阅读说明：本技术 随钻声波测井仪器接收换能器阵列全数字化装置 (Receiving transducer array full digitalization device of acoustic logging while drilling instrument ) 是由 孙云涛 陈文轩 底青云 郑健 张文秀 于 2020-05-14 设计创作，主要内容包括：本发明公开了一种随钻声波接收换能器阵列全数字化装置,属于随钻声波测井技术领域。该随钻声波接收换能器阵列采用全数字化的结构,并采用非充油方式的橡胶灌封布置方式,所述随钻声波接收换能器阵列全数字化装置包括：第一模块,用于对地层的弱接收声波信号进行声电转换；第二模块,用于对所述弱接收声波信号进行放大、滤波、增益控制及数模转换；第三模块,用于所述装置的接口控制及外部输入输出信号转换。本发明提供一种随钻声波接收换能器阵列全数字化的非充油灌封的布置方法,实现随钻过程中的声波接收信号预处理、数字化及采集。(The invention discloses a full digitalization device of an acoustic wave receiving transducer array while drilling, belonging to the technical field of acoustic wave logging while drilling. The while-drilling acoustic wave receiving transducer array adopts a full-digitalization structure and adopts a rubber encapsulation arrangement mode of a non-oil-filling mode, and the full-digitalization device of the while-drilling acoustic wave receiving transducer array comprises: the first module is used for performing sound-electricity conversion on weak received sound wave signals of the stratum; the second module is used for amplifying, filtering, gain control and digital-to-analog conversion of the weak received sound wave signal; and the third module is used for interface control and external input and output signal conversion of the device. The invention provides a full-digital non-oil-filled encapsulation arrangement method for an acoustic wave receiving transducer array while drilling, which realizes the preprocessing, the digitization and the acquisition of acoustic wave receiving signals in the process of while drilling.)

1. The device for completely digitalizing the while-drilling acoustic wave receiving transducer array is characterized in that the while-drilling acoustic wave receiving transducer array adopts a fully digitalized structure after being subjected to digital processing and adopts a rubber encapsulation arrangement mode of a non-oil-filled mode, and the device for completely digitalizing the while-drilling acoustic wave receiving transducer array comprises:

the first module is used for performing sound-electricity conversion on weak received sound wave signals of the stratum;

the second module is used for amplifying, filtering, gain control and digital-to-analog conversion of the weak received sound wave signal;

and the third module is used for interface control and external input and output signal conversion of the device.

2. The all-digital device for while-drilling acoustic receive transducer arrays according to claim 1, wherein the all-digital device for while-drilling acoustic receive transducer comprises an even number of first modules, each first module being packaged independently.

3. The all-digital device for while-drilling acoustic wave receiving transducer array according to claim 1, wherein the first module is a receiving type piezoelectric ceramic wafer.

4. The all-digital device for the while-drilling acoustic wave receiving transducer array is characterized in that the receiving piezoelectric ceramic wafer is 40mm long and 25.4mm wide, and is placed at an interval of 152.4m after being rubber-encapsulated.

5. The all-digital device for while-drilling acoustic wave receiving transducer array according to claim 1, wherein the second module is an internal package circuit.

6. The all-digital device for while-drilling acoustic wave receiving transducer array according to claim 5, wherein the internal packaging circuit comprises:

the pre-amplification circuit is used for amplifying the weak received sound wave signal;

the band-pass filter circuit is used for realizing band-pass filtering;

the automatic gain control circuit is used for realizing automatic gain control of the weak received sound wave signal;

and the analog-to-digital conversion circuit is used for realizing the digital analog-to-digital conversion operation of the weak received sound wave signal.

7. The all-digital device for while-drilling acoustic wave receiving transducer array according to claim 1, wherein the third module is an interface MUX circuit.

8. The all-digital device for while-drilling acoustic wave receiving transducer array according to claim 7, wherein an SPI serial communication interface is adopted as an external output and input of the interface MUX circuit.

9. The all-digital while-drilling acoustic receive transducer array device according to claim 7, wherein the interface MUX circuit is integrated with AGC automatic gain control logic for performing gain control adjustment operations on the second module.

10. The all-digital device for receiving transducer arrays while drilling as recited in any one of claims 1 to 9, wherein the all-digital device for receiving transducers while drilling communicates in a differential manner.

Technical Field

The invention belongs to the technical field of acoustic logging while drilling, and particularly relates to a full digitalization device of an array receiving transducer of an acoustic logging while drilling instrument.

Background

The acoustic logging while drilling, which is one of three major technologies (resistivity, radioactivity and acoustic) of logging while drilling, has an important position in oil drilling logging, and can realize monitoring of formation porosity and pressure early warning in a drilling process, so that the drilling efficiency is improved, and the drilling operation risk is reduced.

The acoustic logging while drilling and the cable logging are the same in principle: 1. and acquiring the time velocity of the stratum sound wave through different propagation speeds of the sound wave in the stratum, thereby reflecting the current stratum to be met. 2. The conversion from electrical to acoustic and acoustic to electrical is achieved by acoustic wave transmitting and receiving transducers. In different aspects: while drilling, acoustic logging while drilling is to measure the acoustic velocity information of the formation being drilled in real time. And the cable logging is to realize the sound velocity measurement of the stratum in a cable suspension mode after the drilling operation is finished.

As shown in fig. 1, when the apparatus works in a well, the transmitting acoustic system excites the transmitting acoustic source to generate acoustic signals through high-voltage excitation pulses, the acoustic signals are transmitted through the stratum after being emitted into the stratum, and then reach the receiver array, and the receiver array arranged at a fixed distance from the transmitting acoustic source realizes the conversion from the received acoustic signals to electrical signals.

The transmitting transducer and the receiving transducer are passive devices mainly composed of piezoelectric ceramics, and the sound wave signals received by the receiving transducer are converted into weak electric signals through a piezoelectric ceramic wafer, and the amplitude of the weak electric signals is greatly different along with the difference of the stratum to be met. The amplitude of the signal is in the order of hundreds of uv to hundreds of mv, so that the signal needs to be subjected to automatic gain control and filtering amplification operation.

In the current well logging instrument development process, a preamplifier circuit and an acquisition circuit (an AGC automatic gain control circuit and an analog-to-digital converter (ADC)) are generally adopted to realize digital sampling of signals. The preamplification circuit is close to the receiving piezoelectric ceramic chip as much as possible, the preamplification circuit is used for amplifying and filtering weak signals, and the subsequent automatic gain control and analog-to-digital conversion (ADC) functions are placed in a receiving acoustic system circuit part. As shown in fig. 1, the receiving transducer is packaged by a single piezoceramic wafer. The pre-amplification circuit and the subsequent acquisition circuit are arranged outside the receiving piezoelectric ceramic wafer, the pre-amplification circuit is very close to the receiving ceramic wafer, but the acquisition circuit needs to be arranged in an instrument inner collar and is far away (generally 30cm to 50 cm). This arrangement has the following features: 1. the ceramic chip is simple in arrangement structure, 2, after the received weak signal is subjected to pre-amplification, the signal ratio is improved to a certain extent, but the signal is still an analog signal, and after the signal is transmitted to an acquisition circuit (30cm to 50cm), the signal is easily influenced by the external environment, the noise is increased, and the signal-to-noise ratio of the signal is reduced.

In order to improve the signal-to-noise ratio of the received weak signal, the most direct method is to digitize nearby, and then transmit the acquired waveform to the receiving acoustic system through the digital signal for subsequent data processing.

Disclosure of Invention

In order to achieve the above purpose, the invention relates to a digital packaging technology of a receiving transducer and a reasonable layout and signal extraction technology for digitalization. The invention provides a full-digitalization device of an acoustic wave receiving transducer array while drilling, which realizes the preprocessing and the acquisition of acoustic wave receiving signals in the while drilling process. The drill bit is simple in structure, easy to realize, suitable for severe environments such as strong vibration, impact and high temperature in the process of drilling, easy to realize and convenient to popularize and apply in the market.

According to one aspect of the invention, a device for fully digitizing an acoustic wave receiving while drilling transducer array is provided, wherein the acoustic wave receiving while drilling transducer array is digitally processed, and adopts a fully digitized structure and a rubber encapsulation arrangement mode of a non-oil-filled mode, and the device for fully digitizing the acoustic wave receiving while drilling transducer array comprises:

the first module is used for performing sound-electricity conversion on weak received sound wave signals of the stratum;

the second module is used for amplifying, filtering, gain control and digital-to-analog conversion of the weak received sound wave signal;

and the third module is used for interface control and external input and output signal conversion of the device.

Further, the all-digital device for the while-drilling acoustic wave receiving transducer comprises an even number of first modules, and each first module is packaged independently.

Further, the first module is a receiving type piezoelectric ceramic wafer.

Further, the size of the receiving piezoelectric ceramic wafer is 40mm in length and 25.4mm in width.

Further, the receiving piezoelectric ceramic wafer is placed at an interval of 152.4m after being rubber-encapsulated.

Further, the second module is an internal packaging circuit.

Further, the internal packaging circuit includes:

the pre-amplification circuit is used for amplifying the weak received sound wave signal;

the band-pass filter circuit is used for realizing band-pass filtering;

the automatic gain control circuit is used for realizing automatic gain control of the weak received sound wave signal;

and the analog-to-digital conversion circuit is used for realizing the digital analog-to-digital conversion operation of the weak received sound wave signal.

Further, the third module is an interface MUX circuit.

Furthermore, the external output and input of the interface MUX circuit adopt an SPI serial communication interface.

Further, the interface MUX circuit is integrated with an AGC automatic gain control logic for performing a gain control adjustment operation on the second module.

Furthermore, the full digitalization device of the while-drilling sound wave receiving transducer adopts a differential mode for communication.

The invention has the beneficial effects that:

through a full-digital structure, the low-noise signal acquisition of the acoustic wave receiving array while drilling is realized, and the installation, debugging and maintenance operation of the instrument are simplified by adopting a rubber tube sealing mode in a non-oil-filling mode. The signal-to-noise ratio and the consistency of the received signals are improved.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the structures shown in the drawings without creative efforts.

FIG. 1 shows a diagram of the operation of an acoustic logging-while-drilling tool;

FIG. 2 is a block diagram of a fully digital device of a receiving transducer array of an acoustic logging-while-drilling instrument according to an embodiment of the invention;

FIG. 3 is a diagram illustrating a second module of the full digitalization method and apparatus for a receiving transducer array of an acoustic logging-while-drilling instrument according to an embodiment of the present invention;

FIG. 4 illustrates a block diagram of a 4-stripe receive switch array device implemented in accordance with an embodiment of the invention;

FIG. 5 illustrates an interface MUX circuit block according to an embodiment of the invention;

FIG. 6 illustrates a packaged circuit module according to an embodiment of the invention;

FIG. 7 shows a schematic diagram of an arrangement according to an embodiment of the invention;

FIG. 8 is a diagram illustrating a received weak signal obtained after digitization according to an embodiment of the invention;

FIG. 9 shows a schematic diagram of the structural layout dimensions of a receive transducer array before potting in accordance with an embodiment of the invention;

FIG. 10 shows a schematic diagram of signals received at a 3Khz excitation source, in accordance with an embodiment of the present invention;

FIG. 11 shows a schematic diagram of signals received at a 12Khz excitation source, in accordance with an embodiment of the present invention;

fig. 12 shows a schematic diagram of signals obtained after potting of a fully digitized receive transducer 8 array (8 receive tiles) in accordance with an embodiment of the invention.

The implementation, functional features and advantages of the objects of the present invention will be further explained with reference to the accompanying drawings.

Detailed Description

Reference will now be made in detail to the exemplary embodiments, examples of which are illustrated in the accompanying drawings. When the following description refers to the accompanying drawings, like numbers in different drawings represent the same or similar elements unless otherwise indicated. The implementations described in the exemplary embodiments below are not intended to represent all implementations consistent with the present disclosure. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the present disclosure, as detailed in the appended claims.

The terms "first," "second," and the like in the description and in the claims of the present disclosure are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used is interchangeable under appropriate circumstances such that the embodiments of the disclosure described herein are, for example, capable of operation in sequences other than those illustrated or otherwise described herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.

A plurality, including two or more.

And/or, it should be understood that, for the term "and/or" as used in this disclosure, it is merely one type of association that describes an associated object, meaning that three types of relationships may exist. For example, a and/or B, may represent: a exists alone, A and B exist simultaneously, and B exists alone.

The invention provides a full-digitalization device of an acoustic wave receiving transducer array while drilling, which realizes the preprocessing and the acquisition of acoustic wave receiving signals in the while drilling process. The device adopts a full-digital structure, and is used for sampling received signals nearby and arranging the whole device. Compared with the prior art, the structure is simple and easy to realize. Meanwhile, the rubber potting arrangement mode of the non-oil-filling mode is different from the prior art.

The entire device 1 consists of three different types of sub-modules, including: submodule 2 (piezoceramic wafers, 0-7, 8 in total), submodule 3 (packaging circuit, 0-7, 8 in total), and submodule 4 (interface MUX, 1). The structure is shown in fig. 2.

The device total length 1300mm, submodule 2 interval 152.4mm place, and the interval between two submodule 2 places the encapsulation circuit.

The device comprises 8 receiving ceramic plates, wherein each receiving ceramic plate is independently packaged, and the receiving ceramic plates are placed at intervals of 152.4m after being encapsulated by rubber. The ceramic chip is a piezoelectric ceramic chip with the size of 40mm long and 25.4mm wide, and is widely used by the development of cable logging and logging-while-drilling instruments.

Submodule 2: receiving the piezoelectric ceramic piece: the acoustic wave signal of the formation is acoustically-to-electrically converted.

Submodule 3: the internal package circuit. The method for realizing amplification, filtering, gain control and analog-to-digital conversion of the weak received signal comprises the following steps: the preamplifier circuit 5: and amplifying and filtering the weak current signal. And (6) filtering: and realizing band-pass filtering. Automatic gain control AGC circuit 7: and realizing automatic gain control of weak signals. Analog-to-digital conversion ADC circuit 8: and realizing the digital analog-to-digital conversion operation of the signal.

Submodule 4: and the interface MUX circuit is used for realizing interface control and external input and output signal conversion of the whole device. The external input and output adopt SPI serial communication interface, and for improving transmission efficiency and reliability, the device adopts differential mode to make communication. AGC automatic gain control logic is integrated in the submodule 4, and a control circuit outside the device can perform gain control adjustment operation on each submodule 3 through an SPI interface.

The details of the sub-module 3 internal package circuits 5, 6, 7, 8 are described in detail below with reference to fig. 3.

Submodule 5: a pre-amplifier circuit. And receiving the weak signal of the ceramic chip, and amplifying and filtering. The specific functional structure is shown in the following figure. 2 times of amplification and 2-order low-pass filtering of the differential signal are realized, and the attenuation point of filtering 3dB is 30 kHz.

Submodule 6: band-pass filtering with a filtering band (3dB point) of 200Hz to 30kHz

Submodule 7: and AGC automatic gain control can realize 4 to 128 times of adjustable gain control.

Submodule 8: and the ADC realizes the conversion from analog to data of signals, the sampling frequency is 10kHz, the sampling bit width is 16 bits, and the sampling dynamic range is 0-3.3 v.

The whole device firstly carries out rubber encapsulation on the sub-module 3, and after the rubber encapsulation is finished, the whole rubber encapsulation is carried out on the sub-module 3 and the sub-module 2.

Use examples: after the device is integrally packaged, as shown in FIG. 4, a 4 strip receiving transducer array device of B1-B4 is realized. After 12 signal lines are connected through external power supply +/-3.3V, the analog acquisition circuit can read the received signals of the receiving transducer array in real time through the SPI interface. The rate reaches a sampling rate of 100 kHz. Meanwhile, after the digital packaging of 8 receiving ceramic chips is realized, the power consumption of the device is controlled within 1W at normal temperature and within 1.6W at 175 ℃. Meanwhile, the rubber can bear the external ring pressure of 172Mpa after being packaged. The device can be simply applied to the development of logging while drilling and cable logging instruments.

The invention can realize the digital operation of the sound wave receiving signal. The sampling frequency is 100kHz and the bit width is 16 bit. The adjustable dynamic gain range is 4 to 128 times. The dynamic range of the sampling voltage is 0 to 3.3 v.

The technical effect verification process comprises the following steps:

(1) the signal-to-noise ratio of signals is improved after the array digitization of the receiving transducer, aiming at weak signal receiving, various processing is carried out on the interface MUX circuit module and the packaging circuit module, and the processing comprises the following steps: and analog signal processing such as weak signal acquisition, matching, filtering, amplification, re-filtering and the like is performed, and then analog-to-digital conversion is realized through an ADC (analog-to-digital converter).

According to the arrangement and method of fig. 7, 6 groups of tiles, an interface MUX circuit module (as shown in fig. 5) and a packaging circuit module (as shown in fig. 6) are subjected to overall electrical fitting and testing (electrical fitting is performed according to the layout method, but encapsulation is not performed), so that full digitalization of 6 receiving tiles is realized, and a received weak signal obtained after digitalization is shown in fig. 8. The consistency, signal-to-noise ratio and anti-interference capability of the signals are improved.

(2) The signal quality obtained after the full digital receiving transducer array (2 ceramic chips) is encapsulated is further improved.

The structural layout size chart before the encapsulation of the receiving transducer array is shown in fig. 9, according to the layout size, the non-oil-filled encapsulation of 2 array full-digital receiving transducers is realized, the receiving transducer array is placed in silicon oil for acoustic system performance test, and the received signal quality is improved under the excitation sources of 3Khz (shown in fig. 10) and 12Khz (shown in fig. 11).

The properties of the tape after the whole encapsulation were obtained as follows:

normal temperature power consumption: 1.14W

Power consumption at 180 ℃: less than 1.5W

Noise: 50mv @20kHz

Sampling rate: 100kHz

Sampling precision: 16bit

Sampling voltage: 0v to 3.3v

Gain: adjustable 4-128 times

Pressure resistance: 125Mpa (actual measurement confining pressure)

(3) The signals obtained after potting of the fully digital receive transducer 8 array (8 receive tiles) are shown in fig. 12.

The properties of the receiving tape after potting were as follows:

time difference: 330m/s

Excitation frequency: 5kHz, single period sine

Actual amplitude of received signal (consistent with hydrophone): 110uv

CH1-CH8 decrements in amplitude

Sampling rate: 100kHz

Sampling precision: 16bit

Minimum resolution: 50nv (effective sampling 10bit)

Sampling dynamic range: 0v to 3.3v

Gain: 6.5 ten thousand times, 64-step adjustable

Normal temperature power consumption: 1.14W

Power consumption at 180 ℃: less than 1.5W

Size: 1300 x 50 x 15mm

Interface: SPI 2, 10Mbps

Power supply: 3.3v

While the present invention has been described with reference to the embodiments shown in the drawings, the present invention is not limited to the embodiments, which are illustrative and not restrictive, and it will be apparent to those skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope of the invention as defined in the appended claims.