Discharge electrode for pulse power device in oil and gas well

Abstract

The utility model discloses a discharge electrode for a pulse power device in an oil and gas well, which comprises two electrode units, each electrode unit comprises an electrode body, a locking cap, a spherical electrode and a conductive rubber elastic pad, one end part of each electrode body is provided with a fixed cavity extending towards the other end part, the locking cap is arranged at the outer port of the fixed cavity, and the spherical electrode is arranged in the fixed cavity. The locking cap is provided with a through hole which is communicated with the fixing cavity and is large in outside and small in inside, the spherical electrode is movably arranged in the fixing cavity, the conductive rubber elastic cushion is installed between the spherical electrode and the cavity bottom of the inner end of the fixing cavity, and the spherical electrode tends to move towards the outer side of the fixing cavity under the elastic force effect of the conductive rubber elastic cushion. Part of the spherical surface of the spherical electrode protrudes out through the through hole; the ends, provided with the spherical electrodes, of the two electrode units are oppositely arranged. The discharge electrode can prevent an electrode discharge point from being located at one position for a long time, has randomness, and effectively solves or relieves the ablation problem of the electrode during continuous pulse discharge.

Description

Technical Field

[0001] The utility model relates to the technical field of discharge electrodes, in particular to a discharge electrode used for a pulse power device in an oil and gas well. Background Art

[0002] When electric explosions occur in oil and gas wells, the high-voltage discharge electrodes are susceptible to erosion due to the high voltage and the medium being broken down. This widens the gap between the electrodes and affects normal discharge. Therefore, to ensure that electric explosion devices (pulse power devices) in wells have a longer operating time and reduce the number of tripping operations, it is necessary to address the erosion of discharge electrodes. Utility Model Content

[0003] To this end, the present invention provides a discharge electrode for a pulse power device in an oil and gas well to solve or alleviate one or more of the above-mentioned technical problems.

[0004] In order to achieve the above purpose, the present invention provides the following technical solutions:

[0005] A discharge electrode for a pulse power device in an oil and gas well comprises two electrode units, wherein the electrode units comprise an electrode body, a locking cap, a spherical electrode and a conductive rubber elastic pad; one end of the electrode body is provided with a fixed cavity extending toward the other end; the locking cap is arranged at the outer port of the fixed cavity; the locking cap is provided with a through hole which is larger on the outside and smaller on the inside and communicates with the fixed cavity; the spherical electrode is movably arranged in the fixed cavity; the conductive rubber elastic pad is installed between the spherical electrode and the inner end bottom of the fixed cavity; the spherical electrode has a tendency to move toward the outside of the fixed cavity under the elastic force of the conductive rubber elastic pad; the radius of the spherical electrode is smaller than the minimum diameter of the through hole; part of the spherical surface of the spherical electrode protrudes outward through the through hole; the ends of the two electrode units provided with the spherical electrodes are arranged facing each other.

[0006] Furthermore, the fixed cavity includes a first cavity on the outside and a second cavity on the inside, the first cavity and the second cavity are connected and coaxial, the diameter of the first cavity is larger than the diameter of the second cavity, and the locking cap is installed in the first cavity; the electrode unit also includes a limiting cylinder, the limiting cylinder includes a cylinder and a convex edge arranged at the outer end of the cylinder, the convex edge is installed in the first cavity and abuts against the locking cap, the cylinder is installed in the second cavity and abuts against the peripheral edge of the conductive rubber elastic pad, and a spherical hole is provided in the middle of the cylinder, which is coaxial with the through hole, the outer end radius of the spherical hole is adapted to the radius of the spherical electrode, and the inner end radius of the spherical hole is smaller than the radius of the spherical electrode.

[0007] Furthermore, a groove connected to the spherical hole is provided on the inner side of the inner end of the cylinder.

[0008] Furthermore, the discharge electrode also includes a shell, the electrode unit is installed in the shell, and the top and side of the shell are respectively provided with openings, wherein the top opening is used for connecting with other devices and routing, and the side opening is used to allow the shock wave and hydroelectric effect generated by the discharge of the electrode unit to be released outside the shell.

[0009] Furthermore, a plurality of the side openings are provided, and the plurality of side openings are distributed at intervals in the circumferential direction of the shell.

[0010] Furthermore, the discharge electrode further includes an insulating sleeve, the insulating sleeve is installed in the shell, and the electrode unit is installed in the insulating sleeve.

[0011] Furthermore, the upper end of the electrode body located in the upper part of the shell is provided with a terminal, and the lower end of the electrode body located in the lower part of the shell is in contact with the shell.

[0012] Furthermore, a communicating hole is provided on the insulating sleeve at a position corresponding to the side opening.

[0013] The utility model has the following advantages:

[0014] A spherical electrode is provided at the end of the electrode body. The spherical electrode is confined in the fixed cavity by a locking cap and receives an outward thrust from a conductive rubber elastic pad. In this way, when the power pulse device is working, high voltage electricity is applied to both ends of the upper and lower spherical electrodes. When the voltage rises to a certain value, it breaks through the gap between the spherical electrodes to generate discharge. During discharge, the arc acts on the exposed surfaces of the upper and lower spherical electrodes respectively. The impact torque generated will cause the spherical electrode to rotate in the fixed cavity. In this way, the position of the spherical electrode acted on each discharge arc is different. Compared with the fixed end face electrode, which only discharges at the same end face all the time, end face ablation will naturally occur as the discharge continues. The embodiment of the present application uses the above technical measures to avoid the electrode discharge point being in one position for a long time, which is random. Therefore, it can effectively solve or alleviate the problem of electrode ablation during continuous pulse discharge.

[0015] The above summary is for illustrative purposes only and is not intended to be limiting in any way. In addition to the illustrative aspects, embodiments and features described above, further aspects, embodiments and features of the present application will be readily apparent by reference to the accompanying drawings and the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for the embodiments or the description of the prior art. Obviously, the drawings described below are merely exemplary, and those skilled in the art can, without inventive effort, derive other implementation drawings based on the provided drawings.

[0017] The structures, proportions, sizes, etc. illustrated in this specification are intended solely to complement the contents disclosed herein and to facilitate understanding and reading by persons familiar with the art. They are not intended to limit the conditions under which the present invention may be implemented and therefore have no substantive technical significance. Any structural modifications, changes in proportions, or adjustments in size, provided they do not affect the efficacy and objectives of the present invention, shall remain within the scope of the technical contents disclosed herein.

[0018] Figure 1 This is a schematic structural diagram of a discharge electrode for a pulse power device in an oil and gas well provided by an embodiment of the present utility model.

[0019] In the figure: 1-electrode body, 2-locking cap, 3-spherical electrode, 4-conductive rubber elastic pad, 5-limiting cylinder, 6-housing, 7-side opening, 8-insulating sleeve, 9-connection terminal. DETAILED DESCRIPTION

[0020] Hereinafter, only certain exemplary embodiments are briefly described. As will be appreciated by those skilled in the art, the described embodiments may be modified in various ways without departing from the spirit or scope of the present application. Therefore, the drawings and description are to be regarded as illustrative in nature and not restrictive.

[0021] In current oil and gas field development, physical methods are often used to increase the recovery rate of oil and gas wells, among which electric blasting is a major method used in wells. By generating shock waves and hydro-electric effects through high-voltage discharge in the well, these shock waves act on the oil and gas reservoir, unblocking the near-well zone of the oil and gas well and improving the recovery rate of the oil and gas well. This is where pulse power devices are used. In pulse power devices, high-voltage discharge electrodes are required, and the positive and negative high voltages are used to break down the medium between the electrodes to form a discharge. When electric blasting occurs in oil and gas wells, due to the high voltage and the broken-down medium at both ends of the high-voltage discharge electrode, ablation is very likely to occur, causing the electrode gap to increase and affecting normal discharge. Experiments have shown that when the power reaches a certain level, the ablation caused by high-voltage discharge can reach 1.2 mm in 5 minutes. Therefore, in order to ensure that the electric blasting device in the well has a long normal working time and reduce the number of tripping operations, it is necessary to solve the problem of discharge electrode ablation. The utility model can effectively alleviate the problem of electrode ablation during high-voltage discharge, allowing electric blasting in oil and gas wells to operate normally and continuously.

[0022] like Figure 1 As shown, this embodiment provides a discharge electrode for a pulse power device in an oil and gas well, comprising two electrode units, the electrode unit comprising an electrode body 1, a locking cap 2, a spherical electrode 3 and a conductive rubber elastic pad 4, one end of the electrode body 1 is provided with a fixed cavity extending toward the other end, the locking cap 2 is arranged at the outer port of the fixed cavity, the locking cap 2 is provided with a through hole which is larger on the outside and smaller on the inside and communicates with the fixed cavity, the spherical electrode 3 is movably arranged in the fixed cavity, the conductive rubber elastic pad 4 is installed between the spherical electrode 3 and the inner end bottom of the fixed cavity, the spherical electrode 3 has a tendency to move toward the outside of the fixed cavity under the elastic force of the conductive rubber elastic pad 4, the radius of the spherical electrode 3 is smaller than the minimum diameter of the through hole, and part of the spherical surface of the spherical electrode 3 protrudes outward through the through hole; the ends of the two electrode units provided with the spherical electrodes 3 are arranged facing each other.

[0023] A spherical electrode 3 is provided at the end of the electrode body 1. The spherical electrode 3 is confined in the fixed cavity by the locking cap 2 and receives an outward thrust from the conductive rubber elastic pad 4. In this way, when the power pulse device is working, high voltage electricity is applied to both ends of the upper and lower spherical electrodes 3. When the voltage rises to a certain value, it breaks through the gap between the spherical electrodes 3 to generate discharge. During discharge, the arc acts on the exposed surfaces of the upper and lower spherical electrodes 3 respectively. The impact torque generated will cause the spherical electrode 3 to rotate in the fixed cavity. In this way, the position of the spherical electrode 3 acted on each discharge arc is different. Compared with the fixed end face electrode, which only discharges at the same end face all the time, end face ablation will naturally occur as the discharge continues. The embodiment of the present application uses the above technical measures to avoid the electrode discharge point being in one position for a long time, which is random. Therefore, it can effectively solve or alleviate the problem of electrode ablation during continuous pulse discharge. Since the spherical electrode 3 is installed in the fixed cavity, its contact area with the electrode body 1 is small, and the conductive effect is not good; the conductive rubber elastic pad 4 has a certain flexibility. On the one hand, it can fit more with the spherical surface of the spherical electrode 3 (larger area), thereby improving the conductive effect between the electrode body 1 and the spherical electrode 3. On the other hand, it can give the spherical electrode 3 a certain outward thrust, thereby avoiding the problem that the spherical electrode 3 retracts into the fixed cavity after discharge and no longer bulges outward (this problem will cause the electrode gap to be too large and discharge cannot or is difficult). In addition, it has a certain elasticity, which can ensure that the spherical electrode 3 is affected by the impact force generated during discharge and moves a certain distance into the fixed cavity, thereby providing conditions for the rotation of the spherical electrode 3 in the fixed cavity.

[0024] In one embodiment, the fixed cavity includes a first cavity on the outside and a second cavity on the inside, the first cavity and the second cavity are connected and coaxial, the diameter of the first cavity is larger than the diameter of the second cavity, and the locking cap 2 is installed in the first cavity; the electrode unit also includes a limiting cylinder 5, the limiting cylinder 5 includes a cylinder body and a convex edge arranged at the outer end of the cylinder, the convex edge is installed in the first cavity and abuts against the locking cap 2, the cylinder body is installed in the second cavity and abuts against the peripheral edge of the conductive rubber elastic pad 4, and a spherical hole coaxial with the through hole is provided in the middle of the cylinder body, the outer end radius of the spherical hole is adapted to the radius of the spherical electrode 3, and the inner end radius of the spherical hole is smaller than the radius of the spherical electrode 3. In this way, by setting the limiting cylinder 5, the conductive rubber elastic pad 4 can be pressed and fixed in the fixed cavity to prevent it from moving and causing changes in elastic force, thereby preventing the inward rotation and outward convex discharge of the spherical electrode 3 from being affected by the change in elastic force; by setting the inner end radius of the spherical hole to be smaller than the radius of the spherical electrode 3, it can be prevented that the spherical electrode 3 is excessively retracted when receiving the impact force. It should be noted that the elastic force of the conductive rubber elastic pad 4 must be within a certain range. It is not good to be too large or too small. Therefore, after preparing the conductive rubber elastic pad 4, other factors should be avoided from affecting its elastic force value; optionally, with the position where the conductive rubber elastic pad 4 contacts the spherical electrode 3 as the center, it extends to the circumference to form a pancake-shaped structure, and the edge of the pancake-shaped structure rolls up toward the side away from the spherical electrode 3 to form a rolled-up structure. The rolled-up structure is against the bottom of the second cavity of the fixed cavity. After the spherical electrode 3 presses the center of the pancake-shaped structure, the center of the pancake structure is concave in an arc shape toward one side of the rolled-up structure. At the same time, the rolled-up structure is compressed to make it roll up more (even if the gap between the rolled-up structure and the pancake-shaped structure becomes slightly smaller, but they are not fitted together), thereby increasing the contact area with the spherical electrode 3. When the spherical electrode 3 receives the impact force and rotates, it will further compress the center of the pancake-shaped structure. At this time, the pancake-shaped structure will continue to be concave toward one side of the rolled-up structure on the one hand, and will continue to compress the rolled-up structure on the other hand to make the two tend to fit together (not necessarily fit together). In this way, the conductive rubber elastic pad 4 can not only improve the conductivity between the electrode body 1 and the spherical electrode 3, but also provide the spherical electrode 3 with suitable elastic force.

[0025] In one embodiment, the inner side of the inner end of the cylinder is provided with a groove connected to the spherical hole, so that the inner end surface of the cylinder has an inclined surface or an arc surface transition when it contacts the conductive rubber elastic pad 4.

[0026] In one embodiment, the discharge electrode further includes a shell 6, and the electrode unit is installed in the shell 6. The top and side of the shell 6 are respectively provided with openings, wherein the top opening is used for connecting to other devices and routing wires, and the height position of the side opening 7 on the shell 6 corresponds to the height position of the spherical electrode 3 in the shell, and the side opening 7 is used to allow the shock wave and the hydroelectric effect generated by the discharge of the electrode unit to be released to the outside of the shell 6. In this way, the two electrode units are fixed by the shell 6, and the opening provided in the shell 6 can both route wires (provide high voltage electricity to the electrode unit) and transmit the shock wave. Exemplarily, the shell 6 can be divided into two sections, upper and lower, connected by threads, and an electrode unit is provided in each of the two sections.

[0027] In one embodiment, a plurality of side openings 7 are provided, and the plurality of side openings 7 are spaced apart and distributed around the circumference of the housing 6. Thus, by providing a plurality of side openings 7, the shock wave generated by the discharge can be transmitted as far as possible, acting on the oil and gas reservoir, removing blockage in the near-wellbore area of the oil and gas well, and improving the recovery rate of the oil and gas well.

[0028] In one embodiment, the discharge electrode further comprises an insulating sleeve 8, which is mounted within the shell 6, and the electrode unit is mounted within the insulating sleeve 8; this prevents high voltage electricity from flowing directly into the formation through the shell 6 without flowing through the spherical electrode 3, thereby preventing the discharge from generating shock waves. Exemplarily, the insulating sleeve 8 is cylindrical and is connected to the shell 6 by threads. Exemplarily, the interior of the insulating sleeve 8 is sequentially arranged from top to bottom as a large-diameter casing hole, a small-diameter casing hole, and a large-diameter casing hole; the electrode body 1 is a two-section cylinder, the large-diameter cylindrical section is threadedly mounted within the large-diameter casing hole, the small-diameter cylindrical section extends into the small-diameter casing hole, and the spherical electrode 3 is located at the end of the small-diameter cylindrical section.

[0029] In one embodiment, the insulating sleeve 8 is provided with a communicating hole at a position corresponding to the side opening 7. In another embodiment, the insulating sleeve 8 is divided into two sections, namely, two sections in the middle, with a gap between the two sections. The gap corresponds to the position of the side opening 7 of the housing 6. This can avoid the problem of the insulating sleeve 8 preventing the shock wave from being transmitted.

[0030] In one embodiment, the upper end of the electrode body 1 located in the upper portion of the housing 6 is provided with a terminal 9, and the lower end of the electrode body 1 located in the lower portion of the housing 6 abuts the housing 6. In this way, one electrode unit is subjected to a high voltage, and the other electrode unit is grounded through the housing 6 and subjected to a low voltage, thereby generating a shock wave by discharging between the two spherical electrodes 3.

[0031] An embodiment of the present application provides a discharge electrode for a pulse power device in an oil and gas well. During normal discharge, the discharge is always conducted on a certain spherical surface of the spherical electrode 3. The discharge impact can cause the two spherical electrodes 3 to rotate in a fixed cavity (because the impact force is not directed towards the sphere in most cases). This allows the discharge position to be different each time, thereby causing the ablation points to appear randomly, avoiding long-term discharge and ablation at a fixed position and extending the service life of the electrode; the conductive rubber elastic pad 4 can not only ensure power loading, but also has a shock-absorbing function, providing conditions for extending the working time of the electrode and ensuring the normal and reliable operation of the spherical electrode 3.

[0032] In the description of this specification, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on this application.

[0033] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of such features. Throughout the description of this application, "plurality" means two or more, unless otherwise specifically defined.

[0034] In this application, unless otherwise expressly specified or limited, terms such as "installed," "connected," "connect," and "fixed" should be understood in a broad sense. For example, they may refer to fixed connection, detachable connection, or integration; mechanical connection, electrical connection, or communication; direct connection or indirect connection through an intermediate medium; and internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0035] In this application, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Moreover, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly below or obliquely below the second feature, or may simply mean that the first feature is lower in level than the second feature.

[0036] The disclosure above provides many different embodiments or examples for realizing different structures of the present application. In order to simplify the disclosure of the present application, the components and settings of specific examples are described above. Of course, they are merely examples and are not intended to limit the present application. In addition, the present application may repeat reference numbers and / or reference letters in different examples. Such repetition is for the purpose of simplicity and clarity and does not in itself indicate the relationship between the various embodiments and / or settings discussed.

[0037] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any person skilled in the art can easily conceive of various modifications or substitutions within the technical scope disclosed in this application, and such modifications or substitutions should be included in the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. A discharge electrode for a pulse power device in an oil and gas well, characterized in that: The invention comprises two electrode units, each comprising an electrode body, a locking cap, a spherical electrode, and a conductive rubber elastic pad. One end of the electrode body is provided with a fixed cavity extending toward the other end. The locking cap is provided at an outer port of the fixed cavity. The locking cap is provided with a through hole that is larger on the outside and smaller on the inside and communicates with the fixed cavity. The spherical electrode is movably disposed within the fixed cavity. The conductive rubber elastic pad is installed between the spherical electrode and the bottom of the inner end of the fixed cavity. The spherical electrode has a tendency to move toward the outside of the fixed cavity under the elastic force of the conductive rubber elastic pad. The radius of the spherical electrode is smaller than the minimum diameter of the through hole. Part of the spherical surface of the spherical electrode protrudes outward through the through hole. The ends of the two electrode units provided with the spherical electrodes are arranged facing each other.

2. The discharge electrode according to claim 1, characterized in that The fixed cavity includes a first cavity on the outside and a second cavity on the inside, the first cavity and the second cavity are connected and coaxial, the diameter of the first cavity is larger than the diameter of the second cavity, and the locking cap is installed in the first cavity; the electrode unit also includes a limiting cylinder, the limiting cylinder includes a cylinder and a convex edge arranged at the outer end of the cylinder, the convex edge is installed in the first cavity and abuts against the locking cap, the cylinder is installed in the second cavity and abuts against the peripheral edge of the conductive rubber elastic pad, the middle part of the cylinder is provided with a spherical hole coaxial with the through hole, the outer end radius of the spherical hole is adapted to the radius of the spherical electrode, and the inner end radius of the spherical hole is smaller than the radius of the spherical electrode.

3. The discharge electrode according to claim 2, characterized in that The inner side of the inner end of the cylinder is provided with a groove connected to the spherical hole.

4. The discharge electrode according to claim 1, characterized in that The discharge electrode also includes a shell, and the electrode unit is installed in the shell. The top and side of the shell are respectively provided with openings, wherein the top opening is used for connecting with other devices and routing wires, and the side opening is used to allow the shock wave and hydroelectric effect generated by the discharge of the electrode unit to be released outside the shell.

5. The discharge electrode according to claim 4, characterized in that There are a plurality of side openings, and the plurality of side openings are distributed at intervals in the circumferential direction of the shell.

6. The discharge electrode according to claim 4, characterized in that The discharge electrode further includes an insulating sleeve, which is installed in the shell, and the electrode unit is installed in the insulating sleeve.

7. The discharge electrode according to claim 6, characterized in that The upper end of the electrode body located in the upper part of the shell is provided with a terminal, and the lower end of the electrode body located in the lower part of the shell is in contact with the shell.

8. The discharge electrode according to claim 6, characterized in that The insulating sleeve is provided with a communicating hole at a position corresponding to the side opening.

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