CN117823146A - Logging instrument for resistivity of stratum through casing and measuring method for resistivity of stratum through casing - Google Patents

Abstract

The invention provides a logging instrument for resistivity of a through-casing stratum and a measuring method for resistivity of the through-casing stratum, wherein the logging instrument for resistivity of the through-casing stratum comprises the following components: at least one transmitting electrode module transmitting alternating current to the metal sleeve; the alternating current is transmitted between the transmitting electrode module and the metal sleeve and between the receiving electrode module and the metal sleeve in a displacement current mode; the adjacent receiving electrode modules are connected through the insulating connecting piece, and the adjacent transmitting electrode modules are connected through the insulating connecting piece; and the electronic circuit module is electrically connected with the transmitting electrode module and the receiving electrode module. The method solves the problem of large measurement error of the resistivity measurement method of the through-casing stratum in the prior art.

Description

Logging instrument for resistivity of stratum through casing and measuring method for resistivity of stratum through casing

Technical Field

The invention relates to the technical field of petroleum exploration and development, in particular to a logging instrument for resistivity of a through-casing stratum and a measuring method for resistivity of the through-casing stratum.

Background

After the oil field development of the old oil area enters the middle and later stages, the water flooding oil extraction for a long time can cause serious flooding of a main oil layer, and the oil-water relationship is complex. Tracking the change of the saturation, knowing and mastering the macroscopic and microscopic spatial distribution of the saturation of the residual oil, evaluating and monitoring the distribution of the residual oil, determining the recoverable reserves of the stratum residual oil, improving the recovery ratio, monitoring the positions of fluid interfaces in production and water injection wells, adjusting the development scheme, prolonging the exploitation life of the oil field, and providing important basis for the operation and management decision of the oil reservoir, which is an urgent problem facing the old oil field at present. Sometimes, in the open hole logging process, the measurement of the resistivity of the open hole stratum is not completed due to the expansion or collapse, and the evaluation of the oil content of a reservoir is very unfavorable. In addition, the old oil field limited by the prior art has some oil layers with negligence, omission judgment and misjudgment, and oil layers with oil gas secondary migration and re-saturation after years of exploitation, and the oil field is also an important problem faced by oil reservoir development.

There are currently two ways of measuring the resistivity of a casing. The first is a commercialized direct current contact type fixed-point casing resistivity logging mode, which has the advantages of low measurement speed, extremely severe requirements on the well bore environment, and requirements that all electrodes are completely closely attached to a casing wall without greasy dirt and rust to give satisfactory results, and as long as one electrode does not meet the conditions, the measurement result is inaccurate, and the acquired data correlation and the data reliability are low. However, in an oil well which is mined for many years, the deformation of a sleeve and the rust on the inner wall are unavoidable, and oil stains on the well wall cannot be completely washed away by well washing. Therefore, the measuring condition of the instrument is too harsh, so that the popularization and application of the instrument are not good. Meanwhile, due to the limitation of a measurement mode, the contact type casing resistivity logging is difficult to form a complete post-casing reservoir evaluation logging series with other post-casing logging. The second is a transient electromagnetic measurement mode, in view of shielding of the metal sleeve, only a very small part of electromagnetic waves emitted by the antenna penetrate through the sleeve to enter the stratum, then a secondary field is induced in the stratum, and for the same reason, only a very small part of the secondary field penetrates through the metal sleeve to enter the well to reach the receiving antenna, but the part of signals are very tiny and difficult to measure, and great difficulty is caused to research and development of instruments.

That is, the method for measuring the resistivity of the stratum through the casing in the prior art has the problem of large measurement error.

Disclosure of Invention

The invention mainly aims to provide a casing-passing stratum resistivity logging instrument and a casing-passing stratum resistivity measuring method, so as to solve the problem that in the prior art, the casing-passing stratum resistivity measuring method is large in measuring error.

To achieve the above object, according to one aspect of the present invention, there is provided a through-casing formation resistivity logging instrument, the through-casing formation resistivity logging instrument being placed in a metal casing, the through-casing formation resistivity logging instrument comprising: at least one transmitting electrode module for transmitting alternating current to the metal sleeve; the alternating current is transmitted between the transmitting electrode module and the metal sleeve and between the receiving electrode module and the metal sleeve in a displacement current mode; the adjacent two receiving electrode modules are connected through the insulating connecting piece, and the adjacent transmitting electrode modules are connected with the receiving electrode modules through the insulating connecting piece; and the electronic circuit module is electrically connected with the transmitting electrode module and the receiving electrode module.

Further, the transmitting electrode module and the receiving electrode module are embedded into the insulating connector.

Further, the insulating connecting piece is one, and the transmitting electrode module and the receiving electrode module are of cylindrical structures and are sleeved on the insulating connecting piece.

Further, the number of the insulating connecting pieces is multiple, and two adjacent insulating connecting pieces are connected through the transmitting electrode module or the receiving electrode module.

Further, the alternating frequency of the alternating current emitted by the emitting electrode module is more than or equal to 10kHz and less than or equal to 500kHz.

Further, the number of the transmitting electrode modules is plural, and the frequencies of the alternating currents transmitted by the different transmitting electrode modules are different.

Further, the emitter electrode module includes: an emitter electrode; and the transmitting circuit module is electrically connected with the transmitting electrode, and is used for generating alternating current and transmitting the alternating current.

Further, the receiving electrode module includes: a receiving electrode for receiving the alternating current transmitted to the metal sleeve; the acquisition circuit module is electrically connected with the receiving electrode and is used for acquiring voltage or current signals on the receiving electrode.

Further, the electronic circuit module includes: the main control module is electrically connected with the transmitting electrode module and controls the transmitting electrode module to transmit alternating current; the data processing and transmitting module is electrically connected with the receiving electrode module and is used for receiving the voltage signals or the current signals acquired on the receiving electrode module and calculating formation electrical parameters through the phase information or the amplitude information of the voltage signals or the current signals, so that the formation information outside the metal sleeve is measured.

According to another aspect of the present invention, there is provided a method for measuring resistivity of a formation through casing, the method for measuring resistivity of a formation through casing using the logging instrument for measuring resistivity of a formation through casing, the method comprising: the electronic circuit module controls the transmitting electrode module to transmit alternating current; the receiving electrode module receives voltage signals or current signals of the metal sleeve and the stratum at the corresponding depth; the electronic circuit module processes the voltage signal or the current signal received by the receiving electrode module and obtains the phase information or the amplitude information of the voltage signal or the current signal of the receiving electrode module; and calculating the formation electrical parameters according to the phase information or the amplitude information received by the different receiving electrode modules.

By applying the technical scheme of the invention, the logging instrument for the formation resistivity through the casing is placed in the metal casing, and the logging instrument for the formation resistivity through the casing comprises at least one transmitting electrode module, a plurality of receiving electrode modules, an insulating connecting piece and an electronic circuit module, wherein the transmitting electrode module is used for transmitting alternating current to the metal casing; the alternating current is transmitted between the transmitting electrode module and the metal sleeve and between the receiving electrode module and the metal sleeve in a displacement current mode; adjacent two receiving electrode modules are connected through an insulating connecting piece, and adjacent transmitting electrode modules are connected with the receiving electrode modules through the insulating connecting piece; the electronic circuit module is electrically connected with the transmitting electrode module and the receiving electrode module.

Through utilizing the transmission electrode module to transmit alternating current for alternating current can be transmitted to metal casing and stratum from the logging instrument of casing formation resistivity, through setting up a plurality of receiving electrode modules, make alternating current can be returned from stratum and metal casing to the logging instrument of casing formation resistivity, and a plurality of receiving electrode modules can increase the vertical measuring range of formation resistivity simultaneously. The transmitting electrode module and the receiving electrode module are connected together by the insulating connecting piece, so that mechanical support can be provided for the transmitting electrode module and the receiving electrode module, and meanwhile, direct transmission of current signals between the transmitting electrode module and the receiving electrode module is avoided. The electronic circuit module is electrically connected with the transmitting electrode module and the receiving electrode module, so that the electronic circuit module can control the transmission of alternating current, and in addition, the phase information or the amplitude information of the voltage signal or the current signal received by the receiving electrode module can be transmitted to the electronic circuit module for calculation and converted into stratum electrical parameters, thereby realizing the measurement of stratum information outside the metal sleeve.

When non-conductive fluid exists among the transmitting electrode module, the receiving electrode module and the metal sleeve or an antirust coating exists inside the metal sleeve, an insulating layer is formed between the stratum resistivity logging instrument passing through the sleeve and the metal sleeve, so that the direct current path is blocked. The alternating current with a certain frequency is emitted by the logging instrument with the resistivity of the stratum passing through the casing, and based on the capacitive coupling principle, the alternating current can be transmitted between the front and rear two-stage circuits in a capacitive coupling mode, so that the alternating current can be transmitted between the transmitting electrode module of the logging instrument with the resistivity of the stratum passing through the casing and the metal casing, namely, the alternating current is transmitted between the transmitting electrode module and the metal casing in the form of displacement current, and returns to the receiving electrode module through the metal casing and the stratum, and is transmitted between the receiving electrode module and the metal casing in the form of displacement current. And the electronic circuit module is used for measuring and receiving the voltage or current phase information or amplitude information on the electrode module, converting the voltage or current phase information or amplitude information into the stratum resistivity outside the metal sleeve, and measuring the stratum information outside the metal sleeve.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the invention. In the drawings:

FIG. 1 shows a schematic representation of displacement currents between a cased formation resistivity logging instrument and a metal casing in accordance with an alternative embodiment of the present invention;

FIG. 2 shows a schematic diagram of displacement current between the emitter electrode module and the metal sleeve of FIG. 1;

FIG. 3 shows a schematic diagram of a through-casing formation resistivity logging instrument and operational mode according to a first embodiment of the invention;

FIG. 4 shows a schematic diagram of a through-casing formation resistivity logging instrument and operational mode according to a second embodiment of the invention;

FIG. 5 shows a schematic diagram of a through-casing formation resistivity logging instrument and operational mode according to a third embodiment of the invention;

FIG. 6 shows a flow chart of a method of measuring resistivity of a cased formation in accordance with any alternative embodiment of the invention.

Wherein the above figures include the following reference numerals:

10. a metal sleeve; 20. a transmitting electrode module; 30. a receiving electrode module; 40. an insulating connector; 50. a non-conductive fluid.

Detailed Description

It should be noted that, in the case of no conflict, the embodiments and features in the embodiments may be combined with each other. The invention will be described in detail below with reference to the drawings in connection with embodiments.

It is noted that all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs unless otherwise indicated.

In the present invention, unless otherwise indicated, terms of orientation such as "upper, lower, top, bottom" are used generally with respect to the orientation shown in the drawings or with respect to the component itself in the vertical, upright or gravitational direction; also, for ease of understanding and description, "inner and outer" refers to inner and outer relative to the profile of each component itself, but the above-mentioned orientation terms are not intended to limit the present invention.

The invention provides a logging instrument for measuring the resistivity of a through-casing stratum and a measuring method for the resistivity of the through-casing stratum, which aim to solve the problem that the measuring error of the measuring method for the resistivity of the through-casing stratum in the prior art is large.

As shown in fig. 1 to 6, a through-casing formation resistivity logging instrument is placed inside a metal casing 10, the through-casing formation resistivity logging instrument including at least one transmitting electrode module 20, a plurality of receiving electrode modules 30, an insulating connector 40, and an electronic circuit module, the transmitting electrode module 20 for transmitting alternating current to the metal casing 10; the plurality of receiving electrode modules 30 are arranged at intervals, the transmitting electrode modules 20 and the receiving electrode modules 30 are arranged at intervals, alternating current returns to the receiving electrode modules 30 through the metal sleeve 10 and stratum, and the alternating current is transmitted between the transmitting electrode modules 20 and the metal sleeve 10 and between the receiving electrode modules 30 and the metal sleeve 10 in the form of displacement current; adjacent two receiving electrode modules 30 are connected through an insulating connecting piece 40, and adjacent transmitting electrode modules 20 are connected with the receiving electrode modules 30 through the insulating connecting piece 40; the electronics module is electrically connected to the transmit electrode module 20 and the receive electrode module 30.

By transmitting alternating current using the transmitting electrode module 20 such that alternating current can be transmitted from the through-casing formation resistivity logging tool to the metal casing 10 and the formation, by providing a plurality of receiving electrode modules 30 such that alternating current can be returned from the formation and the metal casing 10 to the through-casing formation resistivity logging tool, while the plurality of receiving electrode modules 30 can increase the longitudinal measurement range of formation resistivity. Connecting the emitter electrode module 20 and the receiver electrode module 30 together with the insulating connection 40 can provide mechanical support for the emitter electrode module 20 and the receiver electrode module 30 while avoiding direct transmission of current signals between the emitter electrode module 20 and the receiver electrode module 30. The electronic circuit module is electrically connected with the transmitting electrode module 20 and the receiving electrode module 30, so that the electronic circuit module can control the transmission of alternating current, and in addition, the phase information or the amplitude information of the voltage signal or the current signal received by the receiving electrode module 30 can be transmitted to the electronic circuit module for calculation and converted into formation electrical parameters, thereby realizing the measurement of formation information outside the metal sleeve 10.

As shown in fig. 1 and 2, when a non-conductive fluid exists between the transmitting electrode module 20, the receiving electrode module 30 and the metal casing 10 or an anti-rust coating exists inside the metal casing 10, an insulating layer is formed between the casing-passing formation resistivity logging instrument and the metal casing 10, and the passage of direct current is blocked. The logging instrument for resistivity of stratum through casing is utilized to emit alternating current with a certain frequency, based on the principle of capacitive coupling, the alternating current can be transmitted between a front circuit and a rear circuit in a capacitive coupling mode, so that the alternating current can be transmitted between the transmitting electrode module 20 of the logging instrument for resistivity of stratum through casing and the metal casing 10, namely, the alternating current is transmitted between the transmitting electrode module 20 and the metal casing 10 in the form of displacement current, and is returned to the receiving electrode module 30 through the metal casing 10 and stratum, and is transmitted between the receiving electrode module 30 and the metal casing 10 in the form of displacement current. The voltage or current phase information or amplitude information on the electrode module 30 is measured and received by the electronic circuit module and is converted into the formation resistivity outside the metal sleeve 10, so that the formation information outside the metal sleeve 10 is measured.

In fig. 1, the vertical axis represents the length of the instrument, and a 0 is the coordinate starting point, a positive value represents the length extending in the first direction, and a negative value represents the length extending in the direction opposite to the first direction.

It should be noted that, the plurality of receiving electrode modules 30 are located in different strata, so that the voltage or current information at the different receiving electrode modules 30 is different, and the electronic circuit module converts the voltage or the amplitude attenuation of the voltage according to the phase difference value of the voltage at the two different receiving electrode modules 30 into the stratum resistivity outside the metal casing 10, that is, the stratum resistivity outside the metal casing 10 between the two receiving electrode modules 30. Of course, the phase difference value of the current or the amplitude decay of the current may also be used to convert to formation resistivity outside of the metal casing 10.

Example 1

As shown in fig. 3, the insulating connecting member 40 is one, the transmitting electrode module 20 and the receiving electrode module 30 are in a cylindrical structure, and the transmitting electrode module 20 and the receiving electrode module 30 are sleeved on the insulating connecting member 40.

Specifically, the alternating current frequency of the alternating current emitted from the emitter electrode module 20 is 10kHz or more and 500kHz or less.

Specifically, the transmitting electrode module 20 includes a transmitting electrode electrically connected to the transmitting circuit module, and a transmitting circuit module for generating alternating current, the transmitting electrode for transmitting the alternating current. Alternating current is generated through the transmitting circuit module, and the transmitting electrode transmits the alternating current out of the transmitting electrode module, so that the transmitting effect of the alternating current can be ensured.

The transmitting electrode and the transmitting circuit module are connected by a wire.

Specifically, the receiving electrode module 30 includes a receiving electrode for receiving the alternating current transmitted to the metal sleeve 10 and a collecting circuit module; the receiving electrode is electrically connected with the acquisition circuit module, and the acquisition circuit module is used for acquiring voltage or current signals on the receiving electrode. The receiving electrode is used for receiving alternating current, the acquisition circuit module is used for acquiring voltage or current signals, the signal receiving effect can be ensured, and useful voltage or current signals are acquired.

The receiving electrode is connected with the acquisition circuit module through a wire.

Specifically, the electronic circuit module comprises a main control module and a data processing and transmitting module, wherein the main control module is electrically connected with the transmitting electrode module 20 and controls the transmitting electrode module 20 to transmit alternating current; the data processing and transmitting module is electrically connected with the receiving electrode module 30, and is used for receiving the voltage signal or the current signal collected on the receiving electrode module 30, and calculating the formation electrical parameter according to the phase information or the amplitude information of the voltage signal or the current signal, so as to realize the measurement of the formation information outside the metal sleeve 10. The main control module is electrically connected with the transmitting electrode module 20, so that the time, frequency and the like of transmitting alternating current can be controlled. The data processing and transmitting module is used for carrying out data processing on the acquired voltage signals or current signals, so that formation electrical parameters can be obtained, and further formation information outside the metal sleeve 10 is analyzed.

The data processing module and the acquisition circuit module are connected through a wire.

The invention also provides a method for measuring the resistivity of the stratum through the casing, which adopts the logging instrument for measuring the resistivity of the stratum through the casing to measure, and comprises the following steps: step S10: the electronic circuit module controls the transmitting electrode module 20 to transmit alternating current; step S20: the receiving electrode module 30 receives the voltage signal or the current signal of the metal casing 10 and the stratum at the corresponding depth; step S30: the electronic circuit module processes the voltage signal or the current signal received by the receiving electrode module 30 and obtains phase information or amplitude information of the voltage signal or the current signal of the receiving electrode module 30; step S40: the formation electrical parameters are calculated based on the phase information or amplitude information received by the various receive electrode modules 30.

The electronic circuit module controls the transmitting electrode module 20 to transmit alternating current, so that the transmitting time, the alternating current frequency and the like can be controlled, the receiving electrode module 30 receives voltage signals or current signals of the metal sleeve 10 and the stratum at the corresponding depth, the alternating current which changes after passing through the metal sleeve 10 and the stratum can be obtained, and then the electronic circuit module processes the voltage signals or the current signals, namely processes and calculates the change of phase information or amplitude information, so that the electric parameters of the stratum are obtained, and the measurement of stratum information outside the metal sleeve 10 is realized.

As shown in fig. 3, in this embodiment, the metal sleeve 10 has a non-conductive fluid 50 therein. The cased formation resistivity logging instrument has one transmitting electrode module 20 and two receiving electrode modules 30, the two receiving electrode modules 30 being arranged above the transmitting electrode module 20. This arrangement enables the uncased formation resistivity logging instrument to measure formation information above the transmitter electrode module 20.

Example two

The difference from the first embodiment is the relative position between the transmitting electrode module 20 and the receiving electrode module 30.

In the present embodiment, as shown in fig. 4, the transmitting electrode module 20 and the receiving electrode module 30 are strung on one insulating connector 40. One transmitting electrode module 20 is disposed above two receiving electrode modules 30, that is, the uncased formation resistivity logging instrument of the present embodiment is capable of measuring formation information below the transmitting electrode modules 20.

Of course, the number of the receiving electrode modules 30 positioned below the transmitting electrode module 20 may be more than two, and may be designed according to specific requirements.

Example III

The difference from the first embodiment is that the number and positions of the receiving electrode modules 30 are different.

As shown in fig. 5, in the present embodiment, the logging tool for logging resistivity of formation through casing has a transmitting electrode module 20 and four receiving electrode modules 30, and two receiving electrode modules 30 are respectively disposed on the upper and lower sides of the transmitting electrode module 20, and the logging tool for logging resistivity of formation through casing in the present embodiment can measure formation information at two positions above and below the transmitting electrode module 20.

It should be noted that the number of the receiving electrode modules 30 on the upper and lower sides of the transmitting electrode module 20 may be not only two, but also three, four, etc., and may be designed according to specific use requirements, and of course, the number of the receiving electrode modules 30 on the upper and lower sides of the transmitting electrode module 20 may be different, for example, two receiving electrode modules 30 are disposed above the transmitting electrode module 20, and three receiving electrode modules 30 are disposed below the transmitting electrode module 20.

Example IV

The difference from the first embodiment is that the transmitting electrode module 20 and the receiving electrode module 30 are connected to the insulating connector 40 in different manners.

In a specific embodiment, not shown, the transmitting electrode module 20 and the receiving electrode module 30 are embedded within an insulating connector 40. The arrangement can ensure the stability of the transmitting electrode module 20 and the receiving electrode module 30, avoid falling off from the insulating connecting member 40, and ensure the insulating effect.

Example five

The difference from the first embodiment is that the number of insulating connectors 40 is different.

In a specific embodiment, not shown, there are a plurality of insulating connectors 40, and two adjacent insulating connectors 40 are connected by the transmitting electrode module 20 or the receiving electrode module 30. The insulation connecting piece 40 is used for connecting the transmitting electrode module 20 or the receiving electrode module 30, so that the insulation effect can be further ensured, and the influence of direct transmission of alternating current signals on the measurement result is avoided.

Example six

The difference from the first embodiment is the number of emitter electrode modules 20.

In a specific embodiment, not shown, the number of emitter electrode modules 20 is plural, and the ac frequency of the ac power emitted by different emitter electrode modules 20 is different. The data result of different positions can be obtained more accurately when the stratum condition is complex, and the measurement error is reduced.

From the above description, it can be seen that the above embodiments of the present invention achieve the following technical effects:

1. by emitting alternating current using the emitter electrode module 20, when a non-conductive fluid exists in the metal sleeve 10 or an antirust coating is present in the metal sleeve 10, the instrument emits alternating current, and the alternating current is transmitted in the form of displacement current among the emitter electrode module 20, the receiver electrode module 30 and the metal sleeve 10;

2. the received voltage signal or current signal is processed through the electronic circuit module, namely the change of the phase information or the amplitude information is processed and calculated, so that the formation electrical parameters are obtained, and the measurement of the formation information outside the metal sleeve 10 can be realized;

3. by providing a plurality of transmitting electrode modules 20 and receiving electrode modules 30, formation information at different depth positions can be measured longitudinally.

It will be apparent that the embodiments described above are merely some, but not all, embodiments of the invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the present invention without making any inventive effort, shall fall within the scope of the present invention.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments in accordance with the present application. As used herein, the singular is also intended to include the plural unless the context clearly indicates otherwise, and furthermore, it is to be understood that the terms "comprises" and/or "comprising" when used in this specification are taken to specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof.

It should be noted that the terms "first," "second," and the like in the description and claims of the present application and the above figures are used for distinguishing between similar objects and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used may be interchanged where appropriate such that embodiments of the present application described herein may be implemented in sequences other than those illustrated or described herein.

The above description is only of the preferred embodiments of the present invention and is not intended to limit the present invention, but various modifications and variations can be made to the present invention by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims (10)

1. A cased formation resistivity logging instrument, the cased formation resistivity logging instrument being disposed within a metal casing (10), the cased formation resistivity logging instrument comprising:

-at least one emitter electrode module (20), the emitter electrode module (20) being for emitting an alternating current to the metal sleeve (10);

the alternating current is returned to the receiving electrode modules (30) through the metal sleeve (10) and stratum, and is transmitted between the transmitting electrode modules (20) and the metal sleeve (10) and between the receiving electrode modules (30) and the metal sleeve (10) in the form of displacement current;

an insulating connecting piece (40), wherein two adjacent receiving electrode modules (30) are connected through the insulating connecting piece (40), and two adjacent transmitting electrode modules (20) are connected with the receiving electrode modules (30) through the insulating connecting piece (40);

and an electronic circuit module electrically connected to the transmitting electrode module (20) and the receiving electrode module (30).

2. The through-casing formation resistivity logging instrument according to claim 1, wherein the transmitting electrode module (20) and the receiving electrode module (30) are embedded within the insulated connector (40).

3. The logging tool of through-casing formation resistivity according to claim 1, wherein the insulating connector (40) is one, the transmitting electrode module (20) and the receiving electrode module (30) are in a cylindrical structure, and the transmitting electrode module (20) and the receiving electrode module (30) are both sleeved on the insulating connector (40).

4. The through-casing formation resistivity logging tool according to claim 1, wherein a plurality of insulating connectors (40) are provided, and two adjacent insulating connectors (40) are connected through the transmitting electrode module (20) or the receiving electrode module (30).

5. The through-casing formation resistivity logging instrument according to claim 1, wherein the alternating current emitted by the emitter electrode module (20) has an alternating frequency of 10kHz or more and 500kHz or less.

6. The through-casing formation resistivity logging instrument according to claim 1, wherein the number of the transmitting electrode modules (20) is plural, and alternating current frequencies of the alternating currents transmitted by different transmitting electrode modules (20) are different.

7. The uncased formation resistivity logging instrument according to any one of claims 1-6, wherein the transmitting electrode module (20) comprises:

an emitter electrode;

and the transmitting circuit module is electrically connected with the transmitting electrode and is used for generating the alternating current, and the transmitting electrode is used for transmitting the alternating current.

8. The uncased formation resistivity logging instrument according to any one of claims 1-6, wherein the receiving electrode module (30) comprises:

-a receiving electrode for receiving the alternating current transmitted onto the metal sleeve (10);

the acquisition circuit module is electrically connected with the receiving electrode and is used for acquiring voltage or current signals on the receiving electrode.

9. The uncased earth formation resistivity logging instrument of any one of claims 1 to 6, wherein the electronics module includes:

the main control module is electrically connected with the transmitting electrode module (20) and controls the transmitting electrode module (20) to transmit alternating current;

the data processing and transmitting module is electrically connected with the receiving electrode module (30), and is used for receiving the voltage signals or the current signals collected on the receiving electrode module (30) and calculating formation electrical parameters through the phase information or the amplitude information of the voltage signals or the current signals, so that the formation information outside the metal sleeve (10) is measured.

10. A method of measuring resistivity of a cased formation, wherein the measurement is performed using the cased formation resistivity logging instrument of any one of claims 1 to 9, the method comprising:

the electronic circuit module controls the transmitting electrode module (20) to transmit alternating current;

the receiving electrode module (30) receives voltage signals or current signals of the metal sleeve (10) and the stratum at the corresponding depth;

the electronic circuit module processes the voltage signal or the current signal received by the receiving electrode module (30) and obtains phase information or amplitude information of the voltage signal or the current signal of the receiving electrode module (30);

and calculating formation electrical parameters according to the phase information or the amplitude information received by different receiving electrode modules (30).