A seismic sensor for a downhole tool positionable in a wellbore penetrating a subterranean formation. The seismic sensor includes a sensor housing, a bobbin supported in the sensor housing along an axis thereof, at least one coil wound about the bobbin (the coil movably supportable within the sensor housing by at least one spring), at least one magnet positionable about the bobbin to generate a magnetic field with the at least one coil whereby seismic vibrations are detectable, and a filler fluid disposed in the sensor housing to buoy the at least one coil whereby gravitational effects may be neutralized.

Disclosed are methods and systems for calibration of an accelerometer used in a geophysical sensor while deployed in the water. An embodiment may include towing a streamer behind a survey vessel in a body of water, wherein the streamer comprises an accelerometer; causing at least a portion of the streamer to twist; receiving data from the accelerometer at a selected plurality of times during the twist; and based at least in part on the data, determining at least one calibration parameter of the accelerometer.

A data-driven linear filtering method to recover microseismic signals from noisy data/observations based on statistics of background noise and observation, which are directly extracted from recorded data without prior statistical knowledge of the microseismic source signal. The method does not depend on any specific underlying noise statistics and works for any type of noise, e.g., uncorrelated (random/white Gaussian), temporally correlated and spatially correlated noises. The method is suitable for microquake data sets that are recorded in contrastive noise environments. The method is demonstrated with both field and synthetic data sets and shows a robust performance.

A data-driven linear filtering method to recover microseismic signals from noisy data/observations based on statistics of background noise and observation, which are directly extracted from recorded data without prior statistical knowledge of the microseismic source signal. The method does not depend on any specific underlying noise statistics and works for any type of noise, e.g., uncorrelated (random/white Gaussian), temporally correlated and spatially correlated noises. The method is suitable for microquake data sets that are recorded in contrastive noise environments. The method is demonstrated with both field and synthetic data sets and shows a robust performance.

Embodiments included herein are directed towards a marine seismic streamer. The seismic streamer may include an outer skin formed in longitudinally extending tubular shape, an inner surface of the outer skin defining an internal volume containing a gel substance. The seismic streamer may also include a plurality of micro-electro-mechanical (MEMS) sensors and plurality of hydrophones associated with the outer skin, wherein in the plurality of MEMS sensors are spaced non-uniformly in the seismic streamer along an axial direction of the streamer, such that not more than 100 MEMS sensors are located in the seismic streamer over a continuous 100 meter axial length of seismic streamer. The seismic streamer may further include an electronics system extending axially through an inside portion of the outer skin and a strength member core extending axially through an inside portion of the outer skin.