Multi-stage step-by-step progressive bridge plug with ultra-small diameter

Abstract

The invention relates to a multistage step-by-step progressive ultra-small diameter bridge plug, which mainly comprises a first expansion cone, a shroud ring, a middle expansion cone, a second expansion cone, a spiral slip, slip teeth, a lower joint, a pin A, a pin B and a center rod, and is characterized in that the first expansion cone pushes the middle expansion cone and the second expansion cone to move together, and after the second expansion cone is in contact with the lower joint, the spiral slip is driven to rotate; when the sleeve is inserted into the sleeve, the clamping ring on the sleeve and the baffle ring on the middle expansion cone are fractured, the middle expansion cone continues to move to make contact with the lower connector, the clamping ring on the middle expansion cone and the baffle ring on the first expansion cone are fractured, the first expansion cone continues to move, the spiral slip continuously expands, the slip teeth penetrate into the inner wall of the sleeve, setting is completed, along with continuous increase of thrust, the pin A and the pin B are cut off, and releasing is completed. The structure of the metal spiral seal, the shroud ring and the baffle ring is adopted, the problem of multi-stage step-by-step progressive and large-annulus plugging can be solved, and the large-annulus plugging device has the advantages of being extremely small in outer diameter, high in reducing capacity, uniform in expansion and the like, can be normally used in a shale gas casing deformation well and is beneficial to benefit development of shale oil gas.

Description

Technical Field

[0001] The invention relates to a multi-stage progressive ultra-small diameter bridge plug, belonging to the technical field of oil and natural gas exploitation. Technical Background

[0002] In the field of downhole operations such as oil and gas extraction, the complexity and variability of the downhole environment have brought severe challenges to engineering practice. The phenomenon of severe deformation of downhole casing is not uncommon in the process of oil and gas field development. It is caused by a variety of factors, such as geological tectonic movement, long-term changes in production pressure, and erosion of formation materials, which may cause casing deformation. This deformation changes the size and shape of the downhole channel, which brings huge obstacles to the passage and normal operation of downhole tools. Due to the limitations of its design size and structure, traditional downhole bridge plugs are often difficult to effectively pass through the deformed area when facing severe casing deformation, thus affecting the advancement of the entire operation process. In this context, in-depth research on downhole ultra-small diameter bridge plugs is of great significance.

[0003] In view of the above problems, this paper proposes a multi-stage progressive ultra-small diameter bridge plug. The tool adopts a multi-stage progressive diameter change structure and principle. The maximum expansion rate can reach 130%, and the minimum diameter is only 44mm. The spiral slip structure can achieve large diameter change and metal sealing. The retaining ring and hoop ring structure can realize the expansion cone entering in sequence. The tool has the advantages of small outer diameter, strong diameter change ability, uniform expansion, reliable sealing, reliable principle, etc. It can be used normally in most shale gas casing change wells, which is conducive to the efficient development of shale 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 multi-stage progressive ultra-small diameter bridge plug, which is composed of a first expansion cone, a hoop, an intermediate expansion cone, a second expansion cone, a spiral cava, a cava tooth, a lower joint, a pin A, a pin B, and a center rod. Its technical characteristics are that the lower joint is connected to the center rod through pins A and pin B; the spiral cava is connected and limited with the upper end slide groove of the lower joint through the lower end protrusion; the cava tooth is installed in the groove of the straight section of the spiral cava; the lower end of the second expansion cone is positioned by the conical surface of the spiral section of the spiral cava, and its upper end surface contacts the raised retaining ring at the lower end of the intermediate expansion cone; the lower end of the intermediate expansion cone is positioned by the conical surface of the second expansion cone, and its upper end surface contacts the raised retaining ring at the lower end of the first expansion cone; the intermediate expansion cone and the second expansion cone are composed of a petal structure, which are connected and limited by a hoop; the lower end of the first expansion cone is positioned by the conical surface of the intermediate expansion cone; the center rod It is connected to the sealing tool, which acts on the upper end face of the first expansion cone; the first expansion cone transmits the axial thrust to the second expansion cone in sequence through the retaining ring and the hoop ring; the second expansion cone, the middle expansion cone and the first expansion cone move downward together until the lower end face of the second expansion cone contacts the lower joint, and the hoop ring installed on the second expansion cone and the retaining ring of the middle expansion cone break under the continuous increase in thrust; the middle expansion cone enters the inner annulus of the second expansion cone; the spiral slip expands, and the lower end protrusion of the spiral slip gradually slides out of the lower joint slide groove; after the middle expansion cone contacts the lower joint, the thrust continues to increase, and the hoop ring installed on the middle expansion cone and the retaining ring on the first expansion cone break; the first expansion cone enters the inner annulus of the middle expansion cone, and the spiral slip continues to expand until the slip teeth eat into the inner wall of the casing to complete the sealing, and as the thrust continues to increase, pins A and B are sheared off to complete the release.

[0005] The multi-stage progressive ultra-small diameter bridge plug is characterized in that the spiral segment of the spiral slip contacts the inner wall of the casing after expansion to form a spiral metal seal, the number of turns of the spiral segment is 1 to 2, and the pitch of the spiral segment is 50 mm to 100 mm.

[0006] The multi-stage progressive ultra-small diameter bridge plug is characterized in that the slip teeth are arranged in double rows in a staggered manner, and the axial spacing thereof is 15 mm to 30 mm.

[0007] The multi-stage progressive ultra-small diameter bridge plug is characterized in that the middle expansion cone and the second expansion cone adopt a petal structure with 4 to 6 petals, and the second expansion cone has 0.5 to 1 turns.

[0008] The multi-stage progressive ultra-small diameter bridge plug is characterized in that the retaining ring structure and the hoop ring on the first expansion cone and the middle expansion cone ensure that the first expansion cone, the middle expansion cone and the second expansion cone enter the inner annulus of the spiral slip in sequence.

[0009] The multi-stage progressive ultra-small diameter bridge plug is characterized in that the ultra-small diameter bridge plug has a maximum expansion rate of 130% and a maximum outer diameter of 44 mm to 50 mm through multi-stage progressive diameter change.

[0010] In Example 2:

[0011] The structures of the first expansion cone, the hoop, the middle expansion cone and the second expansion cone are changed, and the rest remain the same as in Example 1.

[0012] The outer cone surface of the first expansion cone and the inner cone surface of the middle expansion cone adopt the same parabolic structure, the outer cone surface of the middle expansion cone and the inner cone surface of the second expansion cone adopt the same parabolic structure, and the parabolic curvature radius of the outer cone surface of the middle expansion cone is larger than that of the outer cone surface of the first expansion cone, so that the middle expansion cone can more easily enter the inner annulus of the spiral slip.

[0013] The first expansion cone parabola has a curvature radius of 70 mm to 110 mm, and the middle expansion cone parabola has a curvature radius of 110 mm to 150 mm.

[0014] In Example 3:

[0015] The structure of the middle expansion cone is changed, and the rest is consistent with Example 2.

[0016] The middle expansion cone adopts a spiral petal structure with 4 to 6 petals and 0.5 to 1 turns. The rotation direction should be opposite to that of the second expansion cone.

[0017] Compared with Example 2, the middle expansion cone of Example 3 has better supporting performance, but requires a larger driving force.

[0018] In Example 1, the expansion cone entry sequence is controlled by the retaining ring and the hoop structure. In Example 2 and Example 3, the expansion cone entry sequence is controlled by the expansion cone parabola and the hoop structure.

[0019] Compared with the prior art, the present invention has the following beneficial effects: (1) the present invention adopts a spiral slip structure, which can achieve large diameter change and metal sealing, and has good expansion uniformity; (2) the present invention adopts a hoop ring and / or a retaining ring structure, which can easily solve the problem of sequential entry of multi-stage expansion cones; (3) the present invention has the advantages of extremely small outer diameter, strong diameter change ability, uniform expansion, reliable sealing, reliable principle, etc., and can be normally used in most shale gas casing change wells, which is beneficial to the efficient development of shale oil and gas. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is an application diagram of the present invention in shale gas casing well staged fracturing;

[0021] Figure 2 It is a schematic structural diagram of a multi-stage progressive ultra-small diameter bridge plug of the present invention;

[0022] 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;

[0023] Figure 3 This is a schematic diagram of the structure of Embodiment 2 of the present invention;

[0024] Figure 4 This is a schematic diagram of the structure of Embodiment 3 of the present invention;

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

[0026] Figure 6 This is a schematic diagram of the second expansion cone contacting the lower joint of the present invention;

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

[0028] Figure 8 It is a schematic diagram of setting and releasing of the seal of the present invention;

[0029] Fig. 9 It is a three-dimensional schematic diagram of the first expansion cone of the present invention;

[0030] Fig.10 It is a three-dimensional schematic diagram of the middle expansion cone of the present invention;

[0031] Fig.11 This is a three-dimensional schematic diagram of the middle expansion cone of Example 2 of the present invention;

[0032] Fig.12 This is a three-dimensional schematic diagram of the middle expansion cone of Example 3 of the present invention;

[0033] Fig.13 A three-dimensional schematic diagram of the spiral slip of the present invention;

[0034] Fig.14 It is a three-dimensional schematic diagram of the lower joint of the present invention. Specific implementation plan

[0035] 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.

[0036] 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.

[0037] 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.

[0038] Embodiment 1:

[0039] As shown in the accompanying drawings, the multi-stage progressive ultra-small diameter bridge plug is mainly composed of a first expansion cone 1, a hoop 2, an intermediate expansion cone 3, a second expansion cone 4, a spiral cava 5, a cava tooth 6, a lower joint 7, a pin A8, a pin B9, and a center rod 10. Its technical characteristics are that the lower joint 7 is connected to the center rod 10 through the pin A8 and the pin B9; the spiral cava 5 is connected and limited by the upper end slide groove of the lower joint 7 through the lower end protrusion; the cava tooth 6 is installed in the straight section groove of the spiral cava 5; the lower end of the second expansion cone 4 is positioned by the spiral section conical surface of the spiral cava 5, and its upper end surface contacts the raised retaining ring at the lower end of the intermediate expansion cone 3; the lower end of the intermediate expansion cone 3 is positioned by the conical surface of the second expansion cone 4, and its upper end surface contacts the raised retaining ring at the lower end of the first expansion cone 1; the intermediate expansion cone 3 and the second expansion cone 4 are composed of a petal structure, which is connected and limited by the hoop 2; the lower end of the first expansion cone 1 is positioned by the conical surface of the intermediate expansion cone 3; the center rod 10 is connected to the sealing tool The sealing tool acts on the upper end face of the first expansion cone 1; the first expansion cone 1 transmits the axial thrust to the second expansion cone 4 in sequence through the retaining ring and the hoop ring 2; the second expansion cone 4, the intermediate expansion cone 3 and the first expansion cone 1 move downward together until the lower end face of the second expansion cone 4 contacts the lower joint 7, and the hoop ring 2 installed on the second expansion cone 4 and the retaining ring of the intermediate expansion cone 3 break under the continuous increase of thrust; the intermediate expansion cone 3 enters the inner annulus of the second expansion cone 4; the spiral slip 5 expands, and the lower end protrusion thereof gradually slides out of the slide groove of the lower joint 7; after the intermediate expansion cone 3 contacts the lower joint 7, the thrust continues to increase, and the hoop ring 2 installed on the intermediate expansion cone 3 and the retaining ring on the first expansion cone 1 break; the first expansion cone 1 enters the inner annulus of the intermediate expansion cone 3, and the spiral slip 5 continues to expand until the slip teeth 6 eat into the inner wall of the casing to complete the sealing, and as the thrust continues to increase, the pins A8 and B9 are sheared off to complete the release.

[0040] The multi-stage progressive ultra-small diameter bridge plug is characterized in that the spiral segment of the spiral slip 5 contacts the inner wall of the casing after expansion to form a spiral metal seal, the number of turns of the spiral segment is 1 to 2, and the pitch of the spiral segment is 50 mm to 100 mm.

[0041] The multi-stage progressive ultra-small diameter bridge plug is characterized in that the slip teeth 6 are arranged in double rows in a staggered manner, and the axial spacing thereof is 15 mm to 30 mm.

[0042] The multi-stage progressive ultra-small diameter bridge plug is characterized in that the middle expansion cone 3 and the second expansion cone 4 adopt a petal structure with 4 to 6 petals, and the number of turns of the second expansion cone 4 is 0.5 to 1 turn.

[0043] The multi-stage progressive ultra-small diameter bridge plug is characterized in that the retaining ring structure and the hoop ring 2 on the first expansion cone 1 and the middle expansion cone 3 ensure that the first expansion cone 1, the middle expansion cone 3 and the second expansion cone 4 enter the annulus inside the spiral slip 5 in sequence.

[0044] Embodiment 2:

[0045] The structures of the first expansion cone 1 , the hoop 2 , the middle expansion cone 3 , and the second expansion cone 4 are changed, and the rest remain the same as in Example 1.

[0046] The outer cone surface of the first expansion cone 101 and the inner cone surface of the middle expansion cone 301 adopt the same parabolic structure, the outer cone surface of the middle expansion cone 301 and the inner cone surface of the second expansion cone 4 adopt the same parabolic structure, and the parabolic curvature radius of the outer cone surface of the middle expansion cone 301 is larger than that of the outer cone surface of the first expansion cone 101, so that the middle expansion cone 301 can more easily enter the inner annulus of the spiral slip 5.

[0047] The parabolic curvature radius of the first expansion cone 101 is 70 mm to 110 mm, and the parabolic curvature radius of the middle expansion cone 301 is 110 mm to 150 mm.

[0048] Embodiment 3: The structure of the middle expansion cone 301 is changed, and the rest is consistent with Embodiment 2.

[0049] The middle expansion cone 302 adopts a spiral petal structure, with 4 to 6 petals and 0.5 to 1 turns, and the rotation direction should be opposite to that of the second expansion cone 4.

[0050] Compared with Example 2, the middle expansion cone 302 of Example 3 has better supporting performance, but requires a larger driving force.

[0051] In Example 1, the expansion cone entry sequence is controlled by the retaining ring and the hoop structure. In Example 2 and Example 3, the expansion cone entry sequence is controlled by the expansion cone parabola and the hoop structure.

[0052] Embodiment 1, embodiment 2 and embodiment 3 can all realize the sequential entry of multi-stage expansion cones, have strong diameter-changing capability, large annulus plugging effect and setting performance, the maximum expansion rate is 130%, and the maximum outer diameter is only 44mm-50mm.

Claims

1. A multi-stage progressive ultra-small diameter bridge plug, comprising a first expansion cone (1), a hoop ring (2), an intermediate expansion cone (3), a second expansion cone (4), a spiral slip (5), slip teeth (6), a lower joint (7), a pin A (8), a pin B (9), and a center rod (10), the technical features of which are: The lower joint (7) is connected to the center rod (10) through a pin A (8) and a pin B (9); the spiral slip (5) is connected to the upper end slot of the lower joint (7) through a lower end protrusion for limiting; the slip tooth (6) is installed in the straight section groove of the spiral slip (5); the lower end of the second expansion cone (4) is positioned through the spiral section cone surface of the spiral slip (5), and its upper end surface contacts the raised retaining ring at the lower end of the middle expansion cone (3); the lower end of the middle expansion cone (3) is positioned through the cone surface of the second expansion cone (4) The first expansion cone (1) is provided with a sealing tool for sealing the expansion cone (1) and a sealing tool for sealing the expansion cone (1). The sealing tool ... The second expansion cone (4), the middle expansion cone (3) and the first expansion cone (1) move downward together until the lower end surface of the second expansion cone (4) contacts the lower joint (7), and the hoop ring (2) installed on the second expansion cone (4) and the retaining ring of the middle expansion cone (3) break under the continuous increase of thrust; the middle expansion cone (3) enters the inner annulus of the second expansion cone (4); the spiral slip (5) expands, and the lower end protrusion thereof gradually slides out of the slide groove of the lower joint (7); after the middle expansion cone (3) contacts the lower joint (7), the thrust continues to increase, and the hoop ring (2) installed on the middle expansion cone (3) and the retaining ring on the first expansion cone (1) break; the first expansion cone (1) enters the inner annulus of the middle expansion cone (3), and the spiral slip (5) continues to expand until the slip teeth (6) eat into the inner wall of the casing, completing the sealing, and as the thrust continues to increase, the pin A (8) and the pin B (9) are sheared off, completing the release.

2. The multi-stage progressive ultra-small diameter bridge plug according to claim 1, characterized in that: After the spiral section of the spiral slip (5) expands, it contacts the inner wall of the casing to form a spiral metal seal. The number of turns of the spiral section is 1 to 2, and the pitch of the spiral section is 50 mm to 100 mm.

3. The multi-stage progressive ultra-small diameter bridge plug according to claim 1, characterized in that: The slip teeth (6) are arranged in double rows in a staggered manner, and the axial spacing thereof is 15 mm to 30 mm.

4. The multi-stage progressive ultra-small diameter bridge plug according to claim 1, characterized in that: The middle expansion cone (3) and the second expansion cone (4) adopt a petal structure, the number of petals is 4 to 6, and the number of turns of the second expansion cone (4) is 0.5 to 1.

5. The multi-stage progressive ultra-small diameter bridge plug according to claim 1, characterized in that: The retaining ring structure and the hoop ring (2) on the first expansion cone (1) and the middle expansion cone (3) ensure that the first expansion cone (1), the middle expansion cone (3) and the second expansion cone (4) enter the inner annulus of the spiral slip (5) in sequence.

6. The multi-stage progressive ultra-small diameter bridge plug according to claim 1, characterized in that: The ultra-small diameter bridge plug has a multi-stage step-by-step diameter change, with a maximum expansion rate of 130% and a maximum outer diameter of 44 mm to 50 mm.

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