Bp Corporation North America Inc.

Bp Norge As

John Theodore Etgen

Joseph Anthony Dellinger

Graham Openshaw

Sverre Brandsberg-Dahl

Uwe Karsten Albertin

Allan A Ross

Andrew James Brenders

Min Zhou

Imtiaz Ahmed

Kenneth Howell Matson

Chunlei Chu

Scott T Michell

Gabriel Perez

Olav Inge Barkved

Phuong Vu

Laurent Sirgue

Carl Regone

Ian Threadgold

Graham Anthony Openshaw

Estimation of velocity models inclusive of receiving seismic data inclusive of data that corresponds to a seismic image, adding a velocity perturbation to a current velocity model that represents a portion of the subsurface responsible for a distortion in the seismic image to generate a perturbed velocity model, generating an image via seismic migration of the seismic data and the perturbed velocity model, generating and assigning a measure of quality to the image, determining whether the measure of quality assigned to the image is an optimal measure of quality at a particular location of the current velocity model, and updating the current velocity model to generate a revised velocity model utilizing the measure of quality assigned to the image when the measure of quality assigned to the image is determined to be the optimal measure of quality at the particular location of the current velocity model.

Velocity model construction

A method includes receiving, via a processor, input data based upon received seismic data, migrating, via the processor, the input data via a pre-stack depth migration technique to generate migrated input data, encoding, via the processor, the input data via an encoding function as a migration attribute to generate encoded input data having a migration function that is non-monotonic versus an attribute related to the input data, migrating, via the processor, the encoded input data via the pre-stack depth migration technique to generate migrated encoded input data, and generating an estimated common image gather based upon the migrated input data and the migrated encoded input data. The method also includes generating a seismic image utilizing the estimated common image gather, wherein the seismic image represents hydrocarbons in a subsurface region of the Earth or subsurface drilling hazards.

Wave equation migration offset gathers

According to one embodiment, there is provided a method of correcting recorded seismic data where each receiver clock is potentially inaccurate. Since the seismic wave field is not random, and contains coherent events that are recorded by all receivers in a local area, it is possible to estimate the differences in the time reference by comparing the recordings of different receivers in a local area. With no external time reference, time signal, or pilot trace, an entire seismic data itself can be used to determine how each receiver's clock is drifting from true time.

System and method for correction of receiver clock drift

A method for use in seismic exploration comprises: accessing a set of seismic data representative of a subterranean geological formation and a subsurface attribute model of the subterranean geological formation; performing a wavefield extrapolation on the seismic data in the subsurface attribute model; applying the time-shift extended imaging condition to the extrapolated wavefields; forming shot-indexed, time shift gathers for each image pixel of the subsurface attribute model from the conditioned extrapolated wavefields; adaptively focusing the gathers; and stacking the adaptively focused gathers; and imaging the subterranean geological formation from the stacked, adaptively focused gathers. The method may, in some aspects, be realized by a computing apparatus programmed to perform the method or as a set of instructions encoded on a non-transitory program storage medium that, when executed by a computing apparatus, perform the method.

Seismic adaptive focusing

There is provided herein a system and method of seismic data collection for land and marine data that utilizes narrowband to monochromatic low-frequency non-impulsive sources designed to optimize the ability of migration/inversion algorithms to image the subsurface of the Earth, in particular, full-waveform inversion.

Seismic acquisition using narrowband seismic sources

A technique for use in geophysical surveying acquires seismic data at low seismic frequencies to generate better starting models for subsurface attributes rather than enhancing the bandwidth of airguns for broadband imaging as in conventional practice.

Seismic acquisition method and apparatus

The instant invention is designed to provide an adaptive approach to removing short-period time/phase distortions within a downward-continuation process that is a key component of seismic migration algorithms. Using techniques analogous to residual statics corrections that are used in standard seismic processing, one inventive approach estimates and removes the effects of short wavelength velocity disruptions, thereby creating clearer seismic images of the subsurface of the earth. Additionally, the instant method will provide an updated velocity model that can be used to obtain further image improvement.

System and method for seismic adaptive optics

There is provided herein a method of passive seismic acquisition that utilizes real time or near real time computation to reduce the volume of data that must be moved from the field to the processing center. Much of the computation that is traditionally applied to passive source data can be done in a streaming fashion. The raw data that passes through a field system can be processed in manageable pieces, after which the original data can be discarded and the intermediate results accumulated and periodically saved. These saved intermediate results are at least two, more likely three, orders of magnitude smaller than the raw data they are derived from. Such a volume of data is trivial to store, transport or transmit, allowing passive seismic acquisition to be practically used for continuous near-real-time seismic surveillance.

Field correlation for real-time passive seismic surveillance

One aspect of the invention is a method for building geologic/stratigraphic models of the earth for the purposes of numerical simulations of phenomena of interest, such as seismic wave propagation, or fluid flow, reservoir simulation, etc. An embodiment of the invention uses stochastic methods to create material property models that have desired statistical properties by numerically simulating deposition of geological layers. The method can create multiple material parameter models from numerical implementations of a variety of geological processes.

System and method for computational geology

The instant invention is a method for numerically propagating waves or solving wave equations on a digital computer. This invention can be used to compute highly accurate solutions to the wave equation, in fact in some cases it computes the analytical solution, something previously considered impossible. The instant method can also propagate waves that are not described by differential equations, such as anisotropic scalar waves. The invention has the advantages that it is computationally efficient, accurate, and flexible. Of importance is the ability to propagate waves that simulate the P-wave arrivals in both isotropic and anisotropic media with a scalar as opposed to a vector equation.

Pseudo-analytical method for the solution of wave equations

According to a preferred aspect of the instant invention, there is provided herein a system and method for the imaging and monitoring of the subsurface hydrocarbon reservoirs and other subsurface features, wherein the collected seismic data contain multiples therein. In brief, the instant invention is a method of removing multiples using surface-related multiple elimination (SRME), wherein wide azimuth seismic data are used to directly compute a multiple prediction via a mixed space-wavenumber-frequency domain implementation.

3D surface related multiple elimination for wide azimuth seismic data

According to a first preferred aspect of the instant invention, there is provided an efficient method of computing a 3D frequency domain waveform inversion based on 3D time domain modeling. In the preferred arrangement, 3D frequency domain wavefields are computed using 3D time-domain modeling and a discrete Fourier transformation that is preferably computed 'on the fly' instead of solving the large systems of linear equations that have traditionally been required by direct frequency domain modeling. The instant invention makes use of the theory of gradient-based waveform inversion that estimates model parameters (for example velocities) by matching modeled data to field data sets. Preferably the modeled data are calculated using a forward modeling algorithm.

System and method for 3D frequency domain waveform inversion based on 3D time-domain forward modeling

According to a preferred aspect of the instant invention, there is provided a system and method for acquiring seismic data in a marine environment, wherein at least two source vessels are used in conjunction with a recording vessel which tows a plurality of hydrophone cables. Preferably, the source vessels will be positioned along side of the towed streamer configuration and most preferably one source vessel will be located near the recording vessel and the other at the end of the streamer configuration, preferably along the same side of the streamer configuration as the lead source vessel.

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Houston, TX, United States of America

John Theodore Etgen