Simulated wells may be selected from a subsurface representation to serve as representation of the corresponding simulated subsurface region. Spatial coverage of a simulated well for the simulated subsurface region may be determined based on extent of similarity between the simulated well and other simulated wells in the subsurface representation. The simulated wells may be selected to achieve desired spatial coverage for the simulated subsurface region and to achieve desired representation of properties of interest for the simulated subsurface region.

A subaqueous underground survey system using a reflection seismic survey method includes: multiple sound sources 1 for generating sound waves in the water; a controller 2 for controlling phases of the sound waves; a geophone 3 for receiving reflected waves of the sound waves; and an observation ship 4 equipped with the sound sources 1, wherein the controller 2 controls phases of the sound sources 1 so that the sound waves generated from the respective sound sources 1 have a phase difference at a water bottom surface B, thereby controlling generation of shear waves to propagate into the ground.

Computing device, computer instructions and method for correcting an image, of a surveyed surface, due to a free-surface reflection. The method includes calculating a free surface reflection operator for a seismic source displaced in water based on a position of the source, and an air-water interface datum; receiving recorded seismic data d recorded with seismic sensors (r), wherein the recorded seismic data is associated with a pressure and/or a particle motion produced by a seismic wave in earth; correcting the recorded seismic data d based on the free surface reflection operator to obtain transformed seismic data; and generating an image of the surveyed subsurface, based on the transformed seismic data, wherein the image is indicative of various layers of the earth. The free surface reflection operator varies while a source signal is being emitted by the source.

A method (1200) can include receiving implicit functions values for a mesh that represents a geologic environment that includes intersecting faults defined by fault patches (1210); assigning states to the fault patches (1220); revising the implicit function values based at least in part on the assigned states to provide revised implicit function values (1230); and outputting a structural model of the geologic environment based at least in part on the revised implicit function values (1240).

PP and PS seismic data are jointly inverted in a stratigraphic grid, using different time axes for PP and PS reflections. A ratio of PP and of PS waves'travel times inside a same layer cell maintained to be a function of a ratio of a P-wave propagation velocity and of an S-wave propagation velocity therein. Since PP and PS seismic amplitudes and travel times are due to elastic properties of the same structure, they can be inverted at the same time to provide better estimates of these elastic properties.

Embodiments of methods of creating and interpreting animated mosaics of multiple seismic surveys are disclosed herein. Volumes from individual seismic surveys may be flattened in each seismic cube. Animations/movies may then be produced by capturing a series of z-slice movie frames through each of the flattened volumes. The individual sets of movie frames are geo-referenced to a basemap image of well locations using appropriate composition software. Where overlap exists between surveys, the surveys are prioritized and lower priority volumes are masked by higher priority volumes. This technique provides a matched, unbroken image across overlapping volumes at each stratigraphic layer. As the movie or animation plays, a moving arrow pointer shows the vertical position of the current movie frame on a stratigraphic section consisting of a seismic reference section that is optionally labelled with suitable regional sequence names and other stratigraphic zonation data.

A method for displaying slowness data after defects of anisotropy and heterogeneity have been removed includes visually depicting a slowness image on a computer monitor in which the slowness image includes a log of slowness values at a plurality of depths of a wellbore and a plurality of azimuth angles about a periphery of the wellbore. The image is processed via filtering such as with a bandpass filter. The filter may be obtained via fitting a periodic function to the slowness values at each depth or via a selected periodicity value and center angle. A resultant image is displayed.

A method includes generating a seismic shot by a seismic source, the seismic shot directed at a geological subsurface, and receiving, by one or more receivers, a plurality of reflected seismic traces from the seismic shot. The method further includes generating a correlogram of each reflected seismic trace to generate a plurality of correlograms, isolating a coda wave train of each correlogram of the plurality of correlograms, and computing an energy ratio between an energy of the coda wave train of each correlogram and a total energy of a corresponding correlogram of the plurality of correlograms to generate a plurality of energy ratios. The method further includes determining an average of the plurality of energy ratios to generate an average energy ratio of the seismic shot and determining a likelihood of striking a subsurface geohazard when drilling into the geological subsurface based on the average energy ratio.

A method includes retrieving a seismic data set, receiving training data that includes one or more seed points of an identified geobody, determining a geobody trajectory of the identified geobody, based on the one or more seed points of the identified geobody, displaying the geobody trajectory, receiving inputs expanding the geobody trajectory, shrinking the geobody trajectory, confirming the geobody trajectory, or a combination thereof, training a classification algorithm using the geobody trajectory, running the classification algorithm on the seismic data set, receiving an output of one or more sets of voxels from the classification algorithm, skeletonizing the one or more sets of voxels to present the one or more sets of voxels as a set of possible geobody trajectories, and retraining the classification algorithm based on feedback received from a reviewer.

Strata surfaces can be identified in well logs and correlated across the well logs taking into account manual corrections. For example, a computing device can receive well logs. The computing device can determine multiple stratum-surface correlations based on the well logs. Then, the computing device can receive user input indicating a correction to a particular stratum-surface correlation. Based on the correction to the particular stratum-surface correlation, the computing device can update some or all of the other stratum-surface correlations.