Interlayer gun hydraulic delay dynamic negative pressure device

Abstract

The present invention belongs to the technical field of oilfield production equipment processing, and particularly relates to a sandwich gun hydraulic delay dynamic negative pressure device, which includes a perforating gun, an intermediate joint, a first centralizing pipe, a hydraulic delay dynamic negative pressure device, a hole-opening intermediate joint, a sandwich negative pressure gun, a positioning disc and a second centralizing pipe; the hydraulic delay dynamic negative pressure device is composed of an outer cylinder of the dynamic negative pressure device, a sliding cylinder, a negative pressure opening sliding valve, an inner piston, hydraulic oil, a limit fixing snap ring, a pin, a microporous kit and a liquid inlet hole; the assembled sliding cylinder assembly is installed in the outer cylinder of the dynamic negative pressure device and fixed by the limit fixing snap ring; the assembled negative pressure opening sliding valve and the inner piston are installed in the outer cylinder of the dynamic negative pressure device and are close to each other inside the sliding cylinder; the intermediate joint and the hole-opening intermediate joint are respectively installed at both ends of the hydraulic delay dynamic negative pressure device through threads. Using the sandwich gun to achieve tubing conveyed composite dynamic negative pressure perforation is the development and improvement of the tubing conveyed perforation technology.

Description

Technical Field

[0001] The present invention belongs to the technical field of oilfield production equipment, and particularly relates to a hydraulic delay dynamic negative pressure device for an interlayer gun. Background Art

[0002] Tubing conveyed perforation is the mainstream perforation technology in current oilfields. Especially with the development of new perforation technologies, composite perforation is increasingly used in tubing conveyed perforation. In terms of construction principle, the composite gunpowder in composite perforation takes a longer time to play its role compared to the perforating charge. The perforating charge completes perforation in the microsecond range, while the composite gunpowder completes combustion in the millisecond range to form high pressure and starts high-energy gas fracturing of the formation. That is to say, there is a certain time difference from the detonation of the perforator to complete perforation to the complete combustion of the gunpowder to generate high-energy gas pressure. Then, for combined dynamic negative pressure perforation during composite perforation, in terms of the action mechanism and the moment of dynamic negative pressure generation, it becomes a key technical point. If the dynamic negative pressure is generated earlier than the complete combustion of the composite gunpowder, the formed negative pressure will offset the high pressure energy generated by the high-energy gas, making the high-energy gas fracturing process ineffective, and the negative pressure effect will not achieve a more ideal result due to the reduction of the high and low pressure difference.

[0003] Originally, the purpose of dynamic negative pressure perforation is to clean the perforation channels instantaneously during perforation, and reduce the pollution and damage to the formation under the action of dynamic negative pressure. Under the action of the pressure difference, the compaction zone formed by the broken jet on the surface of the perforation channel wall restores the permeability of the hole wall to its original state. At the same time, the negative pressure difference will also cause the gas and liquid in the geological rock formation of the perforation holes to flow rapidly into the well under the action of the pressure difference. The refluxed gas and liquid carry the broken nitrates in the channels into the well, thereby effectively removing the pollution of the perforation channels during perforation and obtaining a cleaner perforation channel.

[0004] Therefore, to solve the problem of the time difference between the composite perforating composite gunpowder and the dynamic negative pressure, it is necessary to delay the start of the negative pressure. After ensuring that the high-energy gas pressure of the composite gunpowder fully acts on the geological formation, the dynamic negative pressure is started to complete effective tubing-conveyed composite dynamic perforating. The existing delay technology used in composite dynamic perforating uses the mechanical stroke method of the negative pressure device components for delay, and determines the delay time required for composite negative pressure perforating by the moving and falling stroke of the components. This delay technology is limited by the size of the negative pressure gun. In order to ensure that the overall device can provide sufficient delay time, the negative pressure gun is designed in two parts. The upper half of the negative pressure gun provides the space for the delay component to fall, and the perforating device is designed in the middle section of the entire negative pressure gun. During perforation, the detonation energy of the perforating gun activates the delay component, and the delay component accelerates downward under the action of kinetic energy, impacts the piston of the perforating device, and opens the negative pressure gun. Since the negative pressure device is structurally dispersed and assembled at the well site construction site, the two sections of the negative pressure gun are assembled with the negative pressure device and then butt-jointed, resulting in a very high labor intensity for workers. Summary of the Invention

[0005] In order to solve the above technical problems, the present invention provides a sandwich gun hydraulic delay dynamic negative pressure device. To give full play to the advantages of composite dynamic perforating for tubing-conveyed perforating and use the sandwich gun to achieve tubing-conveyed composite dynamic perforating is the development and improvement of tubing-conveyed perforating technology.

[0006] The technical solution adopted by the present invention is: a sandwich gun hydraulic delay dynamic negative pressure device, which includes a perforating gun, an intermediate joint, a first centralizer pipe, a hydraulic delay dynamic negative pressure device, a hole-opening intermediate joint, a sandwich negative pressure gun, a positioning disk and a second centralizer pipe; the hydraulic delay dynamic negative pressure device is composed of an outer cylinder of the dynamic negative pressure device, a sliding cylinder, a negative pressure hole-opening sliding valve, an inner piston, hydraulic oil, a limit fixing snap ring, a pin, a microporous kit and a liquid inlet hole; the sliding cylinder is installed on the sliding cylinder seat, and the microporous kit with micropores is installed on the outside of the sliding cylinder through threads. A syringe is used to fill the inner cavity with hydraulic oil through the micropores. The assembled components are installed in the outer cylinder of the dynamic negative pressure device and fixed by the limit fixing snap ring; the inner piston is installed in the negative pressure hole-opening sliding valve hole and a pin is installed; the assembled negative pressure hole-opening sliding valve and inner piston are installed in the outer cylinder of the dynamic negative pressure device and are close to the inside of the sliding cylinder; the intermediate joint and the hole-opening intermediate joint are respectively installed at both ends of the hydraulic delay dynamic negative pressure device through threads; the first centralizer pipe and the second centralizer pipe are respectively located in the intermediate joint and the hole-opening intermediate joint, the perforating gun and the positioning disk are respectively arranged on both sides of the hydraulic delay dynamic negative pressure device, and the sandwich negative pressure gun is connected to the hole-opening intermediate joint.

[0007] Further, an O-ring seal is provided on the outer circumference of the negative pressure hole-opening sliding valve.

[0008] Furthermore, the key technology of the sandwich gun's dynamic negative pressure perforation lies in the position and time node where the negative pressure zone is generated. Many times, the most direct approach is the most effective one. That is to say, in order to fully utilize the role of dynamic negative pressure during perforation, the acting time is also a crucial factor. The cavity structure of the sandwich gun body is exactly the prerequisite for the formation of negative pressure. Moreover, the position where the sandwich gun is located is the closest to the perforated interval. Therefore, making full use of the sandwich gun and developing its application in dynamic negative pressure precisely solves the problems of the acting position and acting time of dynamic negative pressure.

[0009] Furthermore, the sandwich gun hydraulic delay dynamic negative pressure device can make full use of the space of the idle cavity of the sandwich gun, turning the sandwich gun body into the body of a negative pressure gun. During perforation, the mechanical kinetic energy on the negative pressure device or the chemical kinetic energy of fire and explosives is used to open the liquid inlet hole of the negative pressure gun, connecting the internal and external spaces of the sandwich gun, allowing the high-pressure well fluid to flow through the hatch to the low-pressure area inside the sandwich gun cavity, instantly creating negative pressure in the sandwich gun section. This realizes the dynamic negative pressure perforation construction for tubing conveyed perforation using the sandwich gun. The negative pressure effect is used to instantaneously clean the perforation channels in real time, eliminate the compaction damage of the jet flow on the perforation channel wall during perforation, restore the permeability of the rock pores in the perforation channels, and improve the oil and gas production capacity after perforation.

[0010] The beneficial effects of the present invention: A sandwich gun hydraulic delay dynamic negative pressure device is provided. The required delay mechanism of the device uses hydraulic oil to drain through micropores. After the oil is completely drained, the device is further actuated to push the piston to open the liquid inlet hole of the negative pressure device, starting to establish dynamic negative pressure. The time taken for the oil drainage process is the time required for the delay. The delay time can be calculated and determined by the amount of hydraulic oil in the oil chamber and the diameter of the micropores, controlling the required delay time during the transmission process. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a schematic cross-sectional structure diagram of Embodiment 1.

[0012] Figure 2 It is a schematic structure diagram of the hydraulic delay dynamic negative pressure device in Embodiment 1.

[0013] Figure 3 It is a schematic structure diagram of the outer cylinder of the dynamic negative pressure device in Embodiment 1.

[0014] Figure 4 is Figure 3 The sectional view taken along A - A in EMBODIMENTS Embodiment

[0015] Referring to the various figures, a sandwich gun hydraulic delay dynamic negative pressure device, the sandwich gun hydraulic delay dynamic negative pressure device includes a perforating gun 1, an intermediate joint 2, a first centralizer tube 3, a hydraulic delay dynamic negative pressure device 4, a hole-opening intermediate joint 5, a sandwich negative pressure gun 6, a positioning disc 7 and a second centralizer tube 8; the hydraulic delay dynamic negative pressure device 4 is composed of a dynamic negative pressure device outer cylinder 401, a sliding cylinder 402, a negative pressure opening sliding valve 403, an inner piston 404, hydraulic oil 405, a limit fixing snap ring 406, a pin 407, a microporous kit 408 and a liquid inlet hole 409; the sliding cylinder is installed on the sliding cylinder seat, and the microporous kit with micropores is installed on the outside of the sliding cylinder through threads, and the inner cavity is filled with hydraulic oil through the micropores using a syringe, and the assembled components are installed in the dynamic negative pressure device outer cylinder and fixed by the limit fixing snap ring; the inner piston is installed in the negative pressure opening sliding valve hole and the pin is installed; the assembled negative pressure opening sliding valve and inner piston are installed in the dynamic negative pressure device outer cylinder and are close to the inside of the sliding cylinder; the intermediate joint and the hole-opening intermediate joint are respectively installed at both ends of the hydraulic delay dynamic negative pressure device through threads; the first centralizer tube and the second centralizer tube are respectively located in the intermediate joint and the hole-opening intermediate joint, the perforating gun and the positioning disc are respectively arranged on both sides of the hydraulic delay dynamic negative pressure device, and the sandwich negative pressure gun is connected to the hole-opening intermediate joint; an O-ring seal is provided on the outer circumference of the negative pressure opening sliding valve.

[0016] When implementing tubing conveyed composite dynamic negative pressure perforation on an oil and gas well, first connect it to the upper end of the negative pressure gun, connect the negative pressure gun to the lower end of the adjacent perforating gun, so that the hydraulic delay dynamic negative pressure device is in the middle position between the perforating gun and the negative pressure gun. When the perforating string of the entire oil and gas well is conveyed to the designated perforating geological formation section by the tubing, through mechanical dropping of a bar or pressure initiation method, the perforator is initiated for perforation. The energy generated in the perforating gun acts on the sliding cylinder through the central hole of the intermediate joint. At the same time, the sliding cylinder pushes the negative pressure opening sliding valve forward. During the forward movement of the sliding cylinder, the hydraulic oil in the oil cavity is discharged through the micropores. When the hydraulic oil is completely discharged, the liquid inlet hole closed by the negative pressure opening sliding valve opens, and the well fluid flows into the negative pressure device from the liquid inlet hole. Under the action of the well fluid pressure, the inner piston shears the pin and falls into the sandwich gun. All the channels for the well fluid to enter the sandwich gun are opened, and the well fluid surges into the sandwich gun instantly, causing the confining pressure in the wellbore to drop rapidly, forming a negative pressure and completing the tubing conveyed composite dynamic negative pressure perforation.

[0017] The sandwich gun hydraulic delay dynamic negative pressure device is applied to tubing conveyed composite perforation. The delay mechanism of the device can ensure that the composite gunpowder of the composite perforation can be fully burned to generate sufficient gas pressure and act on the holes and geological strata of the perforation section. The delay mechanism is an important component indispensable for composite perforation. In terms of the working principle, it adopts hydraulic microporous oil drainage to delay the mechanical action of the negative pressure device. During the mechanical action process, the time taken for the oil in the hydraulic oil cavity to be completely discharged is the delay time for the mechanical action to open the liquid inlet hole of the negative pressure device.

[0018] Since the delay time of the hydraulic delay dynamic negative pressure device of the tubing conveyed combined perforating sandwich gun is determined based on the complete combustion time of the combined gunpowder carried by the perforating gun (generally between 10 and 30 ms), therefore, the delay action is usually designed at 30 ms to ensure that the liquid inlet hole 409 of the negative pressure device is opened at a reasonable moment (about 10 ms after the gunpowder combustion generates the maximum pressure peak). Therefore, the diameter of the liquid drainage micropores on the negative pressure device is determined according to the oil volume in the oil chamber and the required delay time of 30 ms.

[0019] The required delay mechanism of the device uses hydraulic oil to drain oil through the micropores. After the oil is completely drained, it further acts on the device mechanism to push the piston of the device to open the liquid inlet hole on the negative pressure device and start to establish dynamic negative pressure. The time taken for the oil drainage process is the delay time required. The delay time can be calculated and determined by the hydraulic oil volume in the oil chamber and the diameter of the micropores. The transfer process controls the required delay time.

[0020] The required delay mechanism of the device is designed using the hydraulic principle, and the required delay time is controlled by the transfer process of the hydraulic oil. Since the hydraulic system and the dynamic negative pressure opening device are designed at the middle connection of the perforating gun and the negative pressure gun, the overall volume of the device is slightly larger than the middle joint of the perforating gun, and they are connected to each other in a sliding sleeve manner that is convenient for operation. Therefore, the overall structure design of the dynamic negative pressure device from the delay mechanism to the opening device is compact, which is convenient for use and installation at the construction site and greatly reduces the labor intensity of the operating workers. The transfer of the hydraulic oil in the hydraulic delay device between two adjacent oil chambers in the device controls the piston movement of the opening device to open the liquid inlet hole of the negative pressure gun. Therefore, the delay time is easy to control.

[0021] Since the hydraulic system and the dynamic negative pressure opening device are designed at the middle connection of the perforating gun and the negative pressure gun, the dynamic negative pressure device is assembled on the upper end of the sandwich gun and then the middle joint is assembled. During the tubing conveyed perforating construction, the sandwich gun with the dynamic negative pressure device replaces the sandwich gun in the original perforating string to realize the tubing conveyed combined dynamic negative pressure perforation. Therefore, the perforation implemented by using the sandwich gun hydraulic delay dynamic negative pressure perforation device does not change the original perforation process, does not increase the difficulty of the construction operation, and the perforating construction is simple and easy to perform.

Claims

1. A method for perforating under negative pressure using a sandwich gun hydraulic delay dynamic negative pressure device, Characterized in that: Perforating is carried out using a sandwich gun hydraulic delay dynamic negative pressure device. The sandwich gun hydraulic delay dynamic negative pressure device includes a perforating gun, an intermediate joint, a first centralizer tube, a hydraulic delay dynamic negative pressure device, a hole-opening intermediate joint, a sandwich negative pressure gun, a positioning disc and a second centralizer tube; the hydraulic delay dynamic negative pressure device is composed of an outer cylinder of the dynamic negative pressure device, a sliding cylinder, a negative pressure opening sliding valve, an inner piston, hydraulic oil, a limit fixing snap ring, a pin, a microporous kit and a liquid inlet hole; the sliding cylinder is installed on the sliding cylinder seat, and the microporous kit with micropores is installed on the outside of the sliding cylinder through threads. A syringe is used to fill the inner cavity with hydraulic oil through the micropores. The assembled components are installed in the outer cylinder of the dynamic negative pressure device and fixed by the limit fixing snap ring. The outer cylinder of the dynamic negative pressure device is provided with a liquid inlet hole; the inner piston is installed in the negative pressure opening sliding valve hole and a pin is installed; the assembled negative pressure opening sliding valve and inner piston are installed in the outer cylinder of the dynamic negative pressure device and are close to the inside of the sliding cylinder; the intermediate joint and the hole-opening intermediate joint are respectively installed at both ends of the hydraulic delay dynamic negative pressure device through threads; the first centralizer tube and the second centralizer tube are respectively located in the intermediate joint and the hole-opening intermediate joint, the perforating gun and the positioning disc are respectively arranged on both sides of the hydraulic delay dynamic negative pressure device, and the sandwich negative pressure gun is connected to the hole-opening intermediate joint.

2. The method for perforating under negative pressure using a sandwich gun hydraulic delay dynamic negative pressure device according to claim 1, Characterized in that: An O-ring seal is provided on the outer circumference of the negative pressure opening sliding valve.

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