A dual laterolog instrument screen current circuit configuration and voltage output method

Abstract

This invention relates to the field of geophysical logging technology, and discloses a dual-lateral instrument current-screening circuit structure and voltage output method. The structure includes a voltage circuit unit, a first amplifier, and a second amplifier. The output terminal of the voltage circuit unit is connected to the negative and positive terminals of the operational amplifier of the first amplifier, respectively. The output terminal of the first amplifier is connected to the positive terminal of the operational amplifier of the second amplifier, and the negative terminal of the operational amplifier of the second amplifier is grounded. The output terminal of the second amplifier is connected to the voltage output terminal. By optimizing the current-screening circuit structure, this invention enables dual-lateral instruments to complete measurement tasks more quickly. This helps improve work efficiency, reduce measurement costs, and provide more timely and accurate data support for geological exploration and oil and gas resource development.

Description

Technical Field

[0001] This invention relates to the field of geophysical logging technology, specifically to a dual-lateral instrument current shielding circuit structure and voltage output method. Background Technology

[0002] Geophysical logging is a key technology for mineral resource exploration and development using various physical methods within a drilled wellbore. These physical methods include, but are not limited to, electromagnetic waves, acoustic waves, radioactivity, nuclear magnetic resonance, and optical fibers. By identifying the electromagnetic parameters, elastic mechanical parameters, and elemental properties of the formation rocks and fluid media within the rock pores, they provide important data for the exploration and development of mineral resources such as oil, gas, and metals.

[0003] In the field of oil and gas logging and evaluation, formation resistivity is a crucial parameter that plays a decisive role in estimating oil and gas reserves. To accurately measure formation resistivity, the dual-lateral logging method based on Ohm's law has emerged and become one of the most effective logging techniques currently available.

[0004] The core of the dual-lateral logging method lies in utilizing Ohm's law for logging, which requires the dual-lateral logging tool to accurately acquire multiple signals from the electrode system. However, current technologies have significant shortcomings in processing these acquired signals. Generally, existing technologies first sum the multiple signals and then calculate the difference to obtain the desired logging information. However, due to design flaws in the summation circuit itself, the signal acquisition results contain significant errors, thus affecting the accuracy and reliability of the logging. Summary of the Invention

[0005] The purpose of this invention is to provide a dual-side instrument current-screening circuit structure and a voltage calculation method to solve the technical problem of how to reduce voltage output error in the prior art.

[0006] This invention is achieved through the following technical solution: In a first aspect, the present invention provides a dual-side instrument current-screening circuit structure, including a voltage circuit unit, a first amplifier, and a second amplifier; The output terminal of the voltage circuit unit is connected to the negative terminal and the positive terminal of the first amplifier, respectively. The output terminal of the first amplifier is connected to the positive terminal of the operational amplifier of the second amplifier, and the negative terminal of the operational amplifier of the second amplifier is grounded; the output terminal of the second amplifier is connected to the voltage output terminal.

[0007] Preferably, the voltage circuit unit includes a first voltage acquisition circuit, a second voltage acquisition circuit, and a third voltage acquisition circuit; The output terminal of the first voltage acquisition circuit is connected to the negative terminal of the operational amplifier of the first amplifier; The output of the second voltage acquisition circuit is branched, with one branch grounded and the other branch connected to the positive terminal of the first amplifier's operational amplifier. The output terminal of the third voltage acquisition circuit is connected in parallel to the grounding branch of the second voltage acquisition circuit.

[0008] Furthermore, the first voltage acquisition circuit is provided with a first resistor; the second voltage acquisition circuit is provided with a second resistor; and the third voltage acquisition circuit is provided with a third resistor.

[0009] Preferably, a fourth resistor is provided on the grounding branch of the second voltage acquisition circuit.

[0010] Preferably, a fifth resistor is connected in parallel between the negative terminal of the operational amplifier and the output terminal of the first amplifier.

[0011] Preferably, a sixth resistor and a first capacitor are sequentially provided between the output terminal of the first amplifier and the positive terminal of the operational amplifier of the second amplifier.

[0012] Preferably, a seventh resistor is connected in parallel to the negative terminal of the first amplifier and the output terminal of the second amplifier.

[0013] Preferably, an eighth resistor is provided on the negative terminal of the second amplifier's operational amplifier.

[0014] Preferably, a ninth resistor and a second capacitor are connected in parallel to the positive terminal of the second amplifier and the output terminal of the second amplifier, respectively.

[0015] Secondly, the present invention also provides a voltage output method for a dual-side instrument current-plate circuit, based on the aforementioned dual-side instrument current-plate circuit structure, comprising the following steps: Step 1: Collect the voltage of the voltage circuit unit; Step 2: The collected voltage is amplified by the first amplifier. Step 3: After the voltage is amplified by one stage, a bandpass filter is applied to remove interference signals and obtain the output voltage.

[0016] Compared with the prior art, the present invention has the following beneficial technical effects: This invention provides a dual-lateral instrument current-screening circuit structure that provides a stable voltage output through a voltage circuit unit. Its output terminals are respectively connected to the negative and positive terminals of the operational amplifier (op-amp) of a first amplifier, providing a base voltage for subsequent amplification and focusing processes. The first amplifier receives the voltage signal from the voltage circuit unit and performs preliminary amplification. Its output terminal is connected to the positive terminal of the op-amp of a second amplifier, transmitting the pre-processed voltage signal. The second amplifier further amplifies the signal from the first amplifier and generates the final output voltage. Its op-amp negative terminal is grounded, which helps stabilize the circuit's operating state. The output terminal of the second amplifier is connected to the voltage output terminal, providing the required voltage output for the dual-lateral instrument. This invention, through its current-screening circuit structure, can significantly improve the focusing capability of the emitted current of a dual-lateral instrument. The current can enter the formation more accurately and vertically, rather than being dispersed to other areas. This focusing capability is crucial for accurately measuring formation resistivity. Through the good focusing and current-screening effect of the current-screening circuit, the dual-lateral instrument can measure the resistivity of the formation more accurately. This helps reduce measurement errors, improve measurement accuracy, and thus meet the measurement needs of different formations. This invention optimizes the current-screening circuit structure, enabling dual-sided instruments to complete measurement tasks more quickly. This helps improve work efficiency, reduce measurement costs, and provide more timely and accurate data support for geological exploration and oil and gas resource development.

[0017] This invention also provides a voltage output method for a dual-sided instrument current-plate circuit. By acquiring the voltage of the voltage circuit unit, this method can directly obtain the voltage signal in the current-plate circuit. After being amplified by the first amplifier U1, the amplitude of the voltage signal is enhanced, thereby improving the measurement sensitivity. The use of a bandpass filter further filters out interference signals, reducing the impact of noise on the measurement results and making the output voltage more accurate. This invention achieves voltage output through simple circuit units and steps, avoiding the use of complex circuit structures. This helps reduce the complexity and cost of circuit design and improves the reliability and maintainability of the circuit. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the dual-side instrument current-screening circuit structure in an embodiment of the present invention; Figure 2 This is a schematic diagram of the dual-side instrument screen current circuit analysis in an embodiment of the present invention; Figure 3 A schematic diagram comparing the circuit curves of a conventional circuit with those of the present invention; In the diagram: A1*, first voltage acquisition circuit; A2, second voltage acquisition circuit; A2”, third voltage acquisition circuit; R1, first resistor; R2, second resistor; R3, third resistor; R4, fourth resistor; R5, fifth resistor; R6, sixth resistor; R7, seventh resistor; R8, eighth resistor; R9, ninth resistor; U1, first amplifier; U2, second amplifier; C1, first capacitor; C2, second capacitor; VOUT - voltage output terminal. Detailed Implementation

[0019] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0020] The present invention will now be described in further detail with reference to the accompanying drawings: The purpose of this invention is to provide a dual-side instrument current-screening circuit structure and a voltage calculation method to solve the technical problem of how to reduce signal acquisition errors in the prior art.

[0021] See Figure 1 In one embodiment of the present invention, a dual-side instrument current shielding circuit structure is provided, including a voltage circuit unit, a first amplifier U1 and a second amplifier U2; the output terminal of the voltage circuit unit is respectively connected to the negative terminal and the positive terminal of the operational amplifier of the first amplifier U1; the output terminal of the first amplifier U1 is connected to the positive terminal of the operational amplifier of the second amplifier U2, and the negative terminal of the operational amplifier of the second amplifier U2 is grounded; the output terminal of the second amplifier U2 is connected to the voltage output terminal VOUT.

[0022] Specifically, the voltage circuit unit includes a first voltage acquisition circuit A1*, a second voltage acquisition circuit A2, and a third voltage acquisition circuit A2”; the output terminal of the first voltage acquisition circuit A1* is connected to the negative terminal of the operational amplifier of the first amplifier U1; the output terminal of the second voltage acquisition circuit A2 is branched, with one branch grounded and the other branch connected to the positive terminal of the operational amplifier of the first amplifier U1; the output terminal of the third voltage acquisition circuit A2” is connected in parallel to the grounded branch of the second voltage acquisition circuit A2.

[0023] In this embodiment, the first voltage acquisition circuit A1* acquires a specific voltage signal and connects its output to the negative terminal of the operational amplifier U1. The second voltage acquisition circuit A2 acquires a voltage signal, but its output is configured with a branch circuit. One branch is grounded to provide a stable reference potential; the other branch is connected to the positive terminal of the operational amplifier U1 to input the voltage signal to be amplified. The third voltage acquisition circuit A2” has its output connected in parallel to the grounded branch of the second voltage acquisition circuit A2 to adjust or modify the voltage characteristics of the grounded branch.

[0024] The structural principle of this embodiment is as follows: The voltage signal acquired by the first voltage acquisition circuit A1* is used as a negative input signal and fed into the negative terminal of the operational amplifier U1. The voltage signal acquired by the second voltage acquisition circuit A2 is used as a positive input signal and is connected to the branch input of the positive terminal of the operational amplifier U1. The first amplifier U1 receives the input signals from the first voltage acquisition circuit A1* and the second voltage acquisition circuit A2, and amplifies them according to the difference between the two signals. This differential amplification method helps to reduce common-mode noise and interference, and improve the signal-to-noise ratio.

[0025] The ground branch of the second voltage acquisition circuit A2 provides a stable reference potential for the circuit. This helps ensure that the amplifier's output signal has a stable zero potential point. The third voltage acquisition circuit A2” is connected in parallel with the ground branch to fine-tune the ground potential or introduce additional voltage characteristics. This helps to further optimize the circuit performance to meet specific measurement or application requirements.

[0026] Specifically, the first voltage acquisition circuit A1* is equipped with a first resistor R1; the second voltage acquisition circuit A2 is equipped with a second resistor R2; and the third voltage acquisition circuit A2” is equipped with a third resistor R3. A fourth resistor R4 is provided on the grounding branch of the second voltage acquisition circuit A2.

[0027] In this embodiment, the first resistor R1 is placed on the first voltage acquisition circuit A1* to limit current, divide voltage, or provide a stable resistance value to ensure the stability and accuracy of the circuit. The second resistor R2 is placed on the second voltage acquisition circuit A2 to limit current, divide voltage, or as part of signal conditioning. It is connected between the input signal and the amplifier, helping to adjust the amplitude and characteristics of the signal. The third resistor R3 is placed on the third voltage acquisition circuit A2” and connected in parallel to the ground branch of the second voltage acquisition circuit A2. It is used to fine-tune the ground potential, balance the current, or provide additional resistance values ​​to meet specific circuit requirements. The fourth resistor R4 is placed on the ground branch of the second voltage acquisition circuit A2, typically used to provide a stable ground potential, and also helps to adjust the gain and stability of the circuit.

[0028] Specifically, a fifth resistor R5 is connected in parallel to the negative terminal of the first amplifier U1 and the output terminal of the first amplifier U1.

[0029] In this embodiment, the parallel connection of resistors R5 forms a feedback path, allowing the output signal of amplifier U1 to be fed back to its inverting input. The addition of resistor R5 affects the closed-loop gain of the amplifier. Closed-loop gain is the actual gain of the amplifier under feedback, and it is usually less than the open-loop gain. By adjusting the value of resistor R5, the feedback amount can be changed, thereby adjusting the closed-loop gain of the amplifier.

[0030] Specifically, a sixth resistor R6 and a first capacitor C1 are sequentially provided between the output terminal of the first amplifier U1 and the positive terminal of the second amplifier U2.

[0031] In this embodiment, the sixth resistor R6 is connected between the output terminal of the first amplifier U1 and the positive terminal of the second amplifier U2, serving to transmit signals and limit current. The first capacitor C1 is connected in series with the resistor R6, and its main function is to filter, decouple, or provide phase compensation.

[0032] The structural principle of this embodiment is as follows: The first amplifier U1 amplifies the input signal and outputs it through its output terminal. The amplified signal is then transmitted to the positive terminal of the second amplifier U2 via the sixth resistor R6. Resistor R6 serves to limit current and match impedance, ensuring stable and efficient signal transmission.

[0033] The first capacitor C1 is connected in series with the resistor R6, and its main function is filtering and decoupling.

[0034] Filtering: Capacitor C1 can filter out high-frequency noise and spurious waves in the signal, making the signal transmitted to the second amplifier U2 cleaner.

[0035] Decoupling: Capacitor C1 can also prevent the DC potential difference between the front and rear amplifier stages from interfering with the signal, thus playing a decoupling role.

[0036] Specifically, a seventh resistor R7 is connected in parallel to the negative terminal of the first amplifier U1 and the output terminal of the second amplifier U2.

[0037] In this embodiment, the seventh resistor R7 provides a feedback path, partially feeding back the output signal of the second amplifier U2 to the negative terminal of the first amplifier U1. The feedback signal is added to the input signal of the first amplifier U1 (under the virtual short characteristic of the operational amplifier), thereby changing the output of the first amplifier U1. By adjusting the value of the seventh resistor R7, the strength of the feedback signal can be affected, thus controlling the gain and stability of the entire circuit. The feedback resistor R7, together with the input and output capacitors of the amplifier, can affect the phase and frequency response of the circuit.

[0038] Specifically, the second amplifier U2 has an eighth resistor R8 on its negative terminal.

[0039] In this embodiment, when a signal is input to the non-inverting input of the second amplifier U2, the signal is amplified and output to the amplifier's output. A portion of the signal at the amplifier's output is attenuated by resistor R8 and fed back to the inverting input, forming negative feedback. This negative feedback stabilizes the amplifier's gain and reduces output signal distortion. By adjusting the value of resistor R8, the strength of the feedback signal can be changed, thereby adjusting the amplifier's closed-loop gain.

[0040] Specifically, a ninth resistor R9 and a second capacitor C2 are connected in parallel to the positive terminal of the second amplifier U2 and the output terminal of the second amplifier U2, respectively.

[0041] In this embodiment, the ninth resistor R9 provides a voltage feedback path, feeding back a portion of the voltage at the output of amplifier U2 to its non-inverting input. Resistor R9 acts as a shunt, diverting a portion of the output signal to the non-inverting input, thereby altering the amplifier's gain and stability.

[0042] The second capacitor C2 is connected in parallel with the resistor R9, and its main functions are filtering and phase compensation.

[0043] Filtering: Capacitor C2 can filter out high-frequency noise and spurious waves in the signal, making the feedback signal transmitted to the non-inverting input terminal purer.

[0044] Phase compensation: In some cases, the internal phase delay of the amplifier may cause instability or oscillation in the circuit. The addition of capacitor C2 can provide phase compensation and improve the stability of the circuit.

[0045] By adjusting the value of resistor R9, the strength of the feedback signal can be changed, thereby adjusting the closed-loop gain of the amplifier. Appropriate feedback can reduce the circuit gain and improve stability.

[0046] The capacitance value of capacitor C2 also affects the gain and stability of the circuit. By selecting an appropriate capacitance value, the performance of the circuit can be further optimized.

[0047] Example 2 according to Figure 2 As shown, this embodiment provides a voltage output method for a dual-side instrument current-screening circuit. Based on the aforementioned dual-side instrument current-screening circuit structure, it is characterized by the following steps: Step 1: Collect the first voltage acquisition circuit A1*, the second voltage acquisition circuit A2, and the third voltage acquisition circuit A2”. The calculation formula is as follows:

[0048]

[0049] in, This indicates the current in the second voltage acquisition circuit A2; This indicates the current in the third voltage acquisition circuit A2”; K1 represents the grounding current of the second voltage acquisition circuit A2; K1 is the first coefficient.

[0050] Step 2: The acquired voltage is amplified by the first amplifier U1. The calculation formula is as follows:

[0051]

[0052] in, This represents the output voltage of the first amplifier U1; This represents the voltage at the negative terminal of the first amplifier U1; This represents the voltage at the positive terminal of the first amplifier U1; This indicates the output voltage of the first voltage acquisition circuit; This represents the second coefficient.

[0053] Step 3: After being amplified by one stage, the voltage is sequentially passed through the sixth resistor R6 and the first capacitor C1 for bandpass filtering to remove interference signals. The output voltage is then obtained through the second amplifier U2, and its calculation formula is as follows:

[0054]

[0055]

[0056] in, Indicates the first capacitive reactance; Indicates the second capacitive reactance; Indicates the first Laplace transform coefficients; Indicates the second Laplace transform coefficients; This represents the third coefficient.

[0057] This embodiment obtains the first coefficient through the above content. Second coefficient and the third coefficient The output voltage can be obtained from the above steps, and its formula is as follows:

[0058] This embodiment acquires the voltages on the electrode system of the first voltage acquisition circuit A1*, the second voltage acquisition circuit A2, and the third voltage acquisition circuit A2”. The voltage difference between these circuits is amplified in the first stage by the first amplifier U1. Subsequently, bandpass filtering is performed using the first capacitor C1, the sixth resistor R6, the second capacitor C2, the seventh resistor R7, and the second amplifier U2 to remove interference signals, improving circuit accuracy and extracting the desired frequency signal. Precise circuit parameters can be obtained through the above circuit calculations. Adjustments ensure the instrument's design principles and circuit accuracy. According to... Figure 3 As shown, the method mentioned in this embodiment has been developed into a corresponding product and method, and applied to the implementation of the instrument. Figure a is a circuit diagram of the prior art; Figure b is a circuit diagram of the present invention.

[0059] This embodiment ensures that the current emitted from the voltage sources of both instruments is focused by the current-blocking circuit of the aforementioned invention, preventing it from flowing elsewhere and instead allowing it to vertically enter the formation and ultimately return to the electrodes. Only when the current-blocking circuit achieves excellent focusing and current-blocking effects can it be guaranteed that the dual-sided instruments are measuring the resistivity of the formation, enabling the instruments to adapt to the measurement needs of different formations and meet the measurement accuracy requirements.

[0060] In summary, this invention provides a dual-side-field instrument current-blocking circuit structure and voltage output method, which provides a stable voltage output through a voltage circuit unit. Its output terminals are respectively connected to the negative and positive terminals of the first amplifier's operational amplifier, providing a base voltage for subsequent amplification and focusing processes. The first amplifier receives the voltage signal from the voltage circuit unit and performs preliminary amplification. Its output terminal is connected to the positive terminal of the second amplifier's operational amplifier, transmitting the pre-processed voltage signal. The second amplifier further amplifies the signal from the first amplifier and generates the final output voltage. Its operational amplifier's negative terminal is grounded, which helps stabilize the circuit's operating state. The output terminal of the second amplifier is connected to the voltage output terminal, providing the required voltage output for the dual-side-field instrument. This invention, through its current-blocking circuit structure, can significantly improve the focusing capability of the emitted current of the dual-side-field instrument. The current can enter the formation more accurately and vertically, rather than being dispersed to other areas. This focusing capability is crucial for accurately measuring formation resistivity. Through the good focusing and current-blocking effect of the current-blocking circuit, the dual-side-field instrument can more accurately measure the resistivity of the formation. This helps reduce measurement errors, improve measurement accuracy, and thus meet the measurement needs of different formations. This invention optimizes the current-screening circuit structure, enabling dual-sided instruments to complete measurement tasks more quickly. This helps improve work efficiency, reduce measurement costs, and provide more timely and accurate data support for geological exploration and oil and gas resource development.

[0061] By acquiring the voltage of the voltage circuit unit, this method can directly obtain the voltage signal in the plate current circuit. After being amplified by the first amplifier U1, the amplitude of the voltage signal is enhanced, thereby improving the measurement sensitivity. The use of a bandpass filter further filters out interference signals, reducing the impact of noise on the measurement results and making the output voltage more accurate. This invention achieves voltage output through simple circuit units and steps, avoiding the use of complex circuit structures. It helps to reduce the complexity and cost of circuit design and improves the reliability and maintainability of the circuit.

[0062] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A dual-side instrument current shielding circuit structure, characterized in that, It includes a voltage circuit unit, a first amplifier (U1), and a second amplifier (U2); The output terminals of the voltage circuit unit are respectively connected to the negative terminal and the positive terminal of the first amplifier (U1); The output terminal of the first amplifier (U1) is connected to the positive terminal of the second amplifier (U2), and the negative terminal of the second amplifier (U2) is grounded; the output terminal of the second amplifier (U2) is connected to the voltage output terminal (VOUT).

2. The dual-side instrument current shielding circuit structure according to claim 1, characterized in that, The voltage circuit unit includes a first voltage acquisition circuit (A1*), a second voltage acquisition circuit (A2), and a third voltage acquisition circuit (A2”). The output terminal of the first voltage acquisition circuit (A1*) is connected to the negative terminal of the first amplifier (U1); The output of the second voltage acquisition circuit (A2) is branched, with one branch grounded and the other branch connected to the positive terminal of the first amplifier (U1). The output terminal of the third voltage acquisition circuit (A2) is connected in parallel to the grounding branch of the second voltage acquisition circuit (A2).

3. The dual-side instrument current shielding circuit structure according to claim 2, characterized in that, The first voltage acquisition circuit (A1) is provided with a first resistor (R1); the second voltage acquisition circuit (A2) is provided with a second resistor (R2); and the third voltage acquisition circuit (A2) is provided with a third resistor (R3).

4. The dual-side instrument current shielding circuit structure according to claim 2, characterized in that, A fourth resistor (R4) is provided on the grounding branch of the second voltage acquisition circuit (A2).

5. The dual-side instrument current shielding circuit structure according to claim 1, characterized in that, A fifth resistor (R5) is connected in parallel to the negative terminal of the first amplifier (U1) and the output terminal of the first amplifier (U1).

6. The dual-side instrument current shielding circuit structure according to claim 1, characterized in that, A sixth resistor (R6) and a first capacitor (C1) are sequentially provided between the output terminal of the first amplifier (U1) and the positive terminal of the second amplifier (U2).

7. The dual-side instrument current shielding circuit structure according to claim 1, characterized in that, A seventh resistor (R7) is connected in parallel to the negative terminal of the first amplifier (U1) and the output terminal of the second amplifier (U2).

8. The dual-side instrument current shielding circuit structure according to claim 1, characterized in that, The second amplifier (U2) has an eighth resistor (R8) on its op-amp negative terminal.

9. The dual-side instrument current shielding circuit structure according to claim 1, characterized in that, A ninth resistor (R9) and a second capacitor (C2) are connected in parallel to the positive terminal of the second amplifier (U2) and the output terminal of the second amplifier (U2).

10. A voltage output method for a dual-side instrument current-screening circuit, based on the dual-side instrument current-screening circuit structure according to any one of claims 1-9, characterized in that, Includes the following steps: Step 1: Collect the voltage of the voltage circuit unit; Step 2: The collected voltage is amplified by the first amplifier (U1). Step 3: After the voltage is amplified by one stage, a bandpass filter is applied to remove interference signals and obtain the output voltage.

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