Program-controlled amplifying circuit applied to acoustic logging

Abstract

The utility model discloses a program-controlled amplifying circuit applied to acoustic logging, which comprises four operational amplifying modules, a first-stage program-controlled amplifying module, a second-stage program-controlled amplifying module, an A / D (analog / digital) conversion module, an MCU (microprogrammed control unit) control module and a master control module which are connected in sequence, the MCU control module consists of an MCU control circuit taking an STM32L496 chip as a main chip, the number of the operational amplifying modules is four, and the number of the A / D conversion module is four. The operational amplification module is electrically connected with an azimuth remote detection dipole, and the four azimuth remote detection dipoles detect 90-degree and 180-degree received signals, interference signals can be effectively filtered through the band-pass filtering module and the high-pass filtering module, the detection accuracy is improved, and the detection precision is improved. The azimuth remote detection dipole adopts independent acquisition of four azimuths, can respond to signals received by 90 degrees and 180 degrees respectively, judges which azimuth the received signals specifically come from through the response, and effectively solves the problem of 180-degree azimuth uncertainty of a traditional dipole measurement mode.

Description

Technical Field

[0001] The utility model relates to the technical field of power electronics, in particular to a program-controlled amplifying circuit used for acoustic well logging. Background Art

[0002] At present, long-range detection sonic logging technology plays an important role in deep detection, especially in ultra-deep oil and gas exploration and development. Long-range detection dipole technology can achieve an out-of-well detection distance of more than 40 meters, but the traditional dipole shear wave long-range detection method has an azimuth uncertainty of 180° and cannot determine the true azimuth. This has led to the emergence of azimuth long-range detection dipole sonic wave technology, which effectively solves the defect that the traditional dipole measurement method SH reflection can only identify the direction of the geological body but cannot determine the true azimuth due to the azimuth uncertainty of 180°; not only that, in the detection process, inaccurate detection often occurs due to signal interference.

[0003] In summary, a program-controlled amplifier circuit for acoustic logging is designed. Utility Model Content

[0004] In order to overcome the above-mentioned shortcomings, the utility model provides a program-controlled amplifier circuit applied to acoustic well logging.

[0005] The utility model achieves the above-mentioned purpose through the following technical solutions:

[0006] A program-controlled amplifier circuit used in acoustic well logging comprises an operational amplifier module, a first-stage program-controlled amplifier module, a second-stage program-controlled amplifier module, an A / D conversion module, an MCU control module and a main control module which are connected in sequence, wherein the MCU control module is composed of an MCU control circuit based on an STM32L496 chip;

[0007] There are four operational amplifier modules, each of which is electrically connected to an azimuth long-range detection dipole. The four azimuth long-range detection dipoles detect signals received at 90° and 180°.

[0008] Preferably, it also includes a bandpass filtering module and a high-pass filtering module. The bandpass filtering module is located between the first-stage programmable amplification module and the second-stage programmable amplification module, and the high-pass filtering module is located between the second-stage programmable amplification module and the A / D conversion module. The bandpass filtering module includes a sixth-order bandpass filter composed of two second-order active high-pass filters and a second-order active low-pass filter, so as to select signals in a specific frequency band. The high-pass filtering module includes a first-order active high-pass filtering, and the first-order active high-pass filtering is composed of a first-stage RC high-pass filtering and two-stage second-order active high-pass filtering cascaded.

[0009] Preferably, the main control module is electrically connected to a communication storage module, and the communication storage module is connected to the main control module via an RS485 communication protocol.

[0010] Preferably, the operational amplifier module is composed of an operational amplifier circuit mainly based on the chip NCS2005. The signal received by the receiving crystal is input into the chip NCS2005 for the first amplification. The chip and its surrounding components achieve a fixed gain of twice.

[0011] Preferably, the first-stage programmable amplifier module is composed of a first gain adjustable circuit mainly composed of a digital potentiometer AD5290 and a second gain adjustable circuit mainly composed of an operation chip OP27. This part of the circuit realizes two gain adjustments. The first digital potentiometer and its surrounding components form a voltage divider circuit to realize the first gain adjustment. The second digital potentiometer serves as an adjustable feedback resistor of the operation chip OP27 to realize the second gain adjustment. The second-stage programmable amplifier module is composed of a gain adjustable circuit mainly composed of another operation chip OP27. Compared with the first stage, the second-stage programmable amplifier module removes a digital potentiometer and its surrounding components to form a gain adjustable circuit composed of a voltage divider circuit, so as to filter out the interference introduced by this stage of amplification.

[0012] The digital potentiometer is compatible with the SPI protocol to achieve adjustable resistance value. The resistance formula is as follows:

[0013]

[0014] Where D is the decimal value corresponding to the received 8-bit binary data, R AB is the maximum resistance of the digital potentiometer, R W is the on-resistance determined by the internal switch.

[0015] Preferably, the A / D conversion module is composed of a circuit mainly composed of an ADS8598H analog-to-digital conversion chip. The A / D conversion module is used to convert multiple analog signals into digital signals. The chip is an 8-channel, 500ksps, 18-bit A / D analog-to-digital converter that can realize parallel data conversion. The chip can set the data conversion mode and internal and external reference voltages by itself. In addition, the chip has an integrated detection circuit that can convert AC signals into DC signals. After that, the digital signal after A / D conversion is input into the STM32L496 main control chip on the receiving board for data processing.

[0016] The beneficial effects of the utility model are as follows: in the programmable amplification circuit applied to sonic logging, interference signals can be effectively filtered through the bandpass filter module and the high-pass filter module, thereby improving the accuracy of detection; the azimuth long-range detection dipole adopts independent collection in four azimuths, and can respond to signals received at 90° and 180° respectively, and judge the specific azimuth from which the received signal comes through the response, thereby effectively solving the 180° azimuth uncertainty of the traditional dipole measurement method. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The present invention will be described by way of examples with reference to the accompanying drawings, in which:

[0018] Figure 1 It is a system principle diagram of the utility model. DETAILED DESCRIPTION

[0019] Now the utility model is further described in detail with reference to the accompanying drawings. These drawings are simplified schematic diagrams, which only illustrate the basic structure of the utility model in a schematic manner, and therefore only show the components related to the utility model.

[0020] like Figure 1 As shown, a program-controlled amplifier circuit used for acoustic well logging includes an operational amplifier module, a first-stage program-controlled amplifier module, a second-stage program-controlled amplifier module, an A / D conversion module, an MCU control module and a main control module connected in sequence, wherein the MCU control module is composed of an MCU control circuit based on an STM32L496 chip;

[0021] There are four operational amplifier modules, each of which is electrically connected to an azimuth long-range detection dipole. The four azimuth long-range detection dipoles detect signals received at 90° and 180°.

[0022] This circuit is located in the receiving transducer. The receiving transducer receives acoustic signals with different frequencies and noise amplitudes from the formation. Then, the program-controlled amplifier circuit used for acoustic logging in the receiving transducer performs data processing, which can effectively solve the defect that the traditional dipole measurement method SH reflection can only identify the direction of the geological body but cannot determine the true direction due to the 180° azimuth uncertainty. The collected signals are respectively processed by a first-stage operational amplification, a two-stage program-controlled amplification, a sixth-order bandpass filter and a sixth-order high-pass filter, and then sent to the A / D conversion module. Under the control of the MCU control module, the analog signal is completely converted into a digital signal and sent to the main control module. The main control module performs noise reduction, analysis and extraction on the sent digital signal. Finally, the processed data is sent through the communication storage module and stored in the storage chip at the same time.

[0023] Specifically, it also includes a bandpass filtering module and a high-pass filtering module. The bandpass filtering module is located between the first-stage program-controlled amplification module and the second-stage program-controlled amplification module, and the high-pass filtering module is located between the second-stage program-controlled amplification module and the A / D conversion module. The bandpass filtering module includes a sixth-order bandpass filter composed of two second-order active high-pass filters and a second-order active low-pass filter, so as to select signals in a specific frequency band. The high-pass filtering module includes a first-order active high-pass filtering, and the first-order active high-pass filtering is composed of a first-stage RC high-pass filtering and two-stage second-order active high-pass filtering cascaded.

[0024] Specifically, the main control module is electrically connected to a communication storage module, and the communication storage module and the main control module are connected via an RS485 communication protocol. The main control module sends data to the main control board A16 via RS485 communication, and the main control board then stores the data and uploads the data to the ground system through the on-chip FPGA module to facilitate users to view in real time and perform subsequent operations.

[0025] Specifically, the operational amplifier module is composed of an operational amplifier circuit mainly based on the chip NCS2005. The signal received by the receiving crystal is input into the chip NCS2005 for the first amplification. The chip and its surrounding components achieve a fixed gain of twice.

[0026] Specifically, the first-stage programmable amplifier module is composed of a first gain adjustable circuit mainly composed of a digital potentiometer AD5290 and a second gain adjustable circuit mainly composed of an operation chip OP27. This part of the circuit realizes two gain adjustments. The first digital potentiometer and its surrounding components form a voltage divider circuit to realize the first gain adjustment. The second digital potentiometer serves as an adjustable feedback resistor of the operation chip OP27 to realize the second gain adjustment. The second-stage programmable amplifier module is composed of a gain adjustable circuit mainly composed of another operation chip OP27. Compared with the first stage, the second-stage programmable amplifier module removes a digital potentiometer and its surrounding components to form a gain adjustable circuit composed of a voltage divider circuit, so as to filter out the interference introduced by this stage of amplification.

[0027] The digital potentiometer is compatible with the SPI protocol to achieve adjustable resistance value. The resistance formula is as follows:

[0028]

[0029] Where D is the decimal value corresponding to the received 8-bit binary data, R AB is the maximum resistance of the digital potentiometer, R W is the on-resistance determined by the internal switch.

[0030] Specifically, the A / D conversion module is composed of a circuit mainly composed of an ADS8598H analog-to-digital conversion chip. The A / D conversion module is used to convert multiple analog signals into digital signals. The chip is an 8-channel, 500ksps, 18-bit A / D analog-to-digital converter that can realize parallel data conversion. The chip can set the data conversion mode and internal and external reference voltages by itself. In addition, the chip has an integrated detection circuit that can convert AC signals into DC signals. After that, the digital signal after A / D conversion is input into the STM32L496 main control chip on the receiving board for data processing.

[0031] The above is based on the enlightenment of this utility model. Through the above description, relevant staff can make various changes and modifications without deviating from the technical idea of ​​this utility model. The technical scope of this utility model is not limited to the content in the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. A program-controlled amplifier circuit for acoustic well logging, characterized in that: It includes an operational amplifier module, a first-stage program-controlled amplifier module, a second-stage program-controlled amplifier module, an A / D conversion module, an MCU control module and a main control module which are connected in sequence. The MCU control module is composed of an MCU control circuit based on an STM32L496 chip. There are four operational amplifier modules, each of which is electrically connected to an azimuth long-range detection dipole. The four azimuth long-range detection dipoles detect signals received at 90° and 180°.

2. The program-controlled amplifier circuit for acoustic logging according to claim 1 is characterized in that: It also includes a bandpass filter module and a high-pass filter module. The bandpass filter module is located between the first-stage program-controlled amplification module and the second-stage program-controlled amplification module. The high-pass filter module is located between the second-stage program-controlled amplification module and the A / D conversion module. The bandpass filter module includes a sixth-order bandpass filter composed of two second-order active high-pass filters and a second-order active low-pass filter. The high-pass filter module includes a first-order active high-pass filter, and the first-order active high-pass filter is composed of a first-stage RC high-pass filter and two second-order active high-pass filters cascaded.

3. The program-controlled amplifier circuit for acoustic logging according to claim 1, characterized in that: The main control module is electrically connected to a communication storage module, and the communication storage module is connected to the main control module via an RS485 communication protocol.

4. The program-controlled amplifier circuit for acoustic logging according to claim 1 is characterized in that: The operational amplifier module is composed of an operational amplifier circuit based on the chip NCS2005.

5. The program-controlled amplifier circuit for acoustic logging according to claim 1 is characterized in that: The first-stage programmable amplifier module is composed of a first gain adjustable circuit based on the digital potentiometer AD5290 and a second gain adjustable circuit based on the operation chip OP27. The second-stage programmable amplifier module is composed of a gain adjustable circuit based on another operation chip OP27.

6. The program-controlled amplifier circuit for acoustic logging according to claim 1, characterized in that: The A / D conversion module is composed of a circuit mainly composed of an ADS8598H analog-to-digital conversion chip.

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