Abstract: A method for detecting and specifying a vibration on the basis of a feature of a fiber-optic signal to determine a time and a spatial location of the present invention includes: Step 1 of acquiring a feature-expanded function vector and C-number of vibration categories by expanding a feature of initial data of a vibration signal from a distributed fiber-optic sensor; Step 2 of calculating a dimensionality reduction matrix based on the feature-expanded function vector; Step 3 of acquiring a dimensionality-reduced feature function by operating the dimensionality reduction matrix to the initial data and the feature-expanded function vector; Step 4 of acquiring a primary classification result of the vibration signal by performing a classification with reference to primary classification parameter acquired from a parameter database; and Step 5 of acquiring and outputting a secondary classification result of the vibration signal by performing removal of a wrong detection result and correction of a wrong classificat

Abstract: An armored DSS cable includes: an inner layer part including a first rope helically wound; and a surface layer part including an optical fiber module and a plurality of third ropes, the optical fiber module having an optical fiber and a plurality of second ropes helically surrounding the optical fiber and having a smaller outer diameter than the first rope, the third ropes having a larger outer diameter than the first rope, such that the optical fiber module and the third ropes are arranged on an identical circle and helically wound, wherein the inner layer part and the surface layer part are formed concentrically.

Abstract: A fiber optic cable includes a braided core defining a plurality of helical grooves, and one or more optical fibers disposed along one or more of the helical grooves of the braided core. The elongated structures braided to form the braided core are composed of braided ropes or monolithic wires. An outer layer disposed over an outer surface of the braided core is composed of a metal layer or a flexible plastic layer.

Abstract: A distributed position detection rope includes: basic optical elements each including an optical fiber, tensile strength bodies, and a sheath material and the tensile strength bodies; a cylindrical inner sheath layer having a first optical element formed by arranging a plurality of the basic optical elements which are arranged at positions on the same circle and are helically wound at a predetermined pitch along the axial direction of the axis; and a cylindrical outer sheath layer on the outer side of the inner sheath layer and having a second optical element which are arranged at positions on the same circle and are helically wound along the axial direction so as to have a placement angle different from that of the basic optical elements of the first optical element.

Abstract: An oil well production method in which a plurality of producers are arranged in a horizontal direction, includes boring a monitor well adjacent to one of the producers in the horizontal direction, installing a measurement optical fiber cable in the monitor well, performing Brillouin measurement and Rayleigh measurement for a strain distribution, a pressure distribution, and a temperature distribution of the monitor well along the measurement optical fiber cable over a period in which a fracture occurs hydraulically in the producers and an oil producing period, analyzing data measured through the Brillouin measurement and the Rayleigh measurement, and determining an arrangement interval of the producers in the horizontal direction and a hydraulic fracturing parameter.

Abstract: A monitoring humidity measurement system includes: a humidity measurement optical fiber including a first optical fiber and a humidity detection layer provided so as to annularly cover the first optical fiber; a reference optical fiber including a second optical fiber; a plurality of optical communication cables; and a signal processing device configured to, with a laser beam entering into the first and second optical fibers, calculate and obtain Brillouin frequency shift and Rayleigh frequency shift of backscatter light from the first and second optical fibers based on the entering laser beam, and store predetermined constants, wherein reference data and target data are measured from the Rayleigh frequency shift and an initial humidity value calculated from the Brillouin frequency shift, and the value of humidity at the present time is calculated on the basis of Rayleigh frequency shift per unit humidity calculated from a difference between the above two data.

Abstract: A method of determining borehole characteristics comprises arranging at least one sensing fiber along a borehole, causing pressure changes in the borehole, and measuring strain along the sensing fiber to obtain strain data. The strain data obtained thereby can be interpreted, for example, to determine borehole fracture geometry and to determine borehole perforation cluster efficiency. These results can be used to improve well completion and stimulation designs, increase field production, and/or decrease costs.

Abstract: An oil well production method in which a plurality of producers are arranged in a horizontal direction, includes boring a monitor well adjacent to one of the producers in the horizontal direction, installing a measurement optical fiber cable in the monitor well, performing Brillouin measurement and Rayleigh measurement for a strain distribution, a pressure distribution, and a temperature distribution of the monitor well along the measurement optical fiber cable over a period in which a fracture occurs hydraulically in the producers and an oil producing period, analyzing data measured through the Brillouin measurement and the Rayleigh measurement, and determining an arrangement interval of the producers in the horizontal direction and a hydraulic fracturing parameter.

Abstract: In a measurement requiring a high space resolution using S-BOTDR, a pulse train composed of a plurality of pulses having the interval between the pulses longer than the phonon lifetime is interpulse-code-modulated. A Golay code is used for the interpulse code modulation to eliminate the sidelobes of the correlation in using a technique of correlation. In a technique without using correlation, an Hadamard matrix is used for the interpulse code modulation and the resultant matrix is inverted in the signal processing.

Abstract: A distributed fibre sensing system and a vibration detection and positioning method therefor are disclosed. The system comprises: a signal generating module, a light source module, an optical frequency comb generating module, a frequency sweeping and pulse generating module, an optical circulator, a sensing fibre, an interference module, a photoelectric conversion module and a detection and position module. The method comprises: obtaining a plurality of Rayleigh backscattering signals of the sensing fibre; performing a fading elimination processing on the Rayleigh backscattering signals, thereby obtaining a plurality of averaged Rayleigh backscattering signals of non-interference fading and polarization fading; performing a phase processing on the averaged Rayleigh backscattering signals, thereby obtaining phase variance curves; and determining a vibration point according to variances in the phase variance curves, and finally obtaining a position and a vibration waveform of the vibration point.

Abstract: A monitoring humidity measurement system includes: a humidity measurement optical fiber including a first optical fiber and a humidity detection layer provided so as to annularly cover the first optical fiber; a reference optical fiber including a second optical fiber; a plurality of optical communication cables; and a signal processing device configured to, with a laser beam entering into the first and second optical fibers, calculate and obtain Brillouin frequency shift and Rayleigh frequency shift of backscatter light from the first and second optical fibers based on the entering laser beam, and store predetermined constants, wherein reference data and target data are measured from the Rayleigh frequency shift and an initial humidity value calculated from the Brillouin frequency shift, and the value of humidity at the present time is calculated on the basis of Rayleigh frequency shift per unit humidity calculated from a difference between the above two data.

Abstract: A DPTSS fiber optic cable includes an optical fiber sheathing cylindrical metal tube accommodating a pressure sensor optical fiber and having a plurality of through holes formed therein; and pressure blocking sections formed at intervals in the axial direction of the cable.

Abstract: Initial data and target data are frequency-analyzed to obtain an initial Rayleigh-scattering spectrum (RSS) and a target RSS, respectively. A distance correction is performed for the target RSS by comparing the target RSS with the initial RSS, and a Rayleigh spectrum shift is determined on the basis of a correlation coefficient between the initial RSS and the target RSS after distance-corrected.

Abstract: A distributed pressure, temperature, strain (DPTS) sensing cable includes at least two slotted fiber optic metal wires each having a slot groove extended along in an outer circumference of the wires to encapsulate optical fibers in the slot grooves. The two slotted fiber optic metal wires have characteristics different from each other.

Abstract: In a measurement requiring a high space resolution using S-BOTDR, a pulse train composed of a plurality of pulses having the interval between the pulses longer than the phonon lifetime is interpulse-code-modulated. A Golay code is used for the interpulse code modulation to eliminate the sidelobes of the correlation in using a technique of correlation. In a technique without using correlation, an Hadamard matrix is used for the interpulse code modulation and the resultant matrix is inverted in the signal processing.

Abstract: Frequency synthesis-based optical frequency domain reflectometry method and system are disclosed. The method is to implement optical frequency reflectometry and comprises: performing an electro-optic modulation and an acousto-optic modulation on a local light to obtain an optical pulse; inputting the optical pulse as a detection pulse optical signal to a test optical fiber; and detecting an obtained Rayleigh backscattered optical signal under coherent detection with the local light, and then performing a photoelectric conversion and a demodulation, wherein: the electro-optic modulation is performed by using a single frequency signal; the acousto-optic modulation is performed by using a pulse signal; and the optical pulse is obtained by simultaneously sweeping multiple frequency components of an optical comb signal which is obtained by the electro-optic modulation.

Abstract: A DPTSS fiber optic cable includes an optical fiber sheathing cylindrical metal tube accommodating a pressure sensor optical fiber and having a plurality of through holes formed therein; and pressure blocking sections formed at intervals in the axial direction of the cable.

Abstract: A distributed fiber optic acoustic detection device employs a novel distributed acoustic detection method using a phase noise cancelling distributed acoustic sensing (PNC-DAS) technique.

Abstract: Initial data and target data are frequency-analyzed to obtain an initial Rayleigh-scattering spectrum (RSS) and a target RSS, respectively. A distance correction is performed for the target RSS by comparing the target RSS with the initial RSS, and a Rayleigh spectrum shift is determined on the basis of a correlation coefficient between the initial RSS and the target RSS after distance-corrected.

Abstract: Frequency synthesis-based optical frequency domain reflectometry method and system are disclosed. The method is to implement optical frequency reflectometry and comprises: performing an electro-optic modulation and an acousto-optic modulation on a local light to obtain an optical pulse; inputting the optical pulse as a detection pulse optical signal to a test optical fiber; and detecting an obtained Rayleigh backscattered optical signal under coherent detection with the local light, and then performing a photoelectric conversion and a demodulation, wherein: the electro-optic modulation is performed by using a single frequency signal; the acousto-optic modulation is performed by using a pulse signal; and the optical pulse is obtained by simultaneously sweeping multiple frequency components of an optical comb signal which is obtained by the electro-optic modulation.