cable head 29, lower section 30 cumulative punch, intermediate section 31 cumulative punch, the upper section 32 of the cumulative punch, the first device 33 for sequential actuation, the second device 34 for sequential work tyvaniya, perforation 35 of the first interval, the second interval of perforation 36, perforation 37 of the third slot, perforated interval 38.

A device for sequentially initiating a perforation system is as follows.

The device body 1, made in the form of a cylindrical body with external threads at both ends, with a stepped through hole, accommodating an electronic contract switching unit 13, a piston 2, consisting of a sealing part 3 with two grooves in which the sealing rings 9 are located, the initiating part 4 of a smaller diameter length, which protrudes from the piston body 5. A threaded hole is made from the end part of the piston sealing part 3 for connection with the contact rod 7. In the initial position of the device, the piston sealing part 3 is completely placed in the sleeve-insulator 11, which is made in the form of a tube with a protrusion-undercut. An insulating washer 12 is installed on the initiating part 4 of the piston. In the initial position of the device, the sleeve-insulator 11 and the insulating washer 10 electrically isolate the piston from the piston body 5, which is made in the form of a cylinder, with two grooves for the sealing rings 8 on the outer surface. On the piston body 5 there is a through central hole, and the hole is made in steps of different diameters: the first diameter and length correspond to the length and diameter of the sleeve-insulator 11, the second diameter of the hole is equal to the diameter of the piston sealing part 3 and the length allowing the piston 2 to be moved by the required amount , the third diameter of the hole is equal to the diameter of the smaller part of the insulating washer 12.

In the initial position, the piston 2 is fixed against movement by a locking washer 10, which is sandwiched between the piston and the contact rod 7 and rests on the sleeve-insulator 11 and the piston body 5. The electronic block 13 switching contacts, the housing 5 of the piston, the locking washer 10 are fixed in the housing 1 of the device by a nut 6.

In the initial position, the piston 2 also does not ensure the tightness of the piston block, because the piston o-rings are located in the bushing-insulator 11.

From the opposite part of the device casing 1, a detonator latch 17 is installed, which is a cylindrical sleeve with a belt abutting against the end groove of the device casing 1. The detonator retainer 17 has three through holes, one of which is located in the center of the sleeve, the second and third are equidistant from the central hole. An explosive chain consisting of an electric detonator 14, a detonating cord 15, a transfer charge 16 is installed in the central through hole of the detonator 17, a terminal 18 is installed in the second and third holes of the detonator retainer 17 sleeve, which is a contact with folded tabs made of non-ferrous metal sheet; terminal 18 provides electrical communication of the device with the intermediate section 31 of the punch.

The entire electrical circuit of the device, presented in the form of a contact rod 7, a piston 2, a sliding contact 22, a central wire 19 of the punch, terminal 18 carries out an end-to-end transmission of the electrical contact when connecting the sections of the punchers with each other.

The electric detonator 14 interacts with the electronic contact switching unit 13 through the wire 20, which forms the primary winding of the electric detonator, and is connected to the electronic key 24, which ensures the disconnection of the electric detonator wire 20 with the central wire of the puncher 19 and the sliding contact 22 closes with the central wire of the puncher 19 in the initial state devices.

The Assembly of the perforation system with a device for sequential initiation of the perforation system is as follows.

An electronic contact switching module 13 is installed in the central hole of the device housing 1 until it stops in the inner step of the device housing 1, while the central wire of the punch 19 is then led out through the central hole of the device housing 1 from the opposite side.

The piston assembly assembly, consisting of a housing 5, a piston 2, sealing rings 8 and 9, an insulating sleeve 11, an insulating washer 12, a contact rod 7 and a fixing washer 10, is installed in the seat of the device housing 1 from the side of the already installed electronic unit 13 switching contacts, while the initiating part 4 of the piston 2 is electrically closed with the sliding contact 22 of the electronic block 12 switching contacts, and the sealing part 3 of the piston is completely located in the sleeve-insulator 11.

To fix the electronic unit 13 for switching contacts and the piston unit, the nut 6 is screwed into the end face of the device 6. Next, the latch 17 and the elements of the explosive circuit are prepared - the transfer charge 16, the detonating cord segment 15, the detonator 14.

Using a special tool, crimp the charge of the transfer 16 on the segment of the detonating cord 15 and, further, crimping the electric detonator 14 on the opposite side of the segment of the detonating cord 15.

The finished blasting chain, with the transfer charge side 16 installed, is installed in the central hole of the detonator lock 17. Next, the terminal 18 is connected to the central wire 19 of the perforator, installed in the free holes of the detonator retainer 17. The wire 20 of the electric detonator is used to form the primary winding of the electric detonator 14, making 5-6 turns around the coil 21 of the electric detonator, they are connected with the electronic key 24 of the electronic contact switching unit 13, which in the initial position opens the wire 20 of the electric detonator with the central wire 19 of the punch. After that, the detonator lock 17 assembly together with the explosive chain is installed in the bore hole of the device body 1 from the side opposite to the installation of the piston block and nut 6.

Similarly, the required number of devices for sequential initiation of the perforation system is assembled, depending on the planned number of perforation intervals performed in one run. Each assembled device is installed in the upper part of the equipped sections of the perforator, while the electrical circuit of the devices in the form of a contact rod 7, a piston 2, a sliding contact 22, the central wire 19 of the perforator, terminal 18 provides a transit electrical communication between adjacent sections of the perforator.

A device for sequential initiation of a perforation system operates as follows

After equipment operations, the assembly of the perforation system is lowered into the well fixed by the casing 25 on the geophysical cable 28 or on a flexible tubing with a missed geophysical cable. After positioning on the required perforation interval by the firing operator, a pulse is emitted from the high-frequency perforator device, which, passing through the central core of the geophysical cable, the central wire of the perforation system, initiates the lower section 30 of the cumulative perforator, cumulative charges pierce the casing 25, annular cement stone 26 and rock breed 27. As a result of actuation of the lower section 30 of the punch due to the pressure of the products of the explosion, the locking washer 10 is cut off, releasing the piston 2 and its movement is carried out. The piston moves all the way into the transition of the second internal diameter of the piston body 5 to the third, while the sealing rings 9 begin to fulfill their function in the metal-metal connection, sealing the intermediate section 31 of the perforator from the bottom fluid perforator filling the lower section 30. The initiating part 4 of the piston, moving, activates the sensor 23 located in the electronic block 13 of the contact switch. The change in the state of the sensor 23 as a result of the movement of the piston 2 leads to the closure of the electronic key 24 connecting the contacts of the electric detonator 14 with the central wire 19 of the punch, i.e. cocking the electric detonator 14 of the first device 33 for sequential perforation into the combat position, the central wire 19 of the perforator with the sliding contact 22 is thus opened.

The time taken to cut the retaining washer 10, move the piston 2, activate and switch the electronic key, connect the electric detonator 14 of the first sequential device 33 to the central wire 19 of the punch, is at least 2 seconds, which is sufficient to exclude the possibility of its operation simultaneously with the electric detonator 14 of the lower section 30. The piston 2 as a result of movement acts as a sealing plug in the housing 5 and does not allow the well fluid to penetrate into the intermediate section 31 erforatora.

After perforation of the first interval 35, the logging station operator performs positioning of the perforation assembly on the second perforation interval. When a second pulse is supplied from an explosive device, the electric detonator 14 of the first device 33 for sequential perforation is triggered, while, similarly to the previously described algorithm for actuating the lower section 30, the pressure of the explosion products of the intermediate section 31 of the perforator cuts the retaining washer 10, moves the piston 2, changes the state of the sensor 23, switches an electronic key 24 and connecting the electric detonator 14 of the second device 34 for sequential perforation.

After perforation of the second interval 36, the assembly of the cumulative perforator is positioned in the third interval, the third pulse is supplied from the explosive machine, and then the process proceeds according to an algorithm similar to the actions when the second signal was applied.

The result of the above works is to obtain perforated scattered intervals 38 for one tripping operation, and the time interval between the supply of the first and second signals from the explosive device, the second and third signals, the third and subsequent signals is not limited and is regulated by the detonator.

The use of this device is not limited to the possibility of use only in conjunction with sections of a cumulative perforator, it can be used to sequentially initiate any downhole equipment, which can be used electric means of initiation. An example of the application of this device can be an arrangement consisting of an explosive slip packer and several sections of a cumulative perforator.

The technical result of the invention is the actuation from the supply of one pulse from an explosive device, only one of several electric detonators of the perforation system, in strict sequence, from the bottom up - 5, 4, 3, 2, 1 sections, placed by the operator, at the time of the pulse, in place the location of one of several disparate intervals, which allows you to create a reliable system of sequential initiation of a perforator for perforation of disparate intervals for one tripping operation, sklyuchayuschuyu probability of simultaneous actuation of several electric detonators and accordingly sections perforator for supplying a single pulse with an explosive device and ensures safe performance to conventional and widespread on the market of RF means of initiation of the setting of high-frequency AC pulse.

Claims (4)

1. A device for sequentially initiating a perforation system, comprising a device body, an electric detonator, a detonating cord, an electric wire, a detonation transmission device, a piston, characterized in that the piston is located in a housing made in the form of a cylinder with a stepped through hole; the piston has a sealing and initiating parts and is fixed in the housing from movement by a locking washer; the piston is isolated from the housing by an insulating sleeve and an insulating washer; An electronic contact switching unit, made in the form of an electronic key triggered by a change in the state of the sensor, is additionally included in the mechanical contact switching chain. 2. The device according to claim 1, characterized in that the electronic key is triggered by a change in the state of the induction sensor. 3. The device according to claim 1, characterized in that the electronic key is triggered by a change in the state of the optical sensor. 4. The device according to claim 1, characterized in that the electronic key is triggered by a change in the state of the capacitive proximity sensor.

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