A coring device with a centripetal elastic bottom precision sealing mechanism

Abstract

The present application belongs to the technical field of coring device, and particularly relates to a coring device with a centripetal elastic bottom precise sealing mechanism. The coring device comprises a coring cylinder, a center rod is sleeved in the coring cylinder, a liquid discharge piston is connected to the lower end of the center rod, and a bottom sealing mechanism is connected to the bottom of the coring cylinder. The bottom sealing mechanism comprises a sealing sheet base connected to the bottom of the coring cylinder, a plurality of petal pieces are formed by cutting the inner side of the sealing sheet base along the center of a circle, an elastic ring fixing piece is fixed on each petal piece, a rubber ring fixing ring is fixed on the elastic ring fixing piece, and a high-elasticity shrink ring is further included, and the high-elasticity shrink ring penetrates through each rubber ring fixing ring. The present application provides a centripetal elastic bottom precise sealing mechanism for drilling, film forming, quality preserving, moisturizing and gloss preserving coring.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of coring devices, and particularly relates to a coring device with a centripetal elastic bottom precise sealing mechanism. BACKGROUND

[0002] It has great scientific significance to obtain core samples accurately reflecting the real information of deep in-situ strata, which can provide guidance for accurate exploration and evaluation of deep oil and gas resources, research on the origin of deep oil and gas resources and scientific exploration of deep microbial life. However, the existing conventional coring process lacks effective protection of the core in the whole process of core drilling, transfer and testing. The core directly contacts the drilling fluid or sealing liquid, and it is difficult to avoid the diffusion and loss of substances in the core pores, which will lead to distortion of the core analysis results and extinction of original microorganisms, and it is impossible to study the mystery of deep life science. Therefore, a deep in-situ quality, moisture and light preserving coring technology is designed and developed. The technology uses a film-forming liquid to cover the surface of the core during the dynamic process of drilling, and a dense high-molecular solid film with high barrier performance is uniformly grown on the surface of the core. The film can preserve the volatile oil and gas components in the core, maintain the internal humidity stability of the core and the in-situ dark and lightless environment, so as to truly obtain core samples that preserve the deep in-situ real state. In order to achieve efficient protection of the core, it is necessary to ensure that the film is completely formed on the surface of the core, especially the bottom surface of the core, in the narrow space of the in-situ coring device. Therefore, a sealing mechanism with low volume is needed to prevent the film-forming liquid from leaking out of the coring barrel during the coring process, and to accurately and adaptively seal the bottom of the coring barrel after coring, so as to ensure that the film-forming liquid completely covers the core and completely solidifies into a film. SUMMARY

[0003] In order to solve the above problems existing in the prior art, the purpose of the present application is to provide a centripetal elastic bottom precise sealing mechanism for drilling film-forming quality, moisture and light preserving coring, which can prevent the film-forming liquid from leaking out of the coring barrel during the coring process in the narrow space of the in-situ coring device, and ensure accurate and stable adaptive sealing of the bottom of the coring barrel after coring.

[0004] The technical scheme adopted by the present application is as follows:

[0005] A coring device with a centripetal elastic bottom precise sealing mechanism, comprising a coring barrel, a center rod sleeved in the coring barrel, a liquid discharge piston connected to the lower end of the center rod, and a bottom sealing mechanism connected to the bottom of the coring barrel; the bottom sealing mechanism comprises a sealing sheet base connected to the bottom of the coring barrel, a plurality of petal pieces formed by cutting the inner side of the sealing sheet base along the center of a circle, an elastic ring fixing piece fixed on each petal piece, a rubber ring fixing ring fixed on the elastic ring fixing piece, and a high-elasticity contraction ring passing through each rubber ring fixing ring.

[0006] During coring, the petals of the sealing piece base and the high-elasticity shrinkable ring are self-adaptively opened to allow the core to pass through. The petals of the sealing piece base are folded by 90°, but no irreversible deformation is caused. After coring, when the core completely passes through the bottom sealing mechanism, the petals of the sealing piece base are subjected to the uniform centripetal elastic force load, which makes up for the insufficient bending resilience potential of the petals of the sealing piece base, avoids the mutual interference and overlapping of the petals during the rebounding process, and makes the petals finally and stably and accurately rebound to the same plane under the action of the centripetal force, so that the bottom of the core is completely sealed through the precise lamination of the sealing petals.

[0007] The mechanism occupies a small space, which is conducive to the coupling integration in a narrow space in situ. The bottom sealing device is provided with a tightening elastic ring to provide the sealing petals with a centripetal elastic force, which can prevent the mutual interference between the petals and the sealing failure caused by the irreversible deformation, and effectively improve the rebound speed, accuracy and stability of the petals.

[0008] As a preferred scheme of the present application, the material of the sealing piece base is a flexible material, and the material of the elastic ring fixing piece is a rigid material. The sealing piece base is made of a flexible material such as polyurethane, silicone rubber or polytetrafluoroethylene, and no irreversible plastic deformation is caused after large folding deformation. Since the elastic ring fixing piece is made of a rigid material and is uniformly attached to the surface of the petals of the sealing piece base, the rigidity of the petals of the sealing piece base in the unfolded position is increased, the point load tension applied to the rubber ring fixing ring is converted into a surface load uniformly distributed on the surface of the petals, the centripetal contraction force is prevented from being too concentrated, the weak part of the petals of the sealing piece base is prevented from being damaged, and the uniformity of the centripetal tightening force applied to the petals of the sealing piece base is effectively improved.

[0009] As a preferred scheme of the present application, the radius of the sealing piece base is 28-30 mm, and the length of the cutting line of the petals on the sealing piece base is 25-28 mm.

[0010] As a preferred scheme of the present application, the outer radius of the high-elasticity shrinkable ring is 5-15 mm.

[0011] As a preferred scheme of the present application, the material of the high-elasticity shrinkable ring is an elastic and stretchable material. The high-elasticity shrinkable ring is made of a high-elasticity and stretchable material such as latex, thermoplastic styrene-butadiene rubber or silicone rubber. The high-elasticity shrinkable ring passes through each rubber ring fixing ring to apply a centripetal tightening elastic force to the elastic ring fixing piece.

[0012] As a preferred scheme of the present application, the film-forming liquid discharge channel is arranged in the discharge piston.

[0013] As a preferred scheme of the present application, a one-way valve is arranged in the film-forming liquid discharge channel.

[0014] As a preferred scheme of the present application, the inner wall of the lower end of the coring barrel is provided with a core claw.

[0015] The present application has the following advantages:

[0016] The present application has the following advantages: BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 is a structural schematic diagram of the present application before coring;

[0018] Figure 2 is a partial enlarged view of A in Figure 1

[0019] Figure 3 is a structural schematic diagram of the present application during coring;

[0020] Figure 4 is a partial enlarged view of B in Figure 3

[0021] Figure 5 is a structural schematic diagram of the present application after coring;

[0022] Figure 6 is a structural schematic diagram of the bottom sealing mechanism;

[0023] Figure 7 is a structural schematic diagram of the bottom sealing mechanism during coring.

[0024] In the figure: 1 - center rod; 2 - coring barrel; 3 - film forming liquid storage cavity; 4 - liquid discharge piston; 5 - film forming liquid discharge channel; 6 - one-way valve; 7 - core claw; 8 - high-elasticity shrink ring; 9 - rubber ring fixing ring; 10 - elastic ring fixing piece; 11 - sealing piece base; 12 - core; 13 - top film forming space; 14 - side film forming space; 15 - bottom film forming space; 16 - bottom sealing mechanism. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme of the embodiments of the present application will be described clearly and completely below in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations.

[0026] ​​The following detailed description of embodiments of the application provided in the accompanying drawings is not intended to limit the scope of the application as claimed, but merely represents selected embodiments of the application. Based on the embodiments in the application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of protection of the application. It should be noted that the embodiments in the application and the features in the embodiments can be combined with each other without conflict.

[0027] As Figures 1-7 shown, the core taking device with the centripetal elastic bottom precise sealing mechanism of the present embodiment comprises a core taking cylinder 2, a center rod 1 is sleeved in the core taking cylinder 2, a liquid discharge piston 4 is connected to the lower end of the center rod 1, and a bottom sealing mechanism 16 is connected to the bottom of the core taking cylinder 2. The bottom sealing mechanism 16 comprises a sealing sheet base 11 connected to the bottom of the core taking cylinder 2, the inner side of the sealing sheet base 11 is cut into a plurality of petal pieces along the center of a circle, an elastic ring fixing piece 10 is fixed on the petal piece, a rubber ring fixing ring 9 is fixed on the elastic ring fixing piece 10, and the bottom sealing mechanism 16 further comprises a high-elasticity shrink ring 8, and the high-elasticity shrink ring 8 passes through each rubber ring fixing ring 9 respectively. A film-forming liquid discharge channel 5 is arranged in the liquid discharge piston 4. A one-way valve 6 is arranged in the film-forming liquid discharge channel 5. The inner wall of the lower end of the core taking cylinder 2 is provided with a core claw 7.

[0028] During core taking, the petal pieces of the sealing sheet base 11 and the high-elasticity shrink ring 8 are self-adaptively opened to allow the core 12 to pass through in the process of the core 12 entering the core taking cylinder 2. The petal pieces of the sealing sheet base 11 are folded by 90°, but do not produce irreversible deformation. After core taking, the core 12 completely passes through the bottom sealing mechanism 16, and due to the existence of the uniform centripetal elastic load acting on the petal pieces of the sealing sheet base 11, the insufficient bending and rebound potential energy of the petal pieces of the sealing sheet base 11 is compensated, the mutual interference and overlapping problems between the petal pieces are solved in the rebound process, and finally the petal pieces are stably, accurately and tightly rebounded to the same plane under the action of the centripetal force, the precise fitting of the sealing petal pieces is realized, and the complete sealing of the bottom of the core 12 is realized.

[0029] The mechanism occupies a small space, which is conducive to the realization of coupling integration in a narrow space in situ. By setting a tightening elastic ring on the bottom sealing device, the centripetal elastic force is provided for the sealing petal pieces, the mutual interference between the petal pieces is prevented, the sealing failure caused by irreversible deformation is prevented, and the rebound speed, accuracy and stability of the petal pieces can be effectively improved.

[0030] Specifically, the material of the sealing sheet base 11 is a flexible material. The sealing sheet base 11 is made of polyurethane, silicone rubber, polytetrafluoroethylene, etc. flexible material, which does not produce irreversible plastic deformation after large folding deformation. The overall radius of the sealing sheet base 11 is 28-30 mm, the thickness is 1-2 mm, and the petal sheet is cut along the center of the circle (which can be divided into four, six, eight, twelve or more petals). The length of the cutting line is 25-28 mm.

[0031] The elastic ring fixing sheet 10 is a fan-shaped sheet made of spring steel material, with a radius of 10-15 mm and a thickness of 0.1-0.2 mm. It is uniformly fixed and attached to each petal sheet of the sealing sheet base 11. The upper center of the elastic ring fixing sheet 10 is fixed with a rubber ring fixing ring 9 with an inner diameter of 0.5-1 mm. The high-elasticity shrink ring 8 is made of latex, thermoplastic butadiene rubber, silicone rubber, etc. high-elasticity, stretchable material, with an outer radius of 5-15 mm and a wire diameter of 0.5-1 mm. The high-elasticity shrink ring 8 passes through each rubber ring fixing ring 9 respectively, and applies a centripetal tightening elastic force to the elastic ring fixing sheet 10. Since the elastic ring fixing sheet 10 is made of rigid material and is uniformly attached to the surface of the petal sheet of the sealing sheet base 11, it can increase the rigidity of the non-folding point of the petal sheet of the sealing sheet base 11, and convert the point load tension applied to the rubber ring fixing ring 9 into a uniformly distributed surface load on the surface of the petal sheet, preventing the centripetal contraction force from being too concentrated, causing damage to the weak part of the petal sheet of the sealing sheet base 11, and effectively improving the uniformity of the centripetal tightening force applied to the petal sheet of the sealing sheet base 11. The overall volume of the centripetal elastic bottom precise sealing mechanism is only 54-56 mm in diameter and 2-3 mm in height, which can be installed at the bottom of the core barrel in the narrow space of 26-28 mm in radius.

[0032] The function of the centripetal elastic bottom sealing mechanism 16:

[0033] Before coring, the high-elasticity shrinkable ring 8 provides uniform centripetal elastic pre-tightening force to each petal of the sealing sheet base 11, so that each petal is in the same plane and tightly closed. During coring, the core 12 (with a radius of 25 mm) enters the coring barrel 2, so that the petals of the sealing sheet base 11 are self-adaptively opened to allow the core 12 to pass through and seal the 2-3 mm gap between the coring barrel and the core 12. During this process, the petals of the sealing sheet base 11 are folded by 90° in the 2-3 mm small space between the coring barrel and the core 12, but do not produce irreversible deformation. The elastic ring fixing sheet 10 and the rubber ring fixing ring 9 are completely in the 2-3 mm gap between the core 12 and the coring barrel and do not fold. After coring, the core 12 completely passes through the centripetal elastic bottom precise sealing mechanism, and due to the uniform centripetal elastic force load acting on the petals of the sealing sheet base 11, the insufficient bending and rebound potential energy of the petals of the sealing sheet base 11 is compensated, the mutual interference and overlapping problem of the petals during the rebound process is avoided, and finally under the action of the centripetal force, the petals are stably, precisely and tightly rebounded to the same plane, the precise fitting of the sealing petals is realized, and the bottom of the core 12 is completely sealed.

[0034] Working process:

[0035] 1) Pre-coring state (as shown in Figure 1 and Figure 2 ):

[0036] The film-forming solution is pre-positioned in the film-forming solution storage cavity 3, and stable sealing storage is realized by the elastic pre-tightening force of the one-way valve 6. The film-forming solution is composed of polymers such as polysulfone, polyether sulfone, polyvinylidene fluoride, polyethylene, polyvinyl alcohol, hydroxymethyl cellulose, methyl cellulose, ethyl cellulose, cellulose acetate butyrate, carboxymethyl cellulose, and microcrystalline cellulose and its solvent / non-solvent system, and water initiates curing to form silicone rubber, polyurethane, isocyanate, and epoxy resin. After the film-forming solution contacts moisture on the core 12 and the outside space, it will automatically produce cross-linking curing reaction to generate a solid sealing film layer.

[0037] 2) Coring state (as shown in Figure 3 and Figure 4 ):

[0038] When the coring operation is started, the central rod 1 is connected with the corer fixing part and remains static. The central rod 1 moves relative to the coring barrel, so that the volume of the film-forming liquid storage cavity 3 is reduced. During the coring drilling process, the film-forming liquid is gradually released into the coring barrel 2 through the film-forming liquid release channel 5 and the one-way valve 6, and the stratum fluid is displaced in situ, covering the surface of the core 12. During the process of the core 12 entering the coring barrel 2, the sealing piece base 11 of the bottom sealing mechanism 16 can automatically adhere to the core 12, and the high-elasticity contraction ring 8 on it expands radially, tightly adheres to the core 12, so that the core 12 is aligned and centered, and at the same time, the gap between the coring barrel 2 and the core 12 is filled, the bottom of the coring barrel is sealed, and the film-forming liquid is prevented from leaking in large quantities.

[0039] 3) the state after coring (as shown in Figure 5

[0040] After drilling enough coring footage, the coring barrel 2 and the central rod 1 are lifted, the core claw 7 pulls out the core 12, the petal piece structure of the sealing piece base 11 of the bottom sealing mechanism 16 is automatically and synchronously rebounded and closed under the centripetal uniform contraction force generated by the high-elasticity contraction ring 8, and the bottom of the coring barrel 2 is accurately sealed. The film-forming liquid released during drilling fills the inside of the coring barrel 2, wraps the top film-forming space 13, the side film-forming space 14 and the bottom film-forming space 15 of the core 12, and after a period of time, a cross-linking solidification reaction occurs, forming a solid sealing film that completely covers the surfaces of the core and has high barrier properties, so as to completely isolate and protect the core 12, and realize in-situ sealing, quality preservation, moisture preservation and light preservation of the core 12.

[0041] The present application is not limited to the above-mentioned optional embodiments, and anyone can derive other various forms of products under the inspiration of the present application, but regardless of any changes in shape or structure, any technical solutions falling within the scope defined by the claims of the present application fall within the protection scope of the present application.​

Claims

1. A core-taking device with a centripetal elastic bottom precision sealing mechanism, characterized in that: The device includes a core sampling cylinder (2), a central rod (1) is fitted inside the core sampling cylinder (2), a drain piston (4) is connected to the lower end of the central rod (1), and a bottom sealing mechanism (16) is connected to the bottom of the core sampling cylinder (2). The bottom sealing mechanism (16) includes a sealing plate base (11) connected to the bottom of the core sampling cylinder (2). The inner side of the sealing plate base (11) is cut into several petal pieces along the center. An elastic ring fixing piece (10) is fixed on the petal piece. A rubber ring fixing ring (9) is fixed on the elastic ring fixing piece (10). The bottom sealing mechanism (16) also includes a high elastic shrink ring (8). The high elastic shrink ring (8) passes through each rubber ring fixing ring (9). The material of the high elastic shrink ring (8) is an elastic stretching material. The material of the sealing plate base (11) is a flexible material. The drain piston (4) is provided with a film-forming liquid discharge channel (5). A one-way valve (6) is provided in the film-forming liquid discharge channel (5).

2. The core-taking device with a centripetal elastic bottom precision sealing mechanism according to claim 1, characterized in that: The material of the elastic ring fixing piece (10) is a rigid material.

3. The core-taking device with a centripetal elastic bottom precision sealing mechanism according to claim 1, characterized in that: The radius of the sealing plate base (11) is 28-30 mm, and the length of the cutting line of the petal on the sealing plate base (11) is 25-28 mm.

4. The core-taking device with a centripetal elastic bottom precision sealing mechanism according to claim 1, characterized in that: The outer radius of the high-elasticity shrinkage ring (8) is 5-15 mm.

5. A core-taking device with a centripetal elastic bottom precision sealing mechanism according to any one of claims 1 to 4, characterized in that: The inner wall of the lower end of the core tube (2) is provided with a core claw (7).

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