G01V1/325

Passive seismic imaging

A virtual seismic shot record is generated based at least in part on seismic interferometry of the passive seismic data. Then, a frequency bandwidth of the virtual seismic shot record is determined, wherein the frequency bandwidth comprises a plurality of frequencies. The virtual seismic shot record is transformed into a frequency-dependent seismic shot record based on a first frequency of the plurality of frequencies. Further, a phase shift is applied to the frequency-dependent seismic shot record. A first velocity model is generated from the phase shifted frequency-dependent seismic shot record. A second velocity model may be generated using full-waveform inversion (FWI). One or more depth slices are identified from the second velocity model. A seismic image is generated based on the one or more depth slices for use with seismic exploration above a region of subsurface including a hydrocarbon reservoir and containing structural features conducive to a presence, migration, or accumulation of hydrocarbons.

Building accurate training images for automatic seismic interpretation

Automatic propagation of real-world parent seismic images to efficiently generate a collection of realistic synthetic child training images to train a model for accurate automatic seismic interpretation. A 3D structural model in a present-day geological space (e.g., G.sub.B) depicting subsurface locations of particles (e.g., in region B) may be transformed by a 3D coordinate space transformation (e.g., uvt.sub.B) to a depositional space (e.g., G*.sub.B) depicting past depositional locations of those particles (e.g., corresponding depositional region B). A real-world parent image depicting subsurface locations of particles (e.g., in region A) may be transformed, via a forward transformation (e.g., uvt.sub.A), to a depositional seismic image in the depositional space of the three-dimensional structural model (e.g., G*.sub.A=G*.sub.B). A reverse transformation (e.g., uut.sub.B.sup.−1) may transform the depositional seismic image from the depositional space into synthetic child training images in the present-day geological space (e.g., G.sub.B) for training the model.

System and method for seismic imaging

A method is described for seismic imaging that will produce a seismic image with correctly focused and positioned reflectors. This is accomplished by adding physical geological information to a beam tomography process to generate an updated earth model for the seismic imaging. The method may be executed by a computer system.

IDENTIFYING GEOLOGIC FEATURES IN A SUBTERRANEAN FORMATION USING SEISMIC DIFFRACTION IMAGING

A system for seismic imaging of a subterranean geological formation uses a two-way imaging condition. A seismic signal is emitted into a subterranean formation and recorded at receiver(s). Source and receiver wavefields are decomposed into respective right-down/left-up and left-down/right-up propagating waves. The right-down/left-up and left-down/right-up direction can be defined along the direction emitted from the source or receiver to corresponding direction in two dimensional (2D) case. An imaging condition for generating both a positive-dip structure image and a negative-dip structure image is the inner product of the wavefields. Applying the sample-by-sample multiplication imaging condition to the opposite dip images, the diffraction energy is retained while the reflection energy is significantly attenuated. The diffraction image can be used to detect faults and fractures in subsurface regions.

IDENTIFYING GEOLOGIC FEATURES IN A SUBTERRANEAN FORMATION USING ANGLE DOMAIN GATHERS SAMPLED IN A SPIRAL COORDINATE SPACE
20210190982 · 2021-06-24 · ·

Systems and methods for seismic imaging of a subterranean geological formation include receiving parameter data representing one or more parameters of a seismic survey, the seismic data specifying an incident angle and an azimuth angle for each trace of the seismic survey; determining a relationship between the incident angle and the azimuth angle for each trace and a location in a spiral coordinate system, and generating a weighting function for applying a weight value to each trace seismic data based on the incident angle and the azimuth angle associated with each trace; and determining a residual moveout value of the seismic data for each location in the spiral coordinate system by applying the weighting function to each; and generating a seismic image representing the residual moveout value of the seismic data for each location in the spiral coordinate system.

SYSTEMS AND METHODS FOR ASSOCIATING ONE OR MORE STANDARD NUMERICAL AGES TO ONE OR MORE ATTRIBUTES OF GEOLOGICAL DATA FROM DISPARATE LOCATIONS

Systems and methods are disclosed for associating a standard numerical age to an attribute of geological data from disparate locations. Exemplary implementations may include generating a standardized geological age dataset by standardizing geological data to a global reference age based on a dimension of the geological data, a local geotemporal marker, and a dimension to age function; and storing the standardized geological age dataset.

Methods and systems to interpolate seismic data

This disclosure is directed to processes and systems that generate enhanced-resolution seismic images by interpolating sparsely recorded seismic data. Structured dictionary learning is employed to train a set of basis vectors, called “atoms,” and corresponding sparse coefficients on patches of the recorded seismic data. The atoms are constrained to represent the geometric structure of reflection events in the recorded seismic data gather. Linear combinations of the atoms are used to compute interpolated patches over a finer receiver-coordinate grid. The interpolated patches replace the original patches in the recorded seismic data to obtain interpolated seismic data that can be used to generate an image of the subterranean formation.

SEISMIC IMAGING WITH SOURCE DECONVOLUTION FOR MARINE VIBRATORS WITH RANDOM SOURCE SIGNATURES

Processes and systems described herein are directed to imaging a subterranean formation from seismic data recorded in a marine survey with moving marine vibrators. The marine vibrators generate random sweeps with random sweep signatures. Processes and systems generate an up-going pressure wavefield from measured pressure and vertical velocity wavefield data recorded in the marine survey and obtain a downgoing vertical acceleration wavefield that records source wavefields, directivity, source ghosts, and random signatures of the random sweeps. The downgoing vertical acceleration wavefield data is deconvolved from the up-going pressure wavefield to obtain a subsurface reflectivity wavefield that is used to generate an image of the subterranean formation with reduced contamination from source wavefields. directivity, source ghosts, and random signatures of the random sweeps.

IMAGING SUBTERRANEAN FEATURES USING FOURIER TRANSFORM INTERPOLATION OF SEISMIC DATA
20200408943 · 2020-12-31 · ·

Systems and methods for generating seismic images of subterranean features including: receiving raw seismic data of a subterranean formation; selecting a portion of the raw seismic data; transforming the selected portion of the raw seismic data from a first domain to a second domain; generating soft constraint data corresponding to the selected portion of the raw seismic data; calculating at least one weight using the generated soft constraint data; generating a weighted transformed data set by applying at least one weight to the transformed selected portion of the raw seismic data; selecting at least one data point of the generated weighted transformed data set; and removing the selected at least one data point from the weighted transformed data set to generate revised seismic data.

Prediction and subtraction of multiple diffractions

Prediction and subtraction of multiple diffractions may include transforming previously acquired seismic data from a time-space domain to a transformed domain using a dictionary of compressive basis functions and separating, within the transformed previously acquired seismic data, a first portion and a second portion of the transformed previously acquired seismic data. Prediction and subtraction of multiple diffractions may also include predicting a plurality of multiple diffractions based on the separated first and second portions and adaptively subtracting the predicted multiple diffractions from the previously acquired seismic data. Prediction and subtraction of multiple diffractions may also include inverse transforming a particular seismic data set from the transformed domain to the time-space domain.