Methods, systems, devices, and products for formation evaluation. Methods include automatically characterizing an acoustic reflective boundary in the earth formation by: generating a plurality of multipole acoustic signals within the borehole; generating acoustic wave data at at least one acoustic receiver on the logging tool in response to a plurality of acoustic reflections of acoustic waves from a corresponding plurality of reflection points along the boundary responsive to the multipole acoustic signals; estimating from the acoustic wave data a location in the formation for each reflection point of the plurality of reflection points, which may include performing coherence processing on at least a portion of the acoustic wave data to generate a coherence map; and identifying acoustic reflections from the coherence map; and using the location in the formation for each reflection point to estimate at least one property of the acoustic reflective boundary.

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.

The method comprises providing at least one seismic source in a seismic source area and providing a plurality of seismic receivers in said seismic source area, said method comprising measuring a first type of ground vibrations induced in a subsurface of the area of interest by the at least one seismic source with the plurality of seismic receivers. The method further comprises measuring with the plurality of seismic receivers at least one second type of ground vibrations induced by a mechanical source different from the or from each seismic source and analyzing the second type of ground vibrations to determine at least one information among: a physical parameter of the subsurface and/or, a presence of human and/or an animal and/or a vehicle.

A leak-detecting assembly can include an array of hydrophones. The array can be moved within a hydrocarbon well. A variation in the Doppler shift caused by a stationary acoustic source (such as a leak) while the array moves towards and away from that source can be determined based on information from the array of hydrophones. The assembly can be associated with a passive system that captures acoustic signals directly from the source or leak and estimates a location of the source or leak based on measurement of Doppler shift in each receiver.

An accelerometer device for determining the acceleration of an object, along three axes X, Y and Z of a main orthonormal reference system and subject to a surrounding pressure, comprises a number N of accelerometer sensors of MEMS type, N at least equal to two, each sensor defined by construction in an auxiliary reference system comprising three orthonormal axes, the set of accelerometer sensors comprising at least one pair of sensors mounted to face in opposite directions and parallel to one another, and: for each of the pairs of accelerometer sensors, the sensors have components of opposite sign along two axes of the main reference system; and the axes of the reference system along which the components of the accelerometer sensors oppose the set of pairs of sensors in twos comprise at least two of the three axes X, Y and Z of the reference system, to compensate for the effect of the pressure on at least two axes of the reference system.

A method for processing seismic data, the method including receiving seismic data acquired by at least one receiver over a water-covered subsurface formation; generating, based on the seismic data, a down-going wavefield; generating, based on the seismic data, a partial down-going wavefield with attenuated water-wave; estimating a subsurface reflectivity R using multi-dimensional deconvolution, which equates (1) a convolution of the down-going wavefield with the subsurface reflectivity R to (2) the partial down-going wavefield; and generating an image of the water-covered subsurface formation based on the subsurface reflectivity R.

Methods, systems, and computer-readable medium to perform operations for suppressing seafloor geophone seismic data noise. A computing system applies a vertical geophone de-noise process to enhance a compressional wave signal that is free from (independent of) shear energy leakage. This enhances the signal to noise (S/N) ratio of the vertical geophone component and concurrently make the vertical geophone component consistent with a hydrophone component

Systems and methods of near surface imaging and hazard detection with increased receiver spacing are provided. The system includes: a first string of one or more acoustic sources, a second string of one or more acoustic sources opposite the first string, a first one or more hydrophones mounted within a predetermined distance of the first string, and a second one or more hydrophones mounted within the predetermined distance of the second string. The first one or more hydrophones records an acoustic shot generated from the first string. The second one or more hydrophones records the acoustic shot and acoustic reflections corresponding to the acoustic shot. The system generates an image from the recorded acoustic shot and the acoustic reflections.

Methods and systems of generating seismic images from primaries and multiples are described. Methods separate pressure data into up-going pressure data and down-going pressure data from pressure data and vertical velocity data. Irregularly spaced receiver coordinates of the down-going and up-going pressure data are regularized to grid points of a migration grid and interpolation is used to fill in down-going and up-going pressure data at grid points of the migration grid. A seismic image is calculated at grid points of the migration grid based on the interpolated and regularized down-going pressure data and the interpolated and regularized up-going pressure data. The seismic images are high-resolution, have lower signal-to-noise ratio than seismic images generated by other methods, and have reduced acquisition artifacts and crosstalk effects.

A technique includes receiving first data acquired by at least a particle motion gradient sensor or a rotation sensor of a streamer that is subject to vibration due to towing of the streamer; and receiving second data acquired by at least one particle motion sensor of the streamer and being indicative of particle motion and vibration noise. The technique includes processing the second data in a processor-based machine to, based at least in part on the first data, attenuate the vibration noise indicated by the second data to generate third data indicative of the particle motion.