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 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: An optical cable includes: an optical fiber for sensing deformation of hydrocarbon absorbing resin having a property of expanding by absorbing hydrocarbon in oil; a strand provided so as to surround the outer circumference of the optical fiber; and hydrocarbon absorbing resin filling a space between the optical fiber and the strand. The optical cable configured as described above is installed along the depth direction of a well that is a measurement subject, over the entire range thereof, and a backscatter light frequency shift signal from the optical fiber is measured by a backscatter light measurement device, to detect presence/absence of leakage of oil from the well over the entire range in the depth direction of the well.

Abstract: This power cable monitoring system includes: a power cable including a power transmission cable provided at an inner circumferential part, an armoring wire provided at an outer circumferential part, and sensor ropes having an optical fiber to detect a physical quantity of a measurement target; and a backscattering light measurement device which measures distribution of the physical quantity of the measurement target, using backscattering light from the optical fiber, wherein distribution of temperature and strain of the power cable is obtained from a frequency shift signal of Rayleigh backscattering light obtained by the backscattering light measurement device on the basis of a signal detected by the sensor ropes, and a polarization distribution signal obtained from the Rayleigh backscattering light.

Abstract: A Rayleigh intensity pattern measurement device includes: a tunable-wavelength LD (1); an optical coupler; a reception unit which receives coherent light from the tunable-wavelength LD and the Rayleigh scattering light; and an RIP digital processing unit which receives an output signal from the reception unit by an A/D converter, calculates a cross-correlation coefficient from two different Rayleigh intensity pattern signals obtained from the Rayleigh scattering light, and stores a cross-correlation coefficient obtained from a result of comparison with a given threshold. If the compared cross-correlation coefficient is smaller than the threshold, the cross-correlation coefficient is calculated until becoming equal to or greater than the threshold, and Rayleigh frequency shift is calculated from the cross-correlation coefficient that has become equal to or greater than the threshold, whereby a strain distribution or a temperature distribution of a measurement target is measured.

Abstract: A seismic monitoring system, including a fiber optic cable defining a central axis and including an axial optical fiber disposed along the central axis, and three helical optical fibers disposed helically around the central axis, said three helical optical fibers being equidistantly spaced apart, a strain sensing unit configured to measure axial strain distribution in the axial optical fiber and in the three helical optical fibers, and a processing server configured to calculate, from the measured axial strain distribution in the axial optical fiber and in the three helical optical fibers, axial strain distribution in the fiber optic cable, pressure distribution in the fiber optic cable, bending distribution in the fiber optic cable in a first direction, and bending distribution in the fiber optic cable in a second direction perpendicular to the first direction.

Abstract: This optical fiber distribution measurement system of distributed optical fiber sensing type includes: a tunable wavelength distributed feedback LD (1) for obtaining a DTSS signal through frequency shift analysis; an external resonance laser (2) for obtaining a DAS signal through phase shift analysis; a pulse compression coding circuit (4) including an intensity modulator (4a) and an phase modulator (4b); an acousto-optic switch (5); an erbium doped optical fiber amplifier (6); a circulator (7); a diversity device (8); a digitizer (11); a CPU (12); and a serial transfer interface (13). Through calculation on discrete signals sent from the digitizer (11), the CPU (12) converts an analyzed Rayleigh frequency shift signal obtained as the DTSS signal, to phase error, and corrects an analyzed phase signal obtained as the DAS signal, by the phase error.

Abstract: An optical cable (31) includes: a stress wave detection optical cable (30) having an optical fiber (7) and a plurality of first steel wires (8) which are helically wound so as to surround the optical fiber (7) and which are surrounded by a flexible material (9); and second steel wires (32) different from the first steel wires (8). The stress wave detection optical cable (30) and the plurality of second steel wires (32) are helically wound to form one annular body as a whole, and a winding angle (?) of the stress wave detection optical cable (30) with respect to the axis is determined by a property value prescribed by Lamé constants of the flexible material (9).

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 method creates a fluid communication path between a first production well and a second production well. At least one hydraulic fracture intersects the first production well and is separated from the second production well by a wall thereof. The method includes identifying, from the second production well, a location of the hydraulic fracture of the first production well, and perforating the wall of the second production well at the identified location. The perforating creates the fluid communication path between the production wells. Injection of fracking fluid and proppant at the first production well allows for additional fluids to be extracted from the second production well, thus generating a flow between the two production wells through the hydraulic fracture.

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 magnetic field measurement cable (10) of the present disclosure includes an electric cable (1) provided at an axial part, and an outer circumferential cable (2) provided on the outer side of the electric cable (1) and helically formed by a plurality of steel wires helically wound and a magnetic field measurement optical cable (3) having an optical fiber cable (3a).

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: A method creates a fluid communication path between a first production well and a second production well. At least one hydraulic fracture intersects the first production well and is separated from the second production well by a wall thereof. The method includes identifying, from the second production well, a location of the hydraulic fracture of the first production well, and perforating the wall of the second production well at the identified location. The perforating creates the fluid communication path between the production wells. Injection of fracking fluid and proppant at the first production well allows for additional fluids to be extracted from the second production well, thus generating a flow between the two production wells through the hydraulic fracture.

Abstract: An optical cable includes: an optical fiber for sensing deformation of hydrocarbon absorbing resin having a property of expanding by absorbing hydrocarbon in oil; a strand provided so as to surround the outer circumference of the optical fiber; and hydrocarbon absorbing resin filling a space between the optical fiber and the strand. The optical cable configured as described above is installed along the depth direction of a well that is a measurement subject, over the entire range thereof, and a backscatter light frequency shift signal from the optical fiber is measured by a backscatter light measurement device, to detect presence/absence of leakage of oil from the well over the entire range in the depth direction of the well.

Abstract: This optical fiber distribution measurement system of distributed optical fiber sensing type includes: a tunable wavelength distributed feedback LD (1) for obtaining a DTSS signal through frequency shift analysis; an external resonance laser (2) for obtaining a DAS signal through phase shift analysis; a pulse compression coding circuit (4) including an intensity modulator (4a) and an phase modulator (4b); an acousto-optic switch (5); an erbium doped optical fiber amplifier (6); a circulator (7); a diversity device (8); a digitizer (11); a CPU (12); and a serial transfer interface (13). Through calculation on discrete signals sent from the digitizer (11), the CPU (12) converts an analyzed Rayleigh frequency shift signal obtained as the DTSS signal, to phase error, and corrects an analyzed phase signal obtained as the DAS signal, by the phase error.

Abstract: An optical cable (31) includes: a stress wave detection optical cable (30) having an optical fiber (7) and a plurality of first steel wires (8) which are helically wound so as to surround the optical fiber (7) and which are surrounded by a flexible material (9); and second steel wires (32) different from the first steel wires (8). The stress wave detection optical cable (30) and the plurality of second steel wires (32) are helically wound to form one annular body as a whole, and a winding angle (?) of the stress wave detection optical cable (30) with respect to the axis is determined by a property value prescribed by Lamé constants of the flexible material (9).

Abstract: A magnetic field measurement cable (10) of the present disclosure includes an electric cable (1) provided at an axial part, and an outer circumferential cable (2) provided on the outer side of the electric cable (1) and helically formed by a plurality of steel wires helically wound and a magnetic field measurement optical cable (3) having an optical fiber cable (3a).

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.