A device for determining a refractive index may be provided. The device including at least one waveguide having a core and a cladding surrounding the core, the cladding being at least partly removed in at least one first longitudinal portion and the core including at least one fiber Bragg grating in at least one second longitudinal portion. A method for determining a refractive index or a pressure change in a fluid may also provided. The method may include at least one waveguide having a core and a cladding surrounding the core, the cladding being at least partly removed in at least one longitudinal portion. A method for producing such a device may also be provided.

A device for determining a refractive index may be provided. The device including at least one waveguide having a core and a cladding surrounding the core, the cladding being at least partly removed in at least one first longitudinal portion and the core including at least one fiber Bragg grating in at least one second longitudinal portion. A method for determining a refractive index or a pressure change in a fluid may also provided. The method may include at least one waveguide having a core and a cladding surrounding the core, the cladding being at least partly removed in at least one longitudinal portion. A method for producing such a device may also be provided.

Methods and systems, including computer programs encoded on a computer storage medium can be used to preserve edges while performing Gaussian grid smoothing of noise components in subsurface grids to generate geological maps. A subsurface grid is generated from data indicating properties of subsurface formations. A weighting grid is generated by: i) receiving seismic data representing the subsurface formations; ii) generating seismic attributes associated with discontinuities in the subsurface formations; and iii) assigning a particular weight value to weighting grid points that the seismic attributes associated with discontinuities in the subsurface formations indicate the presence of a discontinuity. The subsurface grid is processed by iteratively computing local averages of grid points in the subsurface grid using a compact Gaussian filter weighted by values in the weighting grid. A geological map of subsurface formations is generated based on the filtered subsurface grid.

Disclosed are a system, apparatus, and method for optical fiber well deployment in seismic optical surveying. Embodiments of this disclosure may include methods of deploying a spooled optical fiber distributed sensor into the wellbore integrated in a ballast or weight for a seismic optic tool, to achieve deployment of a lightweight disposable fiber optic cable against the wellbore walls via gravity. The method may further include unspooling the spooled optical fiber distributed sensor and using the optical fiber as a distributed seismic receiver. Once the fiber optic distributed sensor is deployed according to methods of the present disclosure, surveys may be obtained and processed by various methods.

Disclosed are a system, apparatus, and method for optical fiber well deployment in seismic optical surveying. Embodiments of this disclosure may include methods of deploying a spooled optical fiber distributed sensor into the wellbore integrated in a ballast or weight for a seismic optic tool, to achieve deployment of a lightweight disposable fiber optic cable against the wellbore walls via gravity. The method may further include unspooling the spooled optical fiber distributed sensor and using the optical fiber as a distributed seismic receiver. Once the fiber optic distributed sensor is deployed according to methods of the present disclosure, surveys may be obtained and processed by various methods.

A logging while drilling tool for measuring a geological formation surrounding a wellbore includes a tool body having one or more sensor pads. Each sensor pad is coupled to the tool body by an extendable coupling that is operable to adjust the radial position of the sensor pad by extending away from or retracting toward the tool body. One or more sensors are mounted to each sensor pads and the sensors are operable to obtain a measurement a property of the formation. The tool also includes a downhole control unit having a transmitter and receiver. The downhole control unit is operable to receive the measurement and transmit the measurement to a surface controller, wherein the transmitted measurement indicates a measurement resolution.

An internal structure detection system includes: two kinds of sensors with different operating principles for receiving reflected waves of vibration applied to an inspection target in an investigation area; and a processing apparatus that detects an internal structure of the inspection target by using the sensor data received by the two kinds of sensors. The two kinds of sensors are deployed in the investigation area with different densities, in a distributed manner.

A building integrity assessment system includes: an earthquake detector including: a building bottom sensor at a bottom of a building and that detects acceleration and an earthquake early-warning receiver that receives an earthquake early warning; a cloud computer; and sensors disposed at a plurality of positions in the building and that measures an influence of an earthquake on the building at each of the positions and wirelessly transmits measurement results to the cloud computer. The cloud computer estimates and evaluates the integrity of the building based on the measurement results. In response to the building bottom sensor detecting preliminary tremors or the earthquake early-warning receiver receiving the earthquake early warning, the plurality of sensors measures the influence of the earthquake on the building from a time before a major motion arrives at the building to a time after the arrival.

A building integrity assessment system includes: an earthquake detector including: a building bottom sensor at a bottom of a building and that detects acceleration and an earthquake early-warning receiver that receives an earthquake early warning; a cloud computer; and sensors disposed at a plurality of positions in the building and that measures an influence of an earthquake on the building at each of the positions and wirelessly transmits measurement results to the cloud computer. The cloud computer estimates and evaluates the integrity of the building based on the measurement results. In response to the building bottom sensor detecting preliminary tremors or the earthquake early-warning receiver receiving the earthquake early warning, the plurality of sensors measures the influence of the earthquake on the building from a time before a major motion arrives at the building to a time after the arrival.

An underwater seismic system for reducing noise due to ghost reflections or motion through the water from seismic signals. The system includes two motion sensors. One sensor has a first response and is sensitive to platform-motion-induced noise as well as to acoustic waves. The other sensor has a different construction that isolates it from the acoustic waves so that its response is mainly to motion noise. The outputs of the two sensor responses are combined to remove the effects of motion noise. When further combined with a hydrophone signal, noise due to ghost reflections is reduced.