An active fiber stretcher assembly can be used for data acquisition systems. A time-break signal can be detected that coincides with a seismic event emitted from a seismic controller. A predetermined waveform can be generated in response to detecting the time-break signal. The predetermined waveform may be encoded onto a fiber optic cable using a fiber stretcher. A data acquisition system connected to the fiber optic cable may detect the predetermined waveform on the fiber optic cable and initiate acquisition operations including: receiving, during the seismic event, light signals returning from a portion of the fiber optic cable in a subterranean environment; determining one or more characteristics of the subterranean environment from the light signals; and storing the one or more characteristics.

An active fiber stretcher assembly can be used for data acquisition systems. A time-break signal can be detected that coincides with a seismic event emitted from a seismic controller. A predetermined waveform can be generated in response to detecting the time-break signal. The predetermined waveform may be encoded onto a fiber optic cable using a fiber stretcher. A data acquisition system connected to the fiber optic cable may detect the predetermined waveform on the fiber optic cable and initiate acquisition operations including: receiving, during the seismic event, light signals returning from a portion of the fiber optic cable in a subterranean environment; determining one or more characteristics of the subterranean environment from the light signals; and storing the one or more characteristics.

A master data acquisitions system is provided. A trigger emits a sync signal to be sensed by each of a plurality of data acquisition systems. A controller is communicatively coupled with each of the plurality of data acquisition systems. The controller receives data from each of the data acquisition systems. The data for each of the plurality of data acquisition systems include the sensed sync signal. The controller synchronizes the data from each of the plurality of data acquisition systems by aligning the sensed sync signal for each of the plurality of data acquisition systems.

A sensor package may include a sensor housing unit and a first sensor that may acquire a first set of measurements within a first measurement range. The sensor package may also include a second sensor configured to acquire a second set of measurements within a second measurement range. The first measurement range and the second measurement range may include an overlapping range used to calibrate the first set of measurements, the second set of measurements, or both.

A sensor package may include a sensor housing unit and a first sensor that may acquire a first set of measurements within a first measurement range. The sensor package may also include a second sensor configured to acquire a second set of measurements within a second measurement range. The first measurement range and the second measurement range may include an overlapping range used to calibrate the first set of measurements, the second set of measurements, or both.

A method of correcting clock drift in at least one slave clock in a seismic node. The method comprises obtaining a number of clock drift measurements of the at least one slave clock in the at least one seismic node. A clock drift correction function as a function of time is calculated by curve fitting the number of clock drift measurements to a 2nd order polynomial. A time of reference of the recorded seismic sensor data is corrected by the 2nd order polynomial clock drift correction function.

A method of correcting clock drift in at least one slave clock in a seismic node. The method comprises obtaining a number of clock drift measurements of the at least one slave clock in the at least one seismic node. A clock drift correction function as a function of time is calculated by curve fitting the number of clock drift measurements to a 2nd order polynomial. A time of reference of the recorded seismic sensor data is corrected by the 2nd order polynomial clock drift correction function.

A timing alignment method for data acquired by monitoring units of a borehole-surface micro-seismic monitoring system includes acquiring two rock-burst waveform data segments with GPS timestamps; calculating a time difference and a number of sampling points between each pair of adjacent GPS timestamps; adding, on an equal-interval basis, a sampling time to a sampling point missing a timestamp between each pair of adjacent GPS timestamps; calculating average sampling frequencies of the two rock-burst waveform data segments, adding, on an equal-interval basis, a sampling time to a sampling point missing a timestamp except first and last GPS timestamps in each of the two data segments; obtaining sampling times of all sampling points, resampling the sampling times according to a uniform sampling frequency; calculating a rock-burst waveform data segment at a new sampling time with a linear interpolation formula, and aligning the sampling times of the two rock-burst waveform data segments.

An article comprising a turbine component formed of a nickel-chromium (Ni—Cr) alloy including from 2 to 50 wt % chromium balanced by nickel is disclosed. The Ni—Cr alloy is thicker than at least 125 μm to make a self-supporting turbine component, and the turbine component includes a rotor blade, a stator, or a vane. The Ni—Cr alloy is electroformed on a mandrel by providing an external supply of current to an anode and a cathode in a plating bath containing a solvent, a surfactant, and an ionic liquid including choline chloride, nickel chloride, and chromium chloride.

A modular downhole logging system includes a transmitter module having a local frequency, wherein the transmitter module transmits interrogation signals into a formation based on the local frequency. The downhole system also includes a receiver module axially-spaced from the transmitter module and that receives response signals corresponding to the interrogation signals, wherein the receiver module includes sampling logic and sync estimation logic. The sync estimation logic is configured to perform sync estimation operations including estimating the local frequency of the transmitter module based on analysis of response signal Fourier transform results corresponding to different frequencies. The sampling logic/clock is configured to sample the response signals based on the estimated local frequency of the transmitter module, wherein a processor derives formation property values using the sampled response signals.