Connecting device for underground fracturing

Abstract

The connecting device comprises a cover body and an inner sealing push head, a flange connecting hole used for being fixedly connected with the upper end of a sealing crack shell through a bolt is formed in the outer side of the upper end of the cover body, and the sealing crack shell used for petroleum underground fracturing operation is arranged at the lower end of the cover body. Compared with the prior art, the sealing device has the advantages that the extension position of the connecting pipe sleeve is adjusted through the connecting pipe sleeve and the movable sleeve, the connecting pipe sleeve is connected and fixed through the positioning bolt, and the sealing device is simple in structure, convenient to use and high in practicability. External pressure water is guided in through the first water inlet end and the second water inlet end, an inner sealing push head is pushed upwards through an electric cylinder, a movable sleeve and a movable column are driven to move upwards, and pressure water in a communication base is guided into a sealing crack shell through an electric control valve.

Description

Technical Field

[0001] The utility model belongs to the technical field of petroleum downhole fracturing and relates to a connecting device for downhole fracturing. Background Art

[0002] Oil fracturing refers to a method of using hydraulic force to form cracks in oil and gas layers during oil or gas production, also known as hydraulic fracturing. The principle is to use a high-pressure ground pump group to inject a large amount of high-viscosity liquid into the formation through the wellbore, and build up high pressure at the bottom of the well. When the pressure exceeds the bearing capacity of the formation, cracks will form in the formation near the bottom of the well. Continue to inject liquid carrying proppants, and the cracks will gradually extend forward. The proppants play a role in supporting the cracks, forming sand-filled cracks with a certain size and high conductivity, so that oil and gas can easily flow into the well through the cracks, thereby increasing the oil and gas seepage channel and greatly increasing production. During the oil fracturing process, if the pressure in the oil fracturing pipe cannot be actively applied, a series of problems may arise, which will not only affect the fracturing effect, but may also lead to production safety accidents.

[0003] The main purpose of oil fracturing is to use high pressure to fracture the rock layer under the well to form cracks so that the oil can flow out more smoothly. If the pressure in the fracturing pipe cannot be actively applied, then it will not be able to form enough pressure to fracture the rock layer, and the goal of increasing production cannot be achieved. This will lead to a decrease in the output of the oil well and affect the economic benefits of oil extraction.

[0004] If the pressure in the fracturing pipe is insufficient, the fracturing fluid may not be able to effectively enter the cracks, or may not be able to form effective support after entering the cracks. In this way, the cracks may close again after the pressure drops, which greatly reduces the fracturing effect. In addition, if the fracturing fluid cannot effectively support the cracks, the direction of crack expansion may be uncontrollable, thereby affecting the stability of the surrounding formations. Therefore, there is an urgent need for a downhole fracturing connection device to solve the above problems. Utility Model Content

[0005] In view of the deficiencies in the prior art, the utility model aims to provide a downhole fracturing connection device to solve the problems raised in the above-mentioned background technology.

[0006] The utility model is realized by the following technical scheme: a downhole fracturing connection device, comprising: a cover body and an inner sealing push head, wherein the outer inner portion of the upper end of the cover body is provided with a flange connection hole for being connected and fixed with the upper end of the sealing crack shell by bolts;

[0007] The lower end of the cover body is provided with a sealing crack shell for oil well fracturing operation, and the lower end of the sealing crack shell is provided with a connecting base for supporting and connecting the sealing crack shell;

[0008] A connecting sleeve for connecting to a support is provided at the lower end of the connecting base, a visual slot is provided inside the right side of the connecting sleeve for easy inspection by staff, and a movable sleeve is provided at the lower end of the connecting sleeve for adjusting the telescopic length of the connecting sleeve. The extension position of the connecting sleeve can be adjusted by using the connecting sleeve and the movable sleeve.

[0009] As a preferred embodiment, an upper connecting seat is provided on the outer side of the movable sleeve for limiting its own position, engaging and fixing the connection. A plurality of positioning bolts are provided on the outer side of the upper end of the upper connecting seat for connecting and fixing with the outer side of the movable sleeve. The connecting pipe sleeve can be connected and fixed by using the positioning bolts.

[0010] As a preferred embodiment, the lower end of the upper connecting seat is provided with a communication seat for connecting water inlet end one and water inlet end two, the left side of the communication seat is provided with water inlet end one for introducing external pressure water body, and the right side of the communication seat is provided with water inlet end two for introducing external pressure water body, and the external pressure water body can be introduced by using water inlet end one and water inlet end two.

[0011] As a preferred embodiment, the lower end of the communication seat is provided with a lower connecting seat for sealing and engaging with the electric cylinder, the lower end of the lower connecting seat is provided with an electric cylinder for pushing the inner sealing push head into the upper connecting seat, and the upper end of the electric cylinder is provided with an inner sealing push head for pushing the movable sleeve upward. The inner sealing push head can be pushed upward by using the electric cylinder, and the movable sleeve and the movable column can be driven to move upward.

[0012] As a preferred embodiment, a movable column for pushing the sealing piston in is provided inside the visual groove, a sealing piston for adjusting the pressure inside the sealing crack shell is provided at the upper end of the movable column, and a group of electric control valves for allowing water to flow are provided in the middle position of the sealing piston, which can guide the pressurized water inside the communication seat into the sealing crack shell through the electric control valve.

[0013] As a preferred embodiment, the water inlet end one and the water inlet end two are respectively sealed and connected to the external water pipe, the interior of the water inlet end one and the interior of the water inlet end two are interconnected with the interior of the communication seat, the interior of the movable sleeve and the interior of the movable column are provided with a water guide cavity, the upper end of the water guide cavity is sealed and connected to the electric control valve, and the water guide cavity can be used to guide the pressurized water into the interior of the sealed crack shell and apply pressure to the interior of the sealed crack shell, thereby completing the fracturing operation.

[0014] As a preferred embodiment, the center of the cross section of the inner sealing push head and the center of the cross section of the movable sleeve are arranged on the same longitudinal line. When the inner sealing push head is at the maximum extension length, its movable sleeve and movable column are at the maximum extension position. The sealing crack shell is an oil fracturing pipe. The inner wall of the sealing crack shell is movably sealed with the sealing piston, and the internal pressure of the sealing crack shell can be further pressurized by using the sealing piston.

[0015] After adopting the above technical scheme, the beneficial effects of the utility model are: by using the connecting pipe sleeve and the movable sleeve to adjust the extension position of the connecting pipe sleeve, by using the positioning bolt to connect and fix the connecting pipe sleeve, by using the water inlet end one and the water inlet end two to introduce the external pressure water body, by using the electric cylinder to push the inner sealing push head upward, and drive the movable sleeve and the movable column to move upward, by using the electric control valve to introduce the pressure water body inside the communication seat into the sealed crack shell, by using the water guide cavity to introduce the pressure water body into the sealed crack shell, and pressurize the inside of the sealed crack shell, so as to complete the fracturing operation, and by using the sealing piston to further pressurize the internal pressure of the sealed crack shell. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0017] Figure 1 This is a schematic diagram of a top view of the right front oblique side of a downhole fracturing connection device of the utility model;

[0018] Figure 2 It is a schematic diagram of the right side front view of the second water inlet end of a downhole fracturing connection device of the utility model;

[0019] Figure 3 It is a schematic diagram of the structure of a downhole fracturing connection device of the utility model when the electric cylinder and the communication seat are separated from each other from the right oblique side;

[0020] In the figure: 100-cover body, 110-flange connecting hole, 120-sealed crack shell, 130-connecting base, 140-connecting pipe sleeve, 150-visible groove, 160-positioning bolt, 170-upper connecting seat, 180-water inlet end one, 190-water inlet end two, 200-lower connecting seat, 210-electric cylinder, 220-sealed piston, 230-inner sealing push head. DETAILED DESCRIPTION

[0021] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0022] See also Figure 1-Figure 3 A downhole fracturing connection device includes: a cover body 100, a sealing crack shell 120, a connecting sleeve 140, a sealing piston 220 and an inner sealing push head 230. The outer inner portion of the upper end of the cover body 100 is provided with a flange connection hole 110 for connecting and fixing with the upper end of the sealing crack shell 120 by bolts;

[0023] The lower end of the cover body 100 is provided with a sealing crack shell 120 for oil well fracturing operation, and the lower end of the sealing crack shell 120 is provided with a connecting base 130 for supporting and connecting the sealing crack shell 120;

[0024] A connecting sleeve 140 for connecting the support is provided at the lower end of the connecting base 130, a visual slot 150 is provided inside the right side of the connecting sleeve 140 for easy inspection by the staff, and a movable sleeve is provided at the lower end of the connecting sleeve 140 for adjusting the telescopic length of the connecting sleeve 140. The extension position of the connecting sleeve 140 can be adjusted by using the connecting sleeve 140 and the movable sleeve.

[0025] An upper connecting seat 170 is provided on the outer side of the movable sleeve for limiting its own position, fitting and fixing. A plurality of positioning bolts 160 are provided on the outer side of the upper end of the upper connecting seat 170 for connecting and fixing with the outer side of the movable sleeve. The connecting sleeve 140 can be connected and fixed by using the positioning bolts 160.

[0026] A communication seat for connecting water inlet end 180 and water inlet end 2 190 is provided at the lower end of the upper connecting seat 170. Water inlet end 180 for introducing external pressure water is provided on the left side of the communication seat, and water inlet end 2 190 for introducing external pressure water is provided on the right side of the communication seat. External pressure water can be introduced by using water inlet end 180 and water inlet end 2 190.

[0027] A lower connecting seat 200 for sealingly engaging with an electric cylinder 210 is provided at the lower end of the communication seat. An electric cylinder 210 for pushing an inner sealing push head 230 into the interior of an upper connecting seat 170 is provided at the lower end of the lower connecting seat 200. An inner sealing push head 230 for pushing a movable sleeve upward is provided at the upper end of the electric cylinder 210. The inner sealing push head 230 can be pushed upward by using the electric cylinder 210, thereby driving the movable sleeve and the movable column to move upward.

[0028] A movable column for pushing the sealing piston 220 is provided inside the visible groove 150, and a sealing piston 220 for adjusting the pressure inside the sealing crack shell 120 is provided at the upper end of the movable column. A group of electric control valves for allowing water to flow are provided in the middle position of the sealing piston 220, and the pressurized water inside the communication seat can be introduced into the sealing crack shell 120 through the electric control valve.

[0029] The water inlet end 180 and the water inlet end 2 190 are respectively sealed and connected to the external water pipe, the interior of the water inlet end 180 and the interior of the water inlet end 2 190 are interconnected with the interior of the communication seat, the interior of the movable sleeve and the interior of the movable column are provided with a water guide cavity, the upper end of the water guide cavity is sealed and connected to the electric control valve, and the water guide cavity can be used to guide the pressurized water into the interior of the sealed crack shell 120, and pressure can be applied to the interior of the sealed crack shell 120, thereby completing the fracturing operation.

[0030] The center of the cross section of the inner sealing push head 230 is arranged on the same longitudinal line as the center of the cross section of the movable sleeve. When the inner sealing push head 230 is at the maximum extension length, its movable sleeve and movable column are at the maximum extension position. The sealing crack shell 120 is an oil fracturing pipe. The inner wall of the sealing crack shell 120 is movably sealed and connected to the sealing piston 220. The internal pressure of the sealing crack shell 120 can be further pressurized by using the sealing piston 220.

[0031] See also Figure 1-Figure 3 As the first embodiment of the utility model: In order to solve the problem that the main purpose of oil fracturing is to fracture the rock layer underground by high pressure to form cracks so that the oil can flow out more smoothly, if the pressure in the fracturing pipe cannot be actively applied, then it is impossible to form sufficient pressure to fracture the rock layer, thereby failing to achieve the problem of increasing production. First, when the staff needs to enter the underground oil fracturing operation, the external pressure water is introduced through the water inlet end 180 and the water inlet end 2 190, and then enters the inside of the communication seat through the water inlet end 180 and the water inlet end 2 190. Since the inside of the movable sleeve and the inside of the movable column are A water conducting chamber is provided, and the pressurized water inside the communication seat enters the sealed crack shell 120 through the water conducting chamber and the electric control valve. When the staff needs to perform fracturing operations on the petroleum rock formation, the staff closes the electric control valve and then starts the electric cylinder 210. The electric cylinder 210 drives the inner sealing push head 230 to move upward, and contacts the bottom of the movable sleeve to push upward. After the movable sleeve is stressed, it drives the movable column to move upward. At the same time, the movable column drives the sealing piston 220 to move inside the sealed crack shell 120, thereby increasing the water pressure inside the sealed crack shell 120, so that the pressurized water bursts out and performs fracturing operations on the rock formation downhole.

[0032] See also Figure 1-Figure 3, as the second embodiment of the utility model: based on the description in the above embodiment, further, since the center of the cross section of the inner sealing push head 230 and the center of the cross section of the movable sleeve are arranged on the same longitudinal line, when the inner sealing push head 230 is at the maximum extension length, its movable sleeve and movable column are at the maximum extension position, and the staff can adjust the extension length of the inner sealing push head 230 through the electric cylinder 210 according to the actual situation of the downhole rock formation, thereby adjusting the pressure inside the sealing fracture shell 120 to prevent excessive pressure from causing excessive fracturing of the rock formation and forming a danger, and to prevent excessive pressure from causing the rock formation to be unable to lead out oil through fracturing.

[0033] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A downhole fracturing connection device, comprising: A cover body (100), a sealing crack shell (120), a connecting pipe sleeve (140), a sealing piston (220) and an inner sealing push head (230), characterized in that: a flange connection hole (110) is provided inside the outer side of the upper end of the cover body (100) for being connected and fixed to the upper end of the sealing crack shell (120) by bolts; The lower end of the cover body (100) is provided with a sealing crack shell (120) for performing fracturing operations in oil wells, and the lower end of the sealing crack shell (120) is provided with a connecting base (130) for supporting and connecting the sealing crack shell (120); A connecting sleeve (140) for connecting to a support is provided at the lower end of the connecting base (130); a visual slot (150) for facilitating inspection by a worker is provided inside the right side of the connecting sleeve (140); and a movable sleeve for adjusting the telescopic length of the connecting sleeve (140) is provided at the lower end of the connecting sleeve (140).

2. A downhole fracturing connection device according to claim 1, characterized in that: An upper connection seat (170) is provided on the outer side of the movable sleeve for limiting the position of the sleeve and for fastening the sleeve to the movable sleeve. A plurality of groups of positioning bolts (160) are provided on the outer side of the upper end of the upper connection seat (170) for fastening the upper connection seat to the outer side of the movable sleeve.

3. A downhole fracturing connection device according to claim 2, characterized in that: A communication seat for connecting the first water inlet end (180) and the second water inlet end (190) is provided at the lower end of the upper connection seat (170); the first water inlet end (180) for introducing external pressure water is provided on the left side of the communication seat; and the second water inlet end (190) for introducing external pressure water is provided on the right side of the communication seat.

4. A downhole fracturing connection device according to claim 3, characterized in that: The lower end of the communication seat is provided with a lower connection seat (200) for sealingly engaging with the electric cylinder (210), the lower end of the lower connection seat (200) is provided with an electric cylinder (210) for pushing an inner sealing push head (230) into the interior of the upper connection seat (170), and the upper end of the electric cylinder (210) is provided with an inner sealing push head (230) for pushing the movable sleeve upward.

5. A downhole fracturing connection device according to claim 1, characterized in that: A movable column for pushing the sealing piston (220) in is provided inside the visual slot (150); a sealing piston (220) for adjusting the pressure inside the sealing crack shell (120) is provided at the upper end of the movable column; a group of electric control valves for allowing water to flow are provided in the middle of the sealing piston (220).

6. A downhole fracturing connection device according to claim 3, characterized in that: The water inlet end 1 (180) and the water inlet end 2 (190) are respectively sealed and connected to an external water pipe, the interior of the water inlet end 1 (180) and the interior of the water inlet end 2 (190) are both connected to the interior of the communication seat, and a water guide cavity is provided inside the movable sleeve and inside the movable column, and the upper end of the water guide cavity is sealed and connected to the electric control valve.

7. A downhole fracturing connection device according to claim 4, characterized in that: The center of the cross section of the inner sealing push head (230) and the center of the cross section of the movable sleeve are arranged on the same longitudinal line; when the inner sealing push head (230) is at the maximum extension length, its movable sleeve and movable column are at the maximum extension position; the sealing crack shell (120) is a petroleum fracturing pipe; the inner wall of the sealing crack shell (120) is movably sealed to the sealing piston (220).

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