The present disclosure belongs to the technical field of seismic exploration imaging, and relates to an interpretive-guided velocity modeling seismic imaging method and system, a medium and a device. The method comprises the following steps: S1. performing first imaging on a given initial velocity model to obtain a first imaging result; S2. performing relative wave impedance inversion on the first imaging result to obtain a relative wave impedance profile; S3. performing Curvelet filtering on the relative wave impedance profile to obtain a first interpretation scheme; S4. superposing the first interpretation scheme and the initial velocity model to obtain a new migration velocity field; S5. performing second imaging on a new migration velocity field to obtain a second imaging result; and S6. repeating steps S2-S4 for the obtained second imaging result until a final seismic imaging result is obtained.

Aspects of the disclosure provide for a method using clusters of sonic peaks from a logging tool to generate a log of an acoustic property of the formation as a function of depth.

Methods and systems for processing seismic data are presented. Primary wave (P) seismic data (PP data) and shear wave (P) seismic data (PS data) are jointly inverted as part of a nonlinear tomography process which adheres to one or more co-depthing constraints.

A computer-implemented method, and system implementing the method, are disclosed for computing a final model of elastic properties, using nonlinear direct prestack seismic inversion for Poisson impedance. User inputs and earth-model data is obtained over points of incidence of a survey region, at various angles of incidence. Various models are then computed that serve for lithology identification and fluid discrimination and take part in preliminary seismic exploration and reservoir characterization. Therefore, further refinement of these models is required due to changes in burial depths, compaction and overburden pressure, as they provide limitations for reservoirs on porous media. The further refinement using nonlinear direct prestack seismic model is performed on a system computer, which produces a final model of elastic properties. This model can then be applied for lithology prediction and fluid detection to identify potential targets of oil and gas exploration and estimating spots in unconventional shale gas applications.

Methods and systems are disclosed for forming an image of a subterranean region of interest. The method includes receiving an observed seismic dataset and a seismic velocity model for the subterranean region of interest, and generating a simulated seismic dataset based on the seismic velocity model and the geometry of the observed seismic dataset. The method further includes determining a transformed observed seismic dataset by applying a nonlinear amplitude transform to the observed seismic dataset and determining a transformed simulated seismic by applying the same transform to the simulated seismic dataset. The method still further includes forming an objective function based on the transformed observed seismic and the transformed simulated seismic dataset, and determining an updated seismic velocity model based upon finding an extremum of the objective function.

A reflection full waveform inversion method updates separately a density model and a velocity model of a surveyed subsurface formation. The method includes generating a model-based dataset corresponding to the seismic dataset using a velocity model and a density model to calculate an objective function measuring the difference between the seismic dataset and the model-based dataset. A high-wavenumber component of the objective function's gradient is used to update the density model of the surveyed subsurface formation. The model-based dataset is then regenerated using the velocity model and the updated density model, to calculate an updated objective function. The velocity model of the surveyed subsurface formation is then updated using a low-wavenumber component of the updated objective function's gradient. A structural image of the subsurface formation is generated using the updated velocity model.

Methods and systems are disclosed for updating a seismic velocity model of a subterranean region of interest. The method includes receiving an observed seismic dataset and a seismic velocity model, and generating a simulated seismic dataset based on the seismic velocity model and the geometry of the observed seismic dataset, wherein each dataset is composed of a plurality of seismic traces. The method further includes determining a transformed observed seismic dataset and a transformed simulated seismic dataset by determining the instantaneous frequency of at least one member of the plurality of observed seismic traces; and at least one member of the plurality of simulated seismic traces. The method still further includes forming an objective function based on the transformed observed seismic dataset and the transformed simulated seismic dataset and determining an updated seismic velocity model based on an extremum of the objective function.

Methods for measuring seismic velocities and for monitoring local changes in inter-well seismic velocities in real time are described. Two or more spaced-apart observation wells are provided. Seismic receiver arrays are placed in the observation wells, and a seismic source array is provided at surface locations away from the well bores and producing areas. Compression (P), vertical shear (Sv) and/or horizontal shear (Sh) seismic wave signals are generated from each element of the seismic source array, and the seismic signals arriving at the receivers in the observation wells are recorded. The virtual source method is then applied to the recorded data to compute emulated cross-well seismic signals of the virtual sources at receiver locations in one observation well propagating toward the receivers at other observation wells. Analysis of direct arrivals of emulated cross-well seismic signals can be completed to extract travel times, inter-well seismic velocities, and rock properties.

This specification describes workflows for, but is not limited to, performing full waveform inversion (FWI) to build high resolution velocity models to improve the accuracy of seismic imaging of a subterranean formation. This specification describes processes to automatically edit and enhance S/N quality of seismic data (such as land seismic data) to prepare the datasets for FWI. The methods for automatic corrections and pre-processing include: automatic iterative surface-consistent residual statics calculation, automatic rejection of anomalous traces (such as dead traces), and the automatic correction of surface-consistent amplitude anomalies (such as by scalar or deconvolution approaches). The operations include automatic “muting” of noise before first arrivals.

Disclosed are a multi-scale photoacoustic detection method of geological structure around a borehole and related devices. The method includes: obtaining depth information and direction information of the borehole; generating trajectory data of the borehole according to the depth information and direction information; obtaining an optical image of the geological structure around the borehole; generating a first velocity model according to the optical image and the trajectory data; obtaining low-frequency acoustic wave data and high-frequency acoustic wave data of the geological structure around the borehole; performing a full waveform inversion on the first velocity model according to the low-frequency acoustic wave data and the high-frequency acoustic wave data to obtain a second velocity model; and determining the geological structure around the borehole according to the second velocity model.