Techniques for generating a geological model from 3D seismic data and rock property data are disclosed. Rock property data and 3D seismic data are received. Based on the rock property data and the 3D seismic data, an adaptive geological model is generated. The adaptive geological model includes a characteristic geological property. Synthetic seismic data is generated from a first region of interest of the adaptive geological model. The synthetic seismic data is adapted to facilitate a comparison between the first region of interest and a corresponding region of interest of the received 3D seismic data. The characteristic geological property is adjusted until the comparison indicates a result that is within a predetermined threshold region of the corresponding value from the rock properties. A validated geologic model is then generated.

Scattered body waves are isolated to primary, shear, and surface waves as a receiver wavefield from recorded near-surface scattered wave data generated by scatters. The isolated receiver wavefield is backward propagated through an earth model from a final to an initial state. A source wavefield and the receiver wavefields are cross-correlated. A source wavefield and the receiver wavefields are stacked, over all time steps and sources, to generate a subsurface image. A display of the subsurface image is initiated.

System and methods for predicting time-dependent rock properties are provided. Seismic data for a subsurface formation is acquired over a plurality of time intervals. A value of at least one rock property of the subsurface formation is calculated for each of the plurality of time intervals, based on the corresponding seismic data acquired for that time interval. At least one of a trend or a spatio-temporal relationship in the seismic data is determined based on the value of the at least one rock property calculated for each time interval. A value of the at least one rock property is estimated for a future time interval, based on the determination. The estimated value of the at least one rock property is used to select a location for a wellbore to be drilled within the subsurface formation. The wellbore is then drilled at the selected location.

Methods and devices for seismic exploration of an underground structure apply W.sup.2-based full-wave inversion to transformed synthetic and seismic data. Data transformation ensures that the synthetic and seismic data are positive definite and have the same mass using an adaptive normalization. This approach yields superior results particularly when the underground structure includes salt bodies.

Methods and systems including computer programs encoded on a computer storage medium, for utilizing equivalent linear velocity for first arrival picking of seismic refraction. In one aspect, a method includes receiving data for the shot gather record, generating a diving wave equation curve for a particular parameter pair of multiple parameter pairs, and integrating the shot gather record data corresponding to the diving wave equation curve over a selected range of offsets of the shot gather to generate an equivalent linear velocity value for the particular parameter pair and the shot gather record data, selecting, from the equivalent linear velocity values for the plurality of parameter pairs, a greatest equivalent linear velocity value of the equivalent linear velocity values, the greatest equivalent linear velocity value corresponding to a first-arrival parameter pair, and determining, using the first-arrival parameter pair, a set of first-arrival onsets for the selected sub-range of offsets.

Techniques are disclosed for reducing noise when computing time-lapse differences between two or more geophysical surveys performed over the same region. In some computer-implemented embodiments, a time-lapse difference is determined between first and second data representing the first and second surveys, respectively. Based on geometry information corresponding to the second survey, first estimated data is generated representing how the first data would have looked if the second survey geometry had been used during the first survey. A noise model is generated based on differences between the first data and the first estimated data. The time-lapse difference is then adjusted using the noise model, thereby reducing noise in the time-lapse difference caused by differences between the geometries of the first and second surveys.

Numerous techniques and apparatus are disclosed relating to the performance of 4D marine geophysical surveys over at least first and second areas covered, respectively, by first and second preexisting baseline surveys. Performing the monitor surveys may include deploying a monitor survey streamer layout that can be used to repeat streamer positions of both the first and the second preexisting baseline surveys, and using the monitor survey streamer layout to perform the monitor survey over the first and second areas in a manner that repeats all streamer positions of the first preexisting baseline survey when over the first area, and that repeats all streamer positions of the second preexisting baseline survey when over the second area. Streamer layouts corresponding to the first and second preexisting baseline surveys may differ in at least one of the following characteristics: streamer separation or total number of streamers.

A method for seismic processing includes receiving measured seismic data collected by recording seismic waves that propagate through a subterranean domain, simulating synthetic seismic data using a model of the subterranean domain, generating a first time-space panel including the measured seismic data and a second time-space panel including the synthetic seismic data, applying a first moving window to the first time-space panel and a second moving window to the second time-space panel, determining a misfit by comparing the measured seismic data in the first moving window with the synthetic seismic data in the second moving window, and adjusting the model based on the misfit.

A method can include receiving seismic survey data of a subsurface environment from a seismic survey that includes a source arrangement of sources that is spatially denser than a receiver arrangement of receivers; processing the seismic survey data using the principle of reciprocity for performing interpolation across the receivers to generate processed seismic survey data; and generating an image of at least a portion of the subsurface environment using the processed seismic survey data.

A multi-wavefield seismic detection method and system based on construction noise of a shield machine. Multi-wavefield seismic information such as a body wave and a surface wave formed during propagation of a seismic wave generated by excitation in a stratum is obtained by using noise information caused by the construction of a shield machine as a seismic source, a stratum velocity model along a tunnel is constructed through joint inversion, and reflection wave information or the like is used for migration imaging, to eventually implement relatively accurate detection of a geological condition in front of a tunnel face of shield construction.