Liquid actuated opening safety primer

Abstract

This invention provides a hydraulically operated safe detonation device, relating to the field of oil and gas well completion technology. It includes: a housing, an inner core assembly embedded within the housing, and a sliding valve assembly located on one working face of the inner core assembly. The housing is a cylindrical hollow structure with a connecting hole for connecting to the sliding valve assembly. The housing has a preset receiving space for installing the inner core assembly. The inner core assembly is adapted to the working dimensions of the receiving space. The sliding valve assembly is connected to the housing via an internal hexagonal screw and is located in the middle of the housing. Under normal ground pressure, this invention automatically isolates the detonation transmission channel between the detonator and the perforating gun. Even if the detonator is accidentally triggered, its explosive energy cannot be transmitted to the perforating gun string, completely eliminating the safety hazard of accidental explosion of the perforating gun string during surface maintenance.

Description

Technical Field

[0001] This invention relates to the field of oil and gas well completion technology, and in particular to a hydraulically operated opening safety detonation device. Background Technology

[0002] In oil and gas field development, perforation is a necessary operation after drilling and cementing. Perforation is a crucial process in which a perforating gun loaded with perforating cartridges is lowered into the wellbore to a predetermined location. The cartridges are then detonated by a detonating device, allowing the metal jet to penetrate the casing and cement sheath, reaching deep into the formation and establishing a fluid channel between the formation and the wellbore. The quality of perforation operations directly affects the productivity and service life of oil and gas wells.

[0003] Currently, the main method of transporting perforating gun strings is cable-driven perforation. However, during actual operations, due to various reasons such as complex downhole environments, equipment malfunctions, and operational errors, situations frequently arise where the perforating gun strings fail to detonate properly after being lowered into the well. In such cases, the perforating gun strings must be lifted to the surface for inspection. During surface inspection, the gun head components must first be removed. These components contain pyrotechnic hazards such as detonators. Because detonators are highly sensitive to external stimuli such as impact, friction, static electricity, and electromagnetic induction, they are easily triggered accidentally during disassembly, handling, and inspection. Once the detonator is accidentally detonated, the resulting explosive energy will be rapidly transferred to the entire perforating gun string through the detonating cord, causing the perforating gun strings to explode on the surface. The perforating gun strings contain a large number of high-energy perforating rounds, whose explosive power is enormous, causing serious consequences such as casualties, equipment damage, and destruction of well site facilities. It may even trigger secondary disasters such as blowouts and fires, with unimaginable consequences. Summary of the Invention

[0004] The purpose of this invention is to provide a hydraulically operated opening safety detonation device to solve the technical problems existing in the prior art.

[0005] To achieve the above-mentioned objectives, the technical solution adopted by this invention is as follows:

[0006] A hydraulically operated open-end safety detonation device includes: a housing, an inner core assembly embedded within the housing, and a slide valve assembly located on one working surface of the inner core assembly; the housing is a cylindrical hollow structure with a connection hole for connecting to the slide valve assembly; the housing has a preset receiving space for installing the inner core assembly; the inner core assembly is adapted to the working dimensions of the receiving space; the slide valve assembly is connected to the housing via an internal hexagonal screw and is located in the middle of the housing.

[0007] Furthermore, the inner core assembly includes: a copper tube, an outer sleeve fitted over the copper tube, an upper contact pin and a lower contact pin located at both ends of the copper tube, and a detonator connected to the lower contact pin by bolts; the upper contact pin is press-fitted into the copper tube by a screw plug, and its lower end is located on a first spring; the positive terminal of the detonator is connected to the lower contact pin, and the negative terminal is connected to the outer sleeve; one end of the detonator is connected to a detonating cord; the outer sleeve is connected to a first pressure cap by a first set screw, which is used to fix the first pressure cap to the outer sleeve; the detonating cord is connected to a detonating tube, which is used to receive the energy of the detonating cord and detonate it; the detonator, detonating cord, and detonating tube are fixedly connected to the outer sleeve by a second set screw.

[0008] Furthermore, the upper end of the upper contact pin has a spherical surface with a radius of 2.5 mm, which is used for electrical contact with the external sliding sleeve assembly.

[0009] Furthermore, the outer casing has a preset strength and a notch is provided on the upper side for connecting the ground wire of the detonator.

[0010] Furthermore, the slide valve assembly includes: a slide valve sleeve, a slide valve inserted into the slide valve sleeve, a push rod sleeved with the slide valve sleeve, and a plug and a pressure cap respectively threaded to both ends of the slide valve sleeve; a second spring is provided between the slide valve and the slide valve sleeve, and one end of the second spring is connected to the plug; the push rod has a preset hardness, and under normal pressure, the push rod is tightly connected to the slide valve sleeve, sealing the through hole in the center of the slide valve sleeve.

[0011] Furthermore, a first sealing ring is provided between the slide valve sleeve and the housing, the first sealing ring being used to seal the gap between the slide valve sleeve and the housing; a second sealing ring is provided between the slide valve sleeve and the push rod, the second sealing ring being used to seal the gap between the push rod and the slide valve sleeve.

[0012] Furthermore, the depths of the upper and lower through grooves in the middle part of the valve sleeve are 3mm and 5mm, respectively.

[0013] Furthermore, the push rod is frustum-shaped, with a large end diameter of 10mm and a small end diameter of 6mm; the length of the push rod is 25mm.

[0014] Compared with the prior art, the present invention has the following beneficial effects:

[0015] (i) Under normal ground pressure, the slide valve assembly of this invention automatically cuts off the explosion transmission channel between the detonator and the perforating gun. Even if the detonator is accidentally triggered, its explosive energy cannot be transmitted to the perforating gun string, thus completely eliminating the safety hazard of accidental explosion of the perforating gun string during ground maintenance.

[0016] (ii) The present invention uses well fluid pressure as a control signal, eliminating the need for power supply and electronic control components, thus avoiding electromagnetic interference and electronic component failure. Furthermore, the slide valve assembly adopts a push rod side-push type and slide valve avoidance type structure, which is flexible in operation and free from jamming, and can still work reliably in the high temperature and high pressure environment downhole.

[0017] (iii) The inner core component of the present invention can be installed and disassembled separately, which shortens the maintenance time, reduces the risk of workers coming into contact with explosives, and improves the safety of use; the present invention can adapt to different well fluid pressure requirements by adjusting the stiffness of the second spring, and has wide applicability. Attached Figure Description

[0018] Figure 1 This is a front view of a hydraulically operated open-end safety detonation device disclosed in this invention;

[0019] Figure 2 This is a schematic diagram of the internal structure of a hydraulically operated open-type safety detonation device disclosed in this invention;

[0020] Figure 3 This is a schematic diagram of the assembly of the inner core components of a hydraulically operated open-end safety detonation device disclosed in this invention;

[0021] Figure 4 This is a schematic diagram of the internal structure of the slide valve assembly of a hydraulically operated open-end safety detonation device disclosed in this invention;

[0022] Figure 5 This is a schematic diagram of the slide valve assembly of a hydraulically operated open-end safety detonation device disclosed in this invention;

[0023] Figure 6 This is a front view of the slide valve sleeve of a hydraulically operated open-end safety detonation device disclosed in this invention;

[0024] Figure 7 This is a front view of the slide valve of a hydraulically operated open-end safety detonation device disclosed in this invention;

[0025] Figure 8 This is a front view of the top rod of a hydraulically operated open-end safety detonation device disclosed in this invention;

[0026] Figure 9 This is a top view of the second pressure cap of a hydraulically operated open-end safety detonation device disclosed in this invention;

[0027] Figure 10 This is a front view of the outer casing of a hydraulically operated open-type safety detonation device disclosed in this invention.

[0028] In the diagram: 1. Housing; 2. Inner core assembly; 201. Upper contact pin; 202. Plug; 203. First pressure cap; 204. Copper tube; 205. First spring; 206. First set screw; 207. Lower contact pin; 208. Bolt; 209. Detonator; 210. Outer casing; 211. Detonating cord; 212. Second set screw; 213. Detonation tube; 3. Socket head screw; 4. Slide valve assembly; 401. Plug; 402. Second spring; 403. Slide valve; 404. Slide valve sleeve; 405. First sealing ring; 406. Push rod; 407. Second sealing ring; 408. Second pressure cap. Detailed Implementation

[0029] To make the content of this invention easier to understand, the technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Identical components are represented by the same reference numerals. It should be noted that the terms "front," "rear," "left," "right," "up," and "down" used in the following description refer to directions in the accompanying drawings, while the terms "inner" and "outer" refer to directions toward or away from the geometric center of a specific component, respectively.

[0030] like Figure 1-2 As shown, this embodiment provides a hydraulically operated open-end safety detonation device, including: a housing 1, an inner core assembly 2 embedded in the housing 1, and a slide valve assembly 4 disposed on one working surface of the inner core assembly 2; the housing 1 is a columnar hollow structure, made of 35CrMo, with a hardness of HRC30-35 after heat treatment; a connecting hole is provided on it, which is used to connect with the slide valve assembly 4; four disassembly hook plate holes with a diameter of 11mm are evenly provided on the outer circle of the upper end of the housing 1, and a transverse stepped hole is provided in the middle part, which is used to install the slide valve assembly 4; The lower end of the housing 1 is provided with an external thread for connecting to the perforation gun interface, and also has two pressure relief holes with a diameter of 7mm and an inner hole with a diameter of 25mm. The inner hole is for inserting the straightening tube of the lower perforation gun. The housing 1 has a preset receiving space for installing the inner core assembly 2. The inner core assembly 2 is adapted to the working size of the receiving space. The slide valve assembly 4 is connected to the housing 1 by a hexagon socket screw 3 and is located in the middle of the housing 1. The hexagon socket screw 3 is used to fix the slide valve assembly 4 in the transverse stepped hole of the housing 1.

[0031] like Figure 3 and Figure 10As shown, the inner core assembly 2 includes: a copper tube 204, an outer sleeve 210 sleeved over the copper tube 204, an upper contact pin 201 and a lower contact pin 207 located at both ends of the copper tube 204, and a detonator 209 connected to the lower contact pin 207 by bolts 208; the upper contact pin 201 is made of H59 copper and is press-fitted into the copper tube 204 by a screw plug 202, with its lower end attached to a first spring 205 made of stainless steel, which applies a certain preload to the upper contact pin 201 to ensure that the upper contact pin 201 is always in close contact with the contact point of the external sliding sleeve assembly; under the action of external force, it can extend and retract axially along the copper tube 204; The plug 202 is made of polytetrafluoroethylene, and two blind holes, each 3mm in diameter, are provided on its upper surface for disassembly and assembly. The upper contact pin 201 has a spherical surface with a radius of 2.5mm at its upper end, which is used for contact with the external sliding sleeve assembly to complete the current conduction. The lower contact pin 207 is made of H59 copper, and its upper end is pressed by the first spring 205. The positive terminal of the detonator 209 is connected to the lower contact pin 207, and the negative terminal is connected to the outer casing 210. The detonator 209 is a high-resistance detonator, and one end of it is connected to the detonating cord 211. When the power is turned on, the energy of the explosion can detonate the detonating cord 211 connected to it at the lower end. The outer casing 210 is secured by the first set screw 2. 06 is connected to the first pressure cap 203, and the first set screw 206 is used to fix the first pressure cap 203 to the outer sleeve 210; the outer sleeve 210 has a preset strength and a notch is opened on the upper side, the notch is used to connect the ground wire of the detonator 209; the detonating cord 211 is connected to the detonating tube 213, the detonating tube 213 is used to receive the energy of the detonating cord 211 and detonate it quickly; the detonator 209, the detonating cord 211 and the detonating tube 213 are fixedly connected to the outer sleeve 210 by the second set screw 212; in use, the operator presses the copper tube 204 into the lower end hole of the first pressure cap 203 and installs the lower contact pin in sequence. 207. First spring 205 and upper contact pin 201; then, the operator screws the plug 202 into the internal threaded hole at the upper end of the first pressure cap 203, and securely connects both ends of the detonating cord 211 to the detonator 209 and the detonating tube 213 respectively; then, the operator assembles the assembled detonator 209, detonating cord 211 and detonating tube 213 into the center hole of the outer casing 210, and fixes it with the second set screw 212; assembles the first pressure cap 203 into the upper hole of the outer casing 210, and fixes it with the first set screw 206; then, the operator uses bolts 208 to press the positive and negative leads of the detonator 209 onto the lower contact pin 207 and the outer casing 210 respectively.

[0032] like Figure 4-9As shown, the slide valve assembly 4 includes: a slide valve sleeve 404, a slide valve 403 inserted into the slide valve sleeve 404, a push rod 406 sleeved with the slide valve sleeve 404, and a plug 401 and a second pressure cap 408 threadedly connected to both ends of the slide valve sleeve 404 respectively; a second spring 402 is provided between the slide valve 403 and the slide valve sleeve 404, one end of the second spring 402 is connected to the plug 401, the second spring 402 is made of stainless steel, and the other end contacts the slide valve 403 to provide pressure to one end of the slide valve 403, so that the slide valve 403 always presses against the slide valve sleeve 404 under normal pressure, blocking the through hole at the center of the slide valve sleeve 404; the upper part of the middle part of the slide valve sleeve 404 The lower through grooves are 3mm and 5mm deep, respectively, and each groove bottom has a 7mm diameter hole, the same as the through hole. The push rod 406 is made of 35CrMo and has a preset hardness. Under normal pressure, the push rod 406 is tightly connected to the slide valve sleeve 404, sealing the through hole in the center of the slide valve sleeve 404, so that the upper and lower through holes are different. When the perforating gun string is lowered to a certain depth in the wellbore, the well fluid pressure pushes the push rod 406 to the left, and the displacement distance is just enough to clear the center of the slide valve sleeve 404, so that the two through holes of the slide valve sleeve 404 are connected. In this embodiment, the push rod 406 is frustum-shaped, with a large end diameter of 10mm and a small end diameter of 6mm. The length of the push rod 406 is 25mm.

[0033] Furthermore, to improve the overall sealing performance of the device, a first sealing ring 405 is provided between the slide valve sleeve 404 and the housing 1. The first sealing ring 405 is used to seal the gap between the slide valve sleeve 404 and the housing 1 to prevent well fluid from entering the slide valve assembly 4. A second sealing ring 407 is provided between the slide valve sleeve 404 and the push rod 406. The second sealing ring 407 is used to seal the gap between the push rod 406 and the slide valve sleeve 404 to prevent well fluid from entering. At this time, the operator sequentially installs the slide valve 403 and the second spring 402 into the center hole of the slide valve sleeve 404; then, screws the plug 401 into the external thread on the left end of the slide valve sleeve 404; puts the first sealing ring 405 into the sealing groove on the right end of the slide valve sleeve 404; at the same time, puts the second sealing ring 407 into the sealing groove on the large end of the push rod 406, and installs the push rod 406 into the eccentric stepped hole on the right end of the slide valve sleeve 404; then, screws the second pressure cap 408 into the internal thread of the eccentric stepped hole on the right end of the slide valve sleeve 404.

[0034] Workflow:

[0035] 1. Ground surface under normal pressure:

[0036] When the hydraulically operated opening safety detonation device is under normal ground pressure, the well fluid pressure is zero. At this time, the elastic force of the second spring 402 acts on the left end of the slide valve 403, causing the slide valve 403 to move to the right and press against the inner end face of the slide valve sleeve 404. At the same time, the right end face of the slide valve 403 pushes the push rod 406 to the right, causing the right end face of the push rod 406 to press against the left end face of the second pressure cap 408. In this state, the right end face of the slide valve 403 completely covers the slide valve sleeve 404. The upper and lower through holes in the middle section isolate the passage between them, completely cutting off the detonation transmission channel. At this time, even if the detonator 209 is triggered due to some accident, the energy generated by the explosion of the detonator 209 can only detonate the detonating cord 211 and the detonation transmission tube 213 at its lower end. Since the detonation transmission channel is isolated by the slide valve 403, the explosion energy cannot be transmitted to the detonating cord inside the perforating gun, so it will not detonate the perforating gun string, thus ensuring safety during ground maintenance.

[0037] 2. Underground working conditions:

[0038] When the hydraulically operated safety detonation device is lowered into the well along with the perforating gun string, the well fluid pressure gradually increases with the well depth. The well fluid acts on the right end face of the push rod 406 through the through hole on the second pressure cap 408, generating a leftward thrust on the push rod 406. When the perforating gun string is lowered to the predetermined depth, the thrust generated by the well fluid pressure is greater than the elastic force of the second spring 402, and the push rod 406 begins to move to the left, pushing the slide valve 403 to the left and compressing the second spring 402. After the push rod 406 moves to the left, the right end face of the slide valve 403 completely opens the upper and lower through holes in the middle part of the slide valve sleeve 404, making the channel between the upper and lower through holes fully open, transmitting... The detonation channel is fully open; at this time, the conductive contacts of the sliding sleeve assembly contact the upper contact pin 201, and the current flows through the upper contact pin 201, copper tube 204, lower contact pin 207, and bolt 208 to the positive terminal of the detonator 209, and then through the negative terminal of the detonator 209, screw plug 202, outer sleeve 210, and housing 1 to the ground, forming a closed circuit; when the current reaches the detonation current of the detonator 209, the detonator 209 explodes, detonating the detonating cord 211 and the detonation transmission tube 213 at its lower end; the energy generated by the explosion of the detonation transmission tube 213 is transmitted to the detonating cord in the perforating gun through the upper through hole, central hole, and lower through hole of the sliding valve sleeve 404, thereby detonating the entire perforating gun string and completing the perforation operation.

[0039] 3. Lifting process:

[0040] After the perforation operation is completed, the perforating gun string is raised to the surface. As the well depth decreases, the well fluid pressure gradually decreases. When the thrust generated by the well fluid pressure is less than the elastic force of the second spring 402, the second spring 402 pushes the slide valve 403 to the right, and the slide valve 403 pushes the push rod 406 to the right, thus re-isolating the explosion transmission channel. Even if an accident occurs during the raising of the perforating gun string, it will not cause the perforating gun string to explode on the surface.

[0041] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A hydraulically operated open-aperture safety detonation device, characterized in that: include: The housing (1), the inner core assembly (2) embedded in the housing (1), and the slide valve assembly (4) located on one end working surface of the inner core assembly (2). The housing (1) is a columnar hollow structure with a connection hole on it, which is used to connect with the slide valve assembly (4); The housing (1) has a preset receiving space for installing the inner core assembly (2). The inner core assembly (2) is adapted to the working dimensions of the receiving space; The slide valve assembly (4) is connected to the housing (1) by an internal hexagon screw (3) and is located in the middle of the housing (1).

2. The hydraulically operated opening safety detonation device according to claim 1, characterized in that: The inner core assembly (2) includes: a copper tube (204), an outer sleeve (210) sleeved outside the copper tube (204), an upper contact pin (201) and a lower contact pin (207) disposed at both ends of the copper tube (204), and a detonator (209) connected to the lower contact pin (207) by a bolt (208). The upper contact pin (201) is press-fitted into the copper tube (204) through a screw plug (202), and its lower end is provided on the first spring (205). The positive terminal of the detonator (209) is connected to the lower contact pin (207), and the negative terminal is connected to the outer casing (210); one end of the detonator (209) is connected to the detonating cord (211); The outer sleeve (210) is connected to the first pressure cap (203) by a first set screw (206), the first set screw (206) being used to fix the first pressure cap (203) to the outer sleeve (210); The detonating cord (211) is connected to a detonating tube (213), which is used to receive the energy of the detonating cord (211) and detonate it. The detonator (209), detonating cord (211), and detonating tube (213) are fixedly connected to the outer casing (210) by a second set screw (212).

3. The hydraulically operated opening safety detonation device according to claim 2, characterized in that: The upper end of the upper contact pin (201) is spherical with a radius of 2.5 mm, and it is used for electric contact with the external sliding sleeve assembly.

4. The hydraulically operated open-end safety detonation device according to claim 3, characterized in that: The outer jacket (210) has a preset strength and a notch is opened on the upper side, the notch being used to connect the ground wire of the detonator (209).

5. The hydraulically operated open-end safety detonation device according to claim 1, characterized in that: The slide valve assembly (4) includes: a slide valve sleeve (404), a slide valve (403) inserted into the slide valve sleeve (404), a push rod (406) sleeved with the slide valve sleeve (404), and a plug (401) and a second pressure cap (408) respectively threaded to both ends of the slide valve sleeve (404). A second spring (402) is provided between the slide valve (403) and the slide valve sleeve (404), and one end of the second spring (402) is connected to the plug (401); The push rod (406) has a preset hardness. Under normal pressure, the push rod (406) is tightly connected to the slide valve sleeve (404) to seal the through hole in the center of the slide valve sleeve (404).

6. The hydraulically operated opening safety detonation device according to claim 5, characterized in that: A first sealing ring (405) is provided between the slide valve sleeve (404) and the housing (1), and the first sealing ring (405) is used to seal the gap between the slide valve sleeve (404) and the housing (1); a second sealing ring (407) is provided between the slide valve sleeve (404) and the push rod (406), and the second sealing ring (407) is used to seal the gap between the push rod (406) and the slide valve sleeve (404).

7. The hydraulically operated opening safety detonator according to claim 5 or 6, characterized in that: The depths of the upper and lower through grooves in the middle part of the slide valve sleeve (404) are 3mm and 5mm, respectively.

8. The hydraulically operated open-end safety detonation device according to claim 1, characterized in that: The top rod (406) is frustum-shaped, with a large end diameter of 10mm and a small end diameter of 6mm; the length of the top rod (406) is 25mm.

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