Push-leaning type azimuth lateral front sensor and well logging method

Abstract

According to the pushing type orientation lateral front sensor and the well logging method, the electrode structure and the insulation isolation layer structure are matched with each other, the effect of mutual insulation between electrodes is achieved, meanwhile, a sealed cavity structure for containing a signal processing circuit is formed in the sensor, the overall strength of the sensor is improved, and the reliability of the sensor is improved. And meanwhile, the weight of the sensor is reduced, and miniaturization and integration of the sensor are realized. The problem that a polar plate of a traditional lateral instrument is placed on a logging instrument body, a certain distance exists between the polar plate and the well wall in the measurement process, and consequently underground mud has a large influence on the measurement result is solved; according to the invention, the sensors are connected to the six-arm sidewall contact device of the instrument body through the sidewall contact device connection result, so that the sensors in six directions are tightly attached to the well wall for measurement, the influence of underground mud on the measurement result is reduced, and the data acquisition efficiency is improved.

Description

Technical Field

[0001] This invention belongs to the field of oil well logging instrument technology, specifically relating to a push-type azimuth side-mounted sensor and a well logging method. Background Technology

[0002] Lateral logging offers significant advantages in measuring formations with saline mud and high resistivity. Based on the principle of like charges repelling each other, the current emitted by the shielding electrode forces the current emitted by the sensor to flow radially into the formation in a flattened pattern. This reduces the diversion of drilling mud and the influence of the surrounding rock, improving measurement accuracy. Currently, the sensors of lateral logging instruments are placed on top of the instrument body, forming a ring electrode. In this design, the outer diameter of the sensor is equal to or close to the outer diameter of the instrument. This is because an excessively large electrode outer diameter can cause the instrument to jam during operation. This prevents the sensor from adhering tightly to the wellbore for signal transmission, making the wellbore size and drilling mud highly influential on the measurement results. This is especially true in low-resistivity saline mud environments, where neither hard nor soft focusing can eliminate the influence of drilling mud on the current flow direction.

[0003] On the other hand, since the lateral logging instrument itself has no push-back device, the instrument will rotate slightly downhole during the measurement process, resulting in it only having the ability to stratify in the vertical direction, but lacking the ability to distinguish the resistivity of the formation in the horizontal direction on the same horizontal plane. Therefore, the development of a lateral logging instrument that can transmit signals close to the well wall, thereby completely eliminating the influence of well size and mud on the measurement process, and that can measure the resistivity of the formation in different directions is particularly important for the field of electrical logging, especially for geological exploration wells.

[0004] For example, Chinese patent application number CN201510958755.7 discloses a lateral main electrode probe based on a soft focusing array. This main electrode achieves the function of acquiring multiple resistivity change curves from the formation invasion zone to the undisturbed formation. However, its mechanical structure dimensions are equal to the logging instrument body in outer diameter, resulting in its measurement process being greatly affected by the wellbore size and mud. On the other hand, the mechanical structure of this main electrode probe is a ring-shaped metal electrode, so it cannot measure the resistivity change curves of the formation in different horizontal directions, which limits its use. Furthermore, lateral logging instrument sensors consist of multiple electrodes, and the circuit processing system placed in the internal cavity of the sensor needs to be insulated and sealed. Therefore, the insulation, continuity, and sealing performance between electrodes are the challenges in sensor design and manufacturing.

[0005] In summary, in existing azimuth lateral instrument sensors, the sensor is placed on the instrument body. During the measurement process, there is a certain distance between the electrode plate and the well wall, which often leads to the measurement results being greatly affected by the well diameter and mud. This results in problems such as poor insulation and sealing performance of the lateral sensor and low measurement accuracy. Summary of the Invention

[0006] To address the problems existing in the prior art, this invention provides a push-type azimuth lateral forward sensor and logging method. This invention can completely eliminate the influence of wellbore size and mud on the measurement process of array lateral instruments, and solve the problems of poor insulation and sealing performance and low measurement accuracy of conventional lateral sensors, thereby improving the data acquisition accuracy, efficiency and horizontal resolution of array lateral logging tools.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] A push-type azimuth side-facing sensor, comprising:

[0009] An electrode system comprising a first electrode, a second electrode, a third electrode, and a fourth electrode, wherein the first electrode is used to emit a shielding current; the second electrode is used to emit a detection current of multiple frequencies; the third electrode is a sampling monitoring electrode for the second electrode; and the fourth electrode is used for data sampling and signal transmission.

[0010] An insulating layer is provided to insulate and isolate the first electrode, the second electrode, the third electrode, and the fourth electrode in the electrode system.

[0011] A signal processing circuit, electrically connected to the electrode system and the ground system; the signal processing circuit, by receiving instructions from the ground system, controls the frequency of the detection current and shielding current output by the electrode system, and simultaneously performs real-time detection and processing of the shielding effect of the current and the collected data, and transmits the collected data back to the ground control system; and,

[0012] The pusher connection structure has one end connected to the electrode system and the other end fixed to the logging tool body. During the operation of the sensor, the thrust of the pusher arm in the pusher connection structure enables the sensor to slide and measure close to the well wall.

[0013] Furthermore, the first electrode in the electrode system is a ring-shaped shielding electrode, which serves as a support structure, and the second, third, and fourth electrodes are all fixed on the first electrode.

[0014] Furthermore, the electrode system also includes an electric clip, to which the second electrode is connected. The electric clip is used to guide the probe current from the circuit board placed inside the electrode plate cavity to the second electrode, and then radially into the formation through the pressure of the shielding current at various frequencies, while preventing the probe current and the shielding current from flowing along the well axis.

[0015] Furthermore, the insulating isolation layer includes an isolation layer, a ceramic insulating sleeve, a radial sealing ring, an end face sealing ring, a sealing cover plate, and fastening screws;

[0016] The isolation layer is fitted with the first electrode, and the isolation layer is used to seal and isolate the second and third electrodes; the ceramic insulating sleeve is used to seal and isolate the fourth electrode; the sealing cover plate is used to cooperate with the first electrode through the end face sealing ring and fastening screw to form a sealed cavity, and the sealed cavity is used to place the signal processing circuit; the radial sealing ring is used to seal the sealing plug in the signal processing circuit.

[0017] Furthermore, the insulating layer is a fluororubber insulating layer.

[0018] Furthermore, the isolation layer and the first electrode are injection molded together.

[0019] Furthermore, the signal processing circuit includes a signal processing board, a signal transmission line, and a sealed plug. The signal processing board is connected to the electrode system and the ground system through the signal transmission line and the sealed plug. The signal transmission line amplifies, calculates, and processes the formation resistivity signal measured by the electrode system, and transmits the measured data back to the ground system through the signal transmission line and the sealed plug.

[0020] Furthermore, the pusher connection structure includes a double connecting sleeve, a retaining key, a retaining ring, a locking screw, and a triple conversion sleeve;

[0021] The double connecting sleeve is used to connect the main push arm and the auxiliary push arm on the six-arm pusher of the logging tool body;

[0022] The electrode system has a boss at its end, and the three-section conversion sleeve is connected to the end boss of the electrode system by a locking screw; the three-section conversion sleeve is connected to the sensor.

[0023] Furthermore, the second electrode emits detection currents at six different frequencies.

[0024] A logging method using a push-type azimuth side-mounted sensor includes the following process: When the logging instrument is working, the thrust of the pusher makes the sensor stick to the well wall. Under the drag of the cable or drill pipe, the sensor slides along the instrument body, sticking to the well wall. The signals emitted and collected by the electrodes on the electrode system are detected and processed by the signal processing circuit to complete the measurement of formation resistivity.

[0025] Furthermore, the formula for calculating the formation resistivity is as follows:

[0026]

[0027] In the formula: R ALi U M0(ALi) I 0(ALi)The apparent resistivity (Ω), main potential (V), and main current (A) measured at a main current frequency of i are respectively; K ALi This is the electrode system coefficient.

[0028] Compared with the prior art, the present invention has the following beneficial technical effects:

[0029] This invention provides a push-type azimuth lateral forward-facing sensor. Through the cooperation of the electrode structure and the insulating isolation layer structure, mutual insulation between the electrodes is achieved. Simultaneously, a sealed cavity structure is formed inside the sensor to house the signal processing circuit, improving the overall strength of the sensor while reducing its weight, thus achieving miniaturization and integration. This invention avoids the problem of traditional lateral instruments where the electrode plates are placed on the logging instrument body, resulting in a certain distance between the electrode plates and the well wall during measurement, leading to significant influence of downhole mud on the measurement results. This invention connects the sensor to the six-arm pusher of the instrument body via a pusher connection, enabling close-fitting measurement of the sensor in six directions against the well wall, thereby reducing the influence of downhole mud on the measurement results and improving data acquisition efficiency.

[0030] Furthermore, through structural optimization design, this invention incorporates stainless steel, rubber, ceramics and other materials into the sensor structure. While ensuring the requirements of insulation and sealing performance, it improves the strength of the sensor itself, enabling it to work stably for a long time in an environment of 155℃ and 100MPa.

[0031] Furthermore, the signal processing circuit inside the sensor in this invention can amplify, calculate, and process the formation electrical signal measured by the electrodes during the measurement process, avoiding signal interference and distortion caused by long-distance transmission, providing a measured resistivity that is closer to the true resistivity of the formation, and ensuring the accuracy of the measurement results.

[0032] This invention provides a logging method using a push-type azimuth lateral forward sensor. The sensor is connected and fixed to the six push arms of the logging instrument through a pusher connection structure, so that the sensor can work closely against the well wall during the logging process. At the same time, the signal processing circuit inside the sensor can detect and process the data measured by the electrode in real time, which greatly improves the accuracy of the azimuth lateral measurement data and the stability of the instrument operation. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the overall structure of a push-type azimuth side-facing sensor according to an embodiment of the present invention;

[0034] Figure 2 This is a schematic diagram of the overall component structure of a push-type azimuth side-facing sensor according to an embodiment of the present invention;

[0035] Figure 3 This is a schematic diagram illustrating the overall working principle of a push-type azimuth side-facing sensor according to an embodiment of the present invention.

[0036] In the attached diagram: 1 is the electrode system; 2 is the insulating isolation layer; 3 is the signal processing circuit; 4 is the pusher connection structure; 100 is the well wall; 101 is the first electrode; 102 is the second electrode; 103 is the third electrode; 104 is the electric buckle; 105 is the fourth electrode; 200 is the sensor; 201 is the isolation layer; 202 is the ceramic insulating sleeve; 203 is the radial sealing ring; 204 is the end face sealing ring; 205 is the sealing cover plate; 206 is the fastening screw; 301 is the signal processing board; 302 is the signal transmission line; 303 is the sealing plug; 401 is the double connecting sleeve; 402 is the locking key; 403 is the locking ring; 404 is the locking screw; 405 is the triple conversion sleeve. Detailed Implementation

[0037] In the following description, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit or scope of the invention. Therefore, the drawings and description are considered to be exemplary in nature and not restrictive.

[0038] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0039] 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 indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0040] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a communication connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0041] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0042] It should be understood that, when used in this specification and the appended claims, the terms "comprising" and "including" indicate the presence of the described features, integrals, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections thereof.

[0043] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0044] It should also be further understood that the term "and / or" as used in this specification and the appended claims refers to any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0045] The accompanying drawings illustrate various structural schematic diagrams according to embodiments disclosed in this invention. These drawings are not to scale, and some details have been enlarged for clarity, and some details may have been omitted. The shapes of the various regions and layers shown in the drawings, as well as their relative sizes and positional relationships, are merely exemplary and may deviate from reality due to manufacturing tolerances or technical limitations. Furthermore, those skilled in the art can design regions / layers with different shapes, sizes, and relative positions as needed.

[0046] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0047] Figure 1 An example of a push-type azimuth side-facing sensor according to an embodiment of this disclosure is shown, such as... Figure 1 As shown, it includes: an electrode system 1, an insulating layer 2, a signal processing circuit 3, and a pusher connection structure 4. The electrode system 1 is the main supporting structure of this application. The insulating layer 2 ensures the insulation performance between the various electrodes in the electrode system 1. The signal processing circuit 3 transmits and receives signals, processes and transmits collected data, and the pusher connection structure 4 connects the sensor body to the pusher arm of the logging instrument, enabling close-fitting wellbore measurements of signals from different azimuth positions.

[0048] like Figure 2 As shown, electrode system 1 includes a first electrode 101, a second electrode 102, a third electrode 103, and a fourth electrode 105. The first electrode 101 is used to emit shielding current; the second electrode 102 is used to emit detection current of multiple frequencies; the third electrode 103 is a sampling monitoring electrode of the second electrode 102; and the fourth electrode 105 is used for data sampling and signal transmission.

[0049] Preferably, in this embodiment of the present disclosure, the first electrode 101 in the electrode system 1 is an annular shielding electrode, which serves as a support structure, and the second electrode 102, the third electrode 103 and the fourth electrode 105 are all fixed on the first electrode 101.

[0050] Furthermore, the electrode system 1 also includes an electrical clip 104, to which the second electrode 102 is connected. The electrical clip 104 is used to guide the probe current from the circuit board placed inside the electrode plate cavity to the second electrode 102, and then radially into the formation through the pressure of the shielding current at various frequencies, while preventing the probe current and the shielding current from flowing along the well axis. It should be noted that the electrical clip 104 is also connected to the internal circuitry to provide power to the corresponding components of the sensor.

[0051] Furthermore, the second electrode 102 emits detection currents at six different frequencies. Specifically, the selection of the emitted current frequency typically depends on the specific detection target, the detection environment, and the required detection depth and resolution. Different applications may require different frequency combinations to achieve optimal detection results. In electromagnetic detection, low-frequency currents are generally used to detect deeper underground structures or media because low-frequency signals attenuate less in the strata and can propagate over longer distances. High-frequency currents are suitable for detecting shallower strata or applications requiring high resolution.

[0052] The insulating layer 2 is used to insulate and isolate the first electrode 101, the second electrode 102, the third electrode 103 and the fourth electrode 105 in the electrode system 1.

[0053] Specifically, in some embodiments, the insulating isolation layer 2 includes an isolation layer 201, a ceramic insulating sleeve 202, a radial sealing ring 203, an end face sealing ring 204, a sealing cover plate 205, and a fastening screw 206.

[0054] The isolation layer 201 is fitted with the first electrode 101, and the isolation layer 201 is used to seal and isolate the second electrode 102 and the third electrode 103; the ceramic insulating sleeve 202 is used to seal and isolate the fourth electrode 105; the sealing cover plate 205 cooperates with the first electrode 101 through the end face sealing ring 204 and the fastening screw 206 to form a sealed cavity, and the sealed cavity is used to house the signal processing circuit 3; the radial sealing ring 203 is used to seal the sealing plug 303 in the signal processing circuit 3.

[0055] Furthermore, in some embodiments, the isolation layer 201 is a fluororubber insulating layer, and the isolation layer 201 and the first electrode 101 are formed into a tightly connected structure by high-temperature injection molding through a mold. The surface of the first electrode 101 is provided with grooves, which can improve the reliability of the connection.

[0056] The signal processing circuit 3 is electrically connected to the electrode system 1 and the ground system. The signal processing circuit 3 receives instructions from the ground system, controls the frequency of the detection current and shielding current output by the electrode system 1, and performs real-time detection and processing of the shielding effect of the current and the collected data, and transmits the collected data back to the ground control system.

[0057] In some embodiments, the signal processing circuit 3 includes a signal processing board 301, a signal transmission line 302, and a sealed plug 303. The signal processing board 301 is connected to the electrode system 1 and the ground system through the signal transmission line 302 and the sealed plug 303. The signal transmission line 302 amplifies, calculates, and processes the formation resistivity signal measured by the electrode system 1, and transmits the measured data back to the ground system through the signal transmission line 302 and the sealed plug 303.

[0058] It should be noted that the main body of the sealing plug 3 is made of a material that can withstand high temperature and high pressure. It uses a sealing ring, such as an axial seal, to form a sealing structure with the first electrode 101. One end is connected to the circuit board 301 through the signal transmission line 302, and the other end is connected to the signal line of the instrument body, thus playing the role of data transmission.

[0059] One end of the pusher connection structure 4 is connected to the electrode system 1, and the other end of the pusher connection structure 4 is fixed to the logging instrument body. During the operation of the sensor, the thrust of the pusher arm in the pusher connection structure 4 enables the sensor to slide and measure close to the well wall.

[0060] Preferably, in some embodiments, the pusher connection structure 4 includes a double connecting sleeve 401, a locking key 402, a retaining ring 403, a locking screw 404, and a triple conversion sleeve 405;

[0061] The double connecting sleeve 401 is used to connect the main push arm and the auxiliary push arm on the six-arm push arm of the logging tool body.

[0062] The electrode system 1 has a boss at its end, and the three-way conversion sleeve 405 is connected to the boss at the end of the electrode system 1 by a locking screw 404; the three-way conversion sleeve 405 is connected to the sensor.

[0063] Specifically, the double connecting sleeve 401 and the triple conversion sleeve 405 are used to connect the sensor to the main push arm and the auxiliary push arm on the six-arm pusher of the logging instrument body, and are fixed by the key 402, the retaining ring 403 and the locking screw 404, forming six sensors evenly distributed in 360° on the logging instrument body. During the operation of the instrument, under the action of the pusher, the six sensors are close to the well wall to collect data, reducing the influence of the mud in the well on the measurement results, realizing the measurement of formation resistivity in six directions, and improving the accuracy and efficiency of data acquisition.

[0064] This disclosure also provides a well logging method using a push-type azimuth side-mounted sensor, such as... Figure 3 As shown, the process includes the following:

[0065] When the logging instrument is working, the thrust of the pusher makes the sensor 200 stick tightly to the well wall 100. Under the drag of the cable or drill pipe, the sensor slides along the instrument body, sticking tightly to the well wall. The signals emitted and collected by the electrodes on the electrode system 1 are detected and processed by the signal processing circuit 3 to complete the measurement of formation resistivity.

[0066] Preferably, the formula for calculating the formation resistivity is:

[0067]

[0068] In the formula: R ALi U M0(ALi) I 0(ALi) The apparent resistivity (Ω), main potential (V), and main current (A) measured at a main current frequency of i are respectively; K ALi This is the electrode system coefficient.

[0069] Specifically, the second electrode 102 is A0, the first electrode 101 is an annular shielded electrode A1 (A1'), and together with the five pairs of shielded electrodes A2 to A6 (A2' to A6') and the six pairs of monitoring electrodes M1 to M6 (M1' to M6') on the instrument body, a total of 25 electrodes are formed.

[0070] During instrument operation, measurements at different depths can be achieved by changing the positions of the shielding electrode and the loop electrode. The second electrode 102, acting as the main electrode A0, can emit detection currents at six different frequencies. During logging, the potentials of A1, A1', A2, A2', A3, A3', A4, A4', A5, A5', A6, and A6' are equal. Therefore, the apparent resistivity of the formation is:

[0071]

[0072] In the formula: R ALi U M0(ALi) I 0(ALi) These represent the apparent resistivity (Ω), main potential (V), and main current (A) measured at a main current frequency of i (i can take 1, 2, 3, 4, 5, for a total of 5 frequencies); K ALi The electrode system coefficient is obtained by experimental measurement or calculation using the finite element method.

[0073] It should be noted that the apparent resistivity of the formation is a parameter used to reflect changes in the electrical conductivity of rocks and ores, especially when the electrical properties of underground rocks are unevenly distributed or the surface is undulating. It is not the true resistivity of a particular type of rock, but rather the result of the combined influence of various factors, such as the true resistivity of each geological stratum, the actual distribution of different electrical bodies underground, and the arrangement of electrodes.

[0074] The resistivity of the formation refers to the degree to which underground rocks or soil impede the passage of electric current. It is an important parameter describing the electrical conductivity of underground formations. The value of the resistivity of the formation is affected by factors such as the composition, water content, and temperature of the underground rocks or soil.

[0075] In homogeneous media, apparent resistivity and formation resistivity may be equal or similar because they both reflect the conductivity of the medium. However, in heterogeneous media, due to the varying resistivity of different rocks or ores and their complex and variable distribution underground, there is often a significant difference between apparent resistivity and formation resistivity. In this case, apparent resistivity reflects more the overall distribution of underground resistivity, while formation resistivity focuses more on describing the resistivity characteristics of a specific stratum.

[0076] Therefore, in some embodiments, when the apparent resistivity of the formation and the formation resistivity are equal or similar, they can be directly used interchangeably. In other embodiments, when the apparent resistivity of the formation and the formation resistivity differ significantly, those skilled in the art can convert the two by comprehensively considering various geological factors, measurement conditions, and data processing methods.

[0077] The transformation process requires clarifying the reasons for the difference between apparent resistivity and actual resistivity. Based on these reasons, data correction and inversion are performed, after which a transformation model can be established. This model should reflect the complex relationship between the two and take into account the influence of various geological factors. The model can be established based on a large amount of measured data and geological information, using methods such as statistical analysis and machine learning.

[0078] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the scope of the invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0079] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can be appropriately combined to form other embodiments that can be understood by those skilled in the art. The above content is only for illustrating the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made based on the technical concept proposed in this invention shall fall within the scope of protection of the claims of this invention.

Claims

1. A push-to-azimuth side-looking forward-looking sensor characterized by, The utility model relates to a kind of well logging sensor, including: Electrode system (1), the electrode system (1) includes first electrode (101), second electrode (102), third electrode (103) and fourth electrode (105), the first electrode (101) is used to emit shield current;The second electrode (102) is used to emit the detection current of multiple frequencies;The third electrode (103) is the sampling supervision electrode of second electrode (102);The fourth electrode (105) is used for data sampling and signal transmission; Insulating isolation layer (2), the insulating isolation layer (2) is used to insulate and isolate first electrode (101), second electrode (102), third electrode (103) and fourth electrode (105) in electrode system (1); Signal processing circuit (3), the signal processing circuit (3) is electrically connected electrode system (1) and ground system;The signal processing circuit (3) controls the frequency of detection current and shield current output by electrode system (1) by receiving the instruction of ground system, while real-time detects and processes the shield effect of current and collected data, and returns the data collected to ground control system; And, Pusher connecting structure (4), one end of the pusher connecting structure (4) is connected with electrode system (1), and the other end of the pusher connecting structure (4) is fixed on the body of logging instrument, and in the working process of sensor, the pushing force of pushing arm in the pusher connecting structure (4) enables the sensor to slide along the well wall closely.

2. A pusher type azimuthally-lateral forward-looking sensor according to claim 1, wherein, The first electrode (101) in the electrode system (1) is a ring-shaped shield electrode, which serves as a support structure, and the second electrode (102), the third electrode (103) and the fourth electrode (105) are fixed on the first electrode (101).

3. A pusher type azimuthally-lateral forward-looking sensor according to claim 1, wherein The electrode system (1) further includes an electric buckle (104), the second electrode (102) is connected with the electric buckle (104), and the electric buckle (104) is used to guide the detection current to flow from the circuit board placed in the inner cavity of the electrode plate to the second electrode (102), and then flow radially into the formation under the pressure of various frequencies of shield current, so that the detection current and the shield current cannot flow along the well axis direction.

4. A pusher type azimuthally-lateral forward looking sensor according to claim 1, wherein, The insulating isolation layer (2) includes an isolation layer (201), a ceramic insulating sleeve (202), a radial sealing ring (203), an end face sealing ring (204), a sealing cover plate (205) and a fastening screw (206). The isolation layer (201) is embedded with the first electrode (101), and is used to seal and isolate the second electrode (102) and the third electrode (103); the ceramic insulating sleeve (202) is used to seal and isolate the fourth electrode (105); the sealing cover plate (205) cooperates with the first electrode (101) to form a sealed cavity through the end face sealing ring (204) and the fastening screw (206), and the sealed cavity is used to place the signal processing circuit (3); the radial sealing ring (203) is used to seal the sealed plug (303) in the signal processing circuit (3).

5. A push-impingement azimuthally-lateral forward-looking sensor according to claim 4, wherein, The isolation layer (201) is a fluorine rubber insulation layer.

6. A push-impinged azimuthally-lateral forward-looking sensor according to claim 4, wherein, The isolation layer (201) and the first electrode (101) are injection-molded.

7. A push-impingement azimuthally-lateral forward-looking sensor according to claim 1, wherein, The signal processing circuit (3) comprises a signal processing board (301), a signal transmission line (302) and a sealing plug (303), the signal processing board (301) is connected with the electrode system (1) and the ground system through the signal transmission line (302) and the sealing plug (303); the signal transmission line (302) amplifies, calculates and processes the formation resistivity signal measured by the electrode system (1), and transmits the measured data back to the ground system through the signal transmission line (302) and the sealing plug (303).

8. A push-impingement azimuthally-lateral forward-looking sensor according to claim 1, wherein, The pusher connecting structure (4) comprises a double connecting sleeve (401), a clamping key (402), a clamping ring (403), a locking screw (404) and a three-connection conversion sleeve (405); The double connecting sleeve (401) is used for connecting the main push arm and the auxiliary push arm on the six-arm pusher of the logging instrument body; The end of the electrode system (1) is provided with a boss, the three-connection conversion sleeve (405) is connected with the end boss of the electrode system (1) through the locking screw 404; and the three-connection conversion sleeve (405) is connected with the sensor.

9. A push-impingement azimuthally-lateral forward-looking sensor according to claim 1, wherein, The second electrode (102) emits six frequencies of detection current.

10. A method of logging a push-against azimuth lateral look-ahead sensor, characterized by, The logging instrument comprises the following process: when the logging instrument works, the push force of the pusher makes the sensor (200) tightly adhere to the well wall (100), under the dragging action of the cable or the drill pipe, the sensor slides along with the instrument body tightly adhering to the well wall, the signal emitted and collected by the electrode on the electrode system (1) is detected and processed by the signal processing circuit (3), and the measurement of the formation resistivity is completed.

11. The method of claim 10, wherein the push-against azimuthal lateral look-ahead sensor is a push-against azimuthal lateral look-ahead sensor. The calculation formula of the formation resistivity is: where: R ALi , U M0(ALi) , I 0(ALi) are the apparent resistivity / Ω, the main potential / V and the main current / A measured at the main current frequency i, respectively; K ALi is the electrode system coefficient.

Images