Three-component distributed fiber optic acoustic sensor array acoustic logging device and measurement method

Abstract

The three-component distributed fiber optic acoustic wave sensor array acoustic logging device of this invention replaces the monopole, dipole, or multipole piezoelectric acoustic wave receiving transducers in conventional array acoustic wave logging devices with a three-component distributed acoustic wave sensing optical cable. This instrument can collect array acoustic wave signals for extended periods in high-temperature deep wells. The downhole receiving sensor requires no electronic components or wiring, solving the problem that downhole monopole, dipole, or multipole piezoelectric acoustic wave receiving transducers and their associated high-cost amplifiers, analog-to-digital converters, data storage devices, and downhole data transmission modules cannot operate for extended periods at high temperatures. Through the armored optoelectronic composite cable connected to the fiber optic array acoustic wave logging device, the backscattered Rayleigh light signal from the three-component distributed acoustic wave sensing optical cable can be transmitted at high speed to the surface multi-channel DAS modulator / demodulator, solving the bottleneck problem of high-speed upward transmission of large amounts of data signals collected by downhole array acoustic wave logging devices.

Description

Technical Field

[0001] This invention relates to the field of geophysical exploration technology, and in particular to an acoustic logging device and measurement method based on a three-component distributed fiber optic acoustic wave sensor array. Background Technology

[0002] When sound waves propagate in different media, their acoustic properties, such as velocity, amplitude, and frequency, vary. Sonic logging is a logging method that utilizes these acoustic properties of rocks to study the geological profile of the well and assess the quality of cementing.

[0003] Sonic logging is a well logging method that determines the properties of rock formations by studying the propagation velocity of sound waves within the formation during borehole drilling. A typical array sonic velocity logging tool consists of a set of sonic generators (T) and two or more receivers (R0, R1). The recorded parameter is the time difference (Δt) between the arrival of the sound wave at the two receivers, i.e., the time required for the sound wave to propagate through the rock formation between the two receivers. In essence, it is a time measurement system. The speed at which sound waves propagate through the rock formation is determined by factors such as the rock's elasticity, density, and the properties of the fluids within the pores.

[0004] A controlled acoustic wave source is placed in the well. The sound waves emitted by the source cause vibrations in surrounding particles, generating body waves (P-waves and S-waves) in the formation and induced interface waves (pseudo-Rayleigh waves and Stoneley waves) at the wellbore-drilling fluid interface. These waves, acting as carriers of formation information, are received by a downhole receiver and recorded at the surface; this is acoustic logging. The receiver and sound source are collectively called the acoustic system. Based on the arrangement and size of the acoustic system, acoustic logging tools can be classified as compensated logging tools (BHC), long-spacing acoustic logging tools (LSS), and array acoustic logging tools. The propagation of sound waves within the formation is affected by changes in the composition, structure, and fluid composition of the formation rocks; the wave velocity, amplitude, and even frequency can vary. Acoustic logging is divided into velocity logging and amplitude logging. Logging that only records changes in sound wave velocity is called velocity logging (AC), while logging that records changes in sound amplitude is called amplitude logging. In acoustic velocity logging, short-source acoustic systems only record the propagation time difference of longitudinal waves (i.e., the first wave), while long-source acoustic systems can record the propagation time differences of various wave trains such as longitudinal waves, transverse waves, pseudo Rayleigh waves, and Stoneley waves. Therefore, it is also called full-wave acoustic logging. Array acoustic instruments, due to their complex acoustic systems, can record longitudinal wave velocity, full-wave train velocity, and acoustic amplitude.

[0005] Sonic logging measures the acoustic velocity of formations. Formation acoustic velocity is related to factors such as lithology, porosity, and pore fluid properties. Based on the propagation speed of acoustic waves in the formation, formation porosity, lithology, and pore fluid properties can be determined. Sonic logging can be used to classify lithology, determine the porosity of oil and gas reservoirs, and delineate gas layers. It can also provide velocity data necessary for seismic exploration.

[0006] Sonic velocity logging, or sonic logging for short, records the time required for a sound wave to travel through 1 meter of rock, measuring the time difference Δt (the reciprocal of the longitudinal wave velocity) of the formation's slip wave. It is primarily used to calculate formation porosity, analyze formation lithology, and identify gas-bearing reservoirs.

[0007] The array acoustic logging tool is an improvement upon the long-spacing acoustic full-waveform logging tool. It features two acoustic transmitting transducers spaced 0.61m apart and eight linearly arranged acoustic receiving probes spaced 0.15m apart. The shortest source distance between the transmitting transducer and the receiving probe is 2.44m, and the longest is 4.12m. It also includes acoustic velocity logging systems with source distances of 0.92m and 1.53m. The acoustic system of the array acoustic logging tool can be considered as a combination of a linear array acoustic system and a dual-transmitter, dual-receiver acoustic system.

[0008] Modern acoustic logging tools generally employ multiple sensors, forming what are known as array acoustic logging tools, such as Atlas Copco's DAC and MAC, and Schlumberger's DSI. By recording multiple curves and performing correlation and superposition processing, interference can be effectively suppressed, and various information about P-waves, S-waves, and Stoneley waves can be accurately extracted. Due to the small spacing between the receivers, the needs of thin-layer research can be met.

[0009] The lower part of the acoustic system for array acoustic logging consists of two piezoelectric ceramic transmitters spaced 2 ft (61 cm) apart, with a transmitter bandwidth of 5–18 kHz. The upper part of the system contains eight piezoelectric ceramic receivers, each spaced 6 in (15.2 cm) apart. This set of receivers is used for array acoustic logging. The source distance between the first receiver and the upper transmitter is 8 ft, and the distance between the first receiver and the lower transmitter is 10 ft. The distance between the first receiver and the fifth receiver is 2 ft. This acoustic system can form long-source-distance acoustic logging systems with source distances of 8 ft and 10 ft respectively.

[0010] The instrument features two receivers spaced 2 feet apart in the center, which, together with the upper and lower transmitters, form a standard wellbore compensation logging system with source distances of 5 feet and 7 feet, suitable for open-hole logging. In casing wells, a 3-foot source-distance system can be used for cement bond logging (CBL), and a 5-foot source-distance system for variable density logging (VDL). These measurements can be used to check the quality of cement consolidation. At the very top of the instrument is a measurement system for measuring the sound velocity of fluids within the well. The transmitter and receiver are very close together, allowing for continuous measurement of the sound velocity of the fluid during logging.

[0011] Current downhole array acoustic sounding instruments use monopole, dipole, or multipole piezoelectric acoustic transducers to receive direct waves from the surrounding formation and reflected waves from the interface of the surrounding wave impedance back into the wellbore. These monopole, dipole, or multipole piezoelectric acoustic transducers, along with their associated amplifiers, analog-to-digital converters, data storage devices, and downhole data transmission modules, cannot operate for extended periods in high-temperature environments (deep wells). Furthermore, since downhole array acoustic well instruments are currently electronic, their downhole data transmission modules cannot yet overcome the bottleneck of high-speed, real-time transmission of large amounts of data from the well to the control computer in the logging truck at the wellhead. Summary of the Invention

[0012] The purpose of this invention is to provide a three-component distributed fiber optic acoustic wave sensing array-based acoustic logging device. This device primarily uses high-temperature resistant three-component distributed acoustic wave sensing optical cables installed above and below the downhole combined acoustic wave emission source to replace the currently widely used monopole, dipole, or multipole piezoelectric acoustic wave receiving transducers. It receives direct waves from the formation surrounding the wellbore and reflected wave signals from the surrounding wave impedance interface back into the wellbore, thereby achieving the purpose of downhole fiber optic array acoustic logging.

[0013] The technical solution of the present invention:

[0014] The three-component distributed fiber optic acoustic wave sensor array acoustic logging device includes an in-well three-component distributed fiber optic acoustic wave sensor array acoustic logging device, a high-temperature resistant armored photoelectric composite logging cable, a surface wellhead logging vehicle, and a surface three-component distributed fiber optic acoustic wave sensor (DAS) modulation and demodulation instrument.

[0015] The aforementioned in-well three-component distributed fiber optic acoustic wave sensor array acoustic logging device includes a high-temperature resistant distributed three-component acoustic wave sensor fiber optic cable as an in-well three-component acoustic wave signal receiving unit; a monopole-dipole-quadrupole combined acoustic wave transmitter, with the combined acoustic wave transmitter circuit short-circuited, a sound insulation body, and a fiber optic gyroscope; the surface wellhead logging vehicle is connected to the in-well three-component distributed fiber optic acoustic wave sensor array acoustic logging device via a high-temperature resistant armored optoelectronic composite cable.

[0016] The surface wellhead logging vehicle controls the lowering and raising of the three-component distributed fiber optic acoustic wave sensor array acoustic wave logging device in the well through a high-temperature resistant armored optical fiber composite cable, and provides a 250-volt DC power supply to the fiber optic acoustic wave sensor array acoustic wave logging device in the well, driving the combined acoustic wave emission source circuit to short-circuit and the combined acoustic wave emission source to continuously and repeatedly emit acoustic wave signals during operation.

[0017] The ground-based three-component distributed optical fiber acoustic wave sensing (DAS) modulator and demodulator installed at the wellhead is connected to the distributed three-component acoustic wave sensing optical cable via a high-temperature resistant armored optoelectronic composite cable. It emits laser pulses into the distributed three-component acoustic wave sensing optical cable and simultaneously collects the backscattered Rayleigh waves inside the distributed three-component acoustic wave sensing optical cable.

[0018] The ground-based three-component distributed optical fiber acoustic sensing (DAS) modulator / demodulator has five DAS data input ports and one fiber optic gyroscope data input port.

[0019] The acoustic wave sensing optical cable is a distributed three-component acoustic wave sensing optical cable with a length between 3 and 5 meters. The distributed three-component acoustic wave sensing optical cable has a built-in square columnar elastomer. A high-temperature resistant straight single-mode optical fiber is embedded in the center of the square columnar elastomer. Four high-temperature resistant, bend-resistant, or bend-insensitive single-mode optical fibers are laid closely on the four sides of the square columnar elastomer in the form of sine or cosine waveforms. The extension surfaces of the two high-temperature resistant, bend-resistant, or bend-insensitive single-mode optical fibers on any two adjacent sides are perpendicular to each other. Extinction devices are installed at the tail ends of the straight single-mode optical fiber and the waveform single-mode optical fiber. The heads of the straight single-mode optical fiber and the four waveform single-mode optical fibers away from the extinction devices are connected to the five DAS data input ports at the wellhead.

[0020] The fiber optic gyroscope, also known as a fiber optic inertial navigation orientation and positioning system, is installed at the top of the downhole three-component distributed fiber optic acoustic wave sensor array logging device. It measures the azimuth, tilt, and dip of the device in real time via a high-temperature resistant armored optical-electric composite cable. When the downhole three-component distributed fiber optic acoustic wave sensor array logging device is operating, the fiber optic gyroscope synchronously records the device's real-time position, velocity, and three-component attitude information. When the downhole fiber optic acoustic wave sensor array logging device is connected to the multi-channel control and data acquisition subsystem in the surface logging vehicle, the device uploads the measured downhole three-component acoustic logging data to the surface control and data acquisition processing subsystem, and the fiber optic gyroscope also uploads the measured real-time position, velocity, and attitude information of the downhole fiber optic acoustic wave sensor array logging device to the surface control and data acquisition processing subsystem. The real-time position, velocity, and attitude information of the downhole fiber optic acoustic wave sensor array acoustic logging device, recorded in real time by the fiber optic gyroscope, will be used to locate and orient the three-component acoustic logging data collected by the system in the well, so as to identify the location and specific orientation of the wave impedance interface around the wellbore, and realize accurate and reliable detection of targets around the downhole wellbore.

[0021] The combined acoustic wave emission source circuit is short-circuited and placed at the upper end of the fiber optic acoustic wave sensor array acoustic logging device. It drives the combined acoustic wave emission source within the device, which is installed in the middle and comprises two monopole acoustic wave emission sources, two orthogonal dipole acoustic wave emission sources, and two quadrupole acoustic wave emission sources. The two monopole emission sources are symmetrically installed on either side of the two orthogonal dipole emission sources, and the two quadrupole emission sources are symmetrically installed on either side of the integral structure formed by the two monopole emission sources.

[0022] Two sound insulation bodies are symmetrically installed at both ends of the combined acoustic wave emission source to block or prevent the bulk wave energy of the combined acoustic wave emission source from being directly coupled to the distributed three-component acoustic wave sensing optical cable.

[0023] The two identical distributed three-component acoustic wave sensing optical cables are symmetrically arranged on both sides of the outside of the combined acoustic wave emission source, respectively, in relation to the combined acoustic wave emission source.

[0024] The monopole acoustic wave emission source, the quadrupole acoustic wave emission source, and two mutually orthogonal dipole acoustic wave emission sources located at the upper end of the dipole acoustic wave emission source are sequentially excited. The distributed three-component acoustic wave sensing optical cable installed on the upper part of the combined acoustic wave emission source collects the three-component acoustic wave signals from the strata surrounding the wellbore.

[0025] Subsequently, a monopole acoustic wave source, a quadrupole acoustic wave source, and two mutually orthogonal dipole acoustic wave sources located at the lower end of the dipole acoustic wave source are sequentially excited. A distributed three-component acoustic wave sensing optical cable installed at the lower part of the combined acoustic wave source collects three-component acoustic wave signals from the strata surrounding the wellbore.

[0026] The fiber optic acoustic wave sensing array acoustic logging device has a distributed three-component acoustic wave sensing optical cable in the middle. Two sets of sound insulation bodies are arranged on both sides of the distributed three-component acoustic wave sensing optical cable. Two sets of identical monopole-dipole-quadrupole combined acoustic wave emission sources are symmetrically arranged on the outside of the whole formed by the two sets of sound insulation bodies. The combined acoustic wave emission source circuit short circuit and the fiber optic gyroscope are arranged on the top of the fiber optic acoustic wave sensing array acoustic logging device. The combined acoustic wave emission source includes a monopole acoustic wave emission source, a quadrupole acoustic wave emission source and two mutually orthogonal dipole acoustic wave emission sources arranged sequentially in the direction away from the distributed three-component acoustic wave sensing optical cable.

[0027] The measurement method of the acoustic logging device based on a three-component distributed fiber optic acoustic sensor array includes the following steps:

[0028] S1: Connect the high-temperature armored optical-electric composite cable on the wellhead logging winch to the three-component distributed fiber optic acoustic wave sensor array acoustic logging device in the well.

[0029] S2: The high-temperature armored optical fiber composite cable on the wellhead logging truck winch is used to lower the three-component distributed fiber optic acoustic wave sensor array acoustic wave logging device into the well bottom.

[0030] S3: The downhole fiber optic acoustic wave sensor array acoustic wave logging device is slowly lifted upwards by the high-temperature armored photoelectric composite cable on the wellhead logging rig winch. The device is then short-circuited and sent to the combined acoustic wave emission source circuit inside the downhole fiber optic array acoustic wave device, driving the two monopole acoustic wave emission sources, two mutually orthogonal dipole acoustic wave emission sources, and two quadrupole acoustic wave emission sources inside the combined acoustic wave emission source to sequentially excite acoustic wave signals.

[0031] S4: Simultaneously activate the fiber optic gyroscope to measure and record in real time the azimuth, dip angle, and inclination of the upward-lifting fiber optic acoustic wave sensor array acoustic logging device along the well trajectory.

[0032] S5: Simultaneously activate the ground three-component distributed optical fiber acoustic wave sensing (DAS) modulation and demodulation instrument, and transmit a high-power multi-frequency narrow pulse laser signal to the distributed three-component acoustic wave sensing optical cable in the downhole optical fiber acoustic wave sensing array acoustic wave logging device through a high-temperature resistant armored optoelectronic composite cable, while simultaneously receiving the back Rayleigh scattering light signal on the straight single-mode fiber and the waveform single-mode fiber in the distributed three-component acoustic wave sensing optical cable.

[0033] S6: The ground-based three-component distributed optical fiber acoustic wave sensing (DAS) modulation and demodulation instrument modulates and demodulates the backscattered Rayleigh light signals on straight single-mode optical fibers and waveform single-mode optical fibers. It demodulates the fiber strain or strain rate data measured on the straight single-mode optical fiber into axial component acoustic wave data parallel to the axis of the downhole fiber acoustic wave sensing array acoustic logging device. It first superimposes the two fiber strain or strain rate data measured by the two waveform single-mode optical fibers on the upper and lower sides of the square cylindrical elastomer in phase, and then demodulates them into north-south horizontal component acoustic wave data perpendicular to the axis of the downhole fiber acoustic wave sensing array acoustic logging device. It first superimposes the two fiber strain or strain rate data measured by the two waveform single-mode optical fibers on the left and right sides of the square cylindrical elastomer in phase, and then demodulates them into east-west horizontal component acoustic wave data perpendicular to the axis of the downhole fiber acoustic wave sensing array acoustic logging device.

[0034] S7: First, the monopole acoustic wave source, quadrupole acoustic wave source and two mutually orthogonal dipole acoustic wave sources at the upper end of the dipole acoustic wave source are excited in sequence. The distributed three-component acoustic wave sensing optical cable installed on the upper part of the combined acoustic wave source collects the three-component acoustic wave signals from the strata around the wellbore.

[0035] S8: Then, the monopole acoustic wave source, quadrupole acoustic wave source and two mutually orthogonal dipole acoustic wave sources at the lower end of the dipole acoustic wave source are excited in sequence. The distributed three-component acoustic wave sensing optical cable installed at the lower part of the combined acoustic wave source collects the three-component acoustic wave signals from the strata around the wellbore.

[0036] S9: Based on the direct acoustic travel time from the locations of one monopole acoustic source, two orthogonal dipole acoustic sources, and one quadrupole acoustic source within the downhole combined acoustic source to each acoustic detector point on the distributed three-component acoustic sensing cable within the downhole fiber optic acoustic sensing array logging device, and the distance from the location of the downhole combined acoustic source to a known detector point, calculate the average formation acoustic velocity from the known combined acoustic source to each known acoustic detector point.

[0037] If the data processor picks up the travel time of the sound wave directly to the P-wave, what is calculated is the average velocity of the P-wave in the stratum.

[0038] If the travel time of the sound wave directly reaches the transverse wave is picked up, the calculated value is the average velocity of the transverse wave in the stratum.

[0039] S10: By recording multiple arrayed acoustic logging curves with different acoustic wave emission sources and different source distances (distance between the emission source and the receiver), correlation and superposition processing can be performed to effectively suppress interference and accurately extract various information of P-waves, S-waves, and Stoneley waves. Since the distance between the receivers can be very small, it can meet the needs of thin-layer research.

[0040] S11: Use long-spacing acoustic logging curves with a source distance of more than 8 feet to extract P-wave, S-wave, and Stoneley wave information of open-hole formations; use short-spacing acoustic systems with a source distance of 3 feet to perform cement bond logging (CBL) in casing wells, and use acoustic systems with a source distance of 5 feet to perform variable density logging (VDL). These two measurement results can be used to check the cement consolidation quality of casing wells.

[0041] S12: By further processing and interpreting the reflected acoustic wave signals (data), it is possible to determine the distance and orientation of the acoustic impedance interface around the well control from the wellbore, the acoustic velocity of the medium on both sides of the acoustic impedance interface, the elastic or viscoelastic parameter characteristics of the medium on both sides, as well as the lithology, porosity, permeability, type and saturation of fluids in the underground medium outside the wellbore, and the distribution patterns of different fluids in the downhole medium.

[0042] The beneficial effects of this invention are:

[0043] The three-component distributed fiber optic acoustic wave sensor array acoustic logging device provided by this invention replaces the monopole, dipole, or multipole piezoelectric acoustic wave receiving transducers in conventional array acoustic wave logging devices with a three-component distributed acoustic wave sensing optical cable. This instrument can collect array acoustic wave signals for extended periods in high-temperature deep wells. The downhole receiving sensor requires no electronic components or wiring, solving the problem that downhole monopole, dipole, or multipole piezoelectric acoustic wave receiving transducers and their associated high-cost amplifiers, analog-to-digital converters, data storage devices, and downhole data transmission modules cannot operate for extended periods at high temperatures. Through an armored optoelectronic composite cable connected to the fiber optic acoustic wave sensor array acoustic logging device, the backscattered Rayleigh light signal from the three-component distributed acoustic wave sensing optical cable can be transmitted at high speed to a surface multi-channel DAS modulator / demodulator, solving the bottleneck problem of high-speed upward transmission of large amounts of data signals collected by downhole fiber optic acoustic wave sensor array acoustic wave logging devices.

[0044] This invention can significantly reduce the manufacturing cost of equipment and instruments for downhole three-component acoustic data acquisition, and achieve high-efficiency acquisition of ultra-high density or extremely high spatial resolution downhole three-component acoustic data. Through processing and analysis, it is possible to understand the distance and orientation of the acoustic impedance interface around the wellbore, the acoustic velocity of the medium on both sides of the acoustic impedance interface, the elastic or viscoelastic parameter characteristics of the medium on both sides, as well as the lithology, porosity, permeability, type and saturation of fluids in the underground medium around the wellbore, and the distribution patterns of different fluids in the downhole medium. It can also obtain information on fractures and pores in the formation around the wellbore, as well as the formation structure information around the well, thereby understanding the orientation, dip angle and distribution of fractures and pores in the formation, and realizing the widespread application of fiber optic array acoustic logging technology. Attached Figure Description

[0045] Figure 1 This is a schematic diagram illustrating the working principle of the three-component distributed fiber optic acoustic wave sensor array acoustic logging device in wells according to the present invention.

[0046] Figure 2 This is a schematic diagram of the structure of the three-component distributed fiber optic acoustic wave sensor array acoustic logging device in well according to Embodiment 1 of the present invention.

[0047] Figure 3 This is a schematic diagram of the three-component distributed acoustic wave sensing optical cable structure of the present invention;

[0048] Figure 4 This is a schematic diagram of the structure of the three-component distributed fiber optic acoustic wave sensor array acoustic logging device in well in Embodiment 2 of the present invention.

[0049] Explanation of reference numerals in the attached figures:

[0050] 1-Fiber optic acoustic wave sensor array acoustic logging device; 2-High temperature resistant armored photoelectric composite logging cable; 3-Surface wellhead logging vehicle; 4-Surface three-component distributed fiber optic acoustic wave sensor (DAS) modulation and demodulation instrument; 5-Distributed three-component acoustic wave sensor optical cable; 51-Square columnar elastomer; 52-Straight single-mode optical fiber; 53-Waveform single-mode optical fiber; 6-Combined acoustic wave emission source; 61-Monopole acoustic wave emission source; 62-Dipole acoustic wave emission source; 63-Quadpole acoustic wave emission source; 7-Combined acoustic wave emission source circuit short circuit; 8-Sound insulation body; 9-Fiber optic gyroscope. Detailed Implementation

[0051] The present invention will be further described in detail below with reference to the embodiments and accompanying drawings, but the embodiments of the present invention are not limited thereto.

[0052] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "longitudinal," "lateral," "horizontal," "inner," "outer," "front," "rear," "top," and "bottom," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this invention is in use. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0053] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set up," "have," "install," "connect," and "connect" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0054] The present invention will now be described in detail with reference to the accompanying drawings and embodiments:

[0055] Example 1:

[0056] like Figure 1 As shown, the well logging device based on the three-component distributed fiber optic acoustic wave sensor array includes a well logging device 1, a high-temperature resistant armored photoelectric composite logging cable 2, a surface wellhead logging vehicle 3, and a surface three-component distributed fiber optic acoustic wave sensor (DAS) modulation and demodulation instrument 4.

[0057] like Figure 2As shown, the well-drilled three-component distributed fiber optic acoustic wave sensor array acoustic logging device 1 system includes a high-temperature resistant distributed three-component acoustic wave sensor optical cable 5, which serves as a well-drilled three-component acoustic wave signal receiving unit; a monopole-dipole-quadrupole combined acoustic wave transmitter 6, a combined acoustic wave transmitter circuit short circuit 7, a sound insulation body 8, and a fiber optic gyroscope 9; the surface wellhead logging vehicle 3 is connected to the well-drilled three-component distributed fiber optic acoustic wave sensor array acoustic logging device 1 via a high-temperature resistant armored photoelectric composite logging cable 2.

[0058] The surface wellhead logging vehicle 3 controls the lowering and raising of the three-component distributed fiber optic acoustic wave sensor array acoustic wave logging device 1 in the well through the high-temperature resistant armored photoelectric composite logging cable 2, and provides 250V DC power to the fiber optic acoustic wave sensor array acoustic wave logging device 1 in the well, driving the combined acoustic wave emission source circuit short circuit 7 and the combined acoustic wave emission source 6 to continuously and repeatedly emit acoustic wave signals during operation.

[0059] The surface three-component distributed optical fiber acoustic wave sensing (DAS) modulation and demodulation instrument 4, installed at the wellhead, is connected to the distributed three-component acoustic wave sensing optical cable 5 through the high-temperature armored photoelectric composite logging cable 2. It emits laser pulses into the distributed three-component acoustic wave sensing optical cable 5 and simultaneously collects the backscattered Rayleigh waves inside the distributed three-component acoustic wave sensing optical cable 5.

[0060] The ground-based three-component distributed optical fiber acoustic wave sensing (DAS) modulator / demodulator 4 has five DAS data input ports and one fiber optic gyroscope 9 data input port.

[0061] like Figure 3 As shown, the acoustic wave sensing optical cable is a distributed three-component acoustic wave sensing optical cable 5, with a length between 3 meters and 5 meters. The distributed three-component acoustic wave sensing optical cable 5 has a built-in square columnar elastic body 51. A high-temperature resistant straight single-mode optical fiber 52 is embedded in the center of the square columnar elastic body 51. Four high-temperature resistant, bending-resistant, or bending-insensitive single-mode optical fibers 53 are laid closely on the four sides of the square columnar elastic body 51 in the form of sine or cosine waveforms. The extension surfaces of the two high-temperature resistant, bending-resistant, or bending-insensitive single-mode optical fibers 53 on any two adjacent sides are perpendicular to each other. An extinction device 54 is installed at the tail end of the straight single-mode optical fiber 52 and the waveform single-mode optical fiber 53. The head ends of the straight single-mode optical fiber 52 and the four waveform single-mode optical fibers 53 away from the extinction device 54 are connected to the five DAS data input ports at the wellhead.

[0062] The fiber optic gyroscope 9, i.e., the fiber optic inertial navigation orientation and positioning system, is installed at the top of the downhole three-component distributed fiber optic acoustic wave sensor array acoustic logging device 1. It measures the azimuth, tilt, and dip of the array acoustic logging device 1 in real time via a high-temperature resistant armored photoelectric composite logging cable 2. When the downhole three-component distributed fiber optic acoustic wave sensor array acoustic logging device 1 is operating, the fiber optic gyroscope 9 synchronously records the real-time position, velocity, and three-component attitude information of the downhole fiber optic acoustic wave sensor array acoustic logging device 1. When the downhole fiber optic acoustic wave sensor array acoustic logging device 1 is connected to the multi-channel control and data acquisition subsystem in the surface logging vehicle 3, the downhole fiber optic acoustic wave sensor array acoustic logging device 1 uploads the measured downhole three-component acoustic logging data to the surface control and data acquisition processing subsystem, and the fiber optic gyroscope 9 also uploads the measured real-time position, velocity, and attitude information of the downhole fiber optic acoustic wave sensor array acoustic logging device 1 to the surface control and data acquisition processing subsystem. The real-time position, velocity, and attitude information of the downhole fiber optic acoustic wave sensor array acoustic logging device 1, recorded in real time by the fiber optic gyroscope 9, will be used to locate and orient the three-component acoustic logging data collected by the system in the well, so as to identify the location and specific orientation of the wave impedance interface around the wellbore, and realize accurate and reliable detection of targets around the downhole wellbore.

[0063] The combined acoustic wave emission source circuit short circuit 7 is placed at the upper end of the fiber optic acoustic wave sensor array acoustic logging device 1 to drive the combined acoustic wave emission source 6 inside the fiber optic acoustic wave sensor array acoustic logging device 1. The combined acoustic wave emission source 6 is installed in the middle of the fiber optic acoustic wave sensor array acoustic logging device 1 and includes two monopole acoustic wave emission sources 61, two mutually orthogonal dipole acoustic wave emission sources 62, and two quadrupole acoustic wave emission sources 63. The two monopole acoustic wave emission sources 61 are symmetrically installed on both sides of the two mutually orthogonal dipole acoustic wave emission sources 62, and the two quadrupole acoustic wave emission sources 63 are respectively symmetrically installed on both sides of the whole formed by the two monopole acoustic wave emission sources 61.

[0064] Two sound insulation bodies 8 are symmetrically installed at both ends of the combined acoustic wave emitting source 6 to block or prevent the bulk wave energy of the combined acoustic wave emitting source 6 from being directly coupled to the distributed three-component acoustic wave sensing optical cable 5.

[0065] Two distributed three-component acoustic wave sensing optical cables 5 with identical structural dimensions are respectively placed on both sides of the two sound insulation bodies 8, symmetrical to the combined acoustic wave emission source 6.

[0066] The monopole acoustic wave source 61, the quadrupole acoustic wave source 63 and the two mutually orthogonal dipole acoustic wave sources 62 at the upper end of the dipole acoustic wave source 62 are excited in sequence. The distributed three-component acoustic wave sensing optical cable 5 installed on the upper part of the combined acoustic wave source 6 collects the three-component acoustic wave signal from the strata around the well.

[0067] Subsequently, the monopole acoustic wave source 61, the quadrupole acoustic wave source 63, and the two mutually orthogonal dipole acoustic wave sources 62 at the lower end of the dipole acoustic wave source 62 are sequentially excited. The distributed three-component acoustic wave sensing optical cable 5, which is installed at the lower part of the combined acoustic wave source 6, collects the three-component acoustic wave signals from the strata surrounding the wellbore.

[0068] The measurement method of the array acoustic logging device 1 based on three-component distributed fiber optic acoustic wave sensing is characterized by comprising the following steps:

[0069] S1: Connect the high-temperature armored photoelectric composite logging cable 2 on the winch of the surface wellhead logging vehicle 3 to the three-component distributed fiber optic acoustic wave sensor array acoustic wave logging device 1 in the well.

[0070] S2: Using the high-temperature armored photoelectric composite logging cable 2 on the winch of the surface wellhead logging vehicle 3, the three-component distributed fiber optic acoustic wave sensor array acoustic wave logging device 1 in the well is lowered to the bottom of the well.

[0071] S3: The high-temperature armored photoelectric composite logging cable 2 on the winch of the surface wellhead logging rig 3 slowly lifts the downhole fiber optic acoustic wave sensor array acoustic wave logging device 1 upward and sends a command to the combined acoustic wave emission source circuit short circuit 7 in the downhole array acoustic wave logging device 1, driving the two monopole acoustic wave emission sources 61, the two mutually orthogonal dipole acoustic wave emission sources 62, and the two quadrupole acoustic wave emission sources 63 in the combined acoustic wave emission source 6 to excite acoustic wave signals in sequence.

[0072] S4: Simultaneously activate the fiber optic gyroscope 9 to measure and record in real time the azimuth, dip angle and dip of the upward-lifting array acoustic logging device 1 along the well trajectory;

[0073] S5: Simultaneously activate the ground multi-channel three-component distributed optical fiber acoustic wave sensing (DAS) modulation and demodulation instrument 4, and transmit a high-power multi-frequency narrow pulse laser signal to the distributed three-component acoustic wave sensing optical cable 5 in the downhole optical fiber acoustic wave sensing array acoustic wave logging device 1 through the high-temperature armored photoelectric composite logging cable 2, while simultaneously receiving the back Rayleigh scattered light signal on the straight single-mode optical fiber 52 and the waveform single-mode optical fiber 53 in the distributed three-component acoustic wave sensing optical cable 5.

[0074] S6: The ground-based three-component distributed optical fiber acoustic wave sensing (DAS) modulation and demodulation instrument 4 modulates and demodulates the back Rayleigh scattering light signals on the straight single-mode fiber 52 and the waveform single-mode fiber 53. It demodulates the fiber strain or strain rate data measured on the straight single-mode fiber 52 into axial component acoustic wave data parallel to the axis of the downhole optical fiber acoustic wave sensing array acoustic wave logging device 1. It first superimposes the two fiber strain or strain rate data measured by the two waveform single-mode fibers 53 on the upper and lower sides of the square cylindrical elastic body 51 in phase, and then demodulates them into north-south horizontal component acoustic wave data perpendicular to the axis of the downhole optical fiber acoustic wave sensing array acoustic wave logging device 1. It first superimposes the two fiber strain or strain rate data measured by the two waveform single-mode fibers 53 on the left and right sides of the square cylindrical elastic body 51 in phase, and then demodulates them into east-west horizontal component acoustic wave data perpendicular to the axis of the downhole optical fiber acoustic wave sensing array acoustic wave logging device 1.

[0075] S7: First, the monopole acoustic wave source 61, the quadrupole acoustic wave source 63 and the two mutually orthogonal dipole acoustic wave sources 62 at the upper end of the dipole acoustic wave source 62 are excited in sequence. The distributed three-component acoustic wave sensing optical cable 5 placed on the upper part of the combined acoustic wave source 6 collects the three-component acoustic wave signal from the strata around the well.

[0076] S8: Then, the monopole acoustic wave source 61, the quadrupole acoustic wave source 63 and the two mutually orthogonal dipole acoustic wave sources 62 at the lower end of the dipole acoustic wave source 62 are excited in sequence. The distributed three-component acoustic wave sensing optical cable 5 installed at the lower part of the combined acoustic wave source 6 collects the three-component acoustic wave signal from the formation around the well.

[0077] S9: Based on the direct acoustic travel time from the locations of one monopole acoustic source 61, two orthogonal dipole acoustic sources 62, and one quadrupole acoustic source 63 within the downhole combined acoustic source 6 to each acoustic detector point on the distributed three-component acoustic sensing cable 5 within the downhole fiber optic acoustic sensing array logging device 1, and the distance from the location of the downhole combined acoustic source 6 to the known detector point, calculate the average formation acoustic velocity from the known combined acoustic source 6 to each known acoustic detector point;

[0078] If the data processor picks up the travel time of the sound wave directly to the P-wave, what is calculated is the average velocity of the P-wave in the stratum.

[0079] If the travel time of the sound wave directly reaches the transverse wave is picked up, the calculated value is the average velocity of the transverse wave in the stratum.

[0080] S10: By recording multiple arrayed acoustic logging curves with different acoustic wave emission sources and different source distances (distance between the emission source and the receiver), correlation and superposition processing can be performed to effectively suppress interference and accurately extract various information of P-waves, S-waves, and Stoneley waves. Since the distance between the receivers can be very small, it can meet the needs of thin-layer research.

[0081] S11: Use long-spacing acoustic logging curves with a source distance of more than 8 feet to extract P-wave, S-wave, and Stoneley wave information of open-hole formations; use short-spacing acoustic systems with a source distance of 3 feet to perform cement bond logging (CBL) in casing wells, and use acoustic systems with a source distance of 5 feet to perform variable density logging (VDL). These two measurement results can be used to check the cement consolidation quality of casing wells.

[0082] S12: By further processing and interpreting the reflected acoustic wave signals (data), it is possible to determine the distance and orientation of the acoustic impedance interface around the well control from the wellbore, the acoustic velocity of the medium on both sides of the acoustic impedance interface, the elastic or viscoelastic parameter characteristics of the medium on both sides, as well as the lithology, porosity, permeability, type and saturation of fluids in the underground medium outside the wellbore, and the distribution patterns of different fluids in the downhole medium.

[0083] Example 2:

[0084] like Figure 4 As shown, the well logging device 1 based on a three-component distributed fiber optic acoustic wave sensor array includes a high-temperature resistant distributed three-component acoustic wave sensor cable 5 installed in the middle of the device, serving as a three-component acoustic wave signal receiving unit. Two sets of sound-insulating bodies 8 are installed on both sides of the distributed three-component acoustic wave sensor cable 5. Two identical monopole-dipole-quadrupole combined acoustic wave transmitters 6 are symmetrically arranged on the outside of the entire structure formed by the two sets of sound-insulating bodies 8. The combined acoustic wave transmitter circuit short circuit 7 and the fiber optic gyroscope 9 are both installed at the top of the well logging device. During operation, the two identical combined acoustic wave transmitters 6 at both ends of the distributed three-component acoustic wave sensor cable 5 are sequentially excited, and the distributed three-component acoustic wave sensor cable 5 sequentially receives the downlink and uplink acoustic wave signals excited by the combined acoustic wave transmitters 6 at the top and bottom of the device, respectively. Because the two identical combined acoustic wave emission sources 6 at the top and bottom of the device are completely symmetrical with the distributed three-component acoustic wave sensing optical cable 5 in the middle of the device, the combined acoustic wave emission source 6 includes a monopole acoustic wave emission source 61, a quadrupole acoustic wave emission source 63, and two mutually orthogonal dipole acoustic wave emission sources 62 arranged sequentially in the direction away from the distributed three-component acoustic wave sensing optical cable 5. The downlink and uplink acoustic wave signals received and recorded sequentially by the distributed three-component acoustic wave sensing optical cable 5 can be superimposed, thereby improving the signal-to-noise ratio of the array acoustic wave data collected by the fiber optic acoustic wave sensing array acoustic logging device.

Claims

1. A three-component distributed fiber optic acoustic wave sensor array acoustic logging device, characterized in that, The system includes a three-component distributed fiber optic acoustic wave sensor array (DAS) logging device (1), a high-temperature resistant armored photoelectric composite logging cable (2), a surface wellhead logging vehicle (3), and a surface three-component distributed fiber optic acoustic wave sensor (DAS) modulation and demodulation instrument (4). The well-drilling three-component distributed fiber optic acoustic wave sensor array acoustic logging device (1) includes a high-temperature resistant distributed three-component acoustic wave sensor optical cable (5) as a well-drilling three-component acoustic wave signal receiving unit, a monopole-dipole-quadrupole combined acoustic wave emission source (6), a combined acoustic wave emission source circuit short circuit (7), a sound insulation body (8), and a fiber optic gyroscope (9). The surface wellhead logging vehicle (3) is connected to the well-drilling three-component distributed fiber optic acoustic wave sensor array acoustic logging device (1) through a high-temperature resistant armored photoelectric composite logging cable (2). The surface wellhead logging vehicle (3) controls the lowering and raising of the three-component distributed fiber optic acoustic wave sensor array acoustic wave logging device (1) in the well through the high temperature resistant armored photoelectric composite logging cable (2), and provides 250V DC power to the fiber optic acoustic wave sensor array acoustic wave logging device (1) in the well, driving the combined acoustic wave emission source circuit short-circuit (7) and the combined acoustic wave emission source (6) to continuously and repeatedly emit acoustic wave signals during operation; The ground three-component distributed optical fiber acoustic wave sensing (DAS) modulation and demodulation instrument (4) installed at the wellhead is connected to the distributed three-component acoustic wave sensing optical cable (5) through the high temperature resistant armored photoelectric composite logging cable (2), and emits laser pulses into the distributed three-component acoustic wave sensing optical cable (5) and simultaneously collects the backscattered Rayleigh waves in the distributed three-component acoustic wave sensing optical cable (5). The combined acoustic wave emission source circuit short circuit (7) is placed at the upper end of the fiber optic acoustic wave sensor array acoustic wave logging device (1) to drive the combined acoustic wave emission source (6) located in the middle of the fiber optic acoustic wave sensor array acoustic wave logging device (1). The combined acoustic wave emission source (6) includes two monopole acoustic wave emission sources (61), two mutually orthogonal dipole acoustic wave emission sources (62), and two quadrupole acoustic wave emission sources (63). The two monopole acoustic wave emission sources (61) are symmetrically installed on both sides of the two mutually orthogonal dipole acoustic wave emission sources (62), and the two quadrupole acoustic wave emission sources (63) are symmetrically installed on both sides of the whole formed by the two monopole acoustic wave emission sources (61). Two sound insulation bodies (8) are symmetrically installed at both ends of the combined acoustic wave emission source (6) to block or prevent the bulk wave energy of the combined acoustic wave emission source (6) from being directly coupled to the distributed three-component acoustic wave sensing optical cable (5). Two distributed three-component acoustic wave sensing optical cables (5) with identical structural dimensions are symmetrically placed on the outer sides of the whole consisting of two sound insulation bodies (8) and the combined acoustic wave emission source (6).

2. The three-component distributed fiber optic acoustic wave sensor array acoustic logging device according to claim 1, characterized in that, The ground-based three-component distributed optical fiber acoustic wave sensing (DAS) modulation and demodulation instrument (4) has five DAS data input ports and one fiber optic gyroscope (9) data input port.

3. The three-component distributed fiber optic acoustic wave sensor array acoustic logging device according to claim 2, characterized in that, The acoustic wave sensing optical cable is a distributed three-component acoustic wave sensing optical cable (5), with a length between 3 meters and 5 meters. The distributed three-component acoustic wave sensing optical cable (5) has a built-in square columnar elastomer (51). A high-temperature resistant straight single-mode optical fiber (52) is embedded in the center of the square columnar elastomer (51). Four high-temperature resistant bending-resistant or bending-insensitive waveform single-mode optical fibers (53) are laid closely on the four sides of the square columnar elastomer (51) in the form of sine or cosine waveforms. The extension surfaces of the two high-temperature resistant bending-resistant or bending-insensitive waveform single-mode optical fibers (53) on any two adjacent sides are perpendicular to each other. The tail ends of the straight single-mode optical fiber (52) and the waveform single-mode optical fiber (53) are all equipped with extinction devices (54). The head ends of the straight single-mode optical fiber (52) and the four waveform single-mode optical fibers (53) away from the extinction device (54) are respectively connected to the five DAS data input ports at the wellhead.

4. The three-component distributed fiber optic acoustic wave sensor array acoustic logging device according to claim 3, characterized in that, The fiber optic gyroscope (9) is installed at the top of the three-component distributed fiber optic acoustic wave sensor array acoustic logging device (1) in the well, and measures the azimuth, tilt and dip of the fiber optic acoustic wave sensor array acoustic logging device (1) in real time through the high-temperature armored photoelectric composite logging cable (2).

5. A measurement method for a three-component distributed fiber optic acoustic wave sensor array acoustic logging device, characterized in that, The three-component distributed fiber optic acoustic wave sensor array acoustic logging device described in claim 4 includes the following steps: S1: Connect the high-temperature armored photoelectric composite logging cable (2) on the winch of the surface wellhead logging vehicle (3) to the three-component distributed fiber optic acoustic wave sensor array acoustic wave logging device (1) in the well. S2: Using the high-temperature armored photoelectric composite logging cable (2) on the winch of the surface wellhead logging vehicle (3), the three-component distributed fiber optic acoustic wave sensor array acoustic wave logging device (1) in the well is lowered to the bottom of the well; S3: The high-temperature armored photoelectric composite logging cable (2) on the winch of the ground wellhead logging vehicle (3) slowly lifts the downhole fiber optic acoustic wave sensor array acoustic wave logging device (1) upward and sends a command to the combined acoustic wave emission source circuit (7) in the downhole fiber optic acoustic wave sensor array acoustic wave logging device (1) to drive the two monopole acoustic wave emission sources (61), two mutually orthogonal dipole acoustic wave emission sources (62), and two quadrupole acoustic wave emission sources (63) in the combined acoustic wave emission source (6) to excite the acoustic wave signal in sequence. S4: Simultaneously activate the fiber optic gyroscope (9) to measure and record in real time the azimuth, dip angle and inclination of the upward-lifting fiber optic acoustic wave sensor array acoustic logging device (1) along the well trajectory. S5: Simultaneously activate the ground three-component distributed fiber optic acoustic wave sensing modulation and demodulation instrument (4), and transmit a high-power multi-frequency narrow pulse laser signal to the distributed three-component acoustic wave sensing optical cable (5) in the downhole fiber optic acoustic wave sensing array acoustic wave logging device (1) through the high-temperature resistant armored photoelectric composite logging cable (2), and simultaneously receive the back Rayleigh scattering light signal on the straight single-mode fiber (52) and the waveform single-mode fiber (53) in the distributed three-component acoustic wave sensing optical cable (5); S6: The ground three-component distributed fiber optic acoustic wave sensing modulation and demodulation instrument (4) modulates and demodulates the back Rayleigh scattering light signals on the straight single-mode fiber (52) and the waveform single-mode fiber (53), and demodulates the fiber strain or strain rate data measured on the straight single-mode fiber (52) into axial component acoustic wave data parallel to the axis of the downhole fiber optic acoustic wave sensing array acoustic logging device (1); and modulates the two waveform single-mode fibers (53) on the upper and lower sides of the square cylindrical elastic body (51) into axial component acoustic wave data. The two fiber strain or strain rate data measured are first superimposed in phase, and then demodulated into north-south horizontal component acoustic data perpendicular to the axis of the downhole fiber acoustic wave sensor array acoustic logging device (1); the two fiber strain or strain rate data measured by the two waveform single-mode optical fibers (53) on the left and right sides of the square columnar elastic body (51) are first superimposed in phase, and then demodulated into east-west horizontal component acoustic data perpendicular to the axis of the downhole fiber acoustic wave sensor array acoustic logging device (1). S7: First, the monopole acoustic wave source (61), the quadrupole acoustic wave source (63) and two orthogonal dipole acoustic wave sources (62) located at the upper end of the dipole acoustic wave source (62) are excited in sequence. The distributed three-component acoustic wave sensing optical cable (5) placed on the upper part of the combined acoustic wave source (6) collects the three-component acoustic wave signal from the strata around the wellbore. S8: Then, the monopole acoustic wave source (61), the quadrupole acoustic wave source (63) and two orthogonal dipole acoustic wave sources (62) located at the lower end of the dipole acoustic wave source (62) are excited in sequence. The distributed three-component acoustic wave sensing optical cable (5) placed at the lower part of the combined acoustic wave source (6) collects the three-component acoustic wave signal from the strata around the wellbore. S9: Based on the direct acoustic travel time from the location of one monopole acoustic source (61), two mutually orthogonal dipole acoustic sources (62), and one quadrupole acoustic source (63) in the downhole combined acoustic source (6) to each acoustic detector point on the distributed three-component acoustic sensing cable (5) in the downhole fiber optic acoustic sensing array logging device (1), and the distance from the location of the downhole combined acoustic source (6) to the known detector point, calculate the formation acoustic average velocity from the known combined acoustic source (6) to each known acoustic detector point; If the data processor picks up the travel time of the sound wave directly to the P-wave, what is calculated is the average velocity of the P-wave in the formation. If the travel time of the sound wave directly reaches the shear wave is picked up, the calculated value is the average velocity of the shear wave in the formation. S10: By recording multiple array acoustic logging curves with different acoustic emission sources and different source distances, correlation and superposition processing can be performed to effectively suppress interference and accurately extract various information of formation P-waves, S-waves and Stoneley waves. Since the distance between receivers can be very small, it can meet the needs of thin-layer research; where the source distance refers to the distance between the emission source and the receiver. S11: Use long-spacing acoustic logging curves with a source distance of more than 8 feet to extract P-wave, S-wave, and Stoneley wave information of open-hole formations; use a short-spacing acoustic system with a source distance of 3 feet to perform cement bonding logging in casing wells, and use an acoustic system with a source distance of 5 feet to perform variable density logging. These two measurement results can be used to check the cement consolidation quality of casing wells. S12: By further processing and interpreting the reflected acoustic wave signal, we can determine the distance and orientation of the wave impedance interface around the wellbore from the wellbore, the acoustic wave velocity of the medium on both sides of the wave impedance interface, the elastic or viscoelastic parameter characteristics of the medium on both sides, as well as the lithology, porosity, permeability, type and saturation of the underground medium outside the wellbore, and the distribution pattern of different fluids in the downhole medium.

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