The present disclosure describes methods and systems, including computer-implemented methods, computer program products, and computer systems, for removing false image in reverse time migration (RTM). One computer-implemented method includes dividing volume of a source wavefield and a receiver wavefield into a plurality of windows, calculating a down-going component of the source wavefield and an up-going component of the receiver wavefield for each window in the plurality of windows and at a particular value of time, calculating a down-going component of the source wavefield at the particular value of time by summing the down-going component of the source wavefield in each window of the plurality of windows, and calculating an up-going component of the receiver wavefield at the particular value of time by summing the up-going component of the receiver wavefield in each window of the plurality of windows.

A simultaneous sources seismic acquisition method is described that introduces notch diversity to improve separating the unknown contributions of one or more sources from a commonly acquired set of wavefield signals while still allowing for optimal reconstruction properties in certain diamond-shaped regions. In particular, notch diversity is obtained by heteroscale encoding.

Systems and methods that include receiving reservoir data of a hydrocarbon reservoir, receive an indication related to selection of a wavefield propagator, application of the wavefield propagator utilizing Fourier Finite Transforms and Finite Differences to model a wavefield associated with a Tilted Orthorhombic media representative of a region of a subsurface comprising the hydrocarbon reservoir, and processing the reservoir data in conjunction the wavefield propagator to generate an output for use with seismic exploration above a region of a subsurface comprising the hydrocarbon reservoir and containing structural or stratigraphic features conducive to a presence, migration, or accumulation of hydrocarbons.

Methods and systems of generating seismic images from primaries and multiples are described. Methods separate pressure data into up-going pressure data and down-going pressure data from pressure data and vertical velocity data. Irregularly spaced receiver coordinates of the down-going and up-going pressure data are regularized to grid points of a migration grid and interpolation is used to fill in down-going and up-going pressure data at grid points of the migration grid. A seismic image is calculated at grid points of the migration grid based on the interpolated and regularized down-going pressure data and the interpolated and regularized up-going pressure data. The seismic images are high-resolution, have lower signal-to-noise ratio than seismic images generated by other methods, and have reduced acquisition artifacts and crosstalk effects.

This disclosure describes processes and systems for generating a seismic image of a subterranean formation from recorded seismic data gathers obtained in a marine seismic survey of the subterranean formation. The seismic data comprises recorded pressure and vertical velocity wavefields that are used to separate the recorded pressure wavefield into upgoing and downgoing pressure wavefields. A seismic image is computed from the subterranean formation based on a product of the downgoing pressure wavefield and a migration operator applied to the upgoing pressure wavefield. The downgoing pressure wavefield is a boundary source wavefield and the upgoing pressure wavefield is boundary receiver wavefield of the migration operator. The seismic image is iteratively updated by computing a residual seismic image based on the upgoing pressure wavefield and adding the residual seismic image to the seismic image. The final seismic image displays increased illumination and reduced crosstalk artifacts compared to conventional seismic imaging techniques.

Wavefield separation methods and systems that adjust near-continuous pressure and particle motion wavefields based on distance moved along a vessel track by the sensors when the wavefields were measured are disclosed. Methods and systems correct for the motion of the receivers in towed streamer seismic data in order to obtain a wavefield with approximately stationary-receiver locations. Wavefield separation may then be applied to the wavefield with approximately stationary-receiver locations.

Methods and systems of analyzing and optimizing a seismic survey design are described. A system includes a plurality of seismic receivers disposed in a survey area at a plurality of receiver locations. The system also includes a plurality of seismic sources disposed in the survey area at a plurality of source locations. The plurality of receiver locations and the plurality of source locations are specified by a seismic survey design minimizing any artifacts identified in a filtered spectrum obtained by applying a frequency-wavenumber filter to a central midpoint space summation. The plurality of receiver locations and the plurality of source locations are determined based on a comparison of the filtered spectrum to a second filtered spectrum. The second filtered spectrum is for a second central midpoint space summation.

Methods of analyzing and optimizing a seismic survey design are described. Specifically, the sampling quality is analyzed as opposed to the overall quality of the whole survey. This allows for analysis of the impact of the offsets, obstacles, and other aspects of the survey on the sampling quality, which will improve the ability to compress the resulting data and minimize acquisition footprints.

A seismic noise mitigation method. The method comprises identifying a wavenumber of a component in a residual wavenumber spectrum having a largest norm based on a preconditioned residual wavenumber spectrum. A contribution to the residual wavenumber spectrum from the identified wavenumber component, is subtracted therefrom. A next residual wavenumber spectrum is based thereon and a relative residual computed based on that. The identifying, subtracting and calculating are repeated until a first to occur termination condition selected from the group consisting of: a current relative residual is less than a threshold residual; a difference between the current relative residual and a smallest relative residual exceeds product of the smallest relative residual and a preselected threshold factor; and a difference between a current number of iterations and a number of iterations corresponding to a currently encountered smallest relative residual encountered exceeds a preselected threshold number of iterations.

Inducing vibrations onto a sensor streamer. At least some of the example embodiments are methods including: towing a sensor streamer through a body of water, the sensor streamer comprising a plurality of geophones spaced along the sensor streamer; inducing a vibration onto the sensor streamer at a predetermined location, the inducing as the sensor streamer is towed; measuring the vibration by a geophone at a distance from the predetermined location, the measuring creates a measured vibration; and creating, by a computer system, a model of noise propagation along the sensor streamer, the creating based on the measured vibration.