Large-expansion-rate all-metal ultra-small-diameter bridge plug

Abstract

The invention relates to a large-expansion-rate all-metal ultra-small-diameter bridge plug which mainly comprises an integral expansion cone, a hoop ring A, a sectioning expansion cone A, slip teeth, a metal spiral slip, a sectioning expansion cone B, a hoop ring B, a pin, a lower joint and a center rod, and is characterized in that the integral expansion cone, the sectioning expansion cone A and the sectioning expansion cone B are pushed by a setting tool to annularly move towards the inner part of the metal spiral slip; due to the limiting effect of the shroud ring, the integral expansion cone and the split expansion cone A cannot generate relative motion, along with continuous increase of thrust, the shroud ring A and the shroud ring B are fractured, the split expansion cone A and the split expansion cone B generate radial displacement, the metal spiral slip continuously expands until slip teeth penetrate into the inner wall of a casing pipe, and setting operation is completed. By adopting an all-metal structure and different expansion cone combinations, the problems of low expansion rate, large outer diameter and the like of a traditional bridge plug can be solved, and the bridge plug has the advantages of large expansion rate, ultra-small outer diameter, high temperature resistance and the like, can be normally used in a deep casing deformation well, and is beneficial to benefit development of unconventional oil gas.

Description

Technical Field

[0001] The invention relates to a large expansion rate all-metal ultra-small diameter bridge plug, belonging to the technical field of oil and natural gas exploitation. Technical Background

[0002] Deep unconventional oil and gas reserves are rich and have broad prospects for exploration and development. However, they have the characteristics of complex formations, variable lithology, strong inhomogeneity of geostress, and easy activation of faults, which makes it difficult to ensure the integrity of deep unconventional oil and gas wells, thereby increasing the difficulty of development and transformation. The casing deformation rate of deep unconventional oil and gas wells is high and the degree of casing deformation is large. Soluble bridge plugs are the main segmentation tools for hydraulic fracturing of unconventional oil and gas wells such as shale gas. The rubber components of traditional bridge plugs are very prone to failure under deep, high-temperature and high-pressure well conditions. Severe casing deformation wells have put forward higher requirements on the passability, expansion, and anchoring of soluble bridge plugs.

[0003] In view of the above problems, this paper proposes a large expansion rate all-metal ultra-small diameter bridge plug. The tool adopts a multi-expansion cone expansion type, a metal spiral sealing structure and principle. The maximum expansion rate can reach 150%, and the maximum outer diameter is only 50mm. The tool has the advantages of high temperature and high pressure resistance, large expansion rate, ultra-small outer diameter, reliable sealing, and reliable principle. It can be used normally in deep casing change wells, which is conducive to the efficient development of unconventional oil and gas. Summary of the invention

[0004] To achieve the above-mentioned purpose, the technical solution adopted by the present invention to solve this problem is: a large expansion rate all-metal ultra-small diameter bridge plug, which is composed of an integral expansion cone, a hoop A, a petal expansion cone A, a slip tooth, a metal spiral slip, a petal expansion cone B, a hoop B, a pin, a lower joint, and a center rod. Its technical characteristics are that the lower joint is connected to the center rod by a pin, which plays an axial limiting role before losing the hand; the slip tooth is installed in the inclined tooth groove of the straight section of the metal spiral slip; the integral expansion cone and the petal expansion cone A are located on the same side of the metal spiral slip; the petal expansion cone A adopts a spiral petal structure, which is connected and limited by the hoop A; the petal expansion cone B adopts a petal structure The center rod is connected to the sealing tool, and the sealing tool directly applies thrust to the integral expansion cone. The integral expansion cone, petal expansion cone A, hoop A, petal expansion cone B, and hoop B move together into the inner annulus of the metal spiral slip. Due to the limiting effect of the hoop, the integral expansion cone and petal expansion cone A will not produce relative movement. As the thrust continues to increase, the hoop A and hoop B break, the petal expansion cone A and the petal expansion cone B produce radial displacement, and the metal spiral slip continues to expand until the slip teeth contact and eat into the inner wall of the casing, completing the sealing operation. The thrust continues to increase, the pins are sheared, and the release operation is completed.

[0005] The large expansion rate all-metal ultra-small diameter bridge plug is characterized in that the metal spiral slip is composed of a straight section and a spiral section, and the spiral section is installed on one side of the lower joint. After the spiral section expands, a metal spiral seal is formed. The number of turns of the spiral section is 0.5 to 2 turns, and the pitch of the spiral section is 30 mm to 100 mm.

[0006] The large expansion rate all-metal ultra-small diameter bridge plug is characterized in that the pitch of the spiral structure of the petal expansion cone A is 100mm to 200mm.

[0007] The large expansion rate all-metal ultra-small diameter bridge plug is characterized in that the petal expansion cone B adopts a straight section or spiral petal structure.

[0008] The large expansion rate all-metal ultra-small diameter bridge plug is characterized in that the installation position of the petal expansion cone B is located between the metal spiral slip and the lower joint or between the integral expansion cone and the petal expansion cone A.

[0009] The large expansion rate all-metal ultra-small diameter bridge plug is characterized in that the ultra-small diameter bridge plug is expanded by expanding the cone, the maximum expansion rate is 150%, and the maximum outer diameter is 50 mm.

[0010] In Example 2:

[0011] Install the petal expansion cone B and the hoop ring B between the integral expansion cone and the petal expansion cone A. The rest is consistent with Example 1.

[0012] Compared with Example 1, the entry sequence of the integral expansion cone, petal expansion cone A, and petal expansion cone B described in Example 2 is better controlled, and the metal spiral cava is not easy to slip, but the thrust required to move each expansion cone increases, and the uneven expansion of the two ends of the metal spiral cava affects the metal spiral sealing effect.

[0013] In Example 3:

[0014] The petal expansion cone B, the petal expansion cone A and the integral expansion cone are installed in reverse order between the metal spiral slip and the lower joint, and the rest is consistent with Example 2.

[0015] Compared with Example 1, the number of expansion cones installed on both sides of the metal spiral cava in Example 3 is greater, and a greater degree of expansion can be achieved, but the order in which the expansion cones enter is more difficult to control, the requirements for the performance of the metal material are higher, and the tool lowering and the difficulty of setting and releasing the seal are greatly increased.

[0016] In Example 4:

[0017] The split expansion cone B and the lower joint are connected by a slider and a slide groove, and the split expansion cone B and the metal spiral slip are changed from cone surface contact to end surface contact, and the rest is consistent with the embodiment.

[0018] Compared with Example 1, the petal expansion cone B described in Example 4 expands together with the straight section of the metal spiral cava and will not enter the inner annulus of the metal spiral cava. The petal expansion cone B has a better axial limiting effect on the metal spiral cava, and the metal spiral cava is not prone to slip, but its expansion rate is relatively low.

[0019] Compared with the prior art, the present invention has the following beneficial effects: (1) the present invention adopts an all-metal structure and has good high temperature and high pressure resistance; (2) the present invention adopts different expansion cone combinations and hoop limiting structures, which can achieve a large diameter change of the metal spiral slip and maintain uniform stability during the diameter change process; (3) the present invention has the advantages of high temperature and high pressure resistance, large expansion rate, ultra-small outer diameter, reliable sealing, reliable principle, etc., can be normally used in deep casing change wells, and is conducive to the efficient development of unconventional oil and gas. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a structural schematic diagram of a large expansion rate all-metal ultra-small diameter bridge plug of the present invention;

[0021] 1-first expansion cone, 2-hoop, 3-middle expansion cone, 4-second expansion cone, 5-spiral slip, 6-slip teeth, 7-lower joint, 8-pin A, 9-pin B, 10-center rod;

[0022] Figure 2 This is a schematic diagram of the structure of Embodiment 2 of the present invention;

[0023] Figure 3 This is a schematic diagram of the structure of Embodiment 3 of the present invention;

[0024] Figure 4 This is a schematic diagram of the structure of Embodiment 4 of the present invention;

[0025] Figure 5 This is a schematic diagram of the initial state of Embodiment 1 of the present invention;

[0026] Figure 6 This is a schematic diagram of the metal spiral slips beginning to expand according to Example 1 of the present invention;

[0027] Figure 7 This is a schematic diagram of the second expansion cone contacting the lower joint in Example 1 of the present invention;

[0028] Figure 8 This is a schematic diagram of the sealing of Example 1 of the present invention;

[0029] Fig. 9 This is a schematic diagram of the throwing hand in Example 1 of the present invention;

[0030] Fig.10 It is a three-dimensional schematic diagram of a slider-type metal spiral slip according to Embodiment 4 of the present invention;

[0031] Fig.11 It is a three-dimensional schematic diagram of the slider-type third expansion cone of Example 4 of the present invention;

[0032] Fig.12 It is a three-dimensional schematic diagram of the slide groove type lower joint of Example 4 of the present invention;

[0033] Fig.13 This is a diagram showing the application of the present invention in shale gas casing well staged fracturing. Specific implementation plan

[0034] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, specific embodiments of the present invention are now described with reference to the accompanying drawings.

[0035] The specific embodiments of the present invention described herein are only used for the purpose of explaining the present invention and cannot be understood as limiting the present invention in any way. Under the guidance of the present invention, technicians can conceive of any possible changes based on the present invention, which should be regarded as belonging to the scope of the present invention. It should be noted that when an element is referred to as "disposed on" another element, it can be directly on the other element or there can also be a central element. When an element is considered to be "connected" to another element, it can be directly connected to the other element or there may be a central element at the same time. The terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it can be a mechanical connection or an electrical connection, or it can be the internal communication of two elements, it can be directly connected, or it can be indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to the specific circumstances. The terms "vertical", "horizontal", "up", "down", "left", "right" and similar expressions used herein are only for illustrative purposes and do not represent the only implementation method.

[0036] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0037] Embodiment 1:

[0038] As shown in the attached drawings, the large expansion rate all-metal ultra-small diameter bridge plug is mainly composed of an integral expansion cone 1, a hoop A2, a petal expansion cone A3, a cava tooth 4, a metal spiral cava 5, a petal expansion cone B6, a hoop B7, a pin 8, a lower joint 9, and a center rod 10. Its technical characteristics are that the lower joint 9 is connected to the center rod 10 by the pin 8, which plays an axial limiting role before losing the hand; the cava tooth 4 is installed in the inclined tooth groove of the straight section of the metal spiral cava 5; the integral expansion cone 1 and the petal expansion cone A3 are located on the same side of the metal spiral cava 5; the petal expansion cone A3 adopts a spiral petal structure, which is connected and limited by the hoop A2; the petal expansion cone B6 adopts a petal structure, which is connected and limited by the hoop Ring B7 is connected and limited; the center rod 10 is connected to the sealing tool, and the sealing tool directly applies thrust to the overall expansion cone 1, and the overall expansion cone 1, the petal expansion cone A3, the hoop ring A2, the petal expansion cone B6, and the hoop ring B7 move together into the inner annulus of the metal spiral cava 5. Due to the limiting effect of the hoop ring, the overall expansion cone 1 and the petal expansion cone A3 will not produce relative movement; as the thrust continues to increase, the hoop ring A2 and the hoop ring B7 break, the petal expansion cone A3 and the petal expansion cone B6 produce radial displacement, and the metal spiral cava 5 continues to expand until the cava teeth 4 contact and eat into the inner wall of the casing, completing the sealing operation, the thrust continues to increase, the pin 8 is sheared, and the release operation is completed.

[0039] The large expansion rate all-metal ultra-small diameter bridge plug is characterized in that the metal spiral slip 5 is composed of a straight section and a spiral section, and the spiral section is installed on one side of the lower joint 9. After the spiral section expands, a metal spiral seal is formed. The number of turns of the spiral section is 0.5 to 2 turns, and the pitch of the spiral section is 30 mm to 100 mm.

[0040] The large expansion rate all-metal ultra-small diameter bridge plug is characterized in that the pitch of the petal expansion cone A3 spiral structure is 100mm to 200mm.

[0041] The large expansion rate all-metal ultra-small diameter bridge plug is characterized in that the petal expansion cone B6 adopts a straight section or spiral petal structure.

[0042] The large expansion rate all-metal ultra-small diameter bridge plug is characterized in that the installation position of the petal expansion cone B6 is located between the metal spiral slip 5 and the lower joint 9 or between the integral expansion cone 1 and the petal expansion cone A3.

[0043] Embodiment 2:

[0044] The petal expansion cone B6 and the hoop B7 are installed between the integral expansion cone 1 and the petal expansion cone A3, and the rest is consistent with Example 1.

[0045] Compared with Example 1, the entry sequence of the integral expansion cone 1, the petal expansion cone A3, and the petal expansion cone B6 described in Example 2 is better controlled, and the metal spiral cava 5 is not easy to slip, but the thrust required for the movement of each expansion cone is increased, and the uneven expansion of the two ends of the metal spiral cava 5 affects the metal spiral sealing effect.

[0046] Embodiment 3:

[0047] The petal expansion cone B6, the petal expansion cone A3 and the integral expansion cone 1 are installed in reverse order between the metal spiral slip 5 and the lower joint 9, and the rest is consistent with Example 2.

[0048] Compared with Example 1, the number of expansion cones installed on both sides of the metal spiral cava 5 in Example 3 is greater, and a greater degree of expansion can be achieved, but the order in which the expansion cones enter is more difficult to control, the requirements for the performance of the metal material are higher, and the tool lowering and sealing difficulty are greatly increased.

[0049] Embodiment 4:

[0050] The split expansion cone B6 and the lower joint 9 are connected by a slider and a slide groove. The cone surface contact between the split expansion cone B6 and the metal spiral slip 5 is changed to end surface contact. The rest is consistent with Example 1.

[0051] Compared with Example 1, the petal expansion cone B6 described in Example 4 expands together with the straight section of the metal spiral cava 5 and will not enter the inner annulus of the metal spiral cava 5. The petal expansion cone B6 has a better axial limiting effect on the metal spiral cava 5, and the metal spiral cava 5 is not prone to slip, but its expansion rate is relatively low.

[0052] Embodiment 1, embodiment 2, embodiment 3, embodiment 4 all have strong expansion performance and setting performance, the maximum expansion rate is 150%, and the maximum outer diameter is 50mm.

Claims

1. A large expansion rate all-metal ultra-small diameter bridge plug, comprising an integral expansion cone (1), a hoop ring A (2), a petal expansion cone A (3), slip teeth (4), a metal spiral slip (5), a petal expansion cone B (6), a hoop ring B (7), a pin (8), a lower joint (9), and a center rod (10), and its technical features are: The lower joint (9) is connected to the center rod (10) by a pin (8), which plays an axial limiting role before the hand is released; the slip teeth (4) are installed in the inclined tooth grooves of the straight section of the metal spiral slip (5); the integral expansion cone (1) and the petal expansion cone A (3) are located on the same side of the metal spiral slip (5); the petal expansion cone A (3) adopts a spiral petal structure, which is connected and limited by a hoop ring A (2); the petal expansion cone B (6) adopts a petal structure, which is connected and limited by a hoop ring B (7); the center rod (10) is connected to a setting tool, and the setting tool directly applies thrust to the integral expansion cone (1), and the integral expansion cone (1 ), the petal expansion cone A (3), the hoop ring A (2), the petal expansion cone B (6), and the hoop ring B (7) move together into the inner annulus of the metal spiral slip (5). Due to the limiting effect of the hoop ring, the overall expansion cone (1) and the petal expansion cone A (3) will not produce relative movement; as the thrust continues to increase, the hoop ring A (2) and the hoop ring B (7) break, the petal expansion cone A (3) and the petal expansion cone B (6) produce radial displacement, and the metal spiral slip (5) continues to expand until the slip teeth (4) contact and eat into the inner wall of the casing, completing the sealing operation. The thrust continues to increase, the pin (8) is sheared, and the release operation is completed.

2. The large expansion rate all-metal ultra-small diameter bridge plug according to claim 1, characterized in that: The metal spiral slip (5) is composed of a straight section and a spiral section. The spiral section is installed on one side of the lower joint (9). After the spiral section is expanded, a metal spiral seal is formed. The number of turns of the spiral section is 0.5 to 2 turns, and the pitch of the spiral section is 30 mm to 100 mm.

3. The large expansion rate all-metal ultra-small diameter bridge plug according to claim 1, characterized in that: The pitch of the spiral structure of the petal expansion cone A (3) is 100 mm to 200 mm.

4. The large expansion rate all-metal ultra-small diameter bridge plug according to claim 1, characterized in that: The petal expansion cone B (6) adopts a straight segment or a spiral petal structure.

5. The large expansion rate all-metal ultra-small diameter bridge plug according to claim 1, characterized in that: The installation position of the split expansion cone B (6) is located between the metal spiral slip (5) and the lower joint (9) or between the integral expansion cone (1) and the split expansion cone A (3).

6. The large expansion rate all-metal ultra-small diameter bridge plug according to claim 1, characterized in that: The ultra-small diameter bridge plug is expanded by expanding the cone, with a maximum expansion rate of 150% and a maximum outer diameter of 50 mm.

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