Self-reducing elastic centralizer

Abstract

The invention discloses a self-variable-diameter elastic centralizer, and belongs to the technical field of oil and gas well cementation engineering, the self-variable-diameter elastic centralizer comprises a centralizing wing body which is configured to be capable of being converted between a first form and a second form; the first fixing ring body is arranged on the sleeve part in a sleeving manner; the second fixing ring body is arranged on the sleeve part in a sleeving manner; the adjusting component is configured to control the centralizing wing body to be converted between the first shape and the second shape. By arranging the centralizer composed of the centralizing wing body, the first fixing ring body, the second fixing ring body and the adjusting component, through the characteristic that the adjusting component deforms when the temperature is changed, and by means of the principle that the underground temperature gradually rises, the adjusting component is changed into a deformation state after descending to a set position along with a casing component, and the centralizing effect is achieved. Therefore, the centralizing wing body is converted into the second form from the first form, namely, the outer diameter of the centralizing wing body can be changed in a self-adaptive mode, and the centralizing effect is guaranteed.

Description

Technical Field

[0001] The invention belongs to the technical field of petroleum and natural gas cementing engineering, and in particular relates to a self-variable elastic centralizer. Background Art

[0002] Hole expansion or post-drilling hole expansion technology is currently a necessary drilling technology for deep wells, ultra-deep wells, and salt-gypsum layer creep sections. This technology greatly saves costs and increases the number of casing openings. It is an indispensable process for deep wells and ultra-deep wells. At the same time, it can solve the exploration and drilling problems caused by the creep and extrusion of the salt-gypsum layer. However, the lowering and straightening effect of the cementing casing in the hole expansion section is an unsolvable technical problem. If the centering of the hole expansion section cannot be guaranteed, the cementing displacement efficiency cannot be guaranteed, which will also affect the cementing quality of the hole expansion section; the hole expansion section diameter is larger than the upper hole diameter. Due to the basic mechanical properties of the elastic deformation of the spring leaf, the starting force and the reset force of the conventional straightener are linearly proportional. In order to ensure a sufficient righting effect, the starting force is often designed to be very large, but the excessive starting force directly leads to excessive friction when the centralizer passes through the upper well section, seriously affecting the safety of casing lowering and causing the casing to be unable to be lowered smoothly; if the starting force of the centralizer is reduced, the centralizer can pass through the smaller well section in the upper wellbore more easily, but after reaching the reaming section, due to the small starting force of the centralizer, its reset force is proportional to the starting force, and the reset force is correspondingly small. No effective reset force can be generated in the reaming section, and the righting effect cannot be achieved, resulting in a large eccentricity of the casing string in the reaming section, seriously affecting the casing centering, and further affecting the cementing displacement efficiency and cementing quality.

[0003] At present, there is no corresponding solution for the centralizer that can achieve good straightening effect and ensure the smooth running of casing in the expanded hole section. The casing is often run in by sacrificing one of the starting force or the resetting force, but it is impossible to fundamentally guarantee the centering degree of the casing and the quality of cementing. In severe cases, the casing stuck accident occurs in the upper well section with smaller wellbore diameter. Summary of the invention

[0004] The object of the present invention is to provide a self-variable elastic centralizer to solve the problems of the centralizer in the use process mentioned in the above background technology.

[0005] To achieve the above object, the present invention provides the following technical solution: a self-variable elastic centralizer, the centralizer is assembled on a casing component, and the centralizer comprises:

[0006] A righting wing body, which is configured to be able to transform between a first state and a second state, and has a deformation portion and a connection portion, wherein the deformation portion is deformed when the righting wing body transforms, and the connection portion has a first portion and a second portion respectively connected to two axial ends of the deformation portion;

[0007] A first fixed ring body, sleeved on the sleeve component and fixedly connected to the first part;

[0008] a second fixing ring body, sleeved on the sleeve component and fixedly connected to the second portion, wherein at least one of the first fixing ring body and the second fixing ring body is connected to the sleeve component when the centralizing wing body is in the first state;

[0009] An adjusting component is sleeved on the sleeve component and is located between the first fixing ring body and the second fixing ring body in the axial direction. At least a part of the adjusting component is configured to change from a stable state to a deformed state at a set temperature. In the stable state, the adjusting component supports the first fixing ring body and the second fixing ring body so that the straightening wing body is maintained in the first form. In the deformed state, the adjusting component releases the support for the first fixing ring body and the second fixing ring body so that the straightening wing body is transformed into the second form.

[0010] Preferably, the deformation portion comprises a plurality of arcuate strips arranged in a ring array, and the arcuate strips have:

[0011] a contact portion that moves radially outward when the righting wing body changes from the first configuration to the second configuration;

[0012] The transition portion includes a first telescopic portion and a second telescopic portion symmetrically arranged on both sides of the contact portion, wherein the first telescopic portion and the second telescopic portion are synchronously retracted outward when the righting wing body is transformed from the first form to the second form.

[0013] Preferably, the first fixing ring and the second fixing ring each have a first section disposed between the connecting portion and the sleeve component and a second section extending axially outward.

[0014] Preferably, any one of the first fixing ring body and the second fixing ring body is connected to the sleeve component when the centralizing wing body is in the first form.

[0015] Preferably, at least a portion of the adjusting component is constituted as an adjusting section made of a thermosensitive material, and the adjusting section changes from a stable state to a deformed state at a set temperature.

[0016] Preferably, the adjusting component has a plurality of adjusting sections, and different adjusting sections are configured to change from a stable state to a deformed state at different set temperatures.

[0017] Preferably, the adjusting component is provided with a plurality of hollow holes.

[0018] Preferably, the first part and the second part are both provided with circular holes distributed in a ring array.

[0019] Preferably, the first fixing ring and the second fixing ring are assembled with the connecting portion by screws.

[0020] Preferably, two axial ends of the adjusting component are fixedly connected to one axial end of the first fixing ring and one axial end of the second fixing ring respectively.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] The present application provides a stabilizer consisting of a straightening wing body, a first fixed ring body, a second fixed ring body and an adjusting component. By utilizing the characteristic that the adjusting component deforms when the temperature changes and the principle of gradual increase in downhole temperature, the adjusting component is transformed into a deformed state after descending to a set position along with the casing component, thereby transforming the straightening wing body from a first form to a second form, i.e., the outer diameter of the straightening wing body can change adaptively to ensure the straightening effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a schematic diagram of the centralizer in use;

[0024] Figure 2 It is a schematic diagram of the righting wing structure;

[0025] Figure 3 Schematic diagram of the assembly of centralizer and casing components;

[0026] Figure 4 It is a schematic diagram of the structure of the regulating component;

[0027] Figure 5 Schematic diagram of the centralizer in different states.

[0028] In the figure:

[0029] 10. Casing parts; 20. Centralizer;

[0030] 100. Righting the wing body;

[0031] 200, deformation portion; 200a, contact portion; 200b, first telescopic portion; 200c, second telescopic portion;

[0032] 300, connecting portion; 300a, first portion; 300b, second portion;

[0033] 400, first fixing ring; 401, second fixing ring; 402a, first section; 402b, second section;

[0034] 500. Adjustment components. DETAILED DESCRIPTION

[0035] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0036] A self-variable elastic centralizer 20 (hereinafter referred to as the centralizer 20) is assembled on a casing component 10 and enters the well from the wellhead together with the casing component 10, and is used for centralizing the casing component 10, that is, the casing component 10 constitutes an installation and transportation carrier of the centralizer 20, and the centralizer 20 has a portion in contact with the well wall, and the radial position of the portion is variable, so that when the centralizer 20 is transported to a well section position with different diameters along with the casing component 10, its diameter can be adaptively changed, so that part of the centralizer 20 keeps in contact with the well wall, and supports the casing component 10 and centralizes it.

[0037] Reference Figure 3 , is a schematic diagram of the assembly of the centralizer 20 and the casing component 10, combined with Figure 1 and 2 In some examples, the centralizer 20 includes a centralizer wing 100, which has a deformation portion 200 and a connection portion 300, wherein the connection portion 300 includes two parts (hereinafter referred to as a first part 300a and a second part 300b) spaced apart in the axial direction, and the first part 300a and the second part 300b are respectively connected to the two ends of the axial direction of the deformation portion 200, and the connection portion 300 is configured as a connector with other parts of the centralizer 20 (such as a subsequent fixing ring body) and a sleeve component 10. In some examples, the first part 300a and the second part 300b of the connection portion 300 are both configured as an annular sheet body so that they can be sleeved on the subsequent fixing ring body, and the first part 300a and the second part 300b of the connection portion 300 are both provided with a plurality of circular holes arranged in an annular array to cooperate with screws and other components to realize the assembly of the centralizer wing 100 and the sleeve component 10 and the subsequent fixing ring body.

[0038] Continue to refer to Figure 2In some examples, the deformation portion 200 is made of an elastic material, that is, the deformation portion 200 can be elastically deformed under the action of an external force (such as an axial or radial force). Specifically, the deformation portion 200 is composed of a plurality of arcuate strips, and the plurality of arcuate strips are arranged in an annular array, that is, the plurality of arcuate strips are uniformly distributed in the circumferential direction. More specifically, the single arcuate strip has a contact portion 200a and a transition portion, wherein the contact portion 200a is configured as a portion where the straightening wing body 100 contacts the well wall, and the transition portion is composed of two portions (hereinafter referred to as a first telescopic portion 200b and a second telescopic portion 200c) respectively connected to both ends of the transition portion, and the first telescopic portion 200b and the second telescopic portion 200c are symmetrically arranged on both sides of the axial direction of the contact portion 200a, and the first telescopic portion 200b (the second telescopic portion 200c) is configured as a connecting piece between the transition portion and the first portion 300a (the second portion 300b) of the connecting portion 300. By way of example, Figure 3 One end of the transition portion is connected to the first part 300a through the first telescopic portion 200b, and the other end of the transition portion is connected to the second part 300b through the second telescopic portion 200c. During the outer diameter adjustment process of the straightening wing body 100, the first part 300a and the second part 300b of the connecting portion 300 can move toward or away from each other, so that the first part 300a and the second part 300b of the connecting portion 300 are close to or away from each other, and the deformation part 200 of the straightening wing body 100 is deformed based on the movement of the first part 300a (the second part 300b). The outer diameter of the righting wing body 100 is changed, thereby realizing the adjustment of the outer diameter of the righting wing body 100. The adjustment process of increasing the outer diameter of the righting wing body 100 is used for explanation. At this time, the first part 300a and the second part 300b move toward each other. Specifically, during the movement process of the first part 300a and the second part 300b moving toward each other (that is, approaching each other), the first telescopic part 200b and the second telescopic part 200c are synchronously contracted inwardly in the axial direction and expanded outwardly in the radial direction, that is, the contact part 200a of the deformation part 200 moves radially outwardly to increase the outer diameter of the righting wing body 100.

[0039] Back to Figure 1 and 3The centralizer 20 further includes a fixing ring group, which includes two fixing ring bodies. For the convenience of description, the two fixing ring bodies are respectively recorded as a first fixing ring 400 and a second fixing ring 401, wherein the first fixing ring 400 and the second fixing ring 401 are both sleeved on the casing component 10 and arranged at intervals in the axial direction. At the same time, the first fixing ring 400 and the second fixing ring 401 are both configured to be able to slide on the outer wall surface of the casing component 10, and the first fixing ring 400 (the second fixing ring 401) has a connection portion 300 located on the centralizing wing body 100 and the casing component 10 The first section 402a between the first fixing ring 400 and the second section 402b extending axially inward (i.e., the direction in which the first fixing ring 400 and the second fixing ring 401 are adjacent), that is, the first section 402a constitutes a connecting section of the first fixing ring 400 (the second fixing ring 401) with the centralizing wing body 100 and the sleeve component 10, and the connection strength between the first fixing ring 400 (the second fixing ring 401) and the centralizing wing body 100 is greater than the connection strength between the first fixing ring 400 (the second fixing ring 401) and the sleeve component 10. In some examples, the centralizing wing body 100, the first fixing ring The first fixing ring 400 (second fixing ring 401) and the sleeve component 10 are connected by screws, that is, the screws enter from the circular hole of the connecting portion 300 of the centralizing wing body 100, and pass through the first section 402a of the first fixing ring 400 (second fixing ring 401) and then enter the sleeve component 10, so as to realize the assembly of the centralizing wing body 100, the fixing ring assembly and the sleeve component 10. At the same time, in this example, the connecting portion 300 of the centralizing wing body 100 and the first fixing ring 400 and the second fixing ring 401 are rigidly connected, that is, the connecting portion 300 of the centralizing wing body 100 and the first fixing ring 400 (The second fixing ring 401) moves synchronously in the axial direction, and correspondingly, the sleeve component 10 is connected to one of the first fixing ring 400 or the second fixing ring 401, and the connection between the sleeve component 10 and the first fixing ring 400 (the second fixing ring 401) can be destroyed under the action of an external force (such as the restoring force of the straightening wing body 100), so that the connecting part 300 of the first fixing ring 400 and the straightening wing body 100 can slide synchronously on the surface of the sleeve component 10, and the deformation part 200 of the straightening wing body 100 is deformed, thereby realizing the adjustment of the diameter size of the straightening wing body 100.

[0040] Reference Figure 1 and 3The centralizer 20 further comprises an adjusting component 500, which is sleeved on the sleeve component 10 and is located between the first fixing ring 400 and the second fixing ring 401 in the axial direction, and the two axial ends of the adjusting component 500 are respectively in contact with one end of the first fixing ring 400 and the second fixing ring 401, so as to support the first fixing ring 400 and the second fixing ring 401 in the axial direction, thereby making the first fixing ring 400 and the second fixing ring 401 spaced apart by a first spacing in the axial direction. Correspondingly, the centralizing wing body 100 is in the first form. In the first form, the first part 300a and the second part 300b constituting the connecting part 300 of the centralizing wing body 100 have a tendency to move toward each other, and the position of the contact part 200a of the centralizing wing body 100 in the radial direction is correspondingly recorded as the first position;

[0041] Continue to refer to Figure 1 and 3 , and combined with Figure 4 In some examples, at least part of the section in the axial direction of the adjusting component 500 is made of a thermosensitive material (hereinafter referred to as a thermosensitive section), that is, at least part of the adjusting component 500 is constituted as a thermosensitive section, which is made of a thermosensitive material and is configured to deform (i.e., melt or soften) when the ambient temperature reaches a first set temperature, that is, the thermosensitive section has a stable state and a deformed state. When the thermosensitive section of the adjusting component 500 is in a stable state, the two axial ends of the adjusting component 500 are respectively connected to one end of the first fixing ring 400 and the second fixing ring 401 to support the first fixing ring 400 and the second fixing ring 401. When the thermosensitive section of the adjusting component 500 is in a deformed state (i.e., after melting or softening), the axial supporting force applied by the adjusting component 500 to the first fixing ring 400 and the second fixing ring 401 disappears, and the first part 300a and the second part 300b of the connecting portion 300 of the straightening wing body 100 in the first state drive the first fixing ring 400 to rotate. The ring 400 and the second fixing ring 401 move toward each other, and after the first fixing ring 400 and the second fixing ring 401 contact the undeformed section of the adjusting component 500 or one axial end of the first fixing ring 400 and the second fixing ring 401 contact, that is, the first fixing ring 400 and the second fixing ring 401 are spaced apart by a second spacing in the axial direction, correspondingly, the above-mentioned straightening wing body 100 is transformed from the first form to the second form. In the process of transforming from the first form to the second form, the first telescopic portion 200b and the second telescopic portion 200c of the deformation portion 200 of the straightening wing body 100 shrink inwardly in the axial direction, and at the same time, the contact portion 200a of the straightening wing body 100 expands radially outward to a second radial position. After the external force on the straightening wing body 100 reaches a balance again (for example, the axial ends of the first fixing ring 400 and the second fixing ring 401 contact), correspondingly, the straightening wing body 100 is transformed into the second form, thereby realizing the outer diameter adjustment of the straightening wing body 100.

[0042] In some examples, the adjustment component 500 has a plurality of different thermally sensitive sections, and different adjustment sections require different deformation temperatures. Correspondingly, the righting wing body 100 can change between a plurality of deformations, that is, the outer diameter of the righting wing body 100 can change between a plurality of values.

[0043] In some embodiments, reference Figure 4 Part of the adjusting component 500 is hollowed out, that is, a plurality of hollow holes are provided on the adjusting component 500 to increase the sensitivity of the adjusting component 500 to temperature, achieve better heat conduction, and thus achieve more precise temperature control.

[0044] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A self-variable elastic centralizer, the centralizer is assembled on a casing component, characterized in that: The centralizer comprises: A righting wing body, which is configured to be able to transform between a first state and a second state, and has a deformation portion and a connection portion, wherein the deformation portion is deformed when the righting wing body transforms, and the connection portion has a first portion and a second portion respectively connected to two axial ends of the deformation portion; A first fixed ring body, sleeved on the sleeve component and fixedly connected to the first part; a second fixing ring body, sleeved on the sleeve component and fixedly connected to the second portion, wherein at least one of the first fixing ring body and the second fixing ring body is connected to the sleeve component when the centralizing wing body is in the first state; An adjusting component is sleeved on the sleeve component and is located between the first fixing ring body and the second fixing ring body in the axial direction. At least a part of the adjusting component is configured to change from a stable state to a deformed state at a set temperature. In the stable state, the adjusting component supports the first fixing ring body and the second fixing ring body so that the straightening wing body is maintained in the first form. In the deformed state, the adjusting component releases the support for the first fixing ring body and the second fixing ring body so that the straightening wing body is transformed into the second form.

2. The self-variable elastic centralizer according to claim 1, characterized in that: The deformation portion includes a plurality of arcuate strips arranged in a ring array, and the arcuate strips have: a contact portion that moves radially outward when the righting wing body changes from the first configuration to the second configuration; The transition portion includes a first telescopic portion and a second telescopic portion symmetrically arranged on both sides of the contact portion, wherein the first telescopic portion and the second telescopic portion are synchronously contracted inward when the righting wing body is transformed from the first form to the second form.

3. The self-variable elastic centralizer according to claim 1, characterized in that: The first fixing ring and the second fixing ring each have a first section disposed between the connecting portion and the sleeve component and a second section extending axially inwardly.

4. The self-variable elastic centralizer according to claim 1, characterized in that: Any one of the first fixing ring body and the second fixing ring body is connected to the sleeve component when the centralizing wing body is in the first state.

5. The self-variable elastic centralizer according to claim 1, characterized in that: At least a portion of the adjusting component is configured as an adjusting section made of a heat-sensitive material, and the adjusting section is transformed from a stable state to a deformed state at a set temperature.

6. The self-variable elastic centralizer according to claim 5, characterized in that: The adjusting component has a plurality of adjusting sections, and different adjusting sections are configured to change from a stable state to a deformed state at different set temperatures.

7. The self-variable elastic centralizer according to claim 1, characterized in that: The adjusting component is provided with a plurality of hollow holes.

8. The self-variable elastic centralizer according to claim 1, characterized in that: The first part and the second part are both provided with circular holes distributed in a ring array.

9. The self-variable elastic centralizer according to claim 1, characterized in that: The first fixing ring and the second fixing ring are both assembled with the connecting portion by screws.

10. The self-variable elastic centralizer according to claim 9, characterized in that: Two axial ends of the adjusting component are fixedly connected to one axial end of the first fixing ring and one axial end of the second fixing ring, respectively.

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