CN116291384A - Distributed optical fiber acoustic logging method and system - Google Patents
Distributed optical fiber acoustic logging method and system Download PDFInfo
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- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B47/00—Survey of boreholes or wells
- E21B47/005—Monitoring or checking of cementation quality or level
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- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B47/00—Survey of boreholes or wells
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- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B47/00—Survey of boreholes or wells
- E21B47/12—Means for transmitting measuring-signals or control signals from the well to the surface, or from the surface to the well, e.g. for logging while drilling
- E21B47/14—Means for transmitting measuring-signals or control signals from the well to the surface, or from the surface to the well, e.g. for logging while drilling using acoustic waves
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- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B49/00—Testing the nature of borehole walls; Formation testing; Methods or apparatus for obtaining samples of soil or well fluids, specially adapted to earth drilling or wells
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Abstract
The invention relates to a distributed optical fiber acoustic logging method and a technical scheme of a system, which comprise the following steps: emitting laser and outputting an optical pulse signal, wherein the period of the optical pulse signal is preset; loading a measurement signal into the optical pulse signal in response to a change in the measurement signal, modulating the optical pulse signal; demodulating the modulated optical pulse signal and outputting the measurement signal. The beneficial effects of the invention are as follows: the distributed optical fiber acoustic wave receiving mode of the full-well Duan Xian type measurement is adopted, so that the signal acquisition with large data quantity and the signal quality with full time, full space and wide frequency are realized, and the signal quality is also greatly improved.
Description
Technical Field
The invention relates to the technical field of geophysical exploration, in particular to a distributed optical fiber acoustic logging method and system.
Background
With the continuous expansion of the drilling scale of oil and gas fields and the development of scientific technology, particularly the rapid development of logging technology, advanced scientific technology is urgently needed to play an important role in oil and gas field exploitation.
Acoustic characteristics such as changes in speed, amplitude, and frequency are also different when acoustic waves propagate in different media. Acoustic logging is a logging method that utilizes these acoustic properties of rock to study the geological profile of the well, judging the quality of the well cementation.
In the prior art, a point-type measurement acoustic logging system is difficult to realize the acquisition of large-data-volume signals with full time, full space and wide frequency. How to realize the whole coverage of time and space and improve the sensitivity and fidelity of the sound wave signal quality in the sound wave measurement is a problem to be solved.
Disclosure of Invention
The invention aims at least solving one of the technical problems in the prior art, and provides a distributed optical fiber acoustic logging method and a system, which realize the whole coverage of time and space and improve the sensitivity and fidelity of acoustic signal quality in acoustic measurement.
The technical scheme of the invention comprises a distributed optical fiber acoustic logging method, which comprises the following steps: s100, emitting laser and outputting an optical pulse signal, wherein the period of the optical pulse signal is preset; s200, loading the measurement signal into the optical pulse signal in response to the change of the measurement signal, modulating the optical pulse signal S300, demodulating the modulated optical pulse signal, and outputting the measurement signal.
According to the distributed optical fiber acoustic logging method, the responding to the change of the measurement signal comprises: the measuring signal is responded by a distributed optical fiber receiving sensor, wherein the distributed optical fiber receiving sensor responds to the change of the measuring signal by measuring the optical pulse signal based on the change of the optical property of the optical pulse signal along with the change of the measuring signal.
According to the distributed optical fiber acoustic logging method, the demodulating the modulated optical pulse signal includes: and decomposing the optical pulse signal to obtain a modulated optical pulse signal and an optical pulse signal to be modulated, and demodulating the modulated optical pulse signal and the optical pulse signal to be modulated according to a corresponding processing mode.
The technical scheme of the invention also comprises a distributed optical fiber acoustic logging system, which comprises an optoelectronic ground system 100, an optical cable system 200 and a downhole measurement system 300; one end of the optical cable system 200 is connected with the downhole measurement system 300, and the other end is connected with the photoelectric surface system 100, and is used for transmitting optical pulse signals and/or adjusting the depth of the downhole measurement system 300 into a well; the optical-electrical terrestrial system 100 is configured to output, receive, and demodulate the optical pulse signal; the downhole measurement system 300 is configured to load a measurement signal into the optical pulse signal and to modulate the optical pulse signal.
According to the distributed fiber acoustic logging system, the optoelectronic surface system 100 includes a laser emission system 110, a signal processing system 120, and a beam splitter 140; the laser emission system 110 is configured to generate the optical pulse signal, and includes a high-power broadband light source 111 and an optical pulse generator 112; the signal processing system 120 is configured to demodulate the optical pulse signal to obtain the measurement signal, and the signal processing system 120 includes an optical pulse signal demodulation processing system 121; the optoelectronic ground system 100 further comprises a display device 130, the display device 130 being configured to display the measurement signal; the optical splitter 140 is configured to split the optical pulse signal into an optical pulse signal to be modulated and a modulated optical pulse signal.
According to the distributed optical fiber acoustic logging system, the demodulation includes: the optical pulse signal modulated by the downhole measurement system 300 is returned to the photoelectric surface system 100 through the optical cable system 200, and the modulated optical pulse signal is demodulated by the optical pulse signal demodulation processing system 121 to obtain the measurement signal.
According to the distributed optical fiber acoustic logging system, the optical cable system 200 includes an optical-electrical composite cable 210 and a hoisting crown block device 220, the optical-electrical composite cable 210 is wound around a pulley of the hoisting crown block device 220, and the optical-electrical composite cable 210 is used for transmitting signals.
According to the distributed fiber acoustic logging system, the adjusting the depth of the downhole measurement system 300 into the well includes: adjusting or fixing the vertical height of the downhole measurement system 300 in the direction of gravity by the lifting crown block device 220; the other end of the photoelectric composite cable 210 is connected with the photoelectric ground system 100, and the horizontal distance between the photoelectric ground system 100 and a wellhead is adjusted in the horizontal direction.
The beneficial effects of the invention are as follows: the invention uses the optical property of the light wave to respond to the tiny signals to be measured such as sound wave in time, and uses the light as a carrier to measure the signals, so that the result has higher accuracy and sensitivity; by adopting the distributed optical fiber acoustic wave receiving scheme of the whole well Duan Xian type measurement, the large data volume signal acquisition of whole time, whole space and wide frequency can be realized, and the signal quality is greatly improved.
Drawings
The invention is further described below with reference to the drawings and examples;
FIG. 1 is a flow chart of distributed fiber optic sonic logging according to an embodiment of the present invention.
FIG. 2 is a block diagram of a distributed fiber acoustic logging system according to an embodiment of the present invention.
Fig. 3 is a schematic structural diagram of an optoelectronic ground system according to an embodiment of the present invention.
Fig. 4 is a diagram showing a structure of a distributed optical fiber acoustic transceiver according to an embodiment of the present invention.
FIG. 5 is a schematic diagram of downhole acoustic propagation according to an embodiment of the present invention.
Detailed Description
Reference will now be made in detail to the present embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein the accompanying drawings are used to supplement the description of the written description so that one can intuitively and intuitively understand each technical feature and overall technical scheme of the present invention, but not to limit the scope of the present invention.
In the description of the present invention, unless explicitly defined otherwise, terms such as arrangement and the like should be construed broadly, and those skilled in the art can reasonably determine the specific meaning of the terms in the present invention in combination with the specific contents of the technical scheme.
As shown in fig. 1, a distributed optical fiber acoustic logging method includes:
s100, emitting laser and outputting an optical pulse signal, wherein the period of the optical pulse signal is preset. Different from sound waves, light is electromagnetic wave with extremely short wavelength, and the optical length of the light is obtained through the phase of the light, so that the light has higher sensitivity; the light has high propagation speed and can transmit two-dimensional information, and can be used for high-speed measurement; the frequency of the light is extremely high, the contained frequency band is wider, and more accurate measuring signals such as sound waves can be obtained by taking the light as a carrier in the modulation and demodulation by combining the advantages, wherein the period of the light pulse signal can be preset to be a numerical value which enables the measuring result to have higher accuracy through experiments.
S200, loading the measurement signal into the optical pulse signal in response to the change of the measurement signal, and modulating the optical pulse signal. The measurement signals include temperature, acoustic waves, fluid flow, etc. The optical pulse signal is transmitted through an optical cable. The invention adopts a distributed optical fiber receiving sensor to respond to the measuring signal so as to measure the signal in a full-segment and sensitive way, and the optical fiber receiving sensor receives the measuring signal and changes the optical properties of the corresponding optical pulse signal such as intensity, wavelength, frequency, phase, off-normal and the like along with the change of the measuring signal.
S300, demodulating the modulated optical pulse signal and outputting the measurement signal. The optical pulse signal is decomposed to obtain a modulated optical pulse signal and an optical pulse signal to be modulated, and the existing demodulation methods such as a difference detection method and a homodyne detection method can be adopted.
Different from the acoustic logging method for direct measurement in the prior art, the method utilizes the optical property of the light wave to respond to tiny signals to be measured such as acoustic waves in time, and takes light as a carrier to measure the signals, so that the result has higher accuracy and sensitivity.
Based on the principle of the distributed optical fiber acoustic logging method, the invention also provides a distributed optical fiber acoustic logging system. As shown in fig. 2, the present embodiment proposes a distributed optical fiber acoustic logging system including: an optoelectronic surface system 100, a fiber optic cable system 200, and a downhole measurement system 300. The optical cable system 200 has one end connected to the downhole measurement system 300 and the other end connected to the photoelectric surface system 100, and is mainly used for transmitting optical pulse signals and adjusting the depth of the downhole measurement system 300 into the well. The photoelectric surface system 100 is mainly used for transmitting, receiving and demodulating optical information, and the demodulation includes demodulating measurement signals such as downhole temperature, pressure, flow, sound wave and the like from received optical pulse signals. The downhole measurement system 300 is configured to load a measurement signal into an optical pulse signal to implement modulation of the optical pulse signal.
As shown in fig. 3, the optoelectronic ground system 100 includes a laser emitting system 110, a signal processing system 120. The laser emitting system 110 is used for generating an optical pulse signal, and mainly includes a high-power broadband light source 111 (not shown in fig. 3) and an optical pulse generator 112 (not shown in fig. 3); the signal processing system 120 is configured to demodulate the modulated optical pulse signal to obtain a measurement signal; the signal processing system 120 includes an optical pulse signal demodulation processing system 121 (not shown in fig. 3). The electro-optical ground system 100 further includes a display device 130 for displaying the result of the measurement signal, and may be displayed in any form such as text or image. The optical-electrical ground system 100 further includes an optical splitter 140, configured to input the transmitted optical pulse signal and the received modulated optical pulse signal into different systems, and the optical pulse signal generated by the laser transmitting system 110 is input into the optical cable system 200, and the downhole measurement system 300 performs signal modulation; the optical cable system 200 outputs a modulated optical pulse signal, and the modulated optical pulse signal is input to the signal processing system 120 through the optical splitter 140 to be demodulated, and the optical pulse signal is decomposed into a sub-modulated optical pulse signal and a modulated optical pulse signal through the optical splitter 140.
The optical cable system 200 comprises a set of photoelectric composite cables 210, a lifting crown block device 220, wherein the photoelectric composite cables 210 are wound on pulleys of the lifting crown block device 220, one end of each photoelectric composite cable 210 is connected with the underground measuring system 300 (not shown in fig. 2), the vertical height of the underground measuring system 300 is adjusted in the gravity direction through the lifting crown block device 220, and the underground measuring system 300 is fixed when reaching a preset well depth; the other end of the photoelectric composite cable 210 is connected to the photoelectric ground system 100, and the horizontal distance between the photoelectric ground system 100 and the wellhead is adjusted in the horizontal direction perpendicular to the gravity direction, so that the depth of the well reached by the downhole measurement system 300 is deeper as the horizontal distance between the photoelectric ground system 100 and the wellhead is closer. The optical-electrical composite cable 210 is used for transmitting signals, and the transmitting signals may be optical, electrical, etc. signals, and the optical-electrical composite cable 210 in the present invention is used for transmitting optical pulse signals.
In order to improve the depth and sensitivity of underground detection, the invention provides a distributed optical fiber acoustic transceiver. Referring to fig. 4, the distributed optical fiber acoustic transceiver includes a housing 310 having a hollow columnar structure; a plurality of backings 322 disposed in the housing 310, and a plurality of backings 322 arranged at intervals along the axial direction of the housing 310, wherein adjacent backings 322 are connected by the photoelectric connector 350; an optical fiber 321 disposed in the housing 310, the optical fiber 321 being provided with a plurality of receiving sections 320, the optical fiber 321 of each receiving section 320 being wound on the backing 322 at a predetermined angle; at least one acoustic signal source 340
In one embodiment, the acoustic wave signal source 340 is configured to emit acoustic wave signals at fixed frequencies in each direction at intervals. The acoustic wave signal source 340 employs a dipole transducer to excite an acoustic wave signal, where the acoustic wave signal source 340 includes an emission electronic circuit, an acoustic source emitter, where the acoustic source generator may be an array monopole, dipole or multipole piezoelectric ceramic, an electric spark source, an electromechanical source, and the like. Under the action of the ground control signal and the driving signal, the acoustic wave signal source 340 continuously emits high-power acoustic wave signals to the periphery of the borehole, the acoustic wave signals are radiated to the wall of the exploratory well at different angles, and acoustic wave signals such as reflection, diffraction, sliding and the like are generated, wherein the sliding acoustic wave signals are also continuously refracted at an incident angle of 90 degrees in the propagation process.
In one embodiment, referring to FIG. 5, the acoustic signal source 340 emits acoustic waves into the medium surrounding the well, and according to Fresnel's law, when a signal propagates from a uniform medium with a refractive index of x1 to another uniform medium with a refractive index of x2, both reflections and refractions are simultaneously released at the junction between the two and the angle of reflection is equal to the angle of incidence, and it is known that the emitted acoustic waves, after encountering the wave packet interface, are reflected back into the well and received by the receiving section 320 through the housing. The positions in the receiving section 320 can generate stretching or compression with the same frequency along with the vibration of the sound wave, and at this time, the phases of the back Rayleigh scattering waves at the positions of the receiving section 320 are correspondingly changed, so that the loading of the sound wave is realized.
In one embodiment, the plurality of receiving segments 320 are arranged according to a predetermined distance to form an optical fiber receiving group 330; the optical fiber receiving group 330 near the acoustic signal source 340 is a first optical fiber receiving group; the optical fiber receiving group 330 far from the acoustic wave signal source 340 is a second optical fiber receiving group; the first optical fiber receiving group is used for receiving the medium-high frequency sound wave signals; the second optical fiber receiving group is used for receiving the low-frequency sound wave signals.
In one embodiment, the optical fiber 321 is wound on the backing 322 at a certain angle to form the receiving section 320, wherein a bragg fiber grating is written in the core of the optical fiber 321, and epoxy resin is used as the packaging material of the optical fiber 321 to sensitize the optical fiber 321 so as to improve the response sensitivity of the acoustic wave signal. The back lining 322 is a miniature cylindrical solid, and the shell of the back lining 322 is made of high-strength corrosion-resistant titanium alloy, metal, high-density alloy steel, cast iron with rust-proof treatment or other unrecited high-density materials; the backing 322 is provided with helical grooves of adjustable pitch and a snap-in structure, the helical grooves of the rigid backing 322 being mutually coupled with the optical fibers 321 to carry the sensitized optical fibers, the properties of the receiving section 320, such as receiving direction, frequency range, etc., being adjustable by adjusting the pitch and size of the helical grooves. The high-frequency sound wave signal has rich frequency resources and large system capacity, but the higher the frequency is, the larger the transmission loss is, and the closer the coverage distance is, the first optical fiber receiving group is used for receiving the medium-frequency sound wave signal and the high-frequency sound wave signal, and the performance of the receiving section 320 formed by the sensitized optical fibers, such as the receiving direction and the frequency range, can be adjusted by adjusting the pitch and the size of the spiral groove; by way of example, the pitch of the spiral groove is adjusted, and the pitch of the spiral groove is further reduced, so that the sensitized optical fiber is tightly wound, and acoustic signals in the middle and high frequency ranges are received as much as possible; the air is little to the sound wave absorption of low frequency, and the attenuation is little, and the sound wave signal transmission of low frequency is farther, and the second optic fibre is received the group and is used for receiving low frequency sound wave signal, and exemplified, the pitch of adjusting the helicla flute further increases the pitch of helicla flute for distributed microstructure sensitization optic fibre winding is sparse, receives the sound wave signal of low frequency range as far as, and optic fibre 321 passes through the wire winding groove wiring in addition, has protected optic fibre 321, has reduced the cracked risk of optic fibre 321. The angle of the helical groove may be adjusted so that the angle of winding the sensitized optical fiber around the backing 322 may be between 20 degrees and 70 degrees to enhance the performance of the receiving section 320.
In one embodiment, the plurality of fiber optic receiving groups 330 are sequentially arranged in a straight line and connected by a plurality of optical electrical connectors 350 to form a continuous structure, i.e. a distributed fiber optic acoustic wave receiver. The optical fiber receiving group 330 near the acoustic wave signal source 340 is a first optical fiber receiving group, which is used for receiving the medium-frequency and high-frequency acoustic wave signals, and the performance of the optical fiber receiving group 330 can be enhanced by adjusting the distance between the receiving sections 320 in the optical fiber receiving group 330, for example, the receiving sections 320 in the first optical fiber receiving group are closely arranged, for example, 10 receiving sections 320 are equally spaced to form a first group, wherein the interval is 10cm; the optical fiber receiving group 330 far from the acoustic wave signal source 340 is a second optical fiber receiving group for receiving the low frequency acoustic wave signal, for example, 10 receiving sections 320 are equally spaced to form the second group, or 10 receiving sections 320 are gradually spaced to form the second group, for example, 20cm,30cm,40cm,50cm, 1m.
The optical fiber receiving group 330 with different frequency bands is arranged, wherein the optical fiber receiving group 330 close to the sound wave signal source 340 is a conventional receiving group; the optical fiber receiving group 330 at the end of the acoustic signal source 340 is a low frequency receiving group. The transmission distance of the acoustic signal of the conventional frequency is relatively short, so that each receiving section 320 in the conventional receiving group is closely arranged to each other and is close to the transmitting unit; the transmission distance of the acoustic signal at the low frequency is relatively long, so that the receiving sections 320 in the low frequency receiving group are arranged sparsely with each other and far from the transmitting unit. The distributed optical fiber receiving groups 330 are arranged, so that the distributed acoustic characteristics in the exploratory well can be extracted in a large range and in an omnibearing manner, and the evaluation and interpretation of logging data are greatly improved.
In one embodiment, the housing 310 is a rigid structure and is provided with an interface for up-down connection, and a plurality of sound-transmitting windows 311 are provided on the housing 310. The housing 310 is provided with a plurality of sound insulation groove structures, and the sound insulation groove structures comprise a plurality of parallel and staggered notch grooves. The housing 310 includes an interface for connecting up and down and a plurality of sound-transmitting windows 311, wherein each sound-transmitting window 311 includes one or more windows for direct transmission of sliding acoustic signals, and loss in transmission of sliding acoustic signals is reduced, and the windows may be symmetrically or asymmetrically distributed, or may be an annular large window. The shell 310 can be further provided with a plurality of parallel and staggered sound insulation groove structures, and the sound insulation groove structures can increase the transmission distance of the direct sound wave signals and further weaken the direct sound wave signals; or the direct sound wave signals with different phases are obtained along different propagation paths, and the direct sound wave signals with different phases are further overlapped to weaken the amplitude of the direct sound wave signals; or to buffer the vibrational coupling of the acoustic signal to the housing 310 to further reduce interference from the vibrational coupling. When the acoustic signal source 340 emits an acoustic signal, the acoustic signal propagating along the housing 310 is a direct acoustic signal, and the acoustic characteristic of the direct acoustic signal about the exploratory well is not recorded as an interference wave, and the direct acoustic signal is mostly attenuated by the sound insulation groove structure of the housing 310; the acoustic signal refracted along the well wall is a sliding acoustic signal, the acoustic property of the logging well is the acoustic signal to be tested, and the sliding acoustic signal enters the receiving section 320 through the window of the acoustic window 311.
The distributed optical fiber receiving groups 330 are arranged, so that the distributed acoustic characteristics in the exploratory well can be extracted in a large range and in an omnibearing manner, wherein the shell 310 adopts a long-distance and parallel staggered grooving and sound insulation groove structure, the interference influence of direct waves can be avoided to a large extent, the optical characteristics of the optical fiber 321 can cause the optical fiber acoustic transceiver to generate larger phase change for slight vibration, the distributed optical fiber receiving groups 330 can sensitively acquire sliding acoustic signals, and the depth and the sensitivity of the distributed optical fiber acoustic transceiver are improved to a large extent.
Unlike traditional piezoelectric ceramic acoustic wave transceiver, which utilizes piezoelectric effect and inverse piezoelectric effect of piezoelectric ceramic to realize mutual conversion of electric energy and acoustic energy, the distributed optical fiber acoustic wave transceiver of the present invention utilizes optical characteristic to realize conversion of optical energy and acoustic energy, is insensitive to electromagnetic interference and can bear extreme conditions including high temperature, high pressure and strong impact and vibration, and can measure geological and petrophysical parameters of stratum being drilled with high precision.
The downhole measurement system 300 may employ a distributed fiber optic sonic transceiver for sonic loading. Light is affected by external factors and the corresponding optical properties, such as intensity, wavelength, frequency, phase, off-normal, etc., change. The distributed optical fiber acoustic wave receiving acoustic system 310 is configured to respond to small changes in a measurement signal, such as small vibrations caused by temperature changes, acoustic waves, fluid flow, etc., with high sensitivity, by loading the measurement signal into an optical pulse signal, for example, by loading an acoustic signal generated by an acoustic source, such as surface-excited seismic waves, small vibrations generated by fluid flow in a well, into the optical pulse signal by the downhole measurement system 300, and if no acoustic source is available, the downhole measurement system 300 further includes an acoustic source transmitter 320, the acoustic source transmitter 320 being positioned at any location, and the acoustic source transmitter 320 being coupled to the distributed optical fiber acoustic wave receiving acoustic system 310 and being in line. The distributed optical fiber sound wave receiving system 310 comprises a plurality of groups of optical fiber receivers 311 and a plurality of groups of photoelectric composite quick connectors 312, wherein the distributed measurement of the plurality of groups of optical fiber receivers 311 further expands the direction and the spatial range of the received measurement signals, can realize the extraction of the distribution information of a large-scale measurement field, and has larger improvement compared with the signal quality of the point measurement distributed measurement. Based on the principle that light is modulated in an optical pulse signal modulation system, optical fiber sensors can be classified into: intensity modulation type, phase modulation type, polarization modulation type frequency modulation type, wavelength modulation type, etc., the present invention adopts any modulation scheme. The optical fiber receivers 311 are distributed on a straight line at intervals or unequal intervals, two ends of the photoelectric composite quick connector 312 are respectively connected with the optical fiber receivers 311, and the optical fiber receiving array is formed by the optical fiber receivers 311 and the photoelectric composite quick connectors 312.
In an embodiment, the photoelectric ground system 100 moves away from or near the wellhead at a constant speed in the horizontal direction, the underground measurement system 300 moves from underground to wellhead or vice versa in the gravity direction through the transmission action of the optical cable system 200, the underground measurement system 300 can reach various positions of different depths of a well through the constant speed in the gravity direction, and the distributed optical fiber receivers 311 are combined.
Unlike available acoustic logging system, the present invention adopts distributed fiber acoustic wave receiving acoustic system of Duan Xian type, and can realize the acquisition of large data amount signal in all time, all space and wide frequency and raise signal quality. In addition, the distributed optical fiber sound wave receiving acoustic system 310 responds to tiny signals to be detected such as sound waves in time based on the optical property of light waves, and has higher sensitivity.
The optical pulse signal modulated by the downhole measurement system 300 is returned to the photoelectric ground system 100 through the optical cable system 200, the optical pulse signal demodulation processing system 121 demodulates the modulated optical pulse signal to obtain a measurement signal, and the obtained measurement signal is saved for subsequent analysis and can be displayed by the display device 130.
It should be appreciated that the method steps in embodiments of the present invention may be implemented or carried out by computer hardware, a combination of hardware and software, or by computer instructions stored in non-transitory computer-readable memory. The method may use standard programming techniques. Each program may be implemented in a high level procedural or object oriented programming language to communicate with a computer system. However, the program(s) can be implemented in assembly or machine language, if desired. In any case, the language may be a compiled or interpreted language. Furthermore, the program can be run on a programmed application specific integrated circuit for this purpose.
Furthermore, the operations of the processes described herein may be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The processes (or variations and/or combinations thereof) described herein may be performed under control of one or more computer systems configured with executable instructions, and may be implemented as code (e.g., executable instructions, one or more computer programs, or one or more applications), by hardware, or combinations thereof, collectively executing on one or more processors. The computer program includes a plurality of instructions executable by one or more processors.
Further, the method may be implemented in any type of computing platform operatively connected to a suitable computing platform, including, but not limited to, a personal computer, mini-computer, mainframe, workstation, network or distributed computing environment, separate or integrated computer platform, or in communication with a charged particle tool or other imaging device, and so forth. Aspects of the invention may be implemented in machine-readable code stored on a non-transitory storage medium or device, whether removable or integrated into a computing platform, such as a hard disk, optical read and/or write storage medium, RAM, ROM, etc., such that it is readable by a programmable computer, which when read by a computer, is operable to configure and operate the computer to perform the processes described herein. Further, the machine readable code, or portions thereof, may be transmitted over a wired or wireless network. When such media includes instructions or programs that, in conjunction with a microprocessor or other data processor, implement the steps described above, the invention described herein includes these and other different types of non-transitory computer-readable storage media. The invention also includes the computer itself when programmed according to the methods and techniques of the present invention.
The computer program can be applied to the input data to perform the functions described herein, thereby converting the input data to generate output data that is stored to the non-volatile memory. The output information may also be applied to one or more output devices such as a display. In a preferred embodiment of the invention, the transformed data represents physical and tangible objects, including specific visual depictions of physical and tangible objects produced on a display.
The embodiments of the present invention have been described in detail with reference to the accompanying drawings, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge of one of ordinary skill in the art without departing from the spirit of the present invention.
Claims (8)
1. A distributed optical fiber acoustic logging method, comprising:
s100, emitting laser and outputting an optical pulse signal, wherein the period of the optical pulse signal is preset;
s200, responding to the change of a measuring signal, loading the measuring signal into the optical pulse signal, and modulating the optical pulse signal;
s300, demodulating the modulated optical pulse signal and outputting the measurement signal.
2. The distributed fiber acoustic logging method of claim 1, said responding to changes in the measurement signal comprising:
the measuring signal is responded by a distributed optical fiber receiving sensor, wherein the distributed optical fiber receiving sensor responds to the change of the measuring signal by measuring the optical pulse signal based on the change of the optical property of the optical pulse signal along with the change of the measuring signal.
3. The distributed fiber acoustic logging method of claim 1, said demodulating the modulated optical pulse signal comprising:
and decomposing the optical pulse signal to obtain a modulated optical pulse signal and an optical pulse signal to be modulated, and demodulating the modulated optical pulse signal and the optical pulse signal to be modulated according to a corresponding processing mode.
4. A distributed fiber acoustic logging system, comprising an optoelectronic surface system (100), an optical cable system (200), and a downhole measurement system (300);
one end of the optical cable system (200) is connected with the underground measuring system (300), and the other end of the optical cable system is connected with the photoelectric ground system (100) and is used for transmitting optical pulse signals and/or adjusting the depth of the underground measuring system (300) into a well;
the optoelectronic ground system (100) is configured to output, receive and demodulate the optical pulse signal;
the downhole measurement system (300) is for loading a measurement signal into the optical pulse signal and for modulating the optical pulse signal.
5. The distributed fiber acoustic logging system of claim 4, said optoelectronic surface system (100) comprising a laser emitting system (110), a signal processing system (120), and a beam splitter (140);
the laser emission system (110) is used for generating the optical pulse signal and comprises a high-power broadband light source (111) and an optical pulse generator (112);
the signal processing system (120) is used for demodulating the optical pulse signal to obtain the measurement signal, and the signal processing system (120) comprises an optical pulse signal demodulation processing system (121);
the optoelectronic ground system (100) further comprises a display device (130), the display device (130) being adapted to display the measurement signal;
the optical splitter (140) is configured to split the optical pulse signal into an optical pulse signal to be modulated and a modulated optical pulse signal.
6. The distributed fiber acoustic logging system of claim 5, said demodulating comprising:
the optical pulse signal modulated by the underground measuring system (300) is returned to the photoelectric ground system (100) through the optical cable system (200), and the modulated optical pulse signal is demodulated by the optical pulse signal demodulation processing system (121) to obtain the measuring signal.
7. The distributed fiber acoustic logging system of claim 4, said fiber optic cable system (200) comprising a photoelectric composite cable (210) and a lifting sheave apparatus (220), said photoelectric composite cable (210) being wrapped around a sheave of said lifting sheave apparatus (220), said photoelectric composite cable (210) being used to transmit signals.
8. The distributed fiber acoustic logging system of claim 7, said adjusting a depth of said downhole measurement system (300) into a well comprising:
adjusting or fixing the vertical height of the downhole measurement system (300) in the direction of gravity by the lifting crown block device (220); the other end of the photoelectric composite cable (210) is connected with the photoelectric ground system (100), and the horizontal distance between the photoelectric ground system (100) and a wellhead is adjusted in the horizontal direction.
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116719138A (en) * | 2023-08-04 | 2023-09-08 | 中国电力科学研究院有限公司 | Optical fiber laying equipment, underground pipeline positioning method and system |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116719138A (en) * | 2023-08-04 | 2023-09-08 | 中国电力科学研究院有限公司 | Optical fiber laying equipment, underground pipeline positioning method and system |
| CN116719138B (en) * | 2023-08-04 | 2023-10-20 | 中国电力科学研究院有限公司 | Optical fiber laying equipment, underground pipeline positioning method and system |
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