Wellhead filling device for capsule dry ice

Abstract

The invention provides a wellhead filling device for capsule dry ice, comprising: a housing, one end of which forms a storage cavity (5) with an opening, the storage cavity (5) being used for storing capsule dry ice; the sealing cover (1) is detachably connected with the opening side of the shell, so that the sealing cover (1) can seal and open the opening; wherein the side wall of the bottom of the storage cavity (5) is provided with a channel, the channel is connected with the wellhead (10) through a connecting flange (8), a valve (6) is arranged in the channel, and the storage cavity (5) can be selectively communicated with the wellhead (10) by operating the valve (6). By the adoption of the technical scheme, the problem that in the prior art, the liquid drainage effect of capsule dry ice gas lift liquid drainage is poor is effectively solved.

Description

Technical Field

[0001] The present invention relates to the technical field of wellhead filling device design, and more particularly, to a wellhead filling device for capsule dry ice. Background Art

[0002] For wells with water production or liquid accumulation after fracturing, there are the following defects in using capsule dry ice gas lift for liquid drainage: during the filling process, the dry ice capsules are exposed to the air or contained in an ordinary closed container. On the one hand, it will cause the sublimation speed to increase, the dry ice in the capsules to be consumed in advance, resulting in insufficient actual filling volume and affecting the liquid drainage effect; on the other hand, in an ordinary closed container, the carbon dioxide generated by the sublimation of dry ice accumulates in the container, which will cause the container pressure to be too high and damage the container.

[0003] For the above problems in the prior art, no effective solution has been proposed yet. Summary of the Invention

[0004] The main object of the present invention is to provide a wellhead filling device for capsule dry ice to solve the problem of poor liquid drainage effect of capsule dry ice gas lift in the prior art.

[0005] To achieve the above object, according to one aspect of the present invention, there is provided a wellhead filling device for capsule dry ice, including: a housing, one end of the housing forms a storage cavity with an opening for storing capsule dry ice; a sealing cover detachably connected to the opening side of the housing so that the sealing cover can close and open the opening; wherein, a channel is provided on the bottom side wall of the storage cavity, the channel is connected to the wellhead through a connecting flange, and a valve is provided in the channel, and operating the valve can selectively communicate the storage cavity with the wellhead.

[0006] Further, the housing includes a heat-reflective metal layer, a foam layer and a corrosion-resistant metal layer, the corrosion-resistant metal layer is located inside the heat-reflective metal layer, and the foam layer is located between the corrosion-resistant metal layer and the heat-reflective metal layer.

[0007] Further, the sealing cover includes a heat-reflective metal layer, a foam layer and a corrosion-resistant metal layer, the corrosion-resistant metal layer is located inside the heat-reflective metal layer, and the foam layer is located between the corrosion-resistant metal layer and the heat-reflective metal layer.

[0008] Further, a mating step is formed at the edge of the opening, and a lapping structure is provided on the side of the sealing cover facing the housing, and the contour of the mating step is adapted to the contour of the lapping structure.

[0009] Further, a sealing ring is also provided between the mating step and the lapping structure, and the sealing ring is made of an elastic material.

[0010] Further, a pre-tightening device is provided on the sealing cover. When the sealing cover is connected to the housing, the pre-tightening device is used to provide a pre-tightening force to the sealing cover so that the sealing cover and the housing jointly enclose a closed space.

[0011] Further, a pressure gauge is provided on the sealing cover, and the pressure gauge is used to detect the air pressure value in the closed space.

[0012] Further, the wellhead filling device for capsule dry ice further includes: a controller, which is electrically connected to the valve, and the controller is used to control the working state of the valve according to the detection signal of the pressure gauge.

[0013] Further, a pressure relief valve communicating with the storage cavity is also provided on the housing. The pressure relief valve is used to connect the storage cavity with the external environment when the gas pressure in the storage cavity exceeds the set dangerous value.

[0014] Further, a guiding structure is provided in the channel, and the guiding structure is used to guide the capsule dry ice to enter the wellhead from the connecting flange.

[0015] Applying the technical solution of the present invention, the opening of the housing is closed and opened by using the sealing cover. Operating the valve can selectively connect the storage cavity with the wellhead, so that the dry ice directly enters the wellhead from the storage cavity, which can avoid the contact between the capsule dry ice and the air, slow down the premature consumption of the dry ice, and ensure the accuracy of the actual filling amount. Adopting the technical solution of the present application effectively solves the problem of poor liquid drainage effect in the prior art of using capsule dry ice for gas lift liquid drainage. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The accompanying drawings forming a part of this application are used to provide a further understanding of the present invention. The schematic embodiments and descriptions thereof of the present invention are used to explain the present invention and do not constitute an improper limitation to the present invention. In the drawings:

[0017] Figure 1 shows a schematic structural diagram of a first embodiment of the wellhead filling device according to the present invention;

[0018] Figure 2 shows a schematic connection diagram of an embodiment of the wellhead filling device according to the present invention and the wellhead;

[0019] Figure 3 shows a schematic cross-sectional view of an embodiment of the sealing cover according to the present invention;

[0020] Figure 4 shows a schematic top view of an embodiment of the sealing cover according to the present invention.

[0021] Among them, the above-mentioned drawings include the following reference numerals:

[0022] 1. Sealing cap; 2. Heat-reflective metal layer; 3. Foam layer; 4. Corrosion-resistant metal layer; 5. Storage cavity; 6. Valve; 7. Pressure gauge; 8. Connecting flange; 9. Wellhead filling device; 10. Wellhead; 11. On-off valve; 12. Surface pipeline; 13. Liquid level; 14. Pay zone. Detailed implementation manners

[0023] It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments may be combined with each other. The present invention will be described in detail below with reference to the drawings and in combination with the embodiments.

[0024] It should be noted that the terms used herein are only for describing the specific implementation manners and are not intended to limit the exemplary implementation manners according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "include" and / or "comprise" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or their combinations.

[0025] It should be noted that the terms "first", "second", etc. in the description, claims and drawings of the present application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such terms can be interchanged under appropriate circumstances so that the implementation manners of the present application described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these process, method, product or device.

[0026] Now, the exemplary implementation manners according to the present application will be described in more detail with reference to the drawings. However, these exemplary implementation manners can be implemented in many different forms and should not be construed as being limited only to the implementation manners set forth herein. It should be understood that these implementation manners are provided to make the disclosure of the present application thorough and complete and to fully convey the concept of these exemplary implementation manners to those of ordinary skill in the art. In the drawings, for clarity, the thickness of layers and regions may be enlarged, and the same reference numerals are used to denote the same devices, and thus their descriptions will be omitted.

[0027] Capsule dry ice is a special form of dry ice, usually made by encapsulating solid carbon dioxide in the form of powder or granules in a capsule. This form of dry ice is mainly used in special application scenarios where more precise control and portability are required.

[0028] Some characteristics and applications of capsule dry ice: Capsule dry ice is usually prepared with precise weight or volume to ensure accurate control of the amount of dry ice released in specific applications. Encapsulated in capsules, this form of dry ice is easier to carry and use, especially in situations where it is inconvenient to carry large pieces of dry ice to the places where dry ice is needed. The shape and size of capsule dry ice can be adjusted according to the requirements of different applications, thus meeting various special environments and occasions.

[0029] Capsule dry ice is used for the liquid drainage of water-producing reservoirs after unconventional fracturing such as tight oil, tight gas, and shale gas. However, during its use process, it is usually transported to the wellhead in a container, and then the container is opened and the dry ice is manually put into the wellhead from the wellhead. The operation process of the whole device is cumbersome and time-consuming, and the capsule dry ice is extremely likely to cause damage to the container.

[0030] Combined with Figures 1 to 4 As shown, according to a specific embodiment of the present application, a wellhead filling device for capsule dry ice is provided, including: a housing, one end of the housing forms a storage cavity 5 with an opening, and the storage cavity 5 is used for storing capsule dry ice; a sealing cover 1, the sealing cover 1 is detachably connected to the opening side of the housing so that the sealing cover 1 can close and open the opening; wherein, a channel is provided on the bottom side wall of the storage cavity 5, the channel is connected to the wellhead 10 through a connecting flange 8, and a valve 6 is provided in the channel, and operating the valve 6 can selectively communicate the storage cavity 5 with the wellhead 10.

[0031] Applying the technical solution of the present invention, the opening of the housing is closed and opened by using the sealing cover 1, and operating the valve 6 can selectively communicate the storage cavity 5 with the wellhead 10, so that the dry ice directly enters the wellhead 10 from the storage cavity 5, which can avoid the contact between the capsule dry ice and the air, slow down the premature consumption of the dry ice, and ensure the accuracy of the actual filling amount. By adopting the technical solution of the present application, the problem of poor liquid drainage effect of capsule dry ice gas lift liquid drainage in the prior art is effectively solved.

[0032] Specifically, the device is installed on the top of the wellhead Christmas tree. The Christmas tree, also known as the wellhead tree, is a key device in oil production. It is usually installed at the oil wellhead to control the oil and gas flow at the wellhead, and to close, open and monitor the wellhead when needed.

[0033] The main components of the Christmas tree include: valves, tubing, tree body, and tree head. The valves located on the Christmas tree are used to control the fluid flow at the oil wellhead. These valves usually include main control valves for controlling the inflow and outflow of oil and gas, safety valves for preventing the wellhead pressure from rising, etc. The tubing is a pipeline connecting the bottom of the well and the Christmas tree, and through the tubing, oil and gas are transported from the bottom of the well to the ground. The main body part of the Christmas tree includes the support structures for the above-mentioned valves and tubing. The tree head is usually located at the top of the Christmas tree and is used to close the wellhead or install various accessories, such as measurement and monitoring equipment.

[0034] The functions of the Christmas tree include: 1. Through the valves on the Christmas tree, the oil and gas flow at the wellhead can be controlled. This includes operations such as adjusting the production rates of oil and gas and sealing the wellhead. 2. The Christmas tree is usually equipped with various sensors and measuring devices for monitoring parameters such as wellhead pressure, temperature, and flow rate, so as to adjust the production parameters in a timely manner. 3. The safety valve on the Christmas tree can be automatically activated when the wellhead pressure rises to a dangerous level, releasing excessive oil and gas to ensure the safe operation of the wellhead. 4. Well sealing and unsealing: The Christmas tree can be used to seal the wellhead for maintenance, repair, or other situations that require closing the wellhead. Similarly, it can also be used to unseal the wellhead to resume production.

[0035] Furthermore, the housing includes a heat-reflective metal layer 2, a foam layer 3, and a corrosion-resistant metal layer 4. The corrosion-resistant metal layer 4 is located inside the heat-reflective metal layer 2, and the foam layer 3 is located between the corrosion-resistant metal layer 4 and the heat-reflective metal layer 2.

[0036] The heat-reflective metal layer 2 can reflect heat radiation, reduce heat absorption, and thus lower the surface temperature of the device. This is of great significance for ensuring the physical and chemical form of dry ice and extending the material life.

[0037] The main function of the corrosion-resistant metal layer 4 is to protect the inside of the device from corrosion.

[0038] Metals are prone to corrosion in humid, acidic, alkaline, or other corrosive environments. The corrosion-resistant metal layer can effectively delay or prevent corrosion by forming a protective barrier on the metal surface. Since a large amount of carbon dioxide gas is generated after the sublimation of dry ice, some of it reacts with water to form carbonic acid, chemically eroding the metal surface.

[0039] The following are some of the main functions of the corrosion-resistant metal layer:

[0040] Corrosion prevention: The corrosion-resistant metal layer can prevent corrosive substances from directly contacting the metal surface, forming a protective barrier to slow down or prevent the corrosion process of the metal.

[0041] Service life extension: By reducing or avoiding metal corrosion, the corrosion-resistant metal layer helps to extend the service life of metal components, equipment, or structures and reduce maintenance costs.

[0042] Weather resistance improvement: The corrosion-resistant metal layer usually has good weather resistance and can maintain its corrosion resistance under different climate conditions, being suitable for extreme environments.

[0043] Appearance beauty maintenance: The corrosion-resistant metal layer can maintain the appearance of the metal surface, avoiding rust or color changes caused by corrosion, and keeping the metal beautiful for a long time.

[0044] Reduce maintenance costs: Since the corrosion-resistant metal layer can slow down or prevent metal corrosion, the need for regular maintenance of equipment or buildings is reduced, thereby lowering maintenance costs.

[0045] Wide range of applications: The corrosion-resistant metal layer is applicable to various metals, including iron, steel, aluminum, copper, etc., and thus has a wide range of uses in different industries and applications. Therefore, this device can be made of a variety of different metals.

[0046] The foam layer 3 is beneficial to maintaining the temperature difference between the inside and the outside.

[0047] The preparation methods of the corrosion-resistant metal layer include technologies such as plating, coating, alloying, etc., and the specific selection depends on the application scenario and the characteristics of the metal.

[0048] That is to say, the capsule dry ice storage chamber is cylindrical, the cavity is a three-layer structure, the inner layer is a metal resistant to carbon dioxide corrosion, the middle layer is a high-density thermal insulation foam, and the outer layer is a heat-reflective metal.

[0049] Adopting the technical solution of this application, a wellhead injection device for capsule dry ice gas lift fluid drainage is provided, which belongs to a technology in petroleum fracturing operations and is applicable to unconventional fracturing production water reservoirs such as tight oil, tight gas, and shale gas. During the capsule dry ice injection process, on the one hand, the dry ice is isolated from the air to slow down the premature consumption of the dry ice, and on the other hand, pressure protection is provided for the wellhead capsule dry ice storage container.

[0050] Furthermore, the sealing cover 1 includes a heat-reflective metal layer 2, a foam layer 3, and a corrosion-resistant metal layer 4. The corrosion-resistant metal layer 4 is located inside the heat-reflective metal layer 2, and the foam layer 3 is located between the corrosion-resistant metal layer 4 and the heat-reflective metal layer 2.

[0051] That is to say, the sealing cover and the storage chamber have the same structure and material.

[0052] Furthermore, a mating step is formed at the edge of the opening. A lapping structure is provided on the side of the sealing cover 1 facing the housing, and the contour of the mating step is arranged to be adapted to the contour of the lapping structure. Adopting the technical solution of this embodiment facilitates the assembly operation by the operator and is beneficial to inspecting the assembly effect.

[0053] Furthermore, a sealing ring is also provided between the mating step and the lapping structure, and the sealing ring is made of an elastic material.

[0054] Furthermore, a pre-tightening device is provided on the sealing cover 1. When the sealing cover 1 is connected to the housing, the pre-tightening device is used to provide a pre-tightening force to the sealing cover 1 so that the sealing cover 1 and the housing jointly enclose a sealed space.

[0055] The pre-tightening device can be an adjustable bolt, which can further improve the airtightness and strength of the device.

[0056] Furthermore, a pressure gauge 7 is provided on the sealing cover 1, and the pressure gauge 7 is used to detect the air pressure value in the enclosed space.

[0057] That is, a pressure gauge is installed on the top of the sealing cover to monitor the gas pressure in the cavity, and a valve is installed at the bottom. The valve can be manually opened, and when the pressure generated by sublimation in the dry ice storage chamber is higher than the pressure in the well, the valve can also be automatically opened; the wellhead filling device is connected to the wellhead through a flange.

[0058] Furthermore, the wellhead filling device for capsule dry ice further includes: a controller, which is electrically connected to the valve 6, and the controller is used to control the working state of the valve 6 according to the detection signal of the pressure gauge 7. With this setting, it is possible to achieve pressure warning and automatic pressure relief of the wellhead filling device, ensuring the operating safety of the device.

[0059] The controller can pre-write a control program to control aspects such as safety warning and gas control of the device.

[0060] Furthermore, a pressure relief valve communicating with the storage chamber 5 is also provided on the housing, and the pressure relief valve is used to connect the storage chamber 5 to the external environment when the gas pressure in the storage chamber 5 exceeds the set dangerous value.

[0061] Furthermore, a guiding structure is provided in the channel, and the guiding structure is used to guide the capsule dry ice from the connecting flange 8 into the wellhead 10. This helps to shorten the time for the capsule dry ice to enter the liquid, preventing insufficient filling amount caused by rapid sublimation of the dry ice.

[0062] The guiding structure can be a guiding groove with an inclined angle.

[0063] Such as Figure 2 also shows the wellhead filling device 9, wellhead 10, switching valve 11, surface pipeline 12, liquid level 13, and pay zone 14.

[0064] When applying the filling device in this application, the operation steps are as follows:

[0065] 1. Open the sealing cover 1 of the capsule dry ice storage chamber and place the capsule dry ice in the capsule dry ice storage chamber.

[0066] 2. Manually open or automatically open the valve 6.

[0067] 3. The capsule dry ice falls below the liquid level 13 of the wellbore fluid due to gravity, and the capsule dry ice starts to work.

[0068] For ease of description, spatial relative terms such as "above", "over", "on the upper surface", "upper" etc. can be used here to describe the spatial positional relationship of a device or feature shown in the figure with other devices or features. It should be understood that the spatial relative terms are intended to encompass different orientations in use or operation in addition to the orientation depicted in the figure for the device. For example, if the device in the drawing is inverted, a device described as "above" or "over" other devices or structures will then be positioned "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both the orientations of "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and corresponding interpretations are made for the spatial relative descriptions used here.

[0069] In addition to the above, it should also be noted that the "one embodiment", "another embodiment", "embodiment" etc. mentioned in this specification refer to the specific features, structures or characteristics described in connection with that embodiment being included in at least one embodiment generally described in this application. The same expression appearing in multiple places in the specification does not necessarily refer to the same embodiment. Further, when describing a specific feature, structure or characteristic in connection with any one embodiment, it is intended that implementing such feature, structure or characteristic in connection with other embodiments also falls within the scope of the present invention.

[0070] In the above embodiments, the descriptions of each embodiment have their own emphases. For parts not detailed in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0071] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A wellhead filling device for capsule dry ice, characterized in that, Comprising: A housing, one end of the housing forms a storage cavity (5) with an opening, and the storage cavity (5) is used for storing capsule dry ice; A sealing cover (1), the sealing cover (1) is detachably connected to the opening side of the housing, so that the sealing cover (1) can close and open the opening; Wherein, a channel is provided on the bottom side wall of the storage cavity (5), the channel is connected to the wellhead (10) through a connecting flange (8), a valve (6) is provided in the channel, and operating the valve (6) can selectively communicate the storage cavity (5) with the wellhead (10).

2. The wellhead filling device for capsule dry ice according to claim 1, characterized in that, The housing includes a heat-reflective metal layer (2), a foam layer (3) and a corrosion-resistant metal layer (4), the corrosion-resistant metal layer (4) is located inside the heat-reflective metal layer (2), and the foam layer (3) is located between the corrosion-resistant metal layer (4) and the heat-reflective metal layer (2).

3. The wellhead filling device for capsule dry ice according to claim 2, wherein, The sealing cover (1) includes a heat-reflective metal layer (2), a foam layer (3) and a corrosion-resistant metal layer (4), the corrosion-resistant metal layer (4) is located inside the heat-reflective metal layer (2), and the foam layer (3) is located between the corrosion-resistant metal layer (4) and the heat-reflective metal layer (2).

4. The wellhead filling device for capsule dry ice according to claim 1, characterized in that, A mating step is formed at the edge of the opening, a lapping structure is provided on the side of the sealing cover (1) facing the housing, and the contour of the mating step is adapted to the contour of the lapping structure.

5. The wellhead filling device for capsule dry ice according to claim 4, characterized in that, A sealing ring is further provided between the mating step and the lapping structure, and the sealing ring is made of an elastic material.

6. The wellhead filling device for capsule dry ice according to claim 1, characterized in that, A pre-tightening device is provided on the sealing cover (1). When the sealing cover (1) is connected to the housing, the pre-tightening device is used to provide a pre-tightening force to the sealing cover (1) so that the sealing cover (1) and the housing jointly enclose a sealed space.

7. The wellhead filling device for capsule dry ice according to claim 6, characterized in that, A pressure gauge (7) is provided on the sealing cover (1), and the pressure gauge (7) is used to detect the air pressure value in the sealed space.

8. The wellhead filling device for capsule dry ice according to claim 7, characterized in that, The wellhead filling device for capsule dry ice further includes: a controller, the controller is electrically connected to the valve (6), and the controller is used to control the working state of the valve (6) according to the detection signal of the pressure gauge (7).

9. The wellhead filling device for capsule dry ice according to claim 1, characterized in that A pressure relief valve communicating with the storage cavity (5) is further provided on the housing, and the pressure relief valve is used to communicate the storage cavity (5) with the external environment when the gas pressure in the storage cavity (5) exceeds a set dangerous value.

10. The wellhead filling device for capsule dry ice according to claim 1, characterized in that, A guiding structure is provided in the channel, and the guiding structure is used to guide the capsule dry ice to enter the wellhead (10) from the connecting flange (8).

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