Computer-implemented methods, apparatus, and computer programs disclosed herein are for obtaining horizon data, and comprise determining at least one extrema binary volume from a seismic data volume comprising a plurality of voxels and assigning a predetermined extrema value to each one of the found extreme voxels; determining an extrema graph from the at least one extrema binary volume; determining a neighbour graph from the extrema graphs; partitioning the nodes of the neighbour graph into a set of clusters, wherein a cluster contains a plurality of connected nodes representing extrema voxels of the at least one extrema binary volume, and each node is part of one cluster only; for each subset of the set of clusters, identifying whether or not the subset is a contradictory set of clusters according to at least one first predetermined condition; hierarchically partitioning the neighbour graph into a plurality of subgraphs, for example using a minimum cut approach, each subgraph being provided by a separate non-contradictory cluster, which is not part of any contradictory sets of clusters; and obtaining horizon data representing a plurality of horizons from the non-contradictory clusters inducing the plurality of subgraphs of the neighbour graph.

A method includes collecting seismic survey data and processing the seismic survey data to identify subterranean conduit coordinates. The method also includes performing a conduit plugging operations using the identified subterranean conduit coordinates. A related system includes at least one seismic source and at least one seismic receiver to collect seismic survey data in response to at least one shot fired by the at least one seismic source. The system also includes a processing unit in communication with the at least one seismic receiver. The processing unit analyzes the collected seismic survey data to identify subterranean conduit coordinates for use with conduit plugging operations.

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.

A method and a system for implementing the method are disclosed wherein the seismic input data and land acquisition input data may be obtained from a non-flat surface, sometimes mild or foothill topography as well as the shot and receiver lines might not necessarily be straight, and often curve to avoid obstacles on the land surface. In particular, the method and system disclosed, decomposes the cross-spread data into sparse common spread beams, then maps those sparse beams into common-spread depth domain, in order to finally stack them to construct the subsurface depth images. The common spread beam migration and processing have higher signal to noise ratio, as well as faster turn-around processing time, for the cross-spread land acquisition over the common-shot or common offset beam migration/processing. The common spread beam migration method and system disclosed, will eventually help illuminate and interpret the hydro-carbonate targets for the seismic processing.

Hydrocarbon exploration and extraction can be facilitated by determining fault surfaces from fault attribute volumes. For example, a system described herein can receive a fault attribute volume for faults in a subterranean formation determined using seismic data. The fault attribute volume may include multiple traces with trace locations. The system can determine a set of fault samples for each trace location. Each fault sample can include fault attributes such as a depth value, an amplitude value, and a vertical thickness value. The system can determine additional fault attributes such as a dip value and an azimuth value for each fault sample of each trace location. The system can determine fault surfaces for the faults using the fault samples and fault attributes. The system can then output the fault surfaces for use in a hydrocarbon extraction operation.

A data seismic sensing system and method for obtaining seismic refraction data and tomography data. The system may comprise a subsurface sensor array, wherein the subsurface sensor array is a fiber optic cable disposed near a wellbore, a seismic source, wherein the seismic source is a truck-mounted seismic vibrator comprising a base plate, and a surface sensor array, wherein the surface sensor array is coupled to the seismic source. The method may comprise disposing a surface sensor array on a surface, disposing a subsurface sensor array into a wellbore, activating a seismic source, wherein the seismic source is configured to create a seismic wave, recording a reflected seismic wave with the surface sensor array and the subsurface sensor array, and creating a seismic refraction data and a seismic tomography data from the reflected seismic wave.

A system is described for determining a likelihood of a type of fluid in a subterranean reservoir. The system may include a processor and a non-transitory computer-readable medium that includes instructions executable by the processor to cause the processor to perform various operations. The processor may receive pre-stack seismic data having seismically-acquired data elements for geometric locations in a subterranean reservoir. The processor may determine, using the pre-stack seismic data, input features for each geometric location and may execute a trained model on the input features for determining a likelihood of a type of fluid in the subterranean reservoir and for determining a list of features affecting the likelihood. The processor may subsequently output the likelihood and the list of features.

A method for modelling and migrating seismic data, that includes using an acoustic wave equation and a spatial distribution of one or more earth-model parameters. The acoustic wave equation is modified by including at least one secondary source term, and based on a seismic acquisition configuration, either calculating the seismic signals that would be detected from the modelled wavefield or migrating observed seismic signals or migrating residual signals as part of an inversion.

A method for subsurface fault extraction using undirected graphs is provided. Extracting faults in the subsurface may assist in various stages of geophysical prospecting. To that end, an undirected graph may be used in order to identify distinctive fault branches in the subsurface. Fault probability data, from seismic data, may be used to establish connections in the undirected graph. Thereafter, some of the connections in the undirected graph may be removed based on analyzing one or more attributes, such as dip, azimuth, or context, associated with the connections or nodes associated with the connections. After which, the undirected graph may be analyzed in order to extract the faults in the subsurface.

Methods and systems, including computer programs encoded on a computer storage medium can be used for adaptive multi-scale geological modeling and well integration. The systems and methods are used to integrate seismic mapping data and well data for a subsurface region that includes a reservoir. The specification describes an example algorithm that is used to adaptively identify and isolate natural length scales in a seismic map. The identified natural length scales are then used to determine appropriate filtering of well information and ultimately achieve an automatic integration of orientation information from seismic map and well information.