The present disclosure provides a TOC prediction method for shale gas reservoirs, including: determining by well-seismic calibration a top interface T.sub.top and a bottom interface T.sub.bottom of the shale gas reservoirs, and performing layer tracking in the entire area; converting the pre-stack CRP gather into angle gather seismic data; performing spectral shaping processing on the pre-stack migration pure wave seismic data; establishing an initial model, and then performing pre-stack simultaneous inversion to obtain P-wave impedance, S-wave impedance, primary-to-shear wave velocity ratio and density data volume; obtaining a TOC inversion volume A through a post-stack inversion; obtaining a TOC inversion volume B by calculation; then adding the well data for correction, and finally determining a planar distribution law of TOC content. The method can eliminate the multiple solutions of pre-stack inversion and improve the accuracy of TOC content prediction of shale.

The present invention relates to geophysics, and more particularly processing of seismic data for analysis and interpretation. A computer implemented method for extracting or estimating rock properties from seismic traces is disclosed. This method assists in understanding the interpretation of post-stack and pre-stack seismic data by predicting density and velocity. The computer implemented method comprising the follow steps: (1) preparing an initial model with initial functions of velocity and density and synthetic traces; (2) generating synthetic traces from the velocity and density functions with added artificial kinematic constraints; (3) creating updated synthetic traces using randomly updated velocity and density functions; for each iteration, artificial waves traveling from a source point to a reflection point and back are simulated as constraint; (4) performing a search of the misfit object function of any norm, and (5) using probabilistic techniques for approximating the global optimum and minimizing the cost function.

Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for determining a velocity model for a geological region. In one aspect, a method comprises: obtaining a current velocity model for the geological region; obtaining pre-stack and post-stack seismic data characterizing the geological region; and for each of a plurality of iterations: identifying a plurality of reflection events from the post-stack seismic data and the current velocity model; determining a respective observed travel time for each of the plurality of reflection events, comprising, for each reflection event, determining the respective observed travel time for the reflection event based at least in part on kinematic features derived from a respective seismic trace included in the pre-stack seismic data; and updating the current velocity model based at least in part on the observed travel times of the plurality of reflection events.

A subsalt imaging tool and seismic imaging process for complex geological environments such as subsalt structures having a rugged seafloor topology are provided. The subsalt imaging tool operates on stacked data as opposed to prestack data and uses a wave equation tomography to iteratively update a velocity model. Improved seismic images that improve the visibility of various events may be produced using the updated velocity model.

A method includes obtaining a digital seismic file, performing autodetection of parameters of the digital seismic file, and registering the parameters of the digital seismic file with the digital seismic file. Performing autodetection comprises a computer processor, repetitively until a candidate template successfully extracts the parameters, selecting a target candidate template, attempting extraction of a binary header using the target candidate template, attempting extraction of a trace header using the target candidate template, attempting extraction of the plurality of parameters when the target candidate template extracts the binary header and the trace header, and moving to a next target candidate template when extraction of the plurality of headers is unsuccessful.

A zero-offset wavefield synthesis workflow to calculate a synthesized zero-offset wavefield output without the commitment to an rms velocity field output to circumvent velocity uncertainty. Said zero-offset wavefield synthesis workflow comprises calculating a migration cube output. Rendering a demigration cube output from said migration cube output with a demigration cube calculation. Rendering said synthesized zero-offset wavefield output from said demigration cube output with a zero-offset wavefield synthesis procedure.

A method includes obtaining a digital seismic file, obtaining a digital seismic file, and performing autodetection of parameters of the digital seismic file. The method further includes extracting seismic data from the digital seismic file according to the parameters to generate normalized seismic data. The method further includes scanning the normalized seismic data to obtain metadata that includes geographic file boundaries and mapping the normalized seismic data to a parent virtual survey based at least in part on the geographic file boundaries being in a geographic region of a parent virtual survey. The method additionally includes storing, in a target store, the normalized seismic data and metadata, the normalized seismic data in a stored relationship with the parent virtual survey in the target store.

The present disclosure describes methods and systems, including computer-implemented methods, computer program products, and computer systems, for suppressing noises in seismic data. One computer-implemented method includes receiving, at a data processing apparatus, a set of seismic data associated with a subsurface region; flattening, by the data processing apparatus, the set of seismic data according to an identified seismic event; dividing, by the data processing apparatus, the set of seismic data into a plurality of spatial windows; randomizing, by the data processing apparatus, the set of seismic data according to a random sequential order; filtering, by the data processing apparatus, the randomized seismic data; and reorganizing, by the data processing apparatus, the filtered seismic data according to a pre-randomization order.

A method includes obtaining a digital seismic file, performing autodetection of parameters of the digital seismic file, and registering the parameters of the digital seismic file with the digital seismic file. Performing autodetection comprises a computer processor, repetitively until a candidate template successfully extracts the parameters, selecting a target candidate template, attempting extraction of a binary header using the target candidate template, attempting extraction of a trace header using the target candidate template, attempting extraction of the plurality of parameters when the target candidate template extracts the binary header and the trace header, and moving to a next target candidate template when extraction of the plurality of headers is unsuccessful.

A method of processing seismic data so as to provide an image of a subsurface region, comprises providing plurality of migrated shot gathers that contain information about the region, summing portions of the migrated shot gathers to provide a pilot stack, partitioning the plurality of gathers into a plurality of groups and summing the gathers in each group to provide a substack, wherein each group includes at least two migrated shots and wherein a substack is generated from each group, applying an amplitude normalization algorithm to the pilot stack so as to generate an amplitude-normalized pilot stack, calculating a weight function by comparing each substack to the normalized pilot stack, weighting each substack using the weight function so as to generate a plurality of weighted substacks, summing overlapping portions of the weighted substacks so as to generate a output stack, and using the output stack to generate an image.