In acoustic well logging, for each inversion depths of a well at which logging of data occurs, acoustic log signals representative of waveforms received at acoustic receivers are processed in a frequency domain to derive field dispersion curve(s). A neural net is operated to generate formation shear slowness value(s) from the curve(s), and resulting signal(s) indicative of shear slowness values are saved, transmitted, plotted, printed or processed. An apparatus for carrying out the method includes a logging tool having at least one activatable acoustic wave source; spaced and acoustically isolated therefrom in the logging tool an array of acoustic detectors that on the detection of acoustic wave energy generate electrical or electronic log signal(s) characteristic of acoustic energy waves detected by the acoustic detector(s); and at least one processing device associated with or forming part of the logging tool for processing the log signal(s).

A monitoring system according to the present disclosure includes an optical fiber (10) laid on a ground or a seabed, an optical fiber sensing unit (21) configured to receive an optical signal from the optical fiber (10) and detect a vibration produced in the ground or the seabed based on the optical signal, and an analyzing unit (22) configured to identify a natural phenomenon that has caused the detected vibration based on a unique pattern of the detected vibration.

A method for seismic exploration of a subsurface formation with a seismic survey system includes directly receiving a message, at a first fleet of seismic sources, from a second fleet; storing the message at the first fleet; verifying one or more constraints related to the first and second fleets, at the first fleet; initiating a triggering sequence of the seismic sources of the first fleet, upon verification of the one or more constraints, with no input from a central unit of the seismic survey system; and performing a sweep based on the triggering sequence.

An optical communication system that enables any deployed fiber-optic cable to function as an earthquake-detection sensor. In an example embodiment, a WDM optical transmitter of one network node operates to transmit a CW optical signal together with legacy data-carrying optical signals. At another network node, a low-complexity, low-latency coherent optical receiver is used to obtain time-resolved measurements of the Stokes parameters of the CW optical signal. The signal-processing chain of the optical receiver employs digital filtering to select frequency components of the measurements streams corresponding to seismic disturbances of the fiber-optical cable connecting the nodes. The selected frequency components are then used to compute values of an earthquake indicator, which are reported to a network controller. Based on such reports from three or more nodes, the network controller can determine the epicenter and magnitude of the earthquake and, if warranted, may generate a tsunami forecast.

A system and method for automatically detecting unauthorized entry into a pool requiring no user involvement, and having a high degree of accuracy. The system comprises a plurality of light beam emitter devices and a plurality of light beam receiver devices positioned along an interior perimeter of the pool and a processor in communication with the plurality of light beam emitter devices and the plurality of light beam receiver devices. The plurality of light beam emitter devices emit a plurality of light beams and the plurality of light beam receiver devices receive a plurality of emitted light beams to form a grid extending across a the pool. Additionally, the processor monitors the grid, detects unauthorized entry into the pool based on an interruption of the grid, and generates and transmits an alarm message based on whether a level of the interruption of the grid exceeds a predetermined threshold.

Methods and systems for adjusting migration gather are disclosed. A method for adjusting migration gather may include generating a first migration gather based on acquired seismic data. The method may also include generating a compensation volume based on reference data produced utilizing a reference seismic model. The method may further include applying the compensation volume to adjust the first migration gather.

Methods of analyzing and optimizing a seismic survey design are described. Specifically, the sampling quality is analyzed as opposed to the overall quality of the whole survey. This allows for analysis of the impact of the offsets, obstacles, and other aspects of the survey on the sampling quality, which will improve the ability to compress the resulting data and minimize acquisition footprints.

Methods, systems, and devices for operating emergency prevention sensor systems are described. Devices can include a plurality of components including a sensor component, a processor, and memory. In an example, a method can include receiving at a processor signaling from a plurality of environmental sensing devices, each having at least one biodegradable component, in an area of concern, wherein the area of concern corresponds to a particular set of coordinates in a database, determining environmental characteristics of an emergency associated with the area of concern based, at least in part, on the signaling, and determining a preventive action based on the determined characteristics. In another example, a number of components of the sensing devices are biodegradable.

Seismic data from seismic exploration surveys are mapped into a hypercube of bins or voxels in a four-dimensional space (X, Y, Offset, and Azimuth) according to Common Mid-Point (or CMP) between source and receivers. The mapped data from individual voxels or bins is then analyzed by multimodal statistics. Robust estimates of first break picks are obtained from the analysis. The first break picks are then used to as seed inputs for autopicking iteration, which proceeds to convergence. Estimates of confidence levels in the data are provided for re-picking to reduce computer processing time in successive autopicking iterations. Analysis is provided of different seismic attributes such as azimuthal velocity variations indicative of anisotropy, positioning errors of sources/receivers, geometry errors, and three dimensional distribution of inversion residuals. Analysis is also performed of standard deviation of the travel time data useful for estimating data errors in the inversion covariance matrix.

An interrogation system includes a light signal switch and a reflection signal switch. The light signal switch may be communicatively coupled to an optical light source. The light signal switch may route a light signal generated by the light source downhole in a wellbore through a single-mode optical fiber cable or a multi-mode optical fiber cable. The reflection signal switch may be communicatively coupled to the single-mode optical fiber cable and the multi-mode optical fiber cable. The reflection signal switch may route a reflection of the light signal from the signal-mode optical fiber cable or the multi-mode optical fiber cable to an optical detector.