Axial hardness changing rubber sleeve and packer and bridge plug comprising same

Abstract

The invention belongs to the technical field of well drilling and completion engineering, and particularly relates to an axial hardness changing rubber sleeve, a packer comprising the rubber sleeve and a bridge plug comprising the rubber sleeve. The axial hardness changing rubber barrel comprises a plurality of barrel bodies which are sequentially connected in the axial direction, the hardness of every two adjacent barrel bodies is different, and all the barrel bodies are integrally formed. The problem that a gap exists between the middle spacer ring and the sleeve in the prior art can be solved.

Description

Technical Field

[0001] The present invention belongs to the technical field of drilling and completion engineering, and in particular, relates to an axial hardness varying rubber cartridge, a packer including the axial hardness varying rubber cartridge, and a bridge plug including the axial hardness varying rubber cartridge. Background Art

[0002] During the drilling and completion process, oil and gas need to be separated, which is mainly achieved by packers and bridge plugs.

[0003] The sealing components of packers and bridge plugs are mainly rubber sleeves, which are generally made of rubber. Their sealing performance determines the reliability of the packers and bridge plugs. For high-temperature and high-pressure wells, three-stage rubber sleeves are generally used for sealing. The rubber sleeve is compressed axially to produce radial deformation, filling the gap between the rubber sleeve and the casing to form a seal.

[0004] The hardness of the upper and lower rubber sections of the three-section rubber cylinder is greater than that of the middle section. When the rubber cylinder is axially compressed, the middle section is squeezed and deformed first, followed by the upper and lower sections. The three-section rubber cylinder can effectively improve the shoulder protrusion problem caused by the compression of the single-section rubber cylinder and improve the sealing performance.

[0005] However, the three-section rubber cartridge requires the use of a middle spacer ring to separate rubber cartridges of different hardness. During compression, the gap between the middle spacer ring and the sleeve is a weak point for leakage. If the gap cannot be completely filled, the seal failure will be accelerated.

[0006] In order to solve the failure problem caused by the inability to completely fill the middle spacer ring of the three-stage rubber cartridge, the present invention proposes a rubber cartridge, a packer and a bridge plug with varying axial hardness, which can effectively fill the space between the rubber cartridge and the casing, improve the reliability of sealing of high-temperature and high-pressure oil and gas wells, provide effective technical means for oil and gas development, increase oil and gas production, and ensure energy security. Summary of the invention

[0007] In view of the technical problems mentioned above, the present invention aims to provide an axially hardness variable rubber cylinder, which can solve the problem of a gap between the intermediate spacer ring and the sleeve in the prior art.

[0008] The present invention also proposes a packer comprising an axially hardness varying rubber sleeve, which can solve the problem of a gap between the intermediate spacer ring and the casing in the prior art.

[0009] The present invention also proposes a bridge plug comprising an axially hardness varying rubber sleeve, which can solve the problem of a gap between the intermediate spacer ring and the casing in the prior art.

[0010] According to the present invention, there is provided an axially hardness-varying rubber cylinder, comprising a plurality of cylinders connected in sequence axially, the hardness of two adjacent cylinders being different, and each of the cylinders being integrally formed.

[0011] In a preferred embodiment, a transition section is integrally formed between two adjacent cylinders, and the hardness of the transition section is between the hardness of the two adjacent cylinders.

[0012] In a preferred embodiment, the hardness of the transition section changes linearly.

[0013] In a preferred embodiment, the hardness of the transition section changes in a curve.

[0014] In a preferred embodiment, the hardness of the transition section changes in steps.

[0015] In a preferred embodiment, the axially hardness varying rubber cylinder comprises an upper cylinder, a first transition section, a middle cylinder, a second transition section and a lower cylinder which are axially connected in sequence.

[0016] In a preferred embodiment, the upper cylinder and the lower cylinder have the same hardness, and the hardness of the upper cylinder and the lower cylinder is greater than that of the middle cylinder.

[0017] In a preferred embodiment, the rubber cylinder with axially varying hardness is made of rubber, and a blank is prepared by axially laying mixed rubbers of different hardnesses to prepare the blank and then vulcanizing it, thereby preparing the rubber cylinder with axially varying hardness.

[0018] According to the present invention, a packer is also provided, comprising the axial hardness varying rubber sleeve provided according to the present invention.

[0019] According to the present invention, there is also provided a bridge plug, comprising the axial hardness varying rubber sleeve provided according to the present invention.

[0020] Compared with the prior art, the present application has at least the following advantages.

[0021] The present invention is constructed as an integrated structure, and the axial hardness varies. Specifically, the present invention includes an upper cylinder, a middle cylinder and a lower cylinder. The three-stage structure can effectively solve the problem of shoulder protrusion of a single-stage rubber cylinder. When the rubber cylinder is compressed, the middle cylinder has a lower hardness and deforms first; then the upper cylinder and the lower cylinder deform, effectively avoiding the problem of shoulder protrusion caused by the upper or lower rubber cylinder being stressed.

[0022] Moreover, since the rubber cylinder is an integrated structure with a variable axial hardness, the gap between the rubber cylinder and the sleeve is filled in sequence by the middle cylinder, the first transition section, the second transition section, the upper cylinder and the lower cylinder, and finally the gap can be completely filled. The present invention can effectively solve the problem of incomplete filling of the gap between the middle spacer ring of the three-stage rubber cylinder in the prior art. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The present invention will be described below with reference to the accompanying drawings.

[0024] Figure 1 A schematic diagram showing an embodiment of an axially hardness varying rubber cartridge according to the present invention;

[0025] Figure 2 A hardness variation curve diagram of a first embodiment of an axially hardness variation rubber cartridge according to the present invention is shown;

[0026] Figure 3 A hardness variation curve diagram of a second embodiment of an axially hardness variation rubber cartridge according to the present invention is shown;

[0027] Figure 4 A hardness variation curve diagram of a third embodiment of an axially hardness variation rubber cartridge according to the present invention is shown;

[0028] Figure 5 A schematic diagram of a prior art cartridge is shown.

[0029] In the figure:

[0030] 1. Upper cylinder;

[0031] 2. Middle cylinder;

[0032] 3. Lower cylinder;

[0033] 4. The first transition section;

[0034] 5. The second transition section;

[0035] 6. Upper support ring;

[0036] 7. Lower support ring;

[0037] 8. Casing;

[0038] 9. Center tube;

[0039] 10. Packer;

[0040] 11. First intermediate spacer ring;

[0041] 12. Second intermediate spacer ring;

[0042] 100. Axial hardness variable rubber cylinder.

[0043] In the present application, all drawings are schematic drawings, which are only used to illustrate the principles of the present invention and are not drawn according to the actual scale. DETAILED DESCRIPTION

[0044] The present invention will be described below with reference to the accompanying drawings.

[0045] It should be noted that the directional terms or qualifiers "upper" and "lower" used in this application are all directed to the referenced Figure 1 They are not intended to define the absolute positions of the components involved, but may vary depending on the specific circumstances.

[0046] Embodiment 1:

[0047] According to the present invention, a structure of an axially hardness varying rubber cylinder 100 is provided. In this embodiment, the axially hardness varying rubber cylinder 100 comprises a plurality of cylinders connected in sequence axially, the hardness of two adjacent cylinders is different, and each cylinder is integrally formed.

[0048] Furthermore, a transition section is integrally formed between two adjacent cylinders, and the hardness of the transition section is between the hardness of the two adjacent cylinders.

[0049] Specifically, in this embodiment, the axial hardness varying rubber cylinder 100 is made of rubber material. During the manufacturing process of the rubber, the hardness of the rubber can be changed by changing the proportion of reinforcing fillers in the rubber (or the molecular weight of the rubber, the proportion of cross-linking groups).

[0050] In the process of preparing the rubber cylinder 100 with axially varying hardness, the rubber cylinder 100 with axially varying hardness is prepared by laying mixed rubbers with different hardnesses in the axial direction to prepare a blank and then vulcanizing it, thereby achieving the preparation of the rubber cylinder 100 with axially varying hardness.

[0051] According to a specific embodiment provided by the present invention, Figure 1 As shown, the axial hardness varying rubber cylinder 100 comprises an upper cylinder body 1, a first transition section 4, a middle cylinder body 2, a second transition section 5 and a lower cylinder body 3 which are coaxially connected in sequence from top to bottom.

[0052] in, Figure 1 The dotted lines are only used to distinguish the upper cylinder 1, the first transition section 4, the middle cylinder 2, the second transition section 5 and the lower cylinder 3. The upper cylinder 1, the first transition section 4, the middle cylinder 2, the second transition section 5 and the lower cylinder 3 are all arranged as an integrally formed structure between the adjacent two parts.

[0053] Embodiment 2:

[0054] In a specific embodiment, Figure 2 The hardness variation curve diagram of the first embodiment of the axial hardness variation rubber cartridge 100 according to the present invention is shown. Figure 2 As shown, section A in the figure is the axial distance of the upper cylinder 1, section B in the figure is the axial distance of the first transition section 4, section C in the figure is the axial distance of the middle cylinder 2, section D in the figure is the axial distance of the second transition section 5, and section E is the axial distance of the lower cylinder 3.

[0055] The hardness of the upper cylinder 1 and the lower cylinder 3 is HA, and the hardness of the middle cylinder 2 is HB. That is to say, the hardness of the upper cylinder 1, the lower cylinder 3 and the middle cylinder 2 is unchanged, and the hardness of the upper cylinder 1 and the lower cylinder 3 is greater than that of the middle cylinder 2.

[0056] In this embodiment, the hardness of the first transition section 4 and the second transition section 5 both change in a linear manner, and the two ends of the first transition section 4 and the second transition section 5 have the same hardness as the adjacent parts.

[0057] Specifically, the left end of the first transition section 4 is connected to the upper cylinder 1, and the hardness of the left end of the first transition section 4 is the same as that of the upper cylinder 1, both of which are HA. The right end of the first transition section 4 is connected to the middle cylinder 2, and the hardness of the right end of the first transition section 4 is the same as that of the middle cylinder 2, both of which are HB.

[0058] The two ends of the first transition section 4 are respectively connected to the upper cylinder 1 and the middle cylinder 2. The hardness of the two ends of the first transition section 4 is respectively the same as that of the upper cylinder 1 and the middle cylinder 2. The overall hardness of the first transition section 4 changes linearly along the axial direction.

[0059] Similarly, the left end of the second transition section 5 is connected to the middle cylinder 2, and the hardness of the left end of the second transition section 5 is the same as that of the middle cylinder 2, both of which are HB. The right end of the second transition section 5 is connected to the lower cylinder 3, and the hardness of the right end of the second transition section 5 is the same as that of the lower cylinder 3, both of which are HA.

[0060] The two ends of the second transition section 5 are respectively connected to the lower cylinder 3 and the middle cylinder 2. The hardness of the two ends of the second transition section 5 is respectively the same as that of the lower cylinder 3 and the middle cylinder 2. The overall hardness of the second transition section 5 changes linearly along the axial direction.

[0061] Embodiment three:

[0062] In a specific embodiment, Figure 3 The hardness variation curve diagram of the second embodiment of the axial hardness variation rubber cartridge 100 according to the present invention is shown. Figure 3 As shown, section A in the figure is the axial distance of the upper cylinder 1, section B in the figure is the axial distance of the first transition section 4, section C in the figure is the axial distance of the middle cylinder 2, section D in the figure is the axial distance of the second transition section 5, and section E is the axial distance of the lower cylinder 3.

[0063] The hardness of the upper cylinder 1 and the lower cylinder 3 is HA, and the hardness of the middle cylinder 2 is HB. That is to say, the hardness of the upper cylinder 1, the lower cylinder 3 and the middle cylinder 2 is unchanged, and the hardness of the upper cylinder 1 and the lower cylinder 3 is greater than that of the middle cylinder 2.

[0064] In this embodiment, the hardness of the first transition section 4 and the second transition section 5 both vary in a curve, and the two ends of the first transition section 4 and the second transition section 5 have the same hardness as the adjacent parts.

[0065] Specifically, the left end of the first transition section 4 is connected to the upper cylinder 1, and the hardness of the left end of the first transition section 4 is the same as that of the upper cylinder 1, both of which are HA. The right end of the first transition section 4 is connected to the middle cylinder 2, and the hardness of the right end of the first transition section 4 is the same as that of the middle cylinder 2, both of which are HB.

[0066] The two ends of the first transition section 4 are respectively connected to the upper cylinder 1 and the middle cylinder 2. The hardness of the two ends of the first transition section 4 is respectively the same as that of the upper cylinder 1 and the middle cylinder 2. The overall hardness of the first transition section 4 changes in a curve along the axial direction.

[0067] Similarly, the left end of the second transition section 5 is connected to the middle cylinder 2, and the hardness of the left end of the second transition section 5 is the same as that of the middle cylinder 2, both of which are HB. The right end of the second transition section 5 is connected to the lower cylinder 3, and the hardness of the right end of the second transition section 5 is the same as that of the lower cylinder 3, both of which are HA.

[0068] The two ends of the second transition section 5 are respectively connected to the lower cylinder 3 and the middle cylinder 2. The hardness of the two ends of the second transition section 5 is respectively the same as that of the lower cylinder 3 and the middle cylinder 2. The overall hardness of the second transition section 5 changes in a curve along the axial direction.

[0069] Embodiment 4:

[0070] In a specific embodiment, Figure 4 FIG. 2 shows a hardness variation curve diagram of a third embodiment of an axially hardness variation rubber cartridge 100 according to the present invention. Figure 4 As shown, section A in the figure is the axial distance of the upper cylinder 1, section B in the figure is the axial distance of the first transition section 4, section C in the figure is the axial distance of the middle cylinder 2, section D in the figure is the axial distance of the second transition section 5, and section E is the axial distance of the lower cylinder 3.

[0071] The hardness of the upper cylinder 1 and the lower cylinder 3 is HA, and the hardness of the middle cylinder 2 is HB. That is to say, the hardness of the upper cylinder 1, the lower cylinder 3 and the middle cylinder 2 is unchanged, and the hardness of the upper cylinder 1 and the lower cylinder 3 is greater than that of the middle cylinder 2.

[0072] In this embodiment, the hardness of the first transition section 4 and the second transition section 5 both change in a step-wise manner, and the two ends of the first transition section 4 and the second transition section 5 have the same hardness as the adjacent parts.

[0073] Specifically, the left end of the first transition section 4 is connected to the upper cylinder 1, and the hardness of the left end of the first transition section 4 is the same as that of the upper cylinder 1, both of which are HA. The right end of the first transition section 4 is connected to the middle cylinder 2, and the hardness of the right end of the first transition section 4 is the same as that of the middle cylinder 2, both of which are HB.

[0074] The two ends of the first transition section 4 are respectively connected to the upper cylinder 1 and the middle cylinder 2. The hardness of the two ends of the first transition section 4 is respectively the same as that of the upper cylinder 1 and the middle cylinder 2. The overall hardness of the first transition section 4 changes in a stepwise manner along the axial direction.

[0075] Similarly, the left end of the second transition section 5 is connected to the middle cylinder 2, and the hardness of the left end of the second transition section 5 is the same as that of the middle cylinder 2, both of which are HB. The right end of the second transition section 5 is connected to the lower cylinder 3, and the hardness of the right end of the second transition section 5 is the same as that of the lower cylinder 3, both of which are HA.

[0076] The two ends of the second transition section 5 are respectively connected to the lower cylinder 3 and the middle cylinder 2. The hardness of the two ends of the second transition section 5 is respectively the same as that of the lower cylinder 3 and the middle cylinder 2. The overall hardness of the second transition section 5 changes in a step-like manner along the axial direction.

[0077] Embodiment five:

[0078] According to the present invention, a packer 10 is provided, comprising the axial hardness varying rubber sleeve 100 provided by any one of the above embodiments.

[0079] Specifically, Figure 1 As shown, the packer 10 includes a central pipe 9 , an axial hardness varying rubber sleeve 100 , an upper support ring 6 , a lower support ring 7 and a casing 8 .

[0080] The center tube 9 is coaxially sleeved in a gap manner inside the sleeve 8, and an upper support ring 6, an axial hardness variation rubber cylinder 100 and a lower support ring 7 are sequentially arranged on the outer wall of the center tube 9 from top to bottom. The lower support ring 7 is fixedly arranged on the center tube 9, and the upper support ring 6 can move axially downward relative to the center tube 9.

[0081] When the packer 10 is set, a downward axial force is applied to the upper support ring 6 to compress the axial hardness variation rubber cylinder 100 , and the axial force is finally transmitted to the lower support ring 7 .

[0082] When the axial hardness changes and the rubber cylinder 100 is compressed, the first thing to deform is the middle cylinder 2, corresponding to Figure 2 to Figure 4 The first transition section 4 and the second transition section 5 are then deformed, corresponding to Figure 2 to Figure 4 The last ones to be deformed are the upper cylinder 1 and the lower cylinder 3, corresponding to Figure 2 to Figure 4 Sections A and E in.

[0083] By using the axial hardness changing rubber cartridge 100 provided by the present invention, the problem of shoulder protrusion is effectively avoided during the packing process of the packer 10. At the same time, due to the change in the axial hardness of the axial hardness changing rubber cartridge 100, the present invention can finally completely fill the gap between the central tube 9 and the casing 8, solving the problem that the gap between the intermediate spacer ring and the casing 8 of the three-stage rubber cartridge in the prior art cannot be completely filled.

[0084] Embodiment five:

[0085] According to the present invention, a bridge plug is provided, comprising the axial hardness varying rubber cartridge provided by the present invention.

[0086] Comparative Example:

[0087] The structure of the rubber cartridge in the prior art is as follows Figure 5 As shown, Figure 5 As shown, the mutually independent upper cylinder 1, middle cylinder 2 and lower cylinder 3 are arranged on the outer wall of the central tube 9 from top to bottom. A first intermediate spacer ring 11 is arranged between the upper cylinder 1 and the middle cylinder 2, and a second intermediate spacer ring 12 is arranged between the middle cylinder 2 and the lower cylinder 3.

[0088] During the setting process of the rubber cylinder of this structure, due to the high hardness of the upper cylinder 1 and the lower cylinder 3, they cannot fill the gap between the first middle spacer ring 11 and the sleeve 8 and the gap between the second middle spacer ring 12 and the sleeve 8 after being compressed. If the axial force is increased, the structure of the middle cylinder 2 may be broken. When the gap exists, if the seal of the upper cylinder 1 or the lower cylinder 3 fails, the fluid dynamic pressure will directly act on the middle cylinder 2, which will accelerate the failure of the seal.

[0089] In the description of the present invention, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0090] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0091] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0092] Finally, it should be noted that the above is only a preferred embodiment of the present invention and does not constitute any limitation to the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for a person skilled in the art to modify the technical solutions described in the aforementioned embodiments or to replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A rubber cylinder with variable axial hardness, characterized in that: include: A plurality of cylinders are axially connected in sequence, the hardness of two adjacent cylinders is different, and each of the cylinders is integrally formed.

2. The axial hardness varying rubber cartridge according to claim 1, characterized in that: A transition section is integrally formed between two adjacent cylinders, and the hardness of the transition section is between the hardness of the two adjacent cylinders.

3. The axial hardness varying rubber cartridge according to claim 2, characterized in that: The hardness of the transition section changes linearly.

4. The axial hardness varying rubber cartridge according to claim 2, characterized in that: The hardness of the transition section changes in a curve.

5. The axial hardness varying rubber cartridge according to claim 2, characterized in that: The hardness of the transition section changes in steps.

6. The axial hardness varying rubber cartridge according to claim 2, characterized in that: The axially hardness varying rubber cylinder comprises an upper cylinder (1), a first transition section (4), a middle cylinder (2), a second transition section (5) and a lower cylinder (3) which are axially connected in sequence.

7. The axial hardness varying rubber cartridge according to claim 6, characterized in that: The upper cylinder (1) and the lower cylinder (3) have the same hardness, and the hardness of the upper cylinder (1) and the lower cylinder (3) is greater than that of the middle cylinder (2).

8. The axially hardness varying rubber cartridge according to any one of claims 1 to 7, characterized in that: The rubber cylinder with axially varying hardness is made of rubber. The rubber cylinder with axially varying hardness is prepared by laying mixed rubbers with different hardnesses in the axial direction to prepare a blank and then vulcanizing it.

9. A packer, characterized in that: It comprises an axially hardness varying rubber cartridge according to any one of claims 1 to 8.

10. A bridge plug, characterized in that: It comprises an axially hardness varying rubber cartridge according to any one of claims 1 to 8.

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