Abstract: A method is described for seismic amplitude analysis that uses a set of artificial and individually separable reflectors consistent with dip fields in the subsurface volume of interest to define an AVA basis functions; the AVA basis functions are used in true-3D AVA modeling and true-3D AVA inversion. The inversion result and well logs representative of the subsurface volume of interest are used to train a model to create a rock property prediction model. The method may apply the rock property prediction model to a second seismic image to generate a rock property volume. The method is executed by a computer system.

Abstract: A method is described for seismic imaging improved by an estimation of attenuation including receiving a pre-migration seismic dataset D(s, r; t) representative of a subsurface volume of interest wherein s indicates source location, r indicates receiver location, and t is the recorded travel time; calculating a pre-migration attenuated travel time t*(s, r; t); computing a time derivative of the pre-migration attenuated travel time wherein 1/Q(s, r; t)=?t*(s, r; t)/?t; performing a first migration on D(s,r;t) to generate common image point (CIP) gathers G(x, h) wherein x is subsurface image point and h is angle or offset; performing a second migration on D(s, r; t)*1/Q(s, r; t) to generate weighted common image point (CIP) gathers G1/Q(x, h); and calculating a conditioned ratio of the weighted CIP gathers G1/Q(x, h) over the CIP gathers G(x, h) to get CIP gathers of 1/Q(x, h) is disclosed.

Abstract: A method is described for seismic data processing including receiving a seismic dataset D(s, r; t) representative of a subsurface volume of interest; calculating a pre-migration attenuated travel time t*(s, r; t); performing a first migration on D(s, r; t) to generate common image point (CIP) gathers G(x, h); performing a second migration on D(s, r; t)*t*(s, r; t) to generate weighted common image point (CIP) gathers Gt*(x, h); and calculating a conditioned ratio of the weighted CIP gathers Gt*(x, h) over the CIP gathers G(x, h) to get CIP gathers of attenuated traveltime t*(x, h). The CIP gathers of attenuated traveltime t*(x, h) may be used to perform seismic tomography to generate an attenuation (Q) model.

Abstract: A method is described for seismic imaging improved by an estimation of attenuation including receiving a pre-migration seismic dataset D(s, r; t) representative of a subsurface volume of interest wherein s indicates source location, r indicates receiver location, and t is the recorded travel time; calculating a pre-migration attenuated travel time t*(s, r; t); computing a time derivative of the pre-migration attenuated travel time wherein 1/Q(s, r; t)=?t*(s, r; t)/?t; performing a first migration on D(s,r;t) to generate common image point (CIP) gathers G(x, h) wherein x is subsurface image point and h is angle or offset; performing a second migration on D(s, r; t)*1/Q(s, r; t) to generate weighted common image point (CIP) gathers G1/Q(x, h); and calculating a conditioned ratio of the weighted CIP gathers G1/Q(x, h) over the CIP gathers G(x, h) to get CIP gathers of 1/Q(x, h) is disclosed.

Abstract: A method is described for seismic imaging of complex subsurface volumes using prismatic seismic energy. The method receives a seismic dataset and an earth model. The earth model is perturbed such that prismatic reflections will generate perturbed seismic amplitudes in a target area and seismic imaging is performed using the perturbed model. A second seismic image is generated using a second earth model; the second earth model may be the original earth model or a second perturbed model wherein the perturbation generates different seismic amplitudes in the target area. The two seismic images are differenced to generate a prismatic seismic image that can be used to identify geologic features that are poorly illuminated in conventional imaging. The method may be executed by a computer system.

Abstract: A method for seismic imaging of a subsurface volume of interest may include an imaging technique such as reverse time migration which uses a conditioned velocity model that replaces at least one sharp velocity transition with a gradual velocity transition including a velocity overshoot layer. The method may be performed by a computer system.

Abstract: A method for seismic imaging of a subsurface volume of interest may include an imaging technique such as reverse time migration which uses a conditioned velocity model that replaces at least one sharp velocity transition with a gradual velocity transition including a velocity overshoot layer. The method may be performed by a computer system.

Abstract: A method is described for processing residual moveout in seismic image data gathers representing critical reflections. The method includes receiving seismic image data arranged as a function of an angle or offset parameter including a high-velocity-contrast event with post-critical. The method also includes applying a wavelet de-stretch filter to the seismic data to correct wavelet stretching. The method also includes applying a fan-filter to remove coherent noise in the one or more post-critical traces; picking residual moveout of the high-velocity-contrast event; adjacent-trace differencing to detect the impact of phase change at critical reflections in residual moveouts, and applying a median-filter to the residual moveout to reduce the impact of phase change of the high-velocity-contrast event in the one or more post-critical traces. The median-filtered and reconstructed residual moveout is used for improving a velocity model used for generating the seismic image gathers.

Abstract: A method is described for seismic imaging of complex subsurface volumes using prismatic seismic energy. The method receives a seismic dataset and an earth model. The earth model is perturbed such that prismatic reflections will generate perturbed seismic amplitudes in a target area and seismic imaging is performed using the perturbed model. A second seismic image is generated using a second earth model; the second earth model may be the original earth model or a second perturbed model wherein the perturbation generates different seismic amplitudes in the target area. The two seismic images are differenced to generate a prismatic seismic image that can be used to identify geologic features that are poorly illuminated in conventional imaging. The method may be executed by a computer system.

Abstract: A method is described for of creating a high-resolution velocity model of a geological medium that includes generating a long-wavelength anisotropic velocity model using tomographic inversion of seismic data gathers and combining the long-wavelength velocity model with an attenuation model. The method further includes performing prestack depth migration on the seismic data gathers using the long-wavelength velocity and attenuation model to produce seismic image gathers, applying a dip-consistent filter to the seismic image gathers, and transforming the filtered seismic image gathers to the time domain. The method further includes generating a full-band impedance model by performing impedance inversion of the time-domain filtered seismic image gathers using the long-wavelength velocity and attenuation model. The full-band impedance or velocity model is calibrated in the frequency domain in a manner independent of the spatial coordinates.

Abstract: A method is described for residual moveout analysis using dynamic warping. The residual moveout curves or surfaces may be used to flatten common image gathers or derive velocity models. The method may be executed by a computer system.

Abstract: A method is described for of creating a high-resolution velocity model of a geological medium that includes generating a long-wavelength anisotropic velocity model using tomographic inversion of seismic data gathers and combining the long-wavelength velocity model with an attenuation model. The method further includes performing prestack depth migration on the seismic data gathers using the long-wavelength velocity and attenuation model to produce seismic image gathers, applying a dip-consistent filter to the seismic image gathers, and transforming the filtered seismic image gathers to the time domain. The method further includes generating a full-band impedance model by performing impedance inversion of the time-domain filtered seismic image gathers using the long-wavelength velocity and attenuation model. The full-band impedance or velocity model is calibrated in the frequency domain in a manner independent of the spatial coordinates.

Abstract: A method is described for processing residual moveout in seismic image data gathers representing critical reflections. The method includes receiving seismic image data arranged as a function of an angle or offset parameter including a high-velocity-contrast event with post-critical. The method also includes applying a wavelet de-stretch filter to the seismic data to correct wavelet stretching. The method also includes applying a fan-filter to remove coherent noise in the one or more post-critical traces; picking residual moveout of the high-velocity-contrast event; adjacent-trace differencing to detect the impact of phase change at critical reflections in residual moveouts, and applying a median-filter to the residual moveout to reduce the impact of phase change of the high-velocity-contrast event in the one or more post-critical traces. The median-filtered and reconstructed residual moveout is used for improving a velocity model used for generating the seismic image gathers.

Abstract: Seismic data may be processed to improve a geologic model of a subsurface volume of interest by receiving an initial geologic model, generating a ?-parameter family of models by perturbing parameters of an initial geologic model, migrating the seismic data using each of the models in the ?-parameter family of models to generate a set of migration images, constructing a ?-volume by scanning the set of migration images wherein each location in the ?-volume is assigned a value representing a preference of one of the migration images; and inverting the ?-volume.

Abstract: Application task management (“ATM”) methods may employ a task list stored in a file on a nonvolatile information storage medium. Parallel processing instances employ an application programming interface (“API”) that enables each processing instance to individually access the task list. The access protocol enforced by the API is sufficient to provide robust, fault-tolerant behavior without requiring a specific process or daemon to be responsible for ATM. The API may employ a locking mechanism based on universal or widely-available operating system calls (such as directory creation) that implicitly or explicitly guarantee atomic operations. Each processing instance performs a check-out of unfinished tasks with a request that includes a timeout value, transforms the unfinished tasks into finished tasks, and provides a check-in of the finished tasks, and repeats. This approach supports the use of a variety of models through the use of chained or nested task lists, and it can be readily scaled.