An integrated casing protection layered fracturing tool assembly

Abstract

The present invention belongs to the technical field of downhole tools for oil and gas fields, and in particular relates to an integrated casing-protected layered fracturing tool assembly. The present invention includes a main body and a valve core component. While satisfying the requirements of anchor shoe anchoring and expansion rubber cartridge sealing, the fine slits on the slit bushing can prevent fracturing sand from entering the inner cavity of the expansion rubber cartridge and anchor shoe, thereby avoiding the anchor shoe and expansion rubber cartridge from not being recovered, causing well jamming. The fracturing fluid is radially sprayed from the sandblasting port to the formation and casing. Since the sandblasting port has a large diameter, the flow rate of the fracturing fluid is greatly reduced, reducing or eliminating the damage of the fracturing sand to the casing, sandblasting port and parts near the sandblasting port. A tungsten carbide wear-resistant layer is welded around the sandblasting port, which greatly increases the wear resistance of the sandblasting port.

Description

Technical Field

[0001] The present invention belongs to the technical field of downhole tools for oil and gas fields, and in particular relates to an integrated casing protection layered fracturing tool assembly. Background Art

[0002] At present, during the stratified fracturing operation in domestic oil fields, the fracturing nozzles equipped with expandable packers all adopt side-spray nozzles. When the nozzles spray sand-carrying fluid into the casing and the formation, the casing is easily damaged due to the high flow rate of the spray. Moreover, when the high-flow sand-carrying fluid is sprayed onto the casing wall, the splashing fracturing sand can easily cause damage to the nozzle and parts near the nozzle. In severe cases, it may affect the setting of the expansion rubber cartridge during fracturing construction and reduce the tensile strength of the tool, which may cause the fracturing construction to fail and the tubing to be broken when the oil tubing is pulled out, resulting in economic losses.

[0003] Therefore, there is an urgent need for an integrated casing protection layered fracturing tool assembly, which can reduce the flow rate of the sand-carrying fluid sprayed by the fracturing nozzle while ensuring the setting of the expandable rubber cartridge and the anchoring of the oil pipe, thereby reducing or eliminating the damage of the sand-carrying fluid to the casing, fracturing nozzle and parts near the nozzle, which is conducive to ensuring the safe construction of the fracturing operation, protecting the casing, increasing the amount of sand added during fracturing construction, and improving the safety of the tubing string. Summary of the Invention

[0004] The purpose of the present invention is to provide an integrated casing protection layered fracturing tool assembly, which can reduce the flow rate of the sand-carrying fluid sprayed by the fracturing nozzle while ensuring the setting of the expandable rubber sleeve and the anchoring of the oil pipe.

[0005] To achieve the above objectives, the present invention provides the following solutions.

[0006] An integrated casing protection layered fracturing tool assembly includes a main body and a valve core component, which is characterized in that: the inner side of the upper end of the main body is connected to the outer side of the lower end of the upper joint and is fixed by an anti-rotation shear nail; the inner side of the upper joint is threadedly connected to the outer side of the slotted bushing; the inner side of the lower end of the slotted bushing is threadedly connected to the outer side of the upper end of the receiving sleeve and is limited by the shoulder of the main body; a sandblasting port is provided on each side of the middle section of the main body, and an axial pressure guide channel is provided through the main body along the axial direction; an anchor shoe hole is provided on the main body, an anchor shoe is installed in the anchor shoe hole, and a blind hole is provided on the anchor shoe, which is elastic The spring is installed in the blind hole of the anchor shoe; a pressure plate groove is also provided on the main body, a pressure plate is provided in the pressure plate groove, and a hole is provided on the pressure plate; a countersunk screw is installed on the hole of the pressure plate, and the countersunk screw is installed in the threaded blind hole of the main body at the same time; the inner side of the lower end of the main body is threadedly connected with the outer side of the upper joint of the rubber cylinder; an expansion rubber cylinder is provided under the upper joint of the rubber cylinder, and a rubber cylinder lower joint is provided on the inner side of the combination of the upper joint of the rubber cylinder and the expansion rubber cylinder; the upper pressure ring is installed on the outer side of the expansion rubber cylinder and the upper joint of the rubber cylinder, and is limited by the upper joint of the rubber cylinder and the shoulder of the main body; the lower end of the lower joint of the rubber cylinder is connected to the upper end of the back cap Threaded connection; a lower pressure ring is provided on the outer side of the expansion rubber sleeve and the lower joint of the rubber sleeve, which is limited by the lower joint of the rubber sleeve and the shoulder of the back cap; a center tube is provided on the inner side of the structure formed by the upper joint of the rubber sleeve, the expansion rubber sleeve and the lower joint of the rubber sleeve, and the outer side of the upper end of the center tube is threadedly connected to the inner side of the upper end of the upper joint of the rubber sleeve; a shear ring is provided in the inner cavity of the upper joint of the rubber sleeve, and the shear ring is limited by the inner shoulder of the main body and the shoulder of the upper end of the center tube; a sliding sleeve is provided on the inner side of the structure formed by the main body, the shear ring and the center tube, and the sliding sleeve and the shear ring are sheared by the sliding sleeve The valve core component includes a valve core back cap, and the inner side of the lower end of the valve core back cap is threadedly connected to the outer side of the upper end of the valve core body; a main body shoulder is provided on the outer side of the valve core body; an elastic ring is provided between the inner side of the lower end of the valve core back cap and the outer side of the valve core body, and the elastic ring is limited by the valve core back cap and the valve core body; a guide head is provided in the inner hole of the valve core body, and the guide head and the valve core body shoulder limit the valve core body, and the guide head and the valve core body are connected with valve core shear nails; a guide head shoulder is provided on the outer side of the guide head.

[0007] Furthermore, the slit bushing is provided with fine slits.

[0008] Furthermore, an annular groove is provided on the inner side of the receiving sleeve, an elastic annular shoulder is provided on the upper portion of the annular groove, and a receiving shoulder is provided on the lower portion of the annular groove.

[0009] Furthermore, a tungsten carbide wear-resistant layer is provided around the sandblasting port.

[0010] Furthermore, the upper joint of the rubber cylinder, the lower joint of the rubber cylinder and the expandable rubber cylinder are vulcanized into a whole.

[0011] Furthermore, a liquid flow groove is provided on the outer side of the upper end of the central tube, and a central tube shoulder is provided on the inner side of the central tube; the outer side of the throttle nozzle is threadedly connected to the inner side of the lower end of the central tube; and the back cap is limited by the central tube and the throttle nozzle shoulder.

[0012] Furthermore, a sliding sleeve shoulder is provided on the inner side of the sliding sleeve.

[0013] Furthermore, the elastic ring is provided with an opening structure and a hook is provided on the outside.

[0014] Beneficial effects of the present invention.

[0015] While satisfying the requirements of anchor shoe anchoring and expandable rubber cartridge setting, the fine slits on the slit bushing can prevent fracturing sand from entering the inner cavity of the expandable rubber cartridge and anchor shoe, thereby avoiding the anchor shoe and expandable rubber cartridge from not being recovered and causing well jamming. The fracturing fluid is radially sprayed from the sandblasting port to the formation and casing. Since the sandblasting port has a large diameter, the flow rate of the fracturing fluid is greatly reduced, reducing or eliminating the damage of the fracturing sand to the casing, sandblasting port and parts near the sandblasting port.

[0016] A tungsten carbide wear-resistant layer is welded around the sandblasting port, which greatly increases the wear resistance of the sandblasting port. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural schematic diagram of the present invention.

[0018] Figure 2 It is a schematic structural diagram of the valve core component of the present invention.

[0019] Figure 3 It is a full cross-sectional view of the sandblasting port of the present invention.

[0020] Figure 4 It is a three-dimensional axonometric drawing of the elastic ring of the present invention.

[0021] Figure 5 It is a front view of the sandblasting port of the present invention.

[0022] Explanation of the numbers in the figure: 1-upper joint, 2-slit bushing, 3-anti-rotation shear nail, 4-connector sleeve, 5-main body, 6-sliding sleeve, 7-countersunk screw, 8-anchor shoe, 9-pressure plate, 10-spring, 11-shear ring, 12-rubber cylinder upper joint, 13-expandable rubber cylinder, 14-upper pressure ring, 15-lower pressure ring, 16-center tube, 17-rubber cylinder lower joint, 18-back cap, 19-valve core back cap, 20- Elastic ring, 21-valve core shear nail, 22-valve core body, 23-guide head, 24-sleeve shear nail, 25-throttle nozzle, 26-slit, 27-elastic ring shoulder, 28-undertaking shoulder, 29-sandblasting mouth, 30-tungsten carbide wear-resistant layer, 31-sleeve shoulder, 32-liquid groove, 33-center tube shoulder, 34-hook, 35-main body shoulder, 36-guide head shoulder, 37-axial pressure guide channel. DETAILED DESCRIPTION

[0023] like Figure 1-5The present invention includes a main body 5 and a valve core component, which is characterized in that: the inner side of the upper end of the main body 5 is connected to the outer side of the lower end of the upper joint 1 and is fixed by an anti-rotation shear nail 3; the inner side of the upper joint 1 is threadedly connected to the outer side of the slit bushing 2; the inner side of the lower end of the slit bushing 2 is threadedly connected to the outer side of the upper end of the receiving sleeve 4, and is limited by the shoulder of the main body 5; a sandblasting port 29 is provided on each side of the middle section of the main body 5, and an axial pressure guide channel 37 is provided axially through the main body 5; an anchor shoe hole is provided on the main body 5, and an anchor shoe 8 is installed in the anchor shoe hole, and a blind hole is provided on the anchor shoe 8, and a spring 10 is installed in the blind hole of the anchor shoe 8; a pressure plate groove is also provided on the main body 5, and the pressure plate A pressure plate 9 is provided in the groove, and a hole is provided on the pressure plate 9; a countersunk screw 7 is installed on the hole of the pressure plate 9, and the countersunk screw 7 is installed in the threaded blind hole of the main body 5 at the same time; the inner side of the lower end of the main body 5 is threadedly connected to the outer side of the upper joint 12 of the rubber cylinder; an expandable rubber cylinder 13 is provided under the upper joint 12 of the rubber cylinder, and a rubber cylinder lower joint 17 is provided on the inner side of the combination of the upper joint 12 of the rubber cylinder and the expandable rubber cylinder 13; an upper pressure ring 14 is installed on the outer side of the expandable rubber cylinder 13 and the upper joint 12 of the rubber cylinder, and is limited by the upper joint 12 of the rubber cylinder and the shoulder of the main body 5; the lower end of the rubber cylinder lower joint 17 is threadedly connected to the upper end of the back cap 18; the outer side of the expandable rubber cylinder 13 and the lower joint 17 of the rubber cylinder A lower pressure ring 15 is provided on the side and is limited by the shoulder of the lower joint 17 of the rubber sleeve and the back cap 18; a center tube 16 is provided on the inner side of the structure formed by the upper joint 12 of the rubber sleeve, the expandable rubber sleeve 13 and the lower joint 17 of the rubber sleeve, and the outer side of the upper end of the center tube 16 is threadedly connected to the inner side of the upper end of the upper joint 12 of the rubber sleeve; a shear ring 11 is provided in the inner cavity of the upper joint 12 of the rubber sleeve, and the shear ring 11 is limited by the inner shoulder of the main body 5 and the upper shoulder of the center tube 16; a sliding sleeve 6 is provided on the inner side of the structure formed by the main body 5, the shear ring 11 and the center tube 16, and the sliding sleeve 6 is connected to the shear ring 11 by a sliding sleeve shear nail 24, and the upper end of the sliding sleeve 6 is connected to the main body 5 The inner shoulder is limited; the valve core component includes a valve core back cap 19, and the inner side of the lower end of the valve core back cap 19 is threadedly connected to the outer side of the upper end of the valve core body 22; a main body shoulder 35 is provided on the outer side of the valve core body 22; an elastic ring 20 is provided between the inner side of the lower end of the valve core back cap 19 and the outer side of the valve core body 22, and the elastic ring 20 is limited by the valve core back cap 19 and the valve core body 22; a guide head 23 is provided in the inner hole of the valve core body 22, and the guide head 23 and the valve core body 22 shoulder limit the valve core body 22, and the guide head 23 and the valve core body 22 are connected with the valve core shear nail 21; a guide head shoulder 36 is provided on the outer side of the guide head 23.

[0024] Furthermore, the slotted bushing 2 is provided with a slit 26 .

[0025] Furthermore, an annular groove is provided on the inner side of the receiving sleeve 4 , an elastic annular shoulder 27 is provided on the upper portion of the annular groove, and a receiving shoulder 28 is provided on the lower portion of the annular groove.

[0026] Furthermore, a tungsten carbide wear-resistant layer 30 is provided around the sandblasting port 29 .

[0027] Furthermore, the upper rubber sleeve joint 12, the lower rubber sleeve joint 17 and the expandable rubber sleeve 13 are vulcanized into a whole.

[0028] Furthermore, a liquid flow groove 32 is provided on the outer side of the upper end of the central tube 16, and a central tube shoulder 33 is provided on the inner side of the central tube 16; the outer side of the throttle nozzle 25 is threadedly connected to the inner side of the lower end of the central tube 16; and the back cap 18 is limited by the central tube 16 and the throttle nozzle 25 shoulders.

[0029] Furthermore, a sliding sleeve shoulder 31 is provided on the inner side of the sliding sleeve 6 .

[0030] Furthermore, the elastic ring 20 is provided with an opening structure, and a hook 34 is provided on the outer side.

[0031] The specific operation mode of the present invention is:

[0032] To fracture the lower layer, the upper joint 1 is connected to the oil pipe string and lowered into the well to the designed position. Fracturing fluid is directly pumped into the oil pipe to fracture the lower layer. When the fracturing fluid flows through the throttle nozzle 25, a throttling pressure is generated to meet the sealing requirements of the expandable rubber cylinder 13. The liquid pressure in the oil pipe is transmitted to the annular space between the upper joint 1 and the receiving sleeve 4 through the slit 26 on the slotted bushing 2, and is transmitted to the inner cavity of the anchor shoe 8 and the expandable rubber cylinder 13 through the axial pressure guide channel 37 on the main body 5. While meeting the requirements of the anchor shoe 8 anchoring and the expandable rubber cylinder 13 sealing, the slit 26 on the slotted bushing 2 can prevent fracturing sand from entering the inner cavity of the expandable rubber cylinder 13 and the anchor shoe 8, thereby avoiding the anchor shoe 8 and the expandable rubber cylinder 13 from not being recovered and causing well jamming. The fracturing fluid is vertically sprayed to the lower layer through the throttle nozzle 25, which can prevent high-flow rate fracturing sand from damaging the casing, the sandblasting port 29 and parts near the sandblasting port 29.

[0033] The upper layer is fractured and the valve core component consisting of the valve core back cap 19, the elastic ring 20, the valve core shear pin 21, the valve core body 22 and the guide head 23 is put into the packer. Under the action of hydraulic pressure and the gravity of the valve core component, the valve core component enters the inner cavity of the packer. When the elastic ring 20 contacts the receiving sleeve 4, due to its elasticity, the outer diameter of the elastic ring 20 is compressed and reduced under the action of hydraulic pressure. After the elastic ring 20 enters the inner ring groove of the receiving sleeve 4, it returns to its original size. The hook 34 on the elastic ring 20 is elastically pressed. The ring shoulder 27 is limited, the main body shoulder 35 is limited by the receiving shoulder 28, the elastic ring 20 and the valve core body 22 are limited in the inner cavity of the receiving sleeve 4 by the elastic ring shoulder 27 and the receiving shoulder 28; under the action of hydraulic pressure, the valve core shear nail 21 is sheared off, the guide head 23 moves downward under the action of hydraulic pressure, the guide head shoulder 36 is limited by the sliding sleeve shoulder 6, and under the action of hydraulic pressure, the sliding sleeve 6 shears the sliding sleeve shear nail 24, the sliding sleeve 6 and the guide head 23 move downward under the action of hydraulic pressure, the sandblasting port 29 is opened, and the sliding sleeve 6 moves downward The end face shoulder is limited by the center pipe shoulder 33; when fracturing the upper layer, the fracturing fluid generates a throttling pressure that satisfies the setting of the expansion rubber cylinder 13 when flowing through the valve core body 22. The liquid pressure in the oil pipe is transmitted to the annular space between the upper joint 1 and the receiving sleeve 4 through the slit 26 on the slotted bushing 2, and is transmitted to the anchor shoe 8 and the inner cavity of the expansion rubber cylinder 13 through the axial pressure guide channel 37 on the main body 5. While satisfying the anchor shoe 8 anchoring and the setting of the expansion rubber cylinder 13, the slit 26 on the slotted bushing 2 can prevent The fracturing sand enters the inner cavity of the expandable rubber cylinder 13 and the anchor shoe 8 to prevent the anchor shoe 8 and the expandable rubber cylinder 13 from not being recovered and causing well jamming. The fracturing fluid is radially sprayed from the sandblasting port 29 on the main body 5 to the formation and casing. Since the sandblasting port 29 has a large diameter, the flow rate of the fracturing fluid is greatly reduced, reducing or eliminating the damage of the fracturing sand to the casing, the sandblasting port 29 and the parts near the sandblasting port 29. A tungsten carbide wear-resistant layer 30 is welded around the sandblasting port 29, which further reduces the damage of the fracturing sand to the sandblasting port 29.

[0034] Unsealing. After the fracturing construction is completed, when the pressure in the oil pipe is balanced with the annular pressure of the oil pipe and casing, the anchor shoe 8 is recovered and unstuck, the expandable rubber sleeve 13 is recovered and unsealed, and the oil pipe string is lifted to bring the product out of the well. If the product encounters resistance when lifting the oil pipe string, the oil pipe string can be rotated forward to cut the anti-rotation shear nail 3, and the oil pipe string can be rotated forward again. The left-hand thread between the upper joint 1 and the main body 5 is disengaged, and the oil pipe string is lifted. The oil pipe string, the upper joint 1, the slit bushing 2, and the socket sleeve 4 are lifted out of the well to avoid the oil pipe string from being stuck, thereby increasing the safety of underground operation.

[0035] It can be understood that the above specific description of the present invention is only used to illustrate the present invention and is not limited to the technical solutions described in the embodiments of the present invention. Ordinary technicians in this field should understand that the present invention can still be modified or replaced by equivalents to achieve the same technical effects; as long as the use requirements are met, they are within the scope of protection of the present invention.

Claims

1. An integrated casing protection layered fracturing tool assembly, comprising a main body (5) and a valve core component, characterized in that: The inner side of the upper end of the main body (5) is connected to the outer side of the lower end of the upper joint (1) and is fixed by an anti-rotation shear nail (3); the inner side of the upper joint (1) is threadedly connected to the outer side of the slit bushing (2); the inner side of the lower end of the slit bushing (2) is threadedly connected to the outer side of the upper end of the receiving sleeve (4) and is limited by the shoulder of the main body (5); a sandblasting port (29) is provided on each side of the middle section of the main body (5), and an axial pressure guide channel (37) is provided along the axial direction of the main body (5); an anchor shoe hole is provided on the main body (5), an anchor shoe (8) is installed in the anchor shoe hole, a blind hole is provided on the anchor shoe (8), and a spring (10) is installed in the blind hole of the anchor shoe (8); a pressure plate groove is also provided on the main body (5), a pressure plate (9) is provided in the pressure plate groove, and a hole is provided on the pressure plate (9); a countersunk screw (7) is installed To the hole of the pressure plate (9), the countersunk screw (7) is installed in the threaded blind hole of the main body (5) at the same time; the inner side of the lower end of the main body (5) is threadedly connected to the outer side of the upper joint (12) of the rubber tube; an expansion rubber tube (13) is provided under the upper joint (12) of the rubber tube, and a rubber tube lower joint (17) is provided on the inner side of the combination of the upper joint (12) and the expansion rubber tube (13); the upper pressure ring (14) is installed on the outer side of the expansion rubber tube (13) and the upper joint (12) of the rubber tube, and is limited by the upper joint (12) of the rubber tube and the shoulder of the main body (5); the lower end of the rubber tube lower joint (17) is threadedly connected to the upper end of the back cap (18); the outer side of the expansion rubber tube (13) and the lower joint (17) of the rubber tube is provided with a rubber tube lower joint (17) and the shoulder of the back cap (18) A lower pressure ring (15); a center tube (16) is provided on the inner side of the structure formed by the upper joint (12) of the rubber cylinder, the expansion type rubber cylinder (13) and the lower joint (17) of the rubber cylinder, and the outer side of the upper end of the center tube (16) is threadedly connected to the inner side of the upper end of the upper joint (12) of the rubber cylinder; a shear ring (11) is provided in the inner cavity of the upper joint (12), and the shear ring (11) is limited by the inner shoulder of the main body (5) and the upper shoulder of the center tube (16); a sliding sleeve (6) is provided on the inner side of the structure formed by the main body (5), the shear ring (11) and the center tube (16), and the sliding sleeve (6) is connected to the shear ring (11) by a sliding sleeve shear pin (24), and the upper end of the sliding sleeve (6) is limited by the inner shoulder of the main body (5); the valve core component includes a valve core back cap ( 19), the inner side of the lower end of the valve core back cap (19) is threadedly connected to the outer side of the upper end of the valve core body (22); the outer side of the valve core body (22) is provided with a body shoulder (35); an elastic ring (20) is provided between the inner side of the lower end of the valve core back cap (19) and the outer side of the valve core body (22), and the elastic ring (20) is limited by the valve core back cap (19) and the valve core body (22); a guide head (23) is provided in the inner hole of the valve core body (22), and the guide head (23) and the valve core body (22) shoulder limit the valve core body (22), and the guide head (23) and the valve core body (22) are connected with the valve core shear nail (21); a guide head shoulder (36) is provided on the outer side of the guide head (23); and a fine slit (26) is provided on the slit bushing (2).

2. The integrated casing protection layered fracturing tool assembly according to claim 1, characterized in that: An annular groove is provided on the inner side of the receiving sleeve (4), an elastic annular shoulder (27) is provided on the upper portion of the annular groove, and a receiving shoulder (28) is provided on the lower portion of the annular groove.

3. The integrated casing protection layered fracturing tool assembly according to claim 1, characterized in that: A tungsten carbide wear-resistant layer (30) is provided around the sandblasting port (29).

4. The integrated casing protection layered fracturing tool assembly according to claim 1, characterized in that: The rubber cylinder upper joint (12), the rubber cylinder lower joint (17) and the expandable rubber cylinder (13) are vulcanized into a whole.

5. The integrated casing protection layered fracturing tool assembly according to claim 1, characterized in that: The outer side of the upper end of the central tube (16) is provided with a liquid trough (32), and the inner side of the central tube (16) is also provided with a central tube shoulder (33); the outer side of the throttle nozzle (25) is threadedly connected to the inner side of the lower end of the central tube (16); and the back cap (18) is limited by the central tube (16) and the throttle nozzle (25) shoulders.

6. The integrated casing protection layered fracturing tool assembly according to claim 1, characterized in that: A sliding sleeve shoulder (31) is provided on the inner side of the sliding sleeve (6).

7. The integrated casing protection layered fracturing tool assembly according to claim 1, characterized in that: The elastic ring (20) is provided with an opening structure, and a hook (34) is provided on the outer side.

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