Composite tubing plug

Abstract

The invention relates to the technical field of petroleum and natural gas, in particular to a composite tubing plug. The problems that in the prior art, the effective pressure bearing time of a soluble blanking plug is short, the full bore cannot be achieved after a conventional blanking plug is opened, and follow-up operation is affected due to the fact that a plugging core is left in a well are solved. The device comprises an upper connector and a lower connector, and further comprises a first blocking assembly and a second blocking assembly. The first blocking assembly comprises an impact sleeve and a soluble mandrel arranged in the impact sleeve; the second plug assembly includes a rupture disk. The rupture disc prevents liquid in a lower well from making contact with the soluble core shaft, long-acting plugging can be guaranteed before a production pipe column is lowered in place, and meanwhile the soluble core shaft and the rupture disc achieve the dual-sealing effect. The soluble mandrel and the rupture disc are independently arranged, and the sealing effect of the blanking plug is not affected when any assembly fails; the broken rupture disc is discharged from the lower connector to the bottom of the pipeline, the soluble mandrel is dissolved in water, and small particles obtained after the rupture disc is broken can be discharged out of the pipeline along with flow-back liquid.

Description

Technical Field

[0001] The invention relates to the technical field of petroleum and natural gas, in particular to a composite oil pipe plugger. Background Art

[0002] In recent years, the soluble bridge plug-perforation joint process has been widely used in reservoir transformation construction. Since the casing fracturing method is adopted, it is necessary to carry out the production string operation under pressure after the fracturing is completed, that is, after the plug is connected to the bottom of the production string to seal the pressure in the well, the small-sized production string is put into production under pressure. At present, the conventional plugs and soluble plugs used in the construction of production strings under pressure are non-full-bore structures, which affect the subsequent continuous oil pipe or steel wire operations; the metal core shaft of the conventional plug falls into and remains in the wellbore after being knocked off, affecting the subsequent test operations; the core shaft of the soluble plug is a soluble material, and the effective pressure-bearing time is limited. There is a risk of plug failure in the wellbore for a long time.

[0003] In summary, the existing technology has the problems that the effective pressure-bearing time of the soluble plug is short, the conventional plug cannot achieve full diameter after opening, and the plugging core remains in the well, affecting subsequent operations. Summary of the invention

[0004] The existing technology has the problems that the effective pressure-bearing time of the soluble plug is short, the conventional plug cannot achieve full diameter after opening, and the plugging core remains in the well, affecting subsequent operations.

[0005] In order to alleviate the above technical problems, the technical solution provided by the present invention is:

[0006] The present invention provides a composite oil pipe plug, comprising an upper joint and a lower joint, and also comprising a first plugging component and a second plugging component; the upper joint is plugged into the upper part of the lower joint; the first plugging component is arranged in the upper joint; the second plugging component is arranged in the lower joint; the first plugging component comprises an impact sleeve and a soluble core shaft arranged in the impact sleeve; the second plugging component comprises a rupture disk.

[0007] Furthermore, the impact sleeve is connected to the soluble core shaft via a first shear nail; the impact sleeve is connected to the upper joint via a second shear nail.

[0008] Furthermore, the size of the second shear nail is smaller than that of the first shear nail.

[0009] Furthermore, a rubber ring is sleeved on the side wall of the rupture disk; the inner wall of the lower joint has a first annular protrusion extending inward; the rubber ring is clamped on the upper surface of the first annular protrusion; and the upper part of the rubber ring abuts against the upper joint.

[0010] Furthermore, the lower end of the impact sleeve has a pointed portion; the pointed portion faces the upper surface of the rupture disk.

[0011] Furthermore, the inner wall of the lower joint is also provided with a second annular protrusion extending inward; the second annular protrusion is arranged below the first annular protrusion; and the upper surface of the second annular protrusion is directly opposite to the tip.

[0012] Furthermore, an annular rubber ring is arranged between the impact sleeve and the soluble core shaft and between the impact sleeve and the upper joint.

[0013] The beneficial effects of the present invention are analyzed as follows:

[0014] The present invention provides a composite oil pipe plug, comprising an upper joint and a lower joint, and also comprising a first plugging component and a second plugging component; the upper joint is plugged into the upper part of the lower joint; the first plugging component is arranged in the upper joint; the second plugging component is arranged in the lower joint; the first plugging component comprises an impact sleeve and a soluble core shaft arranged in the impact sleeve; the second plugging component comprises a rupture disk.

[0015] When the device is lowered into the well, the rupture disk can prevent the liquid in the lower well from contacting the soluble core shaft, so that long-term plugging can be guaranteed before the production pipe is lowered into place. At the same time, the soluble core shaft and the rupture disk achieve a double sealing effect; the soluble core shaft and the rupture disk are independently arranged, and the failure of any component does not affect the sealing effect of the plugger; when it is necessary to release the seal, pressure is applied to the first plugging component from the upper joint through an external device, so that the first plugging component can move downward to destroy the rupture disk, and the soluble core shaft and the broken rupture disk can be discharged from the lower joint to the bottom of the pipeline, the soluble core shaft dissolves in water, and the small particles after the rupture disk is broken can be discharged from the pipeline with the return fluid, so that there is no residue inside. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the related technologies, the drawings required for use in the specific embodiments or the related technical descriptions will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0017] Figure 1 It is a cross-sectional schematic diagram of the present invention;

[0018] Figure 2 is a cross-sectional schematic diagram of a first plugging component;

[0019] Figure 3 is a cross-sectional schematic diagram of a second plugging component;

[0020] Figure 4 This is a schematic diagram of the installation of the upper joint and the lower joint.

[0021] icon:

[0022] 100-upper connector;

[0023] 200-lower joint; 210-first annular protrusion; 220-second annular protrusion;

[0024] 300-first plugging assembly; 310-impact sleeve; 311-tip; 320-soluble mandrel; 330-first shearing nail; 340-second shearing nail;

[0025] 400 - second plugging assembly; 410 - rupture disk; 420 - rubber ring. DETAILED DESCRIPTION

[0026] Embodiment 1

[0027] The metal core shaft of a conventional plug falls into and remains in the wellbore after being knocked off, affecting subsequent testing operations; the core shaft of a soluble plug is made of soluble material, and its effective pressure-bearing time is limited, so there is a risk of the plug failing if it is left in the wellbore for a long time.

[0028] In view of this, the present invention provides a composite oil pipe plug, such as Figure 1 As shown, it includes an upper joint 100 and a lower joint 200, and also includes a first plugging assembly 300 and a second plugging assembly 400; the upper joint 100 is inserted into the upper part of the lower joint 200; the first plugging assembly 300 is arranged in the upper joint 100; the second plugging assembly 400 is arranged in the lower joint 200; the first plugging assembly 300 includes an impact sleeve 310 and a soluble core shaft 320 arranged in the impact sleeve 310; the second plugging assembly 400 includes a rupture disk 410.

[0029] The second plugging component 400 is arranged at the lower part of the first plugging component 300. When the device is lowered into the pipeline, the rupture disk 410 can be used to prevent the liquid in the lower pipeline from contacting the soluble core shaft 320, so that long-term sealing can be guaranteed before the production pipe string is lowered into place. At the same time, the soluble core shaft 320 and the rupture disk 410 achieve a double sealing effect; the soluble core shaft 320 and the rupture disk 410 are independently arranged, and the failure of any component does not affect the sealing effect of the plugger; when it is necessary to release the seal, pressure is applied to the first plugging component 300 from the upper joint 100 through an external device, so that the first plugging component 300 can move downward to destroy the rupture disk 410, and the soluble core shaft 320 and the broken rupture disk 410 can be discharged from the lower joint 200 to the bottom of the pipeline, the soluble core shaft 320 dissolves in water, and the small particles after the rupture disk 410 is broken can be discharged from the pipeline with the return fluid, so that there is no residue inside.

[0030] like Figure 1 , Figure 2 and Figure 4As shown, the impact sleeve 310 and the soluble core shaft 320 are connected via a first shear nail 330 ; the impact sleeve 310 and the upper joint 100 are connected via a second shear nail 340 ; and the size of the second shear nail 340 is smaller than that of the first shear nail 330 .

[0031] Specifically, a through hole is provided at the upper portion of the impact sleeve 310, a countersunk hole is provided at a position of the soluble core shaft 320 corresponding to the through hole, and the first shear nail 330 passes through the through hole at the upper portion of the impact sleeve 310 and is connected with the countersunk hole on the soluble core shaft 320; a through hole is provided at the lower portion of the upper joint 100, a countersunk hole is provided at the lower portion of the impact sleeve 310, and the second shear nail 340 passes through the through hole at the lower portion of the upper joint 100 and is connected with the countersunk hole at the lower portion of the impact sleeve 310; and when the shear nail is sheared, the second shear nail 340 breaks before the first shear nail 330.

[0032] Regarding the shape and result of the second plugging component 400 Figure 3 and Figure 4 As shown:

[0033] The side wall of the rupture disk 410 is sleeved with a rubber ring 420 ; the inner wall of the lower joint 200 has a first annular protrusion 210 extending inward; the rubber ring 420 is clamped on the upper surface of the first annular protrusion 210 ; the upper part of the rubber ring 420 abuts against the upper joint 100 .

[0034] Specifically, the main body of the rupture disk 410 is a cylinder, and grooves are provided on the edges of the upper circular surface and the lower circular surface of the rupture disk 410. The upper and lower parts of the rubber ring 420 are provided with protrusions extending in a circular direction. The rubber ring 420 is sleeved in the groove of the rupture disk 410 through the protrusion. The lower part of the rubber ring 420 abuts against the first annular protrusion 210, and the upper part of the rubber ring 420 abuts against the lower part of the upper joint 100, so that the second blocking assembly 400 is clamped, and the rubber ring 420 helps to improve the air tightness.

[0035] Regarding the shape and structure of the impact sleeve 310, as shown in FIG. Figure 1 and Figure 2 As shown:

[0036] The impact sleeve 310 has a tip 311 at its lower end; the tip 311 faces the upper surface of the rupture disk 410 .

[0037] Preferably, the impact sleeve 310 has a plurality of spikes 311 arranged in an annular shape at the lower end thereof, the spikes 311 facing the upper surface of the rupture disk 410 , and after pressure is applied from the upper joint 100 to the inside, the second shear pins 340 will break, causing the impact sleeve 310 to move downward and break the rupture disk 410 .

[0038] like Figure 1 and Figure 4As shown, the inner wall of the lower joint 200 is further provided with a second annular protrusion 220 extending inwardly; the second annular protrusion 220 is provided below the first annular protrusion 210 ; and the upper surface of the second annular protrusion 220 faces the tip 311 .

[0039] Specifically, when the rupture disk 410 is broken, the impact sleeve 310 will continue to move downward, and the second annular protrusion 220 will press against the tip 311 to stop the impact sleeve 310 from moving. At this time, the pressure will continue to increase, causing the first shear pin 330 to break, allowing the soluble core shaft 320 to fall into the well, and the soluble core shaft 320 will dissolve when it comes into contact with the liquid in the well.

[0040] Preferably, in order to improve the sealing effect of the device, a plurality of groups of annular rubber rings 420 are provided between the impact sleeve 310 and the soluble core shaft 320 and between the impact sleeve 310 and the upper joint 100 .

[0041] The specific steps of this program are as follows:

[0042] The first step is to connect the composite oil pipe plug to the bottom of the oil pipe and lower it to the designated position in the well by an external conveying device to achieve sealing in the well;

[0043] In the second step, when the seal needs to be released, pressure is applied to the upper joint 100. After the pressure rises, the second shear pin 340 breaks, the impact sleeve 310 moves downward, and the tip 311 breaks the rupture disk 410, causing the fragments of the rupture disk 410 to fall into the well, and the fragments will be discharged along the return pipe in the well;

[0044] The third step is to continue to increase the input pressure to break the first shear nail 330, and the dissolving core shaft 320 will move downward into the well and react and dissolve with the liquid in the well. At this time, the pipeline in the well is connected.

[0045] The present invention can achieve the following beneficial effects:

[0046] Before the production tubing is lowered into place, long-term plugging can be guaranteed, and at the same time, the soluble core shaft 320 and the rupture disk 410 achieve a double sealing effect; the soluble core shaft 320 and the rupture disk 410 are independently arranged, and the failure of any component will not affect the sealing effect of the plugger; when it is necessary to release the seal, pressure is applied to the first plugging component 300 from the upper joint 100 through an external device, so that the first plugging component 300 can move downward to destroy the rupture disk 410, and the soluble core shaft 320 and the broken rupture disk 410 can be discharged from the lower joint 200 to the bottom of the pipeline, the soluble core shaft 320 dissolves in water, and the small particles after the rupture disk 410 is broken can be discharged from the pipeline with the return fluid, so that there is no residue inside.

[0047] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A composite oil pipe plug, comprising an upper joint (100) and a lower joint (200), Features: Also included is a first plugging assembly (300) and a second plugging assembly (400); The upper joint (100) is plugged into the upper part of the lower joint (200); The first plugging component (300) is arranged in the upper joint (100); The second plugging component (400) is arranged in the lower joint (200); The first plugging assembly (300) comprises an impact sleeve (310) and a soluble core shaft (320) disposed in the impact sleeve (310); The second plugging assembly (400) includes a rupture disk (410).

2. The composite oil pipe plug according to claim 1, Features: The impact sleeve (310) and the soluble core shaft (320) are connected via a first shear pin (330); The impact sleeve (310) and the upper joint (100) are connected via a second shear pin (340).

3. The composite oil pipe plug according to claim 2, Features: The second shear pin (340) has a smaller size than the first shear pin (330).

4. The composite oil pipe plug according to claim 3, Features: The side wall of the rupture disk (410) is sleeved with a rubber ring (420); The inner wall of the lower joint (200) has a first annular protrusion (210) extending inwards; The rubber ring (420) is clamped on the upper surface of the first annular protrusion (210); The upper portion of the rubber ring (420) abuts against the upper joint (100).

5. The composite oil pipe plug according to claim 4, Features: The impact sleeve (310) has a tip (311) at the lower end; The pointed portion (311) faces the upper surface of the rupture disk (410).

6. The composite oil pipe plug according to claim 5, Features: The inner wall of the lower joint (200) is also provided with a second annular protrusion (220) extending inwards; The second annular protrusion (220) is arranged below the first annular protrusion (210); The upper surface of the second annular protrusion (220) faces the tip (311).

7. The composite oil pipe plug according to claim 6, Features: An annular rubber ring (420) is provided between the impact sleeve (310) and the soluble core shaft (320) and between the impact sleeve (310) and the upper joint (100).

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