Split type resistivity logging button electrode, preparation method and instrument

Abstract

The invention discloses a split resistivity logging button electrode, a preparation method and an instrument, the split resistivity logging button electrode comprises an upper shell, an electrode block, a probe, an insulation assembly, a metal base and a bottom plate, the electrode block is in sealed connection with an upper opening of the upper shell, the electrode block comprises a plurality of electrode assemblies which are not in contact with each other, the metal base is provided with a plurality of probe holes, and the probe holes are communicated with the bottom plate. The electrode assembly is provided with a probe connecting hole, the top end of the probe penetrates through the probe hole and is connected with the electrode block through the probe connecting hole, the bottom end of the probe is provided with a bonding wire hole, the bottom plate is connected to a lower opening of the upper shell in a sealed mode, and a wire is led out of the bonding wire hole and then connected with an instrument through a wire passing hole of the bottom plate. The insulation assemblies enable insulation layers with certain insulation thickness to be formed between the electrode assemblies and between the electrode assemblies and the metal base, the space between the electrode assemblies is filled with the insulation layers in a sealed mode, the upper shell is connected with an instrument in a sealed mode, and the process design and product implementation difficulty is lowered while the performance is not affected.

Description

Technical Field

[0001] The present invention relates to the technical field of instruments, and in particular to a split-type resistivity logging button electrode, a preparation method and an instrument. Background Art

[0002] Oil and gas exploration uses logging while drilling instruments to measure the formation properties around the well wall. Signals can be transmitted from the instrument into the formation, and some signals return to the instrument after passing through the formation. By analyzing the transmitted and recovered signals, the formation properties can be obtained. Electrical signals are one of the commonly used signals. The instrument transmits and receives return electrical signals to the formation. The components or assemblies responsible for transmission and reception are called electrodes. The electrodes are fixed on the instrument housing. The integrated electrode is called a button electrode because of its button-like shape. After the button electrode is installed on the instrument housing, one side contacts the liquid in the wellbore and the other side is connected to the internal circuit of the instrument. The internal circuit controls each electrode to transmit different current signals or receive return currents from different measuring depths.

[0003] As a component of the drilling instrument, the electrode assembly can work continuously for hundreds of hours in wells thousands of meters deep. The working environment temperature can reach over 175 degrees Celsius, the pressure can reach over 140 MPa, and it is accompanied by a large number of severe vibrations caused by drilling.

[0004] The commonly used processing method at present is to combine the electrode part, insulating material and shell of the button electrode as a whole by high-pressure PEEK injection molding or high-temperature glass sintering. The manufacturing process is very complicated, the process is long, and the success rate is low. A lot of process design and debugging work is required for each design, so it is expensive. At the same time, the biggest reliability problem faced by the button electrode is that the high-pressure liquid in the wellbore breaks through the bond between the electrode and the insulating material and enters the instrument, which not only causes the electrode itself to fail, but also causes the failure and scrapping of the internal circuit of the instrument, making it impossible to complete the logging work, resulting in huge time and economic losses. Summary of the invention

[0005] In view of the problems in the related art, the present invention proposes a split resistivity logging button electrode, a preparation method and an instrument to overcome the above technical problems existing in the existing related art.

[0006] To this end, the specific technical scheme adopted by the present invention is as follows: a split resistivity logging button electrode, comprising: an upper shell, an electrode block, a probe, an insulating component, a metal base and a bottom plate, the upper shell is a hollow structure with upper and lower openings, the electrode block is located in the hollow structure of the upper shell, the top of the electrode block is exposed to the outside of the upper shell through the upper opening of the upper shell, the electrode block is sealed and connected to the upper opening of the upper shell, the electrode block comprises a plurality of electrode components that do not contact each other, a plurality of probe holes are provided on the metal base, probe connection holes are provided on the electrode components corresponding to the probe holes, the top of the probe passes through the probe hole and is connected to the electrode block through the probe connection hole, a welding wire hole is provided at the bottom of the probe, the bottom plate is sealed and connected to the lower opening of the upper shell, a wire passing hole is provided on the bottom plate, the wire is led out from the welding wire hole and connected to the instrument through the wire passing hole, the insulating component is formed by injecting insulating material inside the electrode block and between the electrode block and the metal base, the insulating component forms an insulating layer with a certain insulating thickness between each electrode component and between the electrode component and the metal base, each electrode component is sealed and filled with the insulating layer, and the upper shell is sealed and connected to the instrument.

[0007] Furthermore, the upper surface of the upper shell is an arc-shaped structure, the upper surfaces of the electrode block and the insulating assembly match the arc-shaped structure of the upper surface of the upper shell, and the electrode assembly adopts an electrode ring, an electrode sheet or an electrode needle.

[0008] Furthermore, the insulating component is formed by PEEK or rubber injection molding, and a rubber sealing ring is sleeved on the probe to seal the probe hole.

[0009] Furthermore, the electrode block is sealed and connected to the upper opening of the upper shell through a first sealing ring, and the bottom plate is sealed and connected to the lower opening of the upper shell through a second sealing ring.

[0010] Furthermore, a gasket groove is opened on the upper surface of the base plate corresponding to the probe hole, a gasket is built in the gasket groove, a gasket wire groove is opened on the gasket, a base plate wire groove is opened on the base plate, the gasket wire groove is connected to the base plate wire groove, the base plate wire groove is connected to the through-wire hole, the probe is connected to the base plate through the gasket, the wire is led out from the welding wire hole, passes through the gasket wire groove and the base plate wire groove, and then passes through the through-wire hole to connect the instrument.

[0011] Furthermore, a step is provided on the upper shell, and the upper shell presses the split resistivity logging button electrode onto the instrument through the step.

[0012] Furthermore, the probe connection hole is a threaded hole.

[0013] Furthermore, a limit block is connected to the side of the upper shell, and a force measuring unit is connected to the lower part of the upper shell. A compensation oil chamber is provided on the inner side of the instrument corresponding to the force measuring unit and the bottom of the split resistivity logging button electrode. The compensation oil chamber reaches pressure balance with the liquid in the wellbore through the piston. The force measuring unit is connected to the upper shell through a push spring and a push piston. The split resistivity logging button electrode contacts the well wall under the pushing action of the push piston, and floats up and down when encountering irregularities in the well wall. At the same time, the thrust between the well wall and the push spring is controlled by the push spring, and the force measuring unit measures and stores the thrust of the push spring.

[0014] The present application also provides a method for preparing a split-type resistivity logging button electrode, which is used to prepare any of the above-mentioned split-type resistivity logging button electrodes, comprising: S1. According to the shape and size of the split resistivity logging button electrode to be prepared, the electrode components are processed to the same height; S2. According to the position arrangement of the plurality of electrode assemblies, the plurality of electrode assemblies are fixed on the injection molding top plate, and the injection molding top plate is fixed on the upper part of the injection mold; S3, fixing the metal base to the lower part of the injection mold, and controlling a certain insulation space between the metal base and the electrode assembly; S4, tightening the upper and lower parts of the injection mold and injecting insulating material to form an insulating component; S5. Take out the metal base and the insulating component from the injection mold, cut and assemble the electrode component and the insulating component according to the shape and size of the split-type resistivity logging button electrode to be prepared, assemble the probe and connect the wiring, and then connect the upper shell and the bottom plate to obtain the split-type resistivity logging button electrode.

[0015] The present application also provides an instrument, comprising any of the split-type resistivity logging button electrodes described above or a split-type resistivity logging button electrode prepared by the method for preparing the split-type resistivity logging button electrode described above.

[0016] The beneficial effects of the present invention are: 1. This application proposes a split resistivity logging button electrode, which splits the traditional integrated button electrode into several parts and then seals and connects them. Compared with the integrated design, the performance is not affected while reducing the difficulty of process design and product implementation; 2. The split resistivity logging button electrode of the present application can be regularly disassembled and maintained, and the sealing ring and other parts can be replaced to increase the service life; 3. This application uses a sealing rubber ring for sealing, which solves the problem of sealing failure between the electrode and the insulating material that is easy to occur in the integrated design in high temperature, high pressure and high vibration environment; 4. This application proposes an electrode floating design. The electrode contacts the well wall under the pushing action and floats up and down when encountering irregularities in the well wall. At the same time, the thrust between the electrode and the well wall is controlled by a spring, which can ensure sufficient contact without generating excessive friction to affect drilling and wear the electrode. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 It is a schematic diagram of the three-dimensional structure of an instrument according to the first embodiment of the present invention; Figure 2 It is a schematic diagram of the three-dimensional structure at one angle of a split-type resistivity logging button electrode according to the first embodiment of the present invention; Figure 3 It is a schematic diagram of the three-dimensional structure of a split-type resistivity logging button electrode from another angle according to the first embodiment of the present invention; Figure 4 This is an exploded view of a split-type resistivity logging button electrode according to the first embodiment of the present invention; Figure 5 It is a schematic diagram of the three-dimensional structure of an electrode block in a split-type resistivity logging button electrode in the first embodiment of the present invention at one angle; Figure 6 It is a schematic diagram of the three-dimensional structure of an electrode block in a split-type resistivity logging button electrode in the first embodiment of the present invention from another angle; Figure 7 It is a schematic diagram of the three-dimensional structure of a probe in a split-type resistivity logging button electrode at one angle according to the first embodiment of the present invention; Figure 8 It is a schematic diagram of the three-dimensional structure of a probe in a split-type resistivity logging button electrode in another angle according to the first embodiment of the present invention; Fig. 9 It is a schematic diagram of the three-dimensional structure of a metal base in a split-type resistivity logging button electrode at one angle in the first embodiment of the present invention; Fig.10 It is a schematic diagram of a three-dimensional structure of a bottom plate at an angle in a split-type resistivity logging button electrode according to the first embodiment of the present invention; Fig.11 It is a schematic diagram of the three-dimensional structure of the bottom plate in a split-type resistivity logging button electrode in the first embodiment of the present invention from another angle; Fig.12It is a schematic diagram of the three-dimensional structure of an insulating component in a split-type resistivity logging button electrode in the first embodiment of the present invention at one angle; Fig.13 It is a schematic diagram of the three-dimensional structure of an insulating component in a split-type resistivity logging button electrode in the first embodiment of the present invention from another angle; Fig.14 It is a partial cross-sectional structural schematic diagram of an instrument according to the first embodiment of the present invention; Fig.15 It is a schematic diagram of a three-dimensional structure of an injection-molded top plate used in a method for preparing a split-type resistivity logging button electrode in Embodiment 2 of the present invention at one angle; Fig.16 It is a schematic diagram of the position structure of a metal base and an injection molding top plate during the injection molding process in a method for preparing a split-type resistivity logging button electrode according to the second embodiment of the present invention; Fig.17 It is a schematic diagram of the cross-sectional structure of a mold, a metal base and an electrode assembly during injection molding in a method for preparing a split-type resistivity logging button electrode according to a second embodiment of the present invention. DETAILED DESCRIPTION

[0019] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. Embodiment 1

[0020] like Figure 1-14 As shown, a split resistivity logging button electrode, the split resistivity logging button electrode B comprises: an upper shell 1, an electrode block 2, a probe 3, an insulating component 7, a metal base 4 and a bottom plate 5. In this embodiment, the upper surface of the upper shell 1 is an arc-shaped structure with a high middle and low sides. The upper surfaces of the electrode block 2 and the insulating component 7 match the arc-shaped structure of the upper surface of the upper shell 1. Figure 2-4 As shown, the upper shell 1 is a hollow structure with upper and lower openings, the electrode block 2 is located in the hollow structure of the upper shell 1, the top of the electrode block 2 is exposed to the outside of the upper shell 1 through the upper opening of the upper shell 1, and the electrode block 2 is sealed and connected to the upper opening of the upper shell 1 through a first sealing ring 8. The electrode block 2 includes a plurality of electrode assemblies 21 that do not contact each other. Since adjacent electrode assemblies 21 need to ensure sufficient insulation thickness, the electrode assemblies 21 do not contact each other. In this embodiment, the distance between adjacent electrode assemblies 21 is 2 mm.

[0021] like Figure 5 and 6As shown, the electrode assembly 21 of this embodiment adopts electrode rings, and there are insulating gaps between the four electrode rings, and the insulating gaps are filled with insulating components 7, such as Fig. 9 As shown, a plurality of probe holes 41 are provided on the metal base 4, and a probe connection hole 22 is provided on the electrode assembly 21 corresponding to the probe hole 41. The top end of the probe 3 passes through the probe hole 41 and is connected to the electrode block 2 through the probe connection hole 22. The probe connection hole 22 is a threaded hole, and the probe connection hole 22 and the probe 3 are threadedly connected. There is also an insulating gap between the four electrode rings and the metal base 4, and the insulating gap is also filled by the insulating assembly 7. A rubber sealing ring 32 is sleeved on the probe 3 to seal with the probe hole 41, as shown in FIG. Figure 7 and 8 As shown, a welding hole 31 is opened at the bottom end of the probe 3, and the bottom plate 5 is sealed and connected to the lower opening of the upper shell 1 through a second sealing ring 9.

[0022] like Fig.10 and 11 As shown, the bottom plate 5 is provided with a wire hole 53, and the wire is led out from the welding wire hole 31 and connected to the instrument A through the wire hole 53. The insulating component 7 is formed by injection molding an insulating material inside the electrode block 2 and between the electrode block 2 and the metal base 4. In this embodiment, the insulating component 7 is formed by rubber injection molding, such as Fig.12 and 13 As shown, the insulating assembly 7 forms an insulating layer with a certain insulating thickness between each electrode assembly 21 and between the electrode assembly 21 and the metal base 4. Each electrode assembly 21 is sealed and filled with the insulating layer. The upper shell 1 is sealed and connected to the instrument A. The upper shell 1 can be fixed to the instrument A by threaded connection or other fixing methods.

[0023] It should be noted that a gasket groove 52 is provided on the upper surface of the base plate 5 corresponding to the probe hole 41, a gasket 6 is built in the gasket groove 52, a gasket wire groove 61 is provided on the gasket 6, a base plate wire groove 51 is provided on the base plate 5, the gasket wire groove 61 is connected to the base plate wire groove 51, the base plate wire groove 51 is connected to the through-wire hole 53, the probe 3 is connected to the base plate 5 through the gasket 6, the wire is led out from the welding wire hole 31, passes through the gasket wire groove 61 and the base plate wire groove 51, and then passes through the through-wire hole 53 to connect to the instrument A.

[0024] In addition, a step is provided on the upper shell 1, and the upper shell 1 presses the split resistivity logging button electrode B onto the instrument A through the step.

[0025] It should also be noted that a shock-absorbing design such as rubber can be added between the bottom plate 5 and the instrument A, and a pressure-bearing sealed wire-passing design can also be added to the wire-passing hole of the shell of the instrument A to further ensure the safety of the instrument.

[0026] Since instrument A is located in the wellbore, which is full of liquid, the measurement signal will be affected by the liquid in the well. In order to improve the measurement quality, the electrode surface should contact the wellbore wall as much as possible. However, instrument A participates in drilling and rotates at high speed and rubs against the wellbore wall during use. If the outer diameter of instrument A contacts the wellbore wall, it will hinder the normal operation of drilling. Moreover, the inner wall of the wellbore is irregular and has a large number of unevenness. Therefore, the present invention proposes an electrode floating design. Since the liquid pressure in the wellbore exceeds 100 MPa, in order to achieve a floating design, a compensating oil chamber must be set up at the bottom of the electrode. The oil chamber reaches pressure balance with the liquid in the wellbore through a piston. The volume of the liquid in the oil chamber changes with the temperature and pressure, and the piston can adapt to the volume change by moving up and down. A push spring and a push piston must be provided under the electrode, and a limit block is provided above. The electrode contacts the wellbore wall under the push action, and floats up and down when encountering irregularities in the wellbore wall. At the same time, the thrust between the wellbore wall is controlled by a spring, which can ensure sufficient contact, and at the same time, will not generate excessive friction to affect drilling and wear the electrode. Specifically, if Fig.14 As shown, the side of the upper shell 1 is connected to a limit block 12, and the lower part of the upper shell 1 is connected to a force measuring unit 11. A compensation oil chamber A1 is provided on the inner side of the instrument A corresponding to the force measuring unit 11 and the bottom of the split resistivity logging button electrode B. The compensation oil chamber A1 reaches pressure balance with the liquid in the wellbore through a piston. The force measuring unit 11 is connected to the upper shell 1 through a push spring and a push piston. The split resistivity logging button electrode B contacts the well wall under the pushing action of the push piston, and floats up and down when encountering irregularities in the well wall. At the same time, the thrust between the well wall and the push spring is controlled, and the force measuring unit measures and stores the thrust of the push spring. Embodiment 2

[0027] like Figure 15-17 As shown, a method for preparing a split-type resistivity logging button electrode, which is used to prepare the split-type resistivity logging button electrode of Example 1, comprises: S1. According to the shape and size of the arc-shaped split resistivity logging button electrode B prepared in Example 1, four electrode rings are uniformly processed to the height of the middle part of the arc-shaped structure; S2. According to the position arrangement of the four electrode rings, the four electrode rings are fixed on the injection molding top plate 10, and the injection molding top plate 10 is fixed to the upper part of the injection mold; S3, fixing the metal base 4 to the lower part of the injection mold, and ensuring that there is a certain insulating space between the metal base 4 and the four electrode rings; S4, tightening the upper and lower parts of the injection mold and injecting insulating material to form an insulating component 7; S5. Take out the metal base 4 and the insulating component 7 from the injection mold, cut and assemble the electrode ring and the insulating component 7 according to the shape and size of the split resistivity logging button electrode B to be prepared, assemble the probe 3, connect the wiring, and then connect the upper shell 1 and the bottom plate 5 to obtain the split resistivity logging button electrode B. Embodiment 3

[0028] An instrument includes the split-type resistivity logging button electrode of the first embodiment or the split-type resistivity logging button electrode prepared by the preparation method of the split-type resistivity logging button electrode of the second embodiment.

[0029] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A split resistivity logging button electrode, characterized in that: The split resistivity logging button electrode (B) comprises: an upper shell (1), an electrode block (2), a probe (3), an insulating component (7), a metal base (4) and a bottom plate (5); the upper shell (1) is a hollow structure with upper and lower openings; the electrode block (2) is located in the hollow structure of the upper shell (1); the top end of the electrode block (2) is exposed to the outside of the upper shell (1) through the upper opening of the upper shell (1); the electrode block (2) is sealed and connected to the upper opening of the upper shell (1); the electrode block (2) comprises a plurality of electrode components (21) that are not in contact with each other; a plurality of probe holes (41) are provided on the metal base (4); a probe connection hole (22) is provided on the electrode component (21) corresponding to the probe hole (41); the top end of the probe (3) passes through the probe hole (41); ) and connected to the electrode block (2) through the probe connection hole (22); a welding wire hole (31) is provided at the bottom end of the probe (3); the bottom plate (5) is sealed and connected to the lower opening of the upper shell (1); a wire hole (53) is provided on the bottom plate (5); a wire is led out from the welding wire hole (31) and connected to the instrument (A) through the wire hole (53); the insulating component (7) is formed by injection molding an insulating material inside the electrode block (2) and between the electrode block (2) and the metal base (4); the insulating component (7) forms an insulating layer of a certain insulating thickness between each electrode component (21) and between the electrode component (21) and the metal base (4); each electrode component (21) is sealed and filled with the insulating layer; and the upper shell (1) is sealed and connected to the instrument (A).

2. A split resistivity logging button electrode according to claim 1, characterized in that: The upper surface of the upper shell (1) is an arc-shaped structure, the upper surfaces of the electrode block (2) and the insulating component (7) match the arc-shaped structure of the upper surface of the upper shell (1), and the electrode component (21) adopts an electrode ring, an electrode sheet or an electrode needle.

3. A split resistivity logging button electrode according to claim 1 or 2, characterized in that: The insulating component (7) is formed by PEEK or rubber injection molding, and a rubber sealing ring (32) is sleeved on the probe (3) to seal with the probe hole (41).

4. A split resistivity logging button electrode according to claim 1 or 2, characterized in that: The electrode block (2) is sealed and connected to the upper opening of the upper shell (1) via a first sealing ring (8), and the bottom plate (5) is sealed and connected to the lower opening of the upper shell (1) via a second sealing ring (9).

5. A split resistivity logging button electrode according to claim 1 or 2, characterized in that: A gasket groove (52) is provided on the upper surface of the bottom plate (5) corresponding to the probe hole (41), a gasket (6) is built in the gasket groove (52), a gasket wire groove (61) is provided on the gasket (6), a bottom plate wire groove (51) is provided on the bottom plate (5), the gasket wire groove (61) is communicated with the bottom plate wire groove (51), the bottom plate wire groove (51) is connected to the wire hole (53), the probe (3) is connected to the bottom plate (5) through the gasket (6), the wire is led out from the welding wire hole (31), passes through the gasket wire groove (61) and the bottom plate wire groove (51), and then passes through the wire hole (53) to connect to the instrument (A).

6. A split resistivity logging button electrode according to claim 1 or 2, characterized in that: The upper shell (1) is provided with a step, and the upper shell (1) presses the split-type resistivity logging button electrode (B) onto the instrument (A) via the step.

7. A split resistivity logging button electrode according to claim 1 or 2, characterized in that: The probe connection hole (22) is a threaded hole.

8. A split resistivity logging button electrode according to claim 1 or 2, characterized in that: The side of the upper shell (1) is connected to a limit block (12), and the lower part of the upper shell (1) is connected to a force measuring unit (11). A compensation oil chamber (A1) is provided inside the instrument (A) corresponding to the force measuring unit (11) and the bottom of the split-type resistivity logging button electrode (B). The compensation oil chamber (A1) reaches pressure balance with the liquid in the wellbore through a piston. The force measuring unit (11) is connected to the upper shell (1) through a push spring and a push piston. The split-type resistivity logging button electrode (B) contacts the well wall under the pushing action of the push piston and floats up and down when encountering irregularities in the well wall. At the same time, the thrust between the well wall and the push spring is controlled by the push spring. The force measuring unit measures and stores the thrust of the push spring.

9. A method for preparing a split-type resistivity logging button electrode, used for preparing the split-type resistivity logging button electrode according to any one of claims 1 to 8, characterized in that: include: S1. According to the shape and size of the split resistivity logging button electrode (B) to be prepared, the electrode assemblies (21) are processed to the same height; S2. According to the position arrangement of the plurality of electrode assemblies (21), the plurality of electrode assemblies (21) are fixed on the injection molding top plate (10), and the injection molding top plate (10) is fixed on the upper part of the injection mold; S3, fixing the metal base (4) to the lower part of the injection mold, and controlling a certain insulating space between the metal base (4) and the electrode assembly (21); S4, tightening the upper and lower parts of the injection mold and injecting insulating material to form an insulating component (7); S5. The metal base (4) and the insulating component (7) are removed from the injection mold, and the electrode component (21) and the insulating component (7) are cut and assembled according to the shape and size of the split resistivity logging button electrode (B) to be prepared, and then the probe (3) is assembled and connected to the upper shell (1) and the bottom plate (5) to obtain the split resistivity logging button electrode (B).

10. An instrument, characterized in that: It comprises a split-type resistivity logging button electrode as described in any one of claims 1 to 8 or a split-type resistivity logging button electrode prepared by the preparation method of the split-type resistivity logging button electrode as described in claim 9.

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