A high-temperature and high-pressure micro-resistivity imaging logging tool electrode plate

Abstract

The present invention provides a high-temperature and high-pressure resistant micro-resistivity imaging logging tool electrode plate, comprising: an electrode plate pressure-bearing outer shell, on the outer wall of which there is an electrode mounting position; button electrodes mounted in the motor mounting position, with an insulating sleeve outside the button electrodes; an electrode plate pressure-bearing inner lining arranged inside the electrode plate pressure-bearing outer shell, the electrode plate pressure-bearing inner lining being provided with an internal cavity; an electrode plate circuit board arranged in the internal cavity; and an electrode plate pressure-bearing bottom cover embedded in the electrode plate pressure-bearing outer shell, the electrode plate pressure-bearing bottom cover being capable of limiting the electrode plate circuit board in the internal cavity; wherein, the electrode plate pressure-bearing outer shell is configured to include an outer shell body and an inner shell body in interference fit with the outer shell body.

Description

Technical Field

[0001] The present invention belongs to the technical field of supporting equipment for oil geological exploration instruments, and particularly relates to a high-temperature and high-pressure resistant micro-resistivity imaging logging tool electrode plate. Background Art

[0002] As the drilling vertical depth increases, the bottom-hole pressure and temperature also become greater. As a wellbore perimeter exploration and imaging device, the reliability of the structure of the micro-resistivity scanning imaging logging tool plays a crucial role in the accuracy of wellbore resolution.

[0003] The electrode plate of the micro-resistivity scanning imaging logging tool, as an important component of the micro-resistivity scanning imaging logging tool, contains necessary relevant electronic circuits inside. However, the structure adopted by the electrode plate of the existing micro-resistivity scanning imaging logging tool can withstand a maximum pressure of no more than 140 MPa, which cannot meet the needs of future production tasks in "deep sea and deep earth". Its pressure resistance and strength are poor, and its high-temperature and high-pressure resistance performance is poor. In addition, when the pressure bearing is further increased, increasing the thickness cannot effectively improve the pressure resistance and strength. Summary of the Invention

[0004] In view of the above technical problems, the present invention aims to provide a high-temperature and high-pressure resistant micro-resistivity imaging logging tool electrode plate, which has high-temperature and high-pressure resistance performance, can ensure that there is no leakage in the pressure-bearing inner cavity in an environment above 200 °C and 172 MPa, and has high insulation between the button electrode and the electrode plate body.

[0005] To this end, according to the present invention, there is provided a high-temperature and high-pressure resistant micro-resistivity imaging logging tool electrode plate, including: an electrode plate pressure-bearing outer shell, on the outer wall of which there is an electrode installation position; a button electrode installed in the electrode installation position, and an insulating sleeve is provided outside the button electrode; a pressure-bearing inner lining of the electrode plate provided inside the electrode plate pressure-bearing outer shell, and the pressure-bearing inner lining of the electrode plate is provided with an internal cavity; a circuit board of the electrode plate provided in the internal cavity; and a pressure-bearing bottom cover of the electrode plate embedded in the electrode plate pressure-bearing outer shell, and the pressure-bearing bottom cover of the electrode plate can limit the circuit board of the electrode plate in the internal cavity; wherein, the electrode plate pressure-bearing outer shell is configured to include an outer shell and an inner shell in interference fit with the outer shell.

[0006] In one embodiment, the high-temperature limit of the electrode plate exceeds 200 °C, and the pressure-bearing limit exceeds 172 MPa.

[0007] In one embodiment, the electrode installation position is configured as a multi-stage conical frustum-shaped groove body, the button electrode is configured as a multi-step conical frustum-shaped groove body capable of adapting to the electrode installation position, and the insulating sleeve is wrapped on the outer surface of the button electrode.

[0008] In one embodiment, the apex half-angle of each stage of the button electrode is less than 11.3°, preferably set to 5°.

[0009] In one embodiment, the insulating sleeve is made of an inorganic silicon water-based resin material, and the insulation resistance of the insulating sleeve is greater than 10 MΩ.

[0010] In one embodiment, the pressure-bearing bottom cover of the electrode plate and the electrode mounting position are distributed radially opposite to each other.

[0011] In one embodiment, the pressure-bearing inner lining of the electrode plate is press-fitted into the inside of the pressure-bearing outer shell of the electrode plate in a thermal assembly manner, and the compressive strength of the electrode plate body reaches more than 180 MPa.

[0012] In one embodiment, the outer shell and the inner shell are made of the same material, both of which are alloy materials with a yield strength > 1000 Mpa.

[0013] In one embodiment, a pressure-bearing plug is connected to the upper end of the pressure-bearing outer shell of the electrode plate, and the pressure-bearing plug bears a bidirectional pressure greater than 180 MPa.

[0014] In one embodiment, the pressure-bearing plug is hermetically connected to the electrode plate shell.

[0015] Compared with the prior art, the advantages of the present application are as follows:

[0016] According to the electrode plate of the high-temperature and high-pressure micro-resistivity imaging logging tool of the present invention, the pressure-bearing outer shell of the electrode plate adopts a two-layer electrode plate shell structure formed by an outer shell and an inner shell, which significantly improves the compressive capacity and strength of the pressure-bearing outer shell of the electrode plate. The electrode plate can ensure that there is no leakage in the pressure-bearing inner cavity at 200 °C and above 172 MPa, and at the same time, there is high insulation between the button electrode and the pressure-bearing outer shell of the electrode plate. Therefore, the electrode plate can meet the temperature resistance and pressure-bearing requirements of the electrode plate of the micro-resistivity scanning imaging logging tool. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The present invention will be described below with reference to the accompanying drawings.

[0018] Figure 1 Schematically shows the structure of the electrode plate of the high-temperature and high-pressure micro-resistivity imaging logging tool according to the present invention.

[0019] Figure 2 Schematically shows the structure of the button electrode in the electrode plate of the high-temperature and high-pressure micro-resistivity imaging logging tool according to the present invention.

[0020] Figure 3 Schematically shows a schematic diagram of the apex half-angle α of the button electrode.

[0021] Figure 4Schematically shows a schematic diagram of the interference fit of the pressure-bearing housing of the electrode plate.

[0022] In this application, all the drawings are schematic drawings, only used to illustrate the principle of the present invention and not drawn to actual scale. Detailed implementation manners

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

[0024] In the description of the present invention, it should be understood that the orientation or positional relationships indicated by the terms "axial direction", "radial direction", "upper", "lower", "left", "right", etc. are based on the orientation or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying 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 construed as a limitation to the present invention.

[0025] Figure 1 Schematically shows the structure of the electrode plate 100 of the high-temperature and high-pressure micro-resistivity imaging logging tool according to the present invention. As Figure 1 shown, the electrode plate 100 includes a pressure-bearing housing 1 of the electrode plate, a button electrode mounting position 2, a pressure-bearing lining 3 of the electrode plate, a pressure-bearing bottom cover 4 of the electrode plate, an electrode plate circuit board 5, and an upper joint 6 of the electrode plate. The pressure-bearing lining 3 of the electrode plate is arranged inside the pressure-bearing housing 1 of the electrode plate, and the pressure-bearing lining 3 of the electrode plate is provided with an internal cavity. The electrode plate circuit board 5 is arranged inside the internal cavity, and is used for collecting downhole information and performing data processing. The pressure-bearing bottom cover 4 of the electrode plate is embedded in the pressure-bearing housing 1 of the electrode plate. The pressure-bearing bottom cover 4 of the electrode plate can limit the electrode plate circuit board 5 in the internal cavity, and at the same time can play a certain limiting role on the pressure-bearing lining 3 of the electrode plate. The pressure-bearing bottom cover 4 of the electrode plate can jointly bear the pressure with the pressure-bearing housing 1 of the electrode plate, so as to protect the internal components. An electrode mounting position 2 is provided on the outer wall of the pressure-bearing housing 1 of the electrode plate, and the button electrode 8 is correspondingly mounted in the electrode mounting position 2. An insulating sleeve 7 is arranged outside the button electrode 8, so as to ensure high insulation between the button electrode 8 and the pressure-bearing housing 1 of the electrode plate.

[0026] According to the present invention, the electrode mounting position 2 is arranged on the outer wall of the pressure-bearing housing 1 of the electrode plate, and a plurality of electrode mounting positions 2 can be evenly spaced along the axial direction. In Figure 1 the illustrated embodiment, two axially spaced-apart electrode mounting positions 2 are provided on the outer wall of the pressure-bearing housing 1 of the electrode plate. The electrode mounting position 2 is configured as a multi-stage conical frustum-shaped groove for mounting the electrode.

[0027] As Figure 2 shown, the button electrode 8 is configured as a multi-stage conical frustum shape that can be adapted to the electrode mounting position 2. The insulating sleeve 7 is wrapped on the conical outer surface of the button electrode 8. A plurality of button electrodes 8 are correspondingly mounted in the corresponding electrode mounting positions 2 for well logging scanning.

[0028] Taking the button electrode 8 as an example, when the downhole pressure P 液 acts on the end face of the button electrode 8 with an area of S_end, as Figure 3 shown, the generated acting force is F = S 端 ·P 液 . Since the friction coefficient between the high-temperature resistant and insulating material and steel is generally greater than 0.2, the critical friction angle arctan0.2 ≈ 11.3°. Therefore, the apex half-angle α of the button electrode 8 is set to be less than 11.3°, preferably set to 5°. Thus, the button electrode 8 can form a self-locking with the insulating sleeve 7, and the insulating sleeve 7 and the wall of the mounting hole of the plate electrode mounting position 2. Among them, S 端 refers to the end face of the button electrode 8 ( Figure 3 the right end face in 液 ), P

[0029] refers to the drilling hydraulic pressure from the well, and F refers to the force acting on the end face of the button electrode 8.

[0030] σ = F b / S o

[0031] wherein, F b is the maximum force borne when the conical surface deforms, S o is the original cross-sectional area of the specimen, and σ is the tensile strength or strength limit.

[0032] The force on the conical surface of the button electrode 8:

[0033] F 锥 = μ·P·S 电极 << σ·S 锥面

[0034] Therefore, in a high-pressure environment, the force on the installation conical surface of the button electrode 8 does not reach the force when the material deforms, and there will be no high-pressure deformation, and the purpose of withstanding high pressure can be achieved. Thus, after the assembly of the button electrode 8 is pre-tightened, it can be in a stable sealing and insulating state for a long time.

[0035] According to an embodiment of the present invention, the insulating sleeve 7 can be made of a high-temperature resistant inorganic silicon water-based resin material, so that the insulation resistance of the insulating sleeve 7 is greater than 10 MΩ.

[0036] In one embodiment, the plate electrode mounting positions 2 are distributed radially relative to each other. This can avoid mutual influence during installation.

[0037] According to the present invention, as Figure 4As shown, the plate pressure-bearing housing 1 is configured to include an outer housing 9 and an inner housing 10 sleeved inside the outer housing 9, and the outer housing 9 and the inner housing 10 form a combined plate housing structure by an interference fit method.

[0038] In one embodiment, the outer housing 9 and the inner housing 10 are made of the same material, both made of high yield strength high temperature alloy steel material.

[0039] As Figure 4 As shown in the schematic diagram, the plate pressure-bearing housing adopts the outer housing 9 and the inner housing 10 to form a two-layer plate housing structure. Moreover, the inner housing 10 is installed in the inner hole of the outer housing 9 by a thermal assembly process. Thus, after cooling, the outer housing 9 and the inner housing 10 form an interference fit.

[0040] For the convenience of understanding, let the inner radius of the inner housing 10 be represented by a, the outer radius of the inner housing 9 be represented by c, and the inner radius of the outer housing 9 be smaller than the outer radius of the inner housing 13 by △, that is, c - △. The inner radius of the outer housing 9 is b. When the outer housing 9 is heated, the inner hole of the outer housing 9 expands, and then the inner housing is placed inside the outer one. After cooling, a radial assembly pressure Pc is generated between the outer housing 9 and the inner housing 10, and the direction of the radial assembly pressure Pc is radially inward. At this time, the outer radius of the inner housing 10 shrinks and becomes smaller, and at the point on the outer peripheral contact surface of the inner housing 10, a negative displacement u1 is obtained. The inner radius of the outer housing 9 expands and becomes larger, and the displacement generated on the inner peripheral contact surface of the outer housing 9 is u2. Therefore, △ satisfies the following relationship:

[0041] △ = u2 - u1

[0042] As known from mechanics of materials:

[0043]

[0044] Among them, u refers to the radial displacement, μ refers to the material Poisson's ratio, r refers to the radius, E refers to the material elastic modulus, P1 refers to the outward stress of the inner housing 10, and P2 refers to the inward stress of the outer housing 9.

[0045] For the inner housing 10, P1 = 0, P2 = Pc, E = E1, μ = μ1. Let r = b = c and organize to get

[0046] u1 = P c ·c[c 2 (μ1 - 1) - a 2 (1 + μ1) / E1(c 2 - a 2 )]

[0047] Similarly, for the outer housing 9, P2 = 0, P1 = P c, E = E2, μ = μ2. Let r = a = c, then

[0048] u2 = P c ·c[c 2 (1 - μ2) + b 2 (1 + μ2) / E2(b 2 - c 2 )]

[0049] Substitute u1 and u2 into

[0050] △ = μ2 - μ1

[0051] We can get

[0052] △ = P c ·c[c 2 (μ1 - 1) - a 2 (1 + μ1) / E1(c 2 - a 2 )] - P c ·c[c 2 (1 - μ2) + b 2 (1 + μ2) / E2(b 2 - c 2 )]

[0053] If the materials of the outer shell 9 and the inner shell 10 are the same, then μ1 = μ2,

[0054] The stress on the contact surface between the inner and outer shells can be obtained as

[0055]

[0056] Or the change in the inner diameter of the inner and outer shells

[0057]

[0058] Therefore, at the point of maximum force on the pressure-bearing outer shell 1 of the electrode plate between the outer shell 9 and the inner shell 10, the assembly stress of the working stress is of opposite signs, so the total stress decreases. Thus, the pressure-bearing outer shell 1 of this combined electrode plate form can withstand a greater pressure compared to a general electrode plate outer shell, effectively improving the pressure resistance and strength of the pressure-bearing outer shell 1 of the electrode plate.

[0059] According to the present invention, the pressure-bearing inner lining 3 of the electrode plate is press-fitted into the interior of the pressure-bearing outer shell 1 of the electrode plate in a thermal assembly manner. When the electrode plate 100 bears pressure underground, the stress generated by the interference fit of the pressure-bearing inner lining 3 offsets a part of the pressure from underground, achieving a further improvement in the pressure resistance ability; when the electrode plate 100 is in a surface environment, the pressure-bearing outer shell 1 also generates an inward stress, offsetting the outward stress from the pressure-bearing inner lining 3, and this stress is much smaller than σ.

[0060] Furthermore, the bottom cover 4 of the electrode plate under pressure is embedded in the outer shell 1 of the electrode plate under pressure and forms a part of the outer wall of the outer shell 1 of the electrode plate under pressure. The bottom cover 4 of the electrode plate under pressure can limit the electrode plate circuit board 5 within the internal cavity and can also play a certain role in limiting the inner lining 3 of the electrode plate under pressure. The bottom cover 4 of the electrode plate under pressure can jointly bear the pressure with the outer shell 1 of the electrode plate under pressure, thereby playing a protective role for the internal components.

[0061] According to the present invention, a pressure-bearing plug (not shown) is connected to the upper end of the outer shell 1 of the electrode plate under pressure, and the pressure-bearing plug has the ability to bear a pressure of more than 180 MPa in both directions. A sealing ring is used for sealing between the pressure-bearing plug and the outer shell 1 of the electrode plate under pressure.

[0062] According to the present invention, the outer shell 1 of the electrode plate under pressure of the high-temperature and high-pressure micro-resistivity imaging logging tool electrode plate 100 adopts an outer shell 9 and an inner shell 10 to form a two-layer electrode plate outer shell structure, which significantly improves the pressure resistance and strength of the outer shell 1 of the electrode plate under pressure. The electrode plate 100 of the micro-resistivity imaging logging tool can withstand a temperature of 200 °C and a pressure of 172 MPa, enabling it to ensure that there is no leakage in the pressure-bearing inner cavity at a temperature of 200 °C and a pressure of more than 172 MPa. At the same time, there is high insulation between the button electrode 8 and the outer shell 1 of the electrode plate under pressure. Thus, the electrode plate 100 can meet the temperature resistance and pressure-bearing requirements of the electrode plate of the micro-resistivity scanning imaging logging tool.

[0063] In the description of the present invention, unless otherwise clearly defined and limited, terms such as "installed", "connected", "connected", "fixed", etc. should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0064] In the description of this specification, the description with reference to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0065] Finally, it should be noted that the above are only the preferred embodiments of the present invention and do not constitute any limitation to the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions recorded in the foregoing embodiments or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, 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 high-temperature and high-pressure micro-resistivity imaging logging tool electrode plate, characterized in that, Comprising: A plate pressure-bearing housing (1), on the outer wall of which there is an electrode mounting position (2); A plate pressure-bearing inner lining (3) arranged inside the plate pressure-bearing housing, the plate pressure-bearing inner lining having an internal cavity; A plate circuit board (5) arranged in the internal cavity; A plate pressure-bearing bottom cover (4) embedded in the plate pressure-bearing housing, the plate pressure-bearing bottom cover being able to confine the plate circuit board in the internal cavity; and A button electrode (8) mounted in the electrode mounting position, an insulating sleeve (7) being provided outside the button electrode; Wherein, the plate pressure-bearing housing is configured to include an outer shell (9) and an inner shell (10) in interference fit with the outer shell, the plate pressure-bearing inner lining is press-fitted into the interior of the plate pressure-bearing housing in a hot assembly manner, so as to offset part of the pressure from the wellbore through the stress generated during interference fitting, so that the main body of the plate can withstand a pressure of more than 180 MPa, and the high-temperature limit of the plate exceeds 200 °C.

2. The plate of the high-temperature and high-pressure micro-resistivity imaging logging tool according to claim 1, wherein The electrode mounting position is configured as a multi-step conical frustum-shaped groove body, the button electrode is configured as a multi-step conical frustum-shaped groove body capable of adapting to the electrode mounting position, and the insulating sleeve is wrapped on the outer surface of the button electrode.

3. The electrode plate of the high-temperature and high-pressure micro-resistivity imaging logging tool according to claim 2, wherein The half apex angle of each step of the button electrode is less than 11.3°.

4. The polar plate of the high-temperature and high-pressure micro-resistivity imaging logging tool according to claim 2 or 3, characterized in that, The insulating sleeve is made of an inorganic silicon water-based resin material, and the insulation resistance of the insulating sleeve is greater than 10 MΩ.

5. The electrode plate of the high-temperature and high-pressure micro-resistivity imaging logging tool according to claim 1 or 2, characterized in that, The plate pressure-bearing bottom cover and the electrode mounting position are radially distributed opposite to each other.

6. The electrode plate of the high-temperature and high-pressure micro-resistivity imaging logging tool according to claim 1, wherein The outer shell and the inner shell are made of the same material, both using an alloy material with a yield strength > 1000 Mpa.

7. The electrode plate of the high-temperature and high-pressure micro-resistivity imaging logging tool according to claim 1, wherein A pressure-bearing plug is connected to the upper end of the plate pressure-bearing housing, and the two-way pressure borne by the pressure-bearing plug is greater than 180 MPa.

8. The plate of the high-temperature and high-pressure micro-resistivity imaging logging tool according to claim 7, characterized in that, The pressure-bearing plug is hermetically connected to the plate pressure-bearing housing.

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